logo

Information on the distribution, intensity, impact and economic value of mobile bottom contacting gear (MBCG) fisheries within the Bay of Biscay and the Iberian Coast area and associated subdivisions, and estimated consequences and costs (landings weight, landings value) of reducing their relative extent.

Bay of Biscay and the Iberian Coast

Summary

Geographic scope: The assessment in this interactive document covers EU waters of depths shallower than 800 m in the MSFD subdivisions associated with the Bay of Biscay and the Iberian Coast area. EU waters are the waters defined by EU Member States, in this area, for MSFD implementation purposes (Figure E1).

Spatial scales of analyses: Analyses are presented by MSFD subdivision, MSFD broad habitat type (BHT) and for depth strata 0‒200 m, 200‒400 m, and 400‒800 m. The 0.05° × 0.05° c-squares (hereafter c-squares) were allocated to subdivisions based on centroid positions. Mean depths in c-squares were used to allocate c-squares to depth strata. For the Baltic Sea area, the subdivisions are as used in the ICES 2021 advice (ICES, 2021) and based on the HELCOM sub-basins (HELCOM, 2013). For the Greater North Sea, Celtic Seas and Bay of Biscay and the Iberian Coast areas, the subdivisions used are the OSPAR benthic habitat assessment area units (OSPAR, 2022), as used in the OSPAR 2023 Quality Status Report (OSPAR, 2023). The extent of BHTs, as defined under the MSFD, is determined per c-square.

Values of pressure indicators (I‒1 to I‒5) and impact indicators (I‒6a, I‒6b, I‒7a, and I‒7b) by depth strata (Table 1) provide information on the distribution, intensity, and impact of MBCG fisheries. The indicators are described in the “Essential information” tab in this document.

For depths of 0‒200 m, 67.3% of the area is fished with MBCG per year (I‒3). However, 90% of the total MBCG swept area is concentrated in an annual average of 45.7% of the Bay of Biscay and the Iberian Coast area. Nineteen point one per cent of the area at these depths was not fished with MBCG at all from 2017‒2022, based on the data submissions received. For depths of 0‒200m, MBCG fishing was estimated to reduce the total biomass of benthic fauna by 14.8% (I‒6a) and reduce the total biomass of sensitive fauna by 19% (I‒6b). Within this depth strata, the depletion of benthic fauna was less than 20% in 77% (I‒7a) of the area. For sensitive fauna the corresponding area was 68.6% (I‒7b). The heterogeneous distributions of annual mean fishing intensity (swept area ratio [SAR]), annual mean total landings values (euros) and weight (kg), and seabed sensitivity (as estimated median longevity of the benthic fauna), are illustrated in Figure 1. The distributions of the fishing intensity and the seabed sensitivity account for the values of pressure and impact indicators reported in Table 1.

Small-scale fisheries, defined as vessels < 12 m in overall length deploying MBCG, operate in the Bay of Biscay and the Iberian Coast area as well. As these are not required to carry VMS by the EU Control Regulation (EU, 2009), their coverage in the VMS data submissions is unknown. The EU Fisheries Dependent Information (FDI) data does report on small-scale fisheries effort in kW × fishing days. However, the FDI reporting units differ from the subdivisions, BHTs, and depth strata used in these analyses. The correspondence between subdivisions and FDI reporting regions is illustrated in Figure E1. The incomplete data for small-scale fisheries results in underestimates of fishing intensity and impact, especially in inshore areas. In the Bay of Biscay and the Iberian Coast area the proportion of the total kW × fishing days of MBCG fishing attributed to small-scale fisheries (Table 2) varies from 1 - 23% between FAO regions.

References:

EU Council. 2009. Council Regulation (EC) No 1224/2009 of 20 November 2009 establishing a Community control system for ensuring compliance with the rules of the Common Fisheries Policy amending Regulations (EC) No 847/96, (EC) No 2371/2002, (EC) No 811/2004, (EC) No 768/2005, (EC) No 2115/2005, (EC) No 2166/2005, (EC) No 388/2006, (EC) No 509/2007, (EC) No 676/2007, (EC) No 1098/2007, (EC) No 1300/2008, (EC) No 1342/2008 and repealing Regulations (EEC) No 2847/93, (EC) No 1627/94 and (EC) No 1966/2006. Official Journal of the European Union L343, 1−50. http://data.europa.eu/eli/reg/2009/1224/oj

HELCOM. 2013. HELCOM Monitoring and Assessment Strategy. https://helcom.fi/wp-content/uploads/2020/02/Monitoring-and-assessment-strategy.pdf

ICES. 2021. ICES advice to the EU on how management scenarios to reduce mobile bottom fishing disturbance on seafloor habitats affect fisheries landing and value. In Report of the ICES Advisory Committee, 2021. ICES Advice 2021. sr.2021.08. https://doi.org/10.17895/ices.advice.8191

OSPAR. 2022. OSPAR Extent of Physical Disturbance to Benthic Habitats Assessment Units. https://odims.ospar.org/en/submissions/ospar_phys_dist_habs_au_2022_06/

OSPAR. 2023. OSPAR Quality Status Report. https://oap.ospar.org/en/ospar-assessments/quality-status-reports/qsr-2023/

Table 1

Table 1. Values of pressure and impact indicators for 2017‒2022 for three depth strata in the Bay of Biscay and the Iberian Coast area. Values of I‒1, I‒2, I‒3, I‒4, I‒6a, I‒6b, I‒7a and I‒7b are annual means and I‒5 is evaluated over the six years. Descriptions of the pressure and impact indicators are provided in the ‘Essential Information’ Table E1 in this document.

Indicators 0 to 200 m 200 to 400 m 400 to 800 m
I‒1: Average fishing intensity 3.02 3.01 0.73
I‒2: Proportion of area fished, evaluated at c-square scale (%) 80.90 88.00 67.80
I‒3: Proportion of area fished (%) 67.30 72.80 30.20
I‒4: Smallest proportion of area with 90% of fishing intensity, evaluated at c-square scale (%) 45.70 47.40 23.70
I‒5: Proportion of area persistently unfished, evaluated at c-square scale (%) 19.10 12.00 32.20
I‒6a: Average PD impact 14.80 14.00 4.40
I‒6b: Average PD-sens impact 19.00 17.30 5.50
I‒7a: Proportion of area with PD impact < 0.2, evaluated at c-square scale (%) 77.00 77.20 93.40
I‒7b: Proportion of area with PD-sens impact < 0.2, evaluated at c-square scale (%) 68.60 71.50 91.30

Figure 1

Figure 1. Geographic distribution of fishing intensity (swept area ratio), seabed sensitivity (community longevity), total landings value, and total landings weight from mobile bottom-contacting gear (MBCG) in the Bay of Biscay and the Iberian Coast area. The maps of swept area ratio, landings value, and landings weight show annual means evaluated at the c-square scale.

**Figure 1. Geographic distribution of fishing intensity (swept area ratio), seabed sensitivity (community longevity), total landings value, and total landings weight from mobile bottom-contacting gear (MBCG) in the Bay of Biscay and the Iberian Coast area. The maps of swept area ratio, landings value, and landings weight show annual means evaluated at the c-square scale. **

Table 2

Table 2. Contribution of small-scale fisheries (vessels < 12 m overall length) to total fishing effort (kW × fishing days) in the Bay of Biscay and the Iberian Coast area. The table shows the total fishing effort (kW × fishing days) by FAO region over the assessment period, and the mean contribution (%) and observed range in contribution (%) of small-scale MBCG fisheries.

FAO region code FAO region name Total fishing effort (kW × Fishing days) Mean contribution SSF (%) Observed range SSF contribution (%) [min - max]
27.8.a Bay of Biscay - North 10411305 23.2 [21 - 24]
27.8.b Bay of Biscay - Central 3154505 12.3 [11 - 14]
27.8.c Bay of Biscay - South 4221423 2.7 [0 - 5]
27.8.d Bay of Biscay - Offshore 125039 1.0 [0 - 2]
27.9.a Portuguese Waters - East 7567817 23.2 [2 - 34]

Fishing intensity

The extent and relative abundance of BHTs in the Bay of Biscay and the Iberian Coast area are presented in Table 3. This table also presents landings weight and landings value and the intensity of MBCG fisheries operating in these habitats. Note that fishing data is only available at the c-square scale and is assumed to be uniformly distributed over all habitat types present in a c-square. Each habitat type present is proportionally assigned the fishing data registered in a c-square.

The most extensive habitat type is Offshore circalittoral sand occupying 34.97 ×1000 km2 (20.4%). The average fishing intensity (swept area ratio) on this habitat is 2.42, covering annually on average 84.6% of the habitat extent. Ninety per cent of the fishing effort in this BHT however, is concentrated to 68.7% of the habitat extent. Three point seven per cent of this habitat is located in c squares that are persistently not fished. The largest landing (in tonnes) is derived from fishing on Upper bathyal sediment, and the greatest landings values come from fishing on Offshore circalittoral sand.

Temporal variation of the pressure indicators I−1, I−3, and I−4 are shown in Figure 2 for the Bay of Biscay and the Iberian Coast area.

Table 3

Table 3. Extent (in km2 and %) of broad habitat types in the Bay of Biscay and the Iberian Coast area, and mean annual estimates of MBCG fishing intensity, landings weight, and landings value. In addition, estimates of the average annual proportion of the fished extent, the smallest proportion of the habitat extent affected by 90% of the fishing effort, and the proportion of extent persistently unfished are provided.

MSFD broad habitat type Extent of habitat (×1000 km2) Relative habitat extent (%) Landings (×1000 tonnes) Value (×106 euro) Swept area (×1000 km2) Average fishing intensity (I‒1) Average annual extent fished (%) Smallest proportion of extent with 90% of fishing effort (%) Percentage extent persistently unfished (%)
Offshore circalittoral sand 34.97 20.4 15.64 NA 84.68 2.42 84.6 68.7 3.7
Offshore circalittoral mud 31.48 18.3 14.89 NA 121.86 3.87 74.6 54.5 16.4
Upper bathyal sediment 26.40 15.4 21.61 NA 53.25 2.02 51.4 35.3 19.7
Circalittoral sand 16.24 9.5 3.75 NA 46.18 2.84 59.7 44.3 26.5
Offshore circalittoral coarse sediment 11.92 6.9 3.67 NA 33.49 2.81 90.8 74.8 1.1
Circalittoral coarse sediment 8.54 5.0 4.24 NA 51.68 6.05 83.8 61.2 3.9
Upper bathyal sediment or Upper bathyal rock and biogenic reef 8.40 4.9 0.50 NA 3.80 0.45 22.1 21.7 40.9
Offshore circalittoral rock and biogenic reef 7.00 4.1 2.40 NA 10.70 1.53 57.7 50.5 18.1
Circalittoral rock and biogenic reef 6.88 4.0 0.66 NA 4.21 0.61 24.6 23.2 47.1
Circalittoral mud 6.26 3.6 2.10 NA 31.11 4.97 48.4 27.9 32.9
Offshore circalittoral mixed sediment 3.36 2.0 2.34 NA 22.13 6.59 80.5 60.9 14.2
Circalittoral mixed sediment 2.97 1.7 0.20 NA 2.72 0.92 11.9 8.3 79.3
Infralittoral sand 1.91 1.1 0.11 NA 0.94 0.49 10.0 5.9 64.5
Infralittoral rock and biogenic reef 1.65 1.0 0.02 NA 0.15 0.09 5.9 12.4 66.1
Upper bathyal rock and biogenic reef 1.23 0.7 0.89 NA 1.54 1.26 40.6 34.0 37.6
Infralittoral mud 0.56 0.3 0.02 NA 0.11 0.21 5.9 4.7 62.1
Lower bathyal sediment 0.50 0.3 0.03 NA 0.05 0.10 7.4 26.7 28.3
Infralittoral coarse sediment 0.45 0.3 0.02 NA 0.12 0.27 11.4 15.2 41.6
Lower bathyal sediment or Lower bathyal rock and biogenic reef 0.34 0.2 0.01 NA 0.02 0.07 6.4 34.6 43.2
Unknown 0.31 0.2 0.14 NA 0.15 0.48 27.3 27.8 56.9
Infralittoral mixed sediment 0.30 0.2 0.02 NA 0.20 0.66 15.2 8.8 52.3
Lower bathyal rock and biogenic reef 0.04 0.0 0.00 NA 0.00 0.04 3.7 NA 30.5
Abyssal 0.01 0.0 0.00 NA 0.00 0.01 1.3 NA 3.4

Figure 2

Figure 2. Temporal variation of the pressure indicators I‒1, I‒3 and I‒4 in the Bay of Biscay and the Iberian Coast area. Descriptions of the pressure indicators are provided in the ‘Essential Information’ Table E1 in this document.

**Figure 2. Temporal variation of the pressure indicators I‒1, I‒3 and I‒4 in the Bay of Biscay and the Iberian Coast area. Descriptions of the pressure indicators are provided in the ‘Essential Information’ Table E1 in this document.**

Fishing by métier

Relationships between swept area and the landings weight and landings value of the métiers show the landings and economic returns as a function of swept area (Table 4). The most active métier within the Bay of Biscay and the Iberian Coast area is OT_DMF. This métier lands 117.7 kg of fish per km2 swept area.

The métier with the highest landing per swept area is DRB_MOL.

Table 4

Table 4. Landings weight and value by métier and their relationship with swept area in the Bay of Biscay and the Iberian Coast area.

OT_DMF OT_CRU OT_MI SDN_DMF TBB_DMF OT_SPF DRB_MOL
Area swept (×1000 km2) 201.20 146.04 68.44 49.68 2.33 1.76 0.02
Landings (×1000 tonnes) 23.68 10.96 35.23 1.79 0.49 0.99 0.11
Value (×106 euro) NA NA NA NA NA NA NA
Landings / Area swept (kg/km2) 117.70 75.04 514.76 36.00 211.74 564.64 5211.92
Value / Area swept (euro/km2) NA NA NA NA NA NA NA

Core fishing grounds

Note that only the Gulf of Biscay is considered in the identification of the core fishing grounds, due to missing landings values in the other subdivisions.

Core fishing grounds are defined as the smallest area yielding 90% of the landings value, evaluated annually at the c-square scale. The spatial stability of core fishing grounds over the assessment period 2017−2022 is described as the number of years a c-square is identified as a core fishing ground. This spatial extent and stability of the core fishing grounds varies among métiers (Figures 3 and 4).

Métier OT_DMF has 73.8% of the Gulf of Biscay subdivision identified at least once as a core fishing ground. For métier OT_CRU, this extent is much smaller (20.8%). The most stable core fishing grounds (highest fraction of core fishing ground c-squares identified as core fishing ground in all six years) are observed for OT_CRU, whereas the métier OT_SPF shows the least stable core fishing grounds in the Gulf of Biscay subdivision.

Overall, there is considerable variation in the stability of core fishing grounds among métiers. This is expected to be a consequence of interannual movements of fishing locations because of the habitat affinity of the variety of fish and shellfish targeted by different métiers (Table 5 in the main advice document) and the effects of economic and regulatory factors.

Figure 3

Figure 3. Spatial stability of core MBCG fishing grounds, presented as the number of years a c-square is identified as a core fishing ground (smallest area yielding 90% of the landings value) per métier for the Gulf of Biscay subdivision. Only métiers that were active within > 50 unique c-squares during the assessment period are included. The numbers between brackets show the proportion of fished extent compared to the overall assessed area extent.

**Figure 3. Spatial stability of core MBCG fishing grounds, presented as the number of years a c-square is identified as a core fishing ground (smallest area yielding 90% of the landings value) per métier for the Gulf of Biscay subdivision. Only métiers that were active within > 50 unique c-squares during the assessment period are included. The numbers between brackets show the proportion of fished extent compared to the overall assessed area extent.**

Figure 4

Figure 4. Spatial distribution of the stability of the core MBCG fishing grounds, presented as the number of years a c-square is identified as a core fishing ground (smallest area yielding 90% of the landings value) per métier for the Gulf of Biscay subdivision. Only métiers that were active within > 50 unique c-squares during the assessment period are included.

**Figure 4. Spatial distribution of the stability of the core MBCG fishing grounds, presented as the number of years a c-square is identified as a core fishing ground (smallest area yielding 90% of the landings value) per métier for the Gulf of Biscay subdivision. Only métiers that were active within > 50 unique c-squares during the assessment period are included.**

Impact

Fishing impact, as assessed with the PD indicator (I−6a) and the PD-sens indicator (I−6b), results from the fishing intensity for MBCG métiers and the median longevity of the benthic fauna (Figure 1) as well as métier-specific depletion rates per trawl pass (Table 5 in the main advice document). The PD-sens indicator only considers sensitive fauna and shows greater impacts than the PD indicator (Figures 5 and 6).

The spatial distribution of the fishing impact in the Bay of Biscay and the Iberian Coast area is shown in Figure 5. When based on the PD indicator, fishing impact is 0.14 on average (I−6a), with 78% of the area having a fishing impact below 0.2 (I−7a; Figure 6). For the PD-sens indicator, the average impact is 0.18 (I−6b), with 69% of the area having less impact than 0.2 (I−7b; Figure 6).

For the OT_DMF métier, which accounts for the largest proportion of swept area (Table 4), landing weight is 63.3 tonnes per unit of PD impact. Similarly, landing weight is 48.6 tonnes per unit of PD-sens impact (Table 5). The métier with the highest landings weight per unit impact is OT_MIX (111.8 tonnes), .

Métier-related impacts, as measured with the PD and PD-sens indicators, vary among BHTs because of variations in fishing intensity, seabed sensitivity (Figure 1), and the depletion rate of the specific métier (Table 5 in the main advice document; Figure 7). The largest PD and PD sens impacts in the Bay of Biscay and the Iberian Coast area are attributed to the OT_CRU métier fishing on Offshore circalittoral mud.

Figure 5

Figure 5. The spatial distribution of MBCG fisheries impact in the Bay of Biscay and the Iberian Coast area, as assessed with the PD indicator (I‒6a) and PD-sens indicator (I‒6b), shown as annual means for the assessment period, evaluated at the c-square scale. Descriptions of the impact indicators are provided in the ‘Essential Information’ Table E1 in this document.

**Figure 5. The spatial distribution of MBCG fisheries impact in the Bay of Biscay and the Iberian Coast area, as assessed with the PD indicator (I‒6a) and PD-sens indicator (I‒6b), shown as annual means for the assessment period, evaluated at the c-square scale. Descriptions of the impact indicators are provided in the ‘Essential Information’ Table E1 in this document.**

Figure 6

Figure 6. Temporal variation in values of the PD indicator (I‒6a), PD-sens indicator (I‒6b), proportion of the extent with PD impact < 0.2 (I‒7a) and proportion of extent with PD-sens impact < 0.2 (I‒7b), shown for the overall area and for the four most extensive broad habitat types separately in the Bay of Biscay and the Iberian Coast area. Descriptions of the impact indicators are provided in the ‘Essential Information’ Table E1 in this document.

**Figure 6. Temporal variation in values of the PD indicator (I‒6a), PD-sens indicator (I‒6b), proportion of the extent with PD impact < 0.2 (I‒7a) and proportion of extent with PD-sens impact < 0.2 (I‒7b), shown for the overall area and for the four most extensive broad habitat types separately in the Bay of Biscay and the Iberian Coast area. Descriptions of the impact indicators are provided in the ‘Essential Information’ Table E1 in this document.**

Table 5

Table 5. Métier-specific landings weight and value per unit PD or PD-sens impact in the Bay of Biscay and the Iberian Coast area.

OT_DMF OT_CRU OT_MI SDN_DMF TBB_DMF OT_SPF DRB_MOL
Landings (tonnes)/PD impact 63.3 21.1 111.8 64.7 24.2 84.4 35.8
Value (×1000 euro)/PD impact NA NA NA NA NA NA NA
Landings (tonnes)/PD-sens impact 48.6 18.3 85.7 46.2 17.2 81.7 44.2
Value (×1000 euro)/PD-sens impact NA NA NA NA NA NA NA

Figure 7

Figure 7. Métier-related impacts, reported as annual means of the PD indicator (I‒6a, top) and PD-sens indicator (I‒6b, bottom), on the four most extensive broad habitat types in the Bay of Biscay and the Iberian Coast area.

**Figure 7. Métier-related impacts, reported as annual means of the PD indicator (I‒6a, top) and PD-sens indicator (I‒6b, bottom), on the four most extensive broad habitat types in the Bay of Biscay and the Iberian Coast area.**

Scenarios

Footprint reduction

The fishing footprint reduction scenarios illustrate the effects of stepwise MBCG fisheries exclusion from specified proportions of each BHT within the Bay of Biscay and the Iberian Coast area. The stepwise exclusion is conducted in 10% increments, ranging from 10% to 90%. In each successive increment, the c-squares containing the least MBCG swept area are excluded. The resulting reduction in swept area (Table 6), landings weight (Table 7), and landings value (Table 8) is presented for the prevailing BHTs combined and for each type separately.

For example, the analysis shows that the exclusion of MBCG from 30% of all prevailing BHTs types is affecting 4.0% of the footprint (Table 6), 4.8% of the landings weight (Table 7),. No estimation could be provided for the loss in landings value (Table 8). In this example, the pattern reflects the extent to which MBCG fishing activity is concentrated in core areas, with relatively low effort and landings in peripheral areas.

Table 6: Effort

Table 6. The effects of stepwise exclusion of all MBCG fisheries from a specified proportion of a MSFD broad habitat type within the Bay of Biscay and the Iberian Coast area, on swept area (presented as % of total swept area within that habitat type). The stepwise exclusion is conducted in 10% increments, and within each successive increment from 10% to 90% the c-squares with the lowest recorded rank MBCG swept area are excluded. Note that the top row shows the total estimate for all habitats combined.

MSFD broad habitat type Extent of habitat (×1000 km2) Total area swept (×1000 km2 10% 20% 30% 40% 50% 60% 70% 80% 90%
total 171.68 100 0.3 1.5 4.0 8.3 14.4 22.1 31.7 44.7 63.1
Offshore circalittoral sand 34.97 84.68 0.6 4.0 9.3 16.2 25.1 35.2 47.0 60.5 77.1
Offshore circalittoral mud 31.48 121.86 0.0 <0.1 2.2 6.7 13.3 21.3 30.4 41.9 58.6
Upper bathyal sediment 26.4 53.25 0.0 <0.1 0.2 0.9 3.0 7.2 15.0 28.6 51.5
Circalittoral sand 16.24 46.18 0.0 0.0 <0.1 1.6 6.9 14.7 25.1 38.5 58.4
Offshore circalittoral coarse sediment 11.92 33.49 3.1 7.8 12.8 19.6 27.3 36.0 46.2 57.7 72.5
Circalittoral coarse sediment 8.54 51.68 0.1 1.4 4.9 11.6 19.9 28.7 39.1 52.4 69.4
Upper bathyal sediment or Upper bathyal rock and biogenic reef 8.4 3.8 0.0 0.0 0.3 1.7 4.4 8.5 16.5 28.4 52.6
Offshore circalittoral rock and biogenic reef 7 10.7 0.0 <0.1 1.2 5.2 12.0 21.5 34.1 51.3 70.5
Circalittoral rock and biogenic reef 6.88 4.21 0.0 0.0 0.0 <0.1 0.8 3.5 8.3 20.1 43.0
Circalittoral mud 6.26 31.11 0.0 0.0 0.0 <0.1 0.7 3.0 8.8 22.4 47.4
Offshore circalittoral mixed sediment 3.36 22.13 0.0 0.4 4.4 10.9 17.5 26.9 38.1 54.6 76.3
Circalittoral mixed sediment 2.97 2.72 0.0 0.0 0.0 0.0 0.0 0.0 0.0 <0.1 4.8
Infralittoral sand 1.91 0.94 0.0 0.0 0.0 0.0 0.0 <0.1 0.3 1.2 6.6
Infralittoral rock and biogenic reef 1.65 0.15 0.0 0.0 0.0 0.0 0.0 <0.1 1.4 5.4 22.1
Upper bathyal rock and biogenic reef 1.23 1.54 0.0 0.0 0.0 0.2 1.7 7.5 20.9 41.5 67.4
Infralittoral mud 0.56 0.11 0.0 0.0 0.0 0.0 0.0 <0.1 0.7 1.6 3.4
Lower bathyal sediment 0.5 0.05 0.0 0.0 0.0 <0.1 1.4 2.9 9.2 16.3 32.3
Infralittoral coarse sediment 0.45 0.12 0.0 0.0 0.0 <0.1 0.4 1.7 4.0 7.1 13.6
Lower bathyal sediment or Lower bathyal rock and biogenic reef 0.34 0.02 0.0 0.0 <0.1 7.7 7.7 15.1 17.2 25.0 52.3
Unknown 0.31 0.15 <0.1 2.9 10.7 16.8 23.9 39.2 72.4 100.0 100.0
Infralittoral mixed sediment 0.3 0.2 0.0 0.0 0.0 0.0 <0.1 <0.1 0.3 3.4 22.3
Abyssal 0.01 0 0.0 0.0 0.0 0.0 43.9 43.9 100.0 100.0 100.0
Table 7: Landings weight

Table 7. The effects of stepwise exclusion of all MBCG fisheries from a specified proportion of a MSFD broad habitat type within the Bay of Biscay and the Iberian Coast area, on landings weight (presented as % of total landings weight within that habitat type). The stepwise exclusion is conducted in 10% increments, and within each successive increment from 10% to 90% the c-squares with the lowest recorded rank MBCG swept area are excluded. Note that the top row shows the total estimate for all habitats combined.

MSFD broad habitat type Extent of habitat (×1000 km2) Total landings weight (×1000 kg) 10% 20% 30% 40% 50% 60% 70% 80% 90%
Total 171.68 72428.5 0.5 2.0 4.8 9.6 16.3 24.0 33.5 47.1 66.5
Offshore circalittoral sand 34.97 15532.9 0.7 4.7 10.4 19.5 29.1 39.8 51.1 64.5 80.7
Offshore circalittoral mud 31.48 14864.2 0.0 0.1 3.3 9.8 19.8 30.5 42.0 55.1 76.6
Upper bathyal sediment 26.4 21546.3 0.0 <0.1 0.1 0.6 2.1 4.8 10.9 24.8 46.6
Circalittoral sand 16.24 3737.6 0.0 0.0 0.5 3.9 13.4 23.0 33.4 45.6 64.0
Offshore circalittoral coarse sediment 11.92 3662.3 6.5 14.5 21.0 29.2 38.3 48.6 60.9 72.6 84.2
Circalittoral coarse sediment 8.54 4241.9 0.4 3.1 7.2 13.4 20.7 28.2 36.5 48.9 63.6
Upper bathyal sediment or Upper bathyal rock and biogenic reef 8.4 162.1 0.0 0.0 0.5 2.6 4.9 9.3 21.8 32.6 69.2
Offshore circalittoral rock and biogenic reef 7 2252.9 0.0 0.1 1.4 7.0 14.9 26.1 42.3 62.3 83.0
Circalittoral rock and biogenic reef 6.88 637.9 0.0 0.0 0.0 <0.1 1.2 5.1 11.8 30.8 62.2
Circalittoral mud 6.26 2087.5 0.0 0.0 0.0 0.4 2.5 5.9 11.9 25.4 49.4
Offshore circalittoral mixed sediment 3.36 2335.5 0.0 0.8 8.4 17.0 28.9 39.9 52.4 66.2 82.8
Circalittoral mixed sediment 2.97 204.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 <0.1 7.3
Infralittoral sand 1.91 105.4 0.0 0.0 0.0 0.0 0.0 <0.1 1.8 14.5 33.0
Infralittoral rock and biogenic reef 1.65 19.8 0.0 0.0 0.0 0.0 0.0 0.2 5.2 11.6 38.8
Upper bathyal rock and biogenic reef 1.23 869.6 0.0 0.0 0.0 <0.1 1.3 6.0 15.0 35.2 64.0
Infralittoral mud 0.56 16.6 0.0 0.0 0.0 0.0 0.0 0.3 6.8 23.4 38.6
Lower bathyal sediment 0.5 26.4 0.0 0.0 0.0 <0.1 0.8 1.5 5.8 10.7 36.2
Infralittoral coarse sediment 0.45 24.7 0.0 0.0 0.0 <0.1 1.1 7.1 13.2 29.6 39.8
Lower bathyal sediment or Lower bathyal rock and biogenic reef 0.34 3.4 0.0 0.0 0.6 13.4 13.4 24.6 31.0 52.4 72.1
Unknown 0.31 73.2 <0.1 0.9 2.3 2.9 4.0 7.1 50.4 100.0 100.0
Infralittoral mixed sediment 0.3 24.2 0.0 0.0 0.0 0.0 0.4 2.7 7.1 17.3 36.4
Abyssal 0.01 0 0.0 0.0 0.0 0.0 16.2 16.2 100.0 100.0 100.0
Table 8: Landings value

Table 8. The effects of stepwise exclusion of all MBCG fisheries from a specified proportion of a MSFD broad habitat type within the Bay of Biscay and the Iberian Coast area, on landings value (presented as % of total landings value within that habitat type). The stepwise exclusion is conducted in 10% increments, and within each successive increment from 10% to 90% the c-squares with the lowest recorded rank MBCG swept area are excluded. Note that the top row shows the total estimate for all habitats combined.

MSFD broad habitat type Extent of habitat (×1000 km2) Total landings value (×1000 euro) 10% 20% 30% 40% 50% 60% 70% 80% 90%
Total 171.68 NA NA NA NA NA NA NA NA NA NA
Offshore circalittoral sand 34.97 NA NA NA NA NA NA NA NA NA NA
Offshore circalittoral mud 31.48 NA NA NA NA NA NA NA NA NA NA
Upper bathyal sediment 26.4 NA NA NA NA NA NA NA NA NA NA
Circalittoral sand 16.24 NA NA NA NA NA NA NA NA NA NA
Offshore circalittoral coarse sediment 11.92 NA NA NA NA NA NA NA NA NA NA
Circalittoral coarse sediment 8.54 NA NA NA NA NA NA NA NA NA NA
Upper bathyal sediment or Upper bathyal rock and biogenic reef 8.4 NA NA NA NA NA NA NA NA NA NA
Offshore circalittoral rock and biogenic reef 7 NA NA NA NA NA NA NA NA NA NA
Circalittoral rock and biogenic reef 6.88 NA NA NA NA NA NA NA NA NA NA
Circalittoral mud 6.26 NA NA NA NA NA NA NA NA NA NA
Offshore circalittoral mixed sediment 3.36 NA NA NA NA NA NA NA NA NA NA
Circalittoral mixed sediment 2.97 NA NA NA NA NA NA NA NA NA NA
Infralittoral sand 1.91 NA NA NA NA NA NA NA NA NA NA
Infralittoral rock and biogenic reef 1.65 NA NA NA NA NA NA NA NA NA NA
Upper bathyal rock and biogenic reef 1.23 NA NA NA NA NA NA NA NA NA NA
Infralittoral mud 0.56 NA NA NA NA NA NA NA NA NA NA
Lower bathyal sediment 0.5 NA NA NA NA NA NA NA NA NA NA
Infralittoral coarse sediment 0.45 NA NA NA NA NA NA NA NA NA NA
Lower bathyal sediment or Lower bathyal rock and biogenic reef 0.34 NA NA NA NA NA NA NA NA NA NA
Unknown 0.31 NA NA NA NA NA NA NA NA NA NA
Infralittoral mixed sediment 0.3 NA NA NA NA NA NA NA NA NA NA
Abyssal 0.01 NA NA NA NA NA NA NA NA NA NA

Gear modifications

The effects of hypothetical gear modifications or changes in fishing practices were expressed in terms of their effects on the depletion of benthic fauna per gear pass. It was assumed that the modifications or changes in practice would achieve 5%, 10%, or 20% less depletion per gear pass. The effects of these changes in depletion on the quality and extent of the four BHTs that account for the greatest proportion of the Bay of Biscay and the Iberian Coast area are presented in figures 8−11. Impacts of MBCG were calculated as changes in habitat “quality” (measured as 1-PD impact or 1-PD-sens impact) in the fished area and expressed in terms of the increase in the quality of habitat meeting the extent threshold (> 75% of a BHT not adversely affected [EC, 2024]).

References:

EC. 2024. Commission Notice C/2024/2078 on the threshold values set under the Marine Strategy Framework Directive 2008/56/EC and Commission Decision (EU) 2017/848). Official Journal of the European Union C/2024/2078, 5pp. http://data.europa.eu/eli/C/2024/2078/oj

Figure 8: Habitat 1

Figure 8. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the Bay of Biscay and the Iberian Coast area. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).

**Figure 8. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the Bay of Biscay and the Iberian Coast area. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).**
Figure 9: Habitat 2

Figure 9. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the Bay of Biscay and the Iberian Coast area. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).

**Figure 9. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the Bay of Biscay and the Iberian Coast area. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).**
Figure 10: Habitat 3

Figure 10. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the Bay of Biscay and the Iberian Coast area. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).

**Figure 10. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the Bay of Biscay and the Iberian Coast area. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).**
Figure 11: Habitat 4

Figure 11. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the Bay of Biscay and the Iberian Coast area. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).

**Figure 11. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the Bay of Biscay and the Iberian Coast area. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).**

Gulf of Biscay

Summary

Table 1

Table 1. Values of pressure and impact indicators for 2017‒2022 for three depth strata in the Gulf of Biscay subdivision. Values of I‒1, I‒2, I‒3, I‒4, I‒6a, I‒6b, I‒7a and I‒7b are annual means and I‒5 is evaluated over the six years. Descriptions of the pressure and impact indicators are provided in the ‘Essential Information’ Table E1 in this document.

Indicators 0 to 200 m 200 to 400 m 400 to 800 m
I‒1: Average fishing intensity 3.7 2.19 1.16
I‒2: Proportion of area fished, evaluated at c-square scale (%) 97.2 100.00 100.00
I‒3: Proportion of area fished (%) 85.6 90.40 71.90
I‒4: Smallest proportion of area with 90% of fishing intensity, evaluated at c-square scale (%) 60.1 68.60 61.00
I‒5: Proportion of area persistently unfished, evaluated at c-square scale (%) 2.8 0.00 0.00
I‒6a: Average PD impact 19.2 8.80 4.40
I‒6b: Average PD-sens impact 25.4 12.40 6.10
I‒7a: Proportion of area with PD impact < 0.2, evaluated at c-square scale (%) 68.8 90.60 100.00
I‒7b: Proportion of area with PD-sens impact < 0.2, evaluated at c-square scale (%) 56.4 80.80 92.70

Figure 1

Figure 1. Geographic distribution of fishing intensity (swept area ratio), seabed sensitivity (community longevity), total landings value, and total landings weight from mobile bottom-contacting gear (MBCG) in the Gulf of Biscay subdivision. The maps of swept area ratio, landings value, and landings weight show annual means evaluated at the c-square scale.

**Figure 1. Geographic distribution of fishing intensity (swept area ratio), seabed sensitivity (community longevity), total landings value, and total landings weight from mobile bottom-contacting gear (MBCG) in the Gulf of Biscay subdivision. The maps of swept area ratio, landings value, and landings weight show annual means evaluated at the c-square scale. **

Table 2

Table 2. Contribution of small-scale fisheries (vessels < 12 m overall length) to total fishing effort (kW × fishing days) in the Gulf of Biscay subdivision. The table shows the total fishing effort (kW × fishing days) by FAO region over the assessment period, and the mean contribution (%) and observed range in contribution (%) of small-scale MBCG fisheries’.

FAO region code FAO region name Total fishing effort (kW × Fishing days) Mean contribution SSF (%) Observed range SSF contribution (%) [min - max]
27.8.a Bay of Biscay - North 10411305 23.2 [21 - 24]
27.8.b Bay of Biscay - Central 3154505 12.3 [11 - 14]
27.8.c Bay of Biscay - South 4221423 2.7 [0 - 5]
27.8.d Bay of Biscay - Offshore 125039 1.0 [0 - 2]

Fishing intensity

Table 3

Table 3. Extent (in km2 and %) of broad habitat types in the Gulf of Biscay subdivision, and mean annual estimates of MBCG fishing intensity, landings weight, and landings value. In addition, estimates of the average annual proportion of the fished extent, the smallest proportion of the habitat extent affected by 90% of the fishing effort, and the proportion of extent persistently unfished are provided.

MSFD broad habitat type Extent of habitat (×1000 km2) Relative habitat extent (%) Landings (×1000 tonnes) Value (×106 euro) Swept area (×1000 km2) Average fishing intensity (I‒1) Average annual extent fished (%) Smallest proportion of extent with 90% of fishing effort (%) Percentage extent persistently unfished (%)
Offshore circalittoral sand 24.56 29.6 7.80 12.45 62.47 2.54 90.1 73.7 0.0
Offshore circalittoral mud 17.10 20.6 6.93 31.08 82.30 4.81 96.8 72.8 0.1
Offshore circalittoral coarse sediment 10.55 12.7 2.74 8.00 31.49 2.98 93.8 77.3 0.0
Circalittoral sand 9.95 12.0 2.61 13.00 35.14 3.53 84.0 65.3 1.5
Circalittoral coarse sediment 7.95 9.6 4.12 19.98 51.26 6.45 88.0 64.9 0.9
Circalittoral rock and biogenic reef 2.83 3.4 0.36 1.82 3.67 1.30 48.5 44.1 5.2
Circalittoral mud 2.46 3.0 0.36 2.15 5.37 2.18 59.2 45.9 5.8
Offshore circalittoral rock and biogenic reef 2.16 2.6 0.73 2.43 6.96 3.23 96.6 82.9 0.1
Offshore circalittoral mixed sediment 2.00 2.4 1.47 9.22 18.35 9.17 99.3 78.3 0.0
Upper bathyal sediment 1.01 1.2 0.25 0.28 1.57 1.54 73.1 66.4 0.0
Infralittoral rock and biogenic reef 0.77 0.9 0.01 0.07 0.13 0.17 9.9 20.4 39.9
Infralittoral sand 0.59 0.7 0.04 0.19 0.30 0.51 18.2 14.9 36.5
Infralittoral coarse sediment 0.32 0.4 0.00 0.02 0.02 0.06 5.2 34.2 44.7
Infralittoral mud 0.31 0.4 0.01 0.04 0.07 0.22 6.8 4.0 60.1
Circalittoral mixed sediment 0.21 0.3 0.06 0.33 1.05 4.94 91.8 70.8 3.3
Unknown 0.10 0.1 0.01 0.03 0.05 0.53 29.4 40.0 25.0
Infralittoral mixed sediment 0.04 0.0 0.00 0.00 0.00 0.07 7.1 7.5 77.1
Upper bathyal sediment or Upper bathyal rock and biogenic reef 0.01 0.0 0.00 0.00 0.01 0.77 44.7 NA 0.0
Upper bathyal rock and biogenic reef 0.00 0.0 0.00 0.00 0.01 4.38 100.0 NA 0.0

Figure 2

Figure 2. Temporal variation of the pressure indicators I‒1, I‒3 and I‒4 in the Gulf of Biscay subdivision. Descriptions of the pressure indicators are provided in the ‘Essential Information’ Table E1 in this document.

**Figure 2. Temporal variation of the pressure indicators I‒1, I‒3 and I‒4 in the Gulf of Biscay subdivision. Descriptions of the pressure indicators are provided in the ‘Essential Information’ Table E1 in this document.**

Fishing by métier

Table 4

Table 4. Landings weight and value by métier and their relationship with swept area in the Gulf of Biscay subdivision.

OT_DMF OT_CRU SDN_DMF OT_MI TBB_DMF OT_SPF
Area swept (×1000 km2) 140.12 65.03 49.27 42.10 2.33 1.66
Landings (×1000 tonnes) 13.82 5.11 1.75 5.68 0.49 0.63
Value (×106 euro) 34.09 35.40 8.24 18.40 4.07 0.81
Landings / Area swept (kg/km2) 98.64 78.51 35.57 134.89 211.74 377.98
Value / Area swept (euro/km2) 243.30 544.31 167.18 437.11 1746.13 488.75

Core fishing grounds

Figure 3

Figure 3. Spatial stability of core MBCG fishing grounds, presented as the number of years a c-square is identified as a core fishing ground (smallest area yielding 90% of the landings value) per métier for the Gulf of Biscay subdivision. Only métiers that were active within > 50 unique c-squares during the assessment period are included. The numbers between brackets show the proportion of fished extent compared to the overall assessed area extent.

**Figure 3. Spatial stability of core MBCG fishing grounds, presented as the number of years a c-square is identified as a core fishing ground (smallest area yielding 90% of the landings value) per métier for the Gulf of Biscay subdivision. Only métiers that were active within > 50 unique c-squares during the assessment period are included. The numbers between brackets show the proportion of fished extent compared to the overall assessed area extent.**

Figure 4

Figure 4. Spatial distribution of the stability of the core MBCG fishing grounds, presented as the number of years a c-square is identified as a core fishing ground (smallest area yielding 90% of the landings value) per métier for the Gulf of Biscay subdivision. Only métiers that were active within > 50 unique c-squares during the assessment period are included.

**Figure 4. Spatial distribution of the stability of the core MBCG fishing grounds, presented as the number of years a c-square is identified as a core fishing ground (smallest area yielding 90% of the landings value) per métier for the Gulf of Biscay subdivision. Only métiers that were active within > 50 unique c-squares during the assessment period are included.**

Impact

Figure 5

Figure 5. The spatial distribution of MBCG fisheries impact in the Gulf of Biscay subdivision, as assessed with the PD indicator (I‒6a) and PD-sens indicator (I‒6b), shown as annual means for the assessment period, evaluated at the c-square scale. Descriptions of the impact indicators are provided in the ‘Essential Information’ Table E1 in this document.

**Figure 5. The spatial distribution of MBCG fisheries impact in the Gulf of Biscay subdivision, as assessed with the PD indicator (I‒6a) and PD-sens indicator (I‒6b), shown as annual means for the assessment period, evaluated at the c-square scale. Descriptions of the impact indicators are provided in the ‘Essential Information’ Table E1 in this document.**

Figure 6

Figure 6. Temporal variation in values of the PD indicator (I‒6a), PD-sens indicator (I‒6b), proportion of the extent with PD impact < 0.2 (I‒7a) and proportion of extent with PD-sens impact < 0.2 (I‒7b), shown for the overall area and for the four most extensive broad habitat types separately in the Gulf of Biscay subdivision. Descriptions of the impact indicators are provided in the ‘Essential Information’ Table E1 in this document.

**Figure 6. Temporal variation in values of the PD indicator (I‒6a), PD-sens indicator (I‒6b), proportion of the extent with PD impact < 0.2 (I‒7a) and proportion of extent with PD-sens impact < 0.2 (I‒7b), shown for the overall area and for the four most extensive broad habitat types separately in the Gulf of Biscay subdivision. Descriptions of the impact indicators are provided in the ‘Essential Information’ Table E1 in this document.**

Table 5

Table 5. Métier-specific landings weight and value per unit PD or PD-sens impact in the Gulf of Biscay subdivision.

OT_DMF OT_CRU SDN_DMF OT_MI TBB_DMF OT_SPF
Landings (tonnes)/PD impact 59.1 17.7 65.5 30.1 24.2 100.8
Value (×1000 euro)/PD impact 145.8 123.0 307.8 97.4 199.9 130.3
Landings (tonnes)/PD-sens impact 42.3 14.6 46.4 21.7 17.2 95.1
Value (×1000 euro)/PD-sens impact 104.3 101.1 218.2 70.5 141.8 122.9

Figure 7

Figure 7. Métier-related impacts, reported as annual means of the PD indicator (I‒6a, top) and PD-sens indicator (I‒6b, bottom), on the four most extensive broad habitat types in the Gulf of Biscay subdivision.

**Figure 7. Métier-related impacts, reported as annual means of the PD indicator (I‒6a, top) and PD-sens indicator (I‒6b, bottom), on the four most extensive broad habitat types in the Gulf of Biscay subdivision.**

Scenarios

Footprint reduction

Table 6: Effort

Table 6. The effects of stepwise exclusion of all MBCG fisheries from a specified proportion of a MSFD broad habitat type within the Gulf of Biscay subdivision, on swept area (presented as % of total swept area within that habitat type). The stepwise exclusion is conducted in 10% increments, and within each successive increment from 10% to 90% the c-squares with the lowest recorded rank MBCG swept area are excluded. Note that the top row shows the total estimate for all habitats combined.

MSFD broad habitat type Extent of habitat (×1000 km2) Total area swept (×1000 km2 10% 20% 30% 40% 50% 60% 70% 80% 90%
total 82.91 100 2.0 5.7 10.7 17.4 25.0 33.8 43.9 56.3 72.5
Offshore circalittoral sand 24.56 62.47 2.0 6.5 12.5 20.2 29.0 38.8 50.4 63.3 78.8
Offshore circalittoral mud 17.1 82.3 2.5 6.5 11.5 17.5 24.3 31.8 40.5 51.4 67.3
Offshore circalittoral coarse sediment 10.55 31.49 4.1 8.7 14.2 20.9 28.9 37.6 47.3 58.9 73.2
Circalittoral sand 9.95 35.14 0.2 2.4 7.1 13.4 20.4 29.8 40.2 53.7 71.7
Circalittoral coarse sediment 7.95 51.26 0.3 2.4 6.6 13.6 21.8 30.9 41.2 53.8 70.7
Circalittoral rock and biogenic reef 2.83 3.67 <0.1 0.7 1.9 4.4 6.9 12.3 20.7 36.1 55.9
Circalittoral mud 2.46 5.37 <0.1 0.3 1.3 3.5 7.9 14.0 24.3 39.4 59.0
Offshore circalittoral rock and biogenic reef 2.16 6.96 6.1 12.6 19.5 27.4 35.5 46.5 55.4 69.1 82.7
Offshore circalittoral mixed sediment 2 18.35 3.9 9.0 15.3 22.6 30.3 40.8 53.0 67.0 83.2
Upper bathyal sediment 1.01 1.57 1.6 5.8 8.8 14.0 22.3 34.7 46.9 58.1 74.8
Infralittoral rock and biogenic reef 0.77 0.13 0.0 0.0 0.0 <0.1 0.3 1.9 4.0 11.1 24.7
Infralittoral sand 0.59 0.3 0.0 0.0 0.0 <0.1 0.2 0.6 2.1 5.4 23.8
Infralittoral coarse sediment 0.32 0.02 0.0 0.0 0.0 0.0 1.0 5.4 16.3 27.6 57.5
Infralittoral mud 0.31 0.07 0.0 0.0 0.0 0.0 0.0 <0.1 1.0 1.7 3.6
Circalittoral mixed sediment 0.21 1.05 1.1 5.5 11.7 20.2 29.7 38.4 48.9 66.0 90.0
Unknown 0.1 0.05 <0.1 1.1 4.1 15.7 22.0 29.3 37.8 47.6 77.6
Infralittoral mixed sediment 0.04 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.3 24.0
Upper bathyal rock and biogenic reef 0 0.01 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0
Table 7: Landings weight

Table 7. The effects of stepwise exclusion of all MBCG fisheries from a specified proportion of a MSFD broad habitat type within the Gulf of Biscay subdivision, on landings weight (presented as % of total landings weight within that habitat type). The stepwise exclusion is conducted in 10% increments, and within each successive increment from 10% to 90% the c-squares with the lowest recorded rank MBCG swept area are excluded. Note that the top row shows the total estimate for all habitats combined.

MSFD broad habitat type Extent of habitat (×1000 km2) Total landings weight (×1000 kg) 10% 20% 30% 40% 50% 60% 70% 80% 90%
Total 82.91 27387.1 2.4 6.6 12.0 19.2 26.9 36.5 47.1 60.2 75.8
Offshore circalittoral sand 24.56 7755.1 1.8 6.2 11.5 19.7 28.1 39.4 52.2 67.0 82.8
Offshore circalittoral mud 17.1 6919 3.4 8.5 14.7 21.9 29.4 37.8 46.8 58.4 73.7
Offshore circalittoral coarse sediment 10.55 2735.8 4.9 10.7 17.1 24.6 32.9 43.7 54.6 66.8 81.1
Circalittoral sand 9.95 2605.5 0.5 3.1 8.3 14.8 22.5 31.8 42.1 55.0 73.4
Circalittoral coarse sediment 7.95 4115.7 0.4 3.0 7.0 13.3 20.6 28.3 36.5 48.6 63.6
Circalittoral rock and biogenic reef 2.83 356.6 0.2 1.0 2.2 5.0 7.8 12.5 23.3 39.7 60.4
Circalittoral mud 2.46 358.4 <0.1 0.7 2.3 5.8 11.4 19.6 30.5 45.8 65.5
Offshore circalittoral rock and biogenic reef 2.16 725.6 5.9 11.1 18.3 25.9 32.1 42.0 52.6 67.1 80.0
Offshore circalittoral mixed sediment 2 1475 4.0 9.4 15.5 22.8 30.8 41.4 53.8 68.3 83.7
Upper bathyal sediment 1.01 219.2 1.6 5.1 7.7 13.9 21.3 31.7 52.1 60.1 72.5
Infralittoral rock and biogenic reef 0.77 12.6 0.0 0.0 0.0 <0.1 1.4 8.5 11.3 24.1 37.7
Infralittoral sand 0.59 35.3 0.0 0.0 0.0 <0.1 0.2 2.3 3.8 9.4 24.1
Infralittoral coarse sediment 0.32 4.2 0.0 0.0 0.0 0.0 1.1 11.5 24.6 31.2 50.1
Infralittoral mud 0.31 6.3 0.0 0.0 0.0 0.0 0.0 0.2 5.8 9.0 11.0
Circalittoral mixed sediment 0.21 56.4 1.4 6.5 13.9 22.8 32.6 40.8 51.1 66.4 91.9
Unknown 0.1 4.7 <0.1 0.8 2.1 15.4 20.0 25.8 29.2 37.7 74.7
Infralittoral mixed sediment 0.04 0.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.2 29.2
Upper bathyal rock and biogenic reef 0 1.3 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0
Table 8: Landings value

Table 8. The effects of stepwise exclusion of all MBCG fisheries from a specified proportion of a MSFD broad habitat type within the Gulf of Biscay subdivision, on landings value (presented as % of total landings value within that habitat type). The stepwise exclusion is conducted in 10% increments, and within each successive increment from 10% to 90% the c-squares with the lowest recorded rank MBCG swept area are excluded. Note that the top row shows the total estimate for all habitats combined.

MSFD broad habitat type Extent of habitat (×1000 km2) Total landings value (×1000 euro) 10% 20% 30% 40% 50% 60% 70% 80% 90%
Total 82.91 101044.8 1.7 5.0 9.4 15.5 22.3 30.2 39.1 50.7 67.6
Offshore circalittoral sand 24.56 12445.6 2.7 7.6 13.6 21.1 29.9 38.8 49.1 59.6 74.4
Offshore circalittoral mud 17.1 31070.1 1.6 4.3 7.8 12.4 17.2 23.0 29.8 39.8 59.3
Offshore circalittoral coarse sediment 10.55 7995.3 4.3 8.8 14.6 21.2 29.3 37.4 47.0 57.8 72.4
Circalittoral sand 9.95 12998.2 0.4 2.9 8.1 14.6 22.5 32.2 42.1 54.4 72.2
Circalittoral coarse sediment 7.95 19976.2 0.4 3.0 7.0 13.7 21.0 28.8 37.2 49.0 63.5
Circalittoral rock and biogenic reef 2.83 1823.7 0.2 0.9 2.0 4.5 7.0 12.0 21.9 39.4 59.8
Circalittoral mud 2.46 2146.1 <0.1 0.4 1.7 4.4 8.9 15.8 26.5 41.7 61.4
Offshore circalittoral rock and biogenic reef 2.16 2425.1 6.4 13.5 21.4 29.5 39.5 52.6 59.5 73.9 86.3
Offshore circalittoral mixed sediment 2 9216.3 3.0 6.8 12.5 19.9 27.7 38.2 51.4 66.8 83.0
Upper bathyal sediment 1.01 279 2.7 7.9 12.2 17.3 24.6 36.1 46.0 55.9 77.4
Infralittoral rock and biogenic reef 0.77 71.6 0.0 0.0 0.0 <0.1 1.0 6.1 8.1 18.4 31.0
Infralittoral sand 0.59 187.9 0.0 0.0 0.0 <0.1 0.3 1.8 3.4 8.6 23.5
Infralittoral coarse sediment 0.32 21 0.0 0.0 0.0 0.0 1.1 9.1 21.1 27.0 47.7
Infralittoral mud 0.31 36.8 0.0 0.0 0.0 0.0 0.0 0.2 4.4 7.1 8.9
Circalittoral mixed sediment 0.21 326.7 1.4 6.1 11.9 21.1 31.1 39.8 49.1 64.3 91.5
Unknown 0.1 23.2 <0.1 1.0 2.5 15.1 20.1 25.6 29.7 39.6 75.4
Infralittoral mixed sediment 0.04 1.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.2 22.6
Upper bathyal rock and biogenic reef 0 0.1 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0

Gear modifications

Figure 8: Habitat 1

Figure 8. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the Gulf of Biscay subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).

**Figure 8. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the Gulf of Biscay subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).**
Figure 9: Habitat 2

Figure 9. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the Gulf of Biscay subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).

**Figure 9. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the Gulf of Biscay subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).**
Figure 10: Habitat 3

Figure 10. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the Gulf of Biscay subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).

**Figure 10. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the Gulf of Biscay subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).**
Figure 11: Habitat 4

Figure 11. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the Gulf of Biscay subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).

**Figure 11. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the Gulf of Biscay subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).**

North-Iberian Atlantic

Summary

Table 1

Table 1. Values of pressure and impact indicators for 2017‒2022 for three depth strata in the North-Iberian Atlantic subdivision. Values of I‒1, I‒2, I‒3, I‒4, I‒6a, I‒6b, I‒7a and I‒7b are annual means and I‒5 is evaluated over the six years. Descriptions of the pressure and impact indicators are provided in the ‘Essential Information’ Table E1 in this document.

Indicators 0 to 200 m 200 to 400 m 400 to 800 m
I‒1: Average fishing intensity 1.91 3.96 0.76
I‒2: Proportion of area fished, evaluated at c-square scale (%) 77.50 97.70 76.20
I‒3: Proportion of area fished (%) 61.00 83.60 30.80
I‒4: Smallest proportion of area with 90% of fishing intensity, evaluated at c-square scale (%) 44.30 55.40 24.40
I‒5: Proportion of area persistently unfished, evaluated at c-square scale (%) 22.50 2.30 23.80
I‒6a: Average PD impact 7.60 19.20 3.90
I‒6b: Average PD-sens impact 9.50 24.00 5.10
I‒7a: Proportion of area with PD impact < 0.2, evaluated at c-square scale (%) 90.30 59.80 93.90
I‒7b: Proportion of area with PD-sens impact < 0.2, evaluated at c-square scale (%) 84.10 53.70 91.70

Figure 1

Figure 1. Geographic distribution of fishing intensity (swept area ratio), seabed sensitivity (community longevity), total landings value, and total landings weight from mobile bottom-contacting gear (MBCG) in the North-Iberian Atlantic subdivision. The maps of swept area ratio, landings value, and landings weight show annual means evaluated at the c-square scale.

**Figure 1. Geographic distribution of fishing intensity (swept area ratio), seabed sensitivity (community longevity), total landings value, and total landings weight from mobile bottom-contacting gear (MBCG) in the North-Iberian Atlantic subdivision. The maps of swept area ratio, landings value, and landings weight show annual means evaluated at the c-square scale. **

Table 2

Table 2. Contribution of small-scale fisheries (vessels < 12 m overall length) to total fishing effort (kW × fishing days) in the North-Iberian Atlantic subdivision. The table shows the total fishing effort (kW × fishing days) by FAO region over the assessment period, and the mean contribution (%) and observed range in contribution (%) of small-scale MBCG fisheries’.

FAO region code FAO region name Total fishing effort (kW × Fishing days) Mean contribution SSF (%) Observed range SSF contribution (%) [min - max]
27.8.a Bay of Biscay - North 10411305 23.2 [21 - 24]
27.8.b Bay of Biscay - Central 3154505 12.3 [11 - 14]
27.8.c Bay of Biscay - South 4221423 2.7 [0 - 5]
27.8.d Bay of Biscay - Offshore 125039 1.0 [0 - 2]
27.9.a Portuguese Waters - East 7567817 23.2 [2 - 34]

Fishing intensity

Table 3

Table 3. Extent (in km2 and %) of broad habitat types in the North-Iberian Atlantic subdivision, and mean annual estimates of MBCG fishing intensity, landings weight, and landings value. In addition, estimates of the average annual proportion of the fished extent, the smallest proportion of the habitat extent affected by 90% of the fishing effort, and the proportion of extent persistently unfished are provided.

MSFD broad habitat type Extent of habitat (×1000 km2) Relative habitat extent (%) Landings (×1000 tonnes) Value (×106 euro) Swept area (×1000 km2) Average fishing intensity (I‒1) Average annual extent fished (%) Smallest proportion of extent with 90% of fishing effort (%) Percentage extent persistently unfished (%)
Upper bathyal sediment 15.27 37.3 19.82 NA 34.99 2.29 57.4 39.2 10.4
Offshore circalittoral sand 7.58 18.5 7.58 NA 20.18 2.66 81.8 64.2 3.3
Offshore circalittoral mud 4.39 10.7 6.15 NA 15.31 3.49 93.6 78.1 1.1
Offshore circalittoral rock and biogenic reef 2.89 7.1 1.63 NA 3.41 1.18 57.7 54.5 14.9
Circalittoral rock and biogenic reef 2.28 5.6 0.29 NA 0.47 0.21 12.1 15.3 64.8
Circalittoral sand 1.55 3.8 0.34 NA 0.50 0.33 15.7 15.4 64.8
Upper bathyal sediment or Upper bathyal rock and biogenic reef 1.46 3.6 0.15 NA 0.25 0.17 13.5 19.9 42.8
Offshore circalittoral coarse sediment 1.24 3.0 0.91 NA 1.75 1.40 70.0 64.4 7.3
Upper bathyal rock and biogenic reef 0.86 2.1 0.88 NA 1.43 1.66 50.3 42.0 28.9
Offshore circalittoral mixed sediment 0.66 1.6 0.74 NA 2.12 3.21 92.1 75.9 4.3
Infralittoral rock and biogenic reef 0.53 1.3 0.01 NA 0.02 0.03 2.8 6.1 84.9
Lower bathyal sediment 0.50 1.2 0.03 NA 0.05 0.10 7.4 26.7 28.2
Circalittoral coarse sediment 0.49 1.2 0.10 NA 0.15 0.31 16.6 22.3 50.8
Circalittoral mud 0.31 0.8 0.02 NA 0.04 0.15 8.6 11.4 68.6
Infralittoral sand 0.27 0.7 0.00 NA 0.00 0.02 1.6 7.5 88.1
Lower bathyal sediment or Lower bathyal rock and biogenic reef 0.24 0.6 0.01 NA 0.01 0.04 4.1 43.4 48.0
Circalittoral mixed sediment 0.12 0.3 0.01 NA 0.01 0.09 4.7 9.3 69.0
Infralittoral mud 0.08 0.2 0.00 NA 0.00 0.00 0.2 3.8 94.2
Infralittoral mixed sediment 0.07 0.2 0.00 NA 0.00 0.00 0.2 4.7 88.8
Unknown 0.06 0.1 0.12 NA 0.08 1.49 83.9 49.2 13.1
Lower bathyal rock and biogenic reef 0.04 0.1 0.00 NA 0.00 0.04 3.7 64.9 30.5
Infralittoral coarse sediment 0.03 0.1 0.00 NA 0.01 0.19 7.8 5.3 78.4
Abyssal 0.01 0.0 0.00 NA 0.00 0.01 1.4 NA 0.0

Figure 2

Figure 2. Temporal variation of the pressure indicators I‒1, I‒3 and I‒4 in the North-Iberian Atlantic subdivision. Descriptions of the pressure indicators are provided in the ‘Essential Information’ Table E1 in this document.

**Figure 2. Temporal variation of the pressure indicators I‒1, I‒3 and I‒4 in the North-Iberian Atlantic subdivision. Descriptions of the pressure indicators are provided in the ‘Essential Information’ Table E1 in this document.**

Fishing by métier

Table 4

Table 4. Landings weight and value by métier and their relationship with swept area in the North-Iberian Atlantic subdivision.

OT_DMF OT_MI SDN_DMF OT_SPF
Area swept (×1000 km2) 54.35 25.87 0.41 0.10
Landings (×1000 tonnes) 8.92 29.45 0.04 0.37
Value (×106 euro) NA NA NA NA
Landings / Area swept (kg/km2) 164.12 1138.55 89.00 3718.83
Value / Area swept (euro/km2) NA NA NA NA

Core fishing grounds

Core fishing grounds could not be identified in this subdivision.

Impact

Figure 5

Figure 5. The spatial distribution of MBCG fisheries impact in the North-Iberian Atlantic subdivision, as assessed with the PD indicator (I‒6a) and PD-sens indicator (I‒6b), shown as annual means for the assessment period, evaluated at the c-square scale. Descriptions of the impact indicators are provided in the ‘Essential Information’ Table E1 in this document.

**Figure 5. The spatial distribution of MBCG fisheries impact in the North-Iberian Atlantic subdivision, as assessed with the PD indicator (I‒6a) and PD-sens indicator (I‒6b), shown as annual means for the assessment period, evaluated at the c-square scale. Descriptions of the impact indicators are provided in the ‘Essential Information’ Table E1 in this document.**

Figure 6

Figure 6. Temporal variation in values of the PD indicator (I‒6a), PD-sens indicator (I‒6b), proportion of the extent with PD impact < 0.2 (I‒7a) and proportion of extent with PD-sens impact < 0.2 (I‒7b), shown for the overall area and for the four most extensive broad habitat types separately in the North-Iberian Atlantic subdivision. Descriptions of the impact indicators are provided in the ‘Essential Information’ Table E1 in this document.

**Figure 6. Temporal variation in values of the PD indicator (I‒6a), PD-sens indicator (I‒6b), proportion of the extent with PD impact < 0.2 (I‒7a) and proportion of extent with PD-sens impact < 0.2 (I‒7b), shown for the overall area and for the four most extensive broad habitat types separately in the North-Iberian Atlantic subdivision. Descriptions of the impact indicators are provided in the ‘Essential Information’ Table E1 in this document.**

Table 5

Table 5. Métier-specific landings weight and value per unit PD or PD-sens impact in the North-Iberian Atlantic subdivision.

OT_DMF OT_MI SDN_DMF OT_SPF
Landings (tonnes)/PD impact 81.4 238.4 41.0 65.9
Value (×1000 euro)/PD impact NA NA NA NA
Landings (tonnes)/PD-sens impact 70.3 200.2 37.2 65.8
Value (×1000 euro)/PD-sens impact NA NA NA NA

Figure 7

Figure 7. Métier-related impacts, reported as annual means of the PD indicator (I‒6a, top) and PD-sens indicator (I‒6b, bottom), on the four most extensive broad habitat types in the North-Iberian Atlantic subdivision.

**Figure 7. Métier-related impacts, reported as annual means of the PD indicator (I‒6a, top) and PD-sens indicator (I‒6b, bottom), on the four most extensive broad habitat types in the North-Iberian Atlantic subdivision.**

Scenarios

Footprint reduction

Table 6: Effort

Table 6. The effects of stepwise exclusion of all MBCG fisheries from a specified proportion of a MSFD broad habitat type within the North-Iberian Atlantic subdivision, on swept area (presented as % of total swept area within that habitat type). The stepwise exclusion is conducted in 10% increments, and within each successive increment from 10% to 90% the c-squares with the lowest recorded rank MBCG swept area are excluded. Note that the top row shows the total estimate for all habitats combined.

MSFD broad habitat type Extent of habitat (×1000 km2) Total area swept (×1000 km2 10% 20% 30% 40% 50% 60% 70% 80% 90%
total 40.93 100 0.5 2.6 5.7 10.3 15.9 23.6 34.3 49.5 69.6
Upper bathyal sediment 15.27 34.99 0.0 <0.1 0.5 1.7 4.3 9.4 19.2 36.8 60.5
Offshore circalittoral sand 7.58 20.18 0.3 2.2 6.7 13.1 20.6 30.7 43.6 57.9 76.6
Offshore circalittoral mud 4.39 15.31 2.0 8.9 17.0 26.7 36.2 45.1 55.4 67.4 82.3
Offshore circalittoral rock and biogenic reef 2.89 3.41 0.0 0.2 2.1 6.8 13.8 22.3 35.6 51.3 73.6
Circalittoral rock and biogenic reef 2.28 0.47 0.0 0.0 0.0 0.0 0.0 0.0 0.4 4.3 22.2
Circalittoral sand 1.55 0.5 0.0 0.0 0.0 0.0 0.0 0.0 0.5 5.2 23.4
Upper bathyal sediment or Upper bathyal rock and biogenic reef 1.46 0.25 0.0 0.0 0.0 0.0 0.2 1.5 4.4 10.1 32.8
Offshore circalittoral coarse sediment 1.24 1.75 0.1 1.7 6.5 13.9 22.2 33.5 43.4 58.1 74.6
Upper bathyal rock and biogenic reef 0.86 1.43 0.0 0.0 <0.1 0.5 2.9 12.0 29.5 47.6 68.1
Offshore circalittoral mixed sediment 0.66 2.12 2.5 7.8 15.1 24.5 34.1 48.7 58.7 67.9 81.1
Infralittoral rock and biogenic reef 0.53 0.02 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.8
Lower bathyal sediment 0.5 0.05 0.0 0.0 <0.1 1.5 1.9 3.6 9.6 17.6 40.3
Circalittoral coarse sediment 0.49 0.15 0.0 0.0 0.0 0.0 0.0 0.7 3.5 11.1 29.8
Circalittoral mud 0.31 0.04 0.0 0.0 0.0 0.0 0.0 0.0 0.3 2.3 13.8
Infralittoral sand 0.27 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.1
Lower bathyal sediment or Lower bathyal rock and biogenic reef 0.24 0.01 0.0 0.0 0.0 0.0 0.5 12.1 23.7 36.8 51.3
Circalittoral mixed sediment 0.12 0.01 0.0 0.0 0.0 0.0 0.0 0.0 0.9 4.8 10.7
Infralittoral mud 0.08 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Infralittoral mixed sediment 0.07 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 30.8
Unknown 0.06 0.08 0.0 32.9 32.9 32.9 32.9 64.6 64.6 100.0 100.0
Lower bathyal rock and biogenic reef 0.04 0 0.0 0.0 0.0 40.1 40.1 65.0 100.0 100.0 100.0
Infralittoral coarse sediment 0.03 0.01 0.0 0.0 0.0 0.0 0.0 0.0 0.0 <0.1 1.7
Abyssal 0.01 0 4.5 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0
Table 7: Landings weight

Table 7. The effects of stepwise exclusion of all MBCG fisheries from a specified proportion of a MSFD broad habitat type within the North-Iberian Atlantic subdivision, on landings weight (presented as % of total landings weight within that habitat type). The stepwise exclusion is conducted in 10% increments, and within each successive increment from 10% to 90% the c-squares with the lowest recorded rank MBCG swept area are excluded. Note that the top row shows the total estimate for all habitats combined.

MSFD broad habitat type Extent of habitat (×1000 km2) Total landings weight (×1000 kg) 10% 20% 30% 40% 50% 60% 70% 80% 90%
Total 40.93 38782.7 0.5 2.4 5.6 10.1 15.0 21.5 31.5 45.9 64.9
Upper bathyal sediment 15.27 19822.7 0.0 <0.1 0.3 1.2 3.0 7.0 16.0 32.3 53.4
Offshore circalittoral sand 7.58 7576.2 0.4 2.4 7.9 16.9 26.8 37.2 51.1 65.0 82.9
Offshore circalittoral mud 4.39 6152.9 2.1 9.7 20.4 30.9 40.2 48.0 56.3 67.1 80.6
Offshore circalittoral rock and biogenic reef 2.89 1626.9 0.0 0.1 2.1 7.3 12.9 19.9 32.0 49.6 73.0
Circalittoral rock and biogenic reef 2.28 290.7 0.0 0.0 0.0 0.0 0.0 0.0 0.3 4.3 18.2
Circalittoral sand 1.55 335.9 0.0 0.0 0.0 0.0 0.0 0.0 0.5 3.6 17.4
Upper bathyal sediment or Upper bathyal rock and biogenic reef 1.46 148.3 0.0 0.0 0.0 0.0 0.2 1.1 4.0 10.1 51.8
Offshore circalittoral coarse sediment 1.24 905.6 0.1 1.6 6.2 16.0 22.2 35.1 42.1 53.8 68.4
Upper bathyal rock and biogenic reef 0.86 881.1 0.0 0.0 <0.1 0.4 3.1 11.7 27.8 45.4 68.1
Offshore circalittoral mixed sediment 0.66 742.6 3.0 9.1 15.7 25.4 33.3 48.7 61.0 65.9 79.6
Infralittoral rock and biogenic reef 0.53 9.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.4
Lower bathyal sediment 0.5 28.4 0.0 0.0 <0.1 1.1 1.1 1.7 5.3 11.8 46.3
Circalittoral coarse sediment 0.49 96.2 0.0 0.0 0.0 0.0 0.0 0.8 2.7 10.3 30.4
Circalittoral mud 0.31 24.1 0.0 0.0 0.0 0.0 0.0 0.0 0.2 0.9 9.4
Infralittoral sand 0.27 2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 3.3
Lower bathyal sediment or Lower bathyal rock and biogenic reef 0.24 5.6 0.0 0.0 0.0 0.0 0.7 17.0 26.9 40.1 50.7
Circalittoral mixed sediment 0.12 5.6 0.0 0.0 0.0 0.0 0.0 0.0 0.2 1.3 7.2
Infralittoral mud 0.08 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Infralittoral mixed sediment 0.07 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 100.0
Unknown 0.06 124 0.0 46.1 46.1 46.1 46.1 70.7 70.7 100.0 100.0
Lower bathyal rock and biogenic reef 0.04 0.8 0.0 0.0 0.0 11.4 11.4 30.6 100.0 100.0 100.0
Infralittoral coarse sediment 0.03 3.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.1 0.9
Abyssal 0.01 0 7.8 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0
Table 8: Landings value

Table 8. The effects of stepwise exclusion of all MBCG fisheries from a specified proportion of a MSFD broad habitat type within the North-Iberian Atlantic subdivision, on landings value (presented as % of total landings value within that habitat type). The stepwise exclusion is conducted in 10% increments, and within each successive increment from 10% to 90% the c-squares with the lowest recorded rank MBCG swept area are excluded. Note that the top row shows the total estimate for all habitats combined.

MSFD broad habitat type Extent of habitat (×1000 km2) Total landings value (×1000 euro) 10% 20% 30% 40% 50% 60% 70% 80% 90%
Total 40.93 NA NA NA NA NA NA NA NA NA NA
Upper bathyal sediment 15.27 NA NA NA NA NA NA NA NA NA NA
Offshore circalittoral sand 7.58 NA NA NA NA NA NA NA NA NA NA
Offshore circalittoral mud 4.39 NA NA NA NA NA NA NA NA NA NA
Offshore circalittoral rock and biogenic reef 2.89 NA NA NA NA NA NA NA NA NA NA
Circalittoral rock and biogenic reef 2.28 NA NA NA NA NA NA NA NA NA NA
Circalittoral sand 1.55 NA NA NA NA NA NA NA NA NA NA
Upper bathyal sediment or Upper bathyal rock and biogenic reef 1.46 NA NA NA NA NA NA NA NA NA NA
Offshore circalittoral coarse sediment 1.24 NA NA NA NA NA NA NA NA NA NA
Upper bathyal rock and biogenic reef 0.86 NA NA NA NA NA NA NA NA NA NA
Offshore circalittoral mixed sediment 0.66 NA NA NA NA NA NA NA NA NA NA
Infralittoral rock and biogenic reef 0.53 NA NA NA NA NA NA NA NA NA NA
Lower bathyal sediment 0.5 NA NA NA NA NA NA NA NA NA NA
Circalittoral coarse sediment 0.49 NA NA NA NA NA NA NA NA NA NA
Circalittoral mud 0.31 NA NA NA NA NA NA NA NA NA NA
Infralittoral sand 0.27 NA NA NA NA NA NA NA NA NA NA
Lower bathyal sediment or Lower bathyal rock and biogenic reef 0.24 NA NA NA NA NA NA NA NA NA NA
Circalittoral mixed sediment 0.12 NA NA NA NA NA NA NA NA NA NA
Infralittoral mud 0.08 NA NA NA NA NA NA NA NA NA NA
Infralittoral mixed sediment 0.07 NA NA NA NA NA NA NA NA NA NA
Unknown 0.06 NA NA NA NA NA NA NA NA NA NA
Lower bathyal rock and biogenic reef 0.04 NA NA NA NA NA NA NA NA NA NA
Infralittoral coarse sediment 0.03 NA NA NA NA NA NA NA NA NA NA
Abyssal 0.01 NA NA NA NA NA NA NA NA NA NA

Gear modifications

Figure 8: Habitat 1

Figure 8. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the North-Iberian Atlantic subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).

**Figure 8. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the North-Iberian Atlantic subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).**
Figure 9: Habitat 2

Figure 9. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the North-Iberian Atlantic subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).

**Figure 9. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the North-Iberian Atlantic subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).**
Figure 10: Habitat 3

Figure 10. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the North-Iberian Atlantic subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).

**Figure 10. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the North-Iberian Atlantic subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).**
Figure 11: Habitat 4

Figure 11. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the North-Iberian Atlantic subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).

**Figure 11. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the North-Iberian Atlantic subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).**

South-Iberian Atlantic

Summary

Table 1

Table 1. Values of pressure and impact indicators for 2017‒2022 for three depth strata in the South-Iberian Atlantic subdivision. Values of I‒1, I‒2, I‒3, I‒4, I‒6a, I‒6b, I‒7a and I‒7b are annual means and I‒5 is evaluated over the six years. Descriptions of the pressure and impact indicators are provided in the ‘Essential Information’ Table E1 in this document.

Indicators 0 to 200 m 200 to 400 m 400 to 800 m
I‒1: Average fishing intensity 0.15 1.02 0.56
I‒2: Proportion of area fished, evaluated at c-square scale (%) 27.10 55.10 61.40
I‒3: Proportion of area fished (%) 11.20 29.50 24.20
I‒4: Smallest proportion of area with 90% of fishing intensity, evaluated at c-square scale (%) 12.30 19.30 20.40
I‒5: Proportion of area persistently unfished, evaluated at c-square scale (%) 72.90 44.90 38.60
I‒6a: Average PD impact 0.50 3.80 2.60
I‒6b: Average PD-sens impact 0.70 4.20 3.10
I‒7a: Proportion of area with PD impact < 0.2, evaluated at c-square scale (%) 99.70 97.90 97.10
I‒7b: Proportion of area with PD-sens impact < 0.2, evaluated at c-square scale (%) 99.70 97.40 96.30

Figure 1

Figure 1. Geographic distribution of fishing intensity (swept area ratio), seabed sensitivity (community longevity), total landings value, and total landings weight from mobile bottom-contacting gear (MBCG) in the South-Iberian Atlantic subdivision. The maps of swept area ratio, landings value, and landings weight show annual means evaluated at the c-square scale.

**Figure 1. Geographic distribution of fishing intensity (swept area ratio), seabed sensitivity (community longevity), total landings value, and total landings weight from mobile bottom-contacting gear (MBCG) in the South-Iberian Atlantic subdivision. The maps of swept area ratio, landings value, and landings weight show annual means evaluated at the c-square scale. **

Table 2

Table 2. Contribution of small-scale fisheries (vessels < 12 m overall length) to total fishing effort (kW × fishing days) in the South-Iberian Atlantic subdivision. The table shows the total fishing effort (kW × fishing days) by FAO region over the assessment period, and the mean contribution (%) and observed range in contribution (%) of small-scale MBCG fisheries’.

FAO region code FAO region name Total fishing effort (kW × Fishing days) Mean contribution SSF (%) Observed range SSF contribution (%) [min - max]
27.9.a Portuguese Waters - East 7567817 23.2 [2 - 34]

Fishing intensity

Table 3

Table 3. Extent (in km2 and %) of broad habitat types in the South-Iberian Atlantic subdivision, and mean annual estimates of MBCG fishing intensity, landings weight, and landings value. In addition, estimates of the average annual proportion of the fished extent, the smallest proportion of the habitat extent affected by 90% of the fishing effort, and the proportion of extent persistently unfished are provided.

MSFD broad habitat type Extent of habitat (×1000 km2) Relative habitat extent (%) Landings (×1000 tonnes) Value (×106 euro) Swept area (×1000 km2) Average fishing intensity (I‒1) Average annual extent fished (%) Smallest proportion of extent with 90% of fishing effort (%) Percentage extent persistently unfished (%)
Offshore circalittoral mud 8.72 23.7 0.35 NA 3.44 0.39 18.0 17.2 58.4
Upper bathyal sediment or Upper bathyal rock and biogenic reef 6.93 18.8 0.35 NA 3.54 0.51 23.9 21.9 40.6
Upper bathyal sediment 6.04 16.4 0.58 NA 5.07 0.84 31.8 25.3 35.6
Circalittoral sand 2.95 8.0 0.00 NA 0.02 0.01 0.7 2.3 95.1
Circalittoral mixed sediment 2.49 6.8 0.00 NA 0.02 0.01 0.6 2.7 90.9
Offshore circalittoral sand 2.26 6.1 0.18 NA 1.09 0.48 33.2 33.4 46.3
Offshore circalittoral rock and biogenic reef 1.95 5.3 0.04 NA 0.33 0.17 14.7 30.8 42.7
Circalittoral mud 1.77 4.8 0.00 NA 0.02 0.01 1.2 1.0 93.9
Circalittoral rock and biogenic reef 1.64 4.4 0.00 NA 0.02 0.01 1.1 3.2 93.5
Offshore circalittoral mixed sediment 0.64 1.7 0.02 NA 0.22 0.34 8.0 6.7 70.5
Infralittoral sand 0.62 1.7 0.00 NA 0.00 0.00 0.0 0.0 99.9
Upper bathyal rock and biogenic reef 0.24 0.7 0.00 NA 0.03 0.10 9.1 19.8 67.6
Infralittoral rock and biogenic reef 0.21 0.6 0.00 NA 0.00 0.00 0.0 0.0 99.8
Unknown 0.15 0.4 0.00 NA 0.01 0.06 5.2 4.9 94.0
Lower bathyal sediment or Lower bathyal rock and biogenic reef 0.10 0.3 0.00 NA 0.01 0.12 11.7 27.7 32.0
Infralittoral mixed sediment 0.06 0.2 0.00 NA 0.00 0.00 0.0 0.0 97.5
Offshore circalittoral coarse sediment 0.05 0.1 0.00 NA 0.00 0.09 8.5 5.3 87.2
Infralittoral mud 0.05 0.1 0.00 NA 0.00 0.00 0.0 0.0 97.6
Abyssal 0.00 0.0 0.00 NA 0.00 0.00 0.4 NA 58.3
Circalittoral coarse sediment 0.00 0.0 0.00 NA 0.00 0.00 0.0 NA 100.0
Lower bathyal sediment 0.00 0.0 0.00 NA 0.00 0.00 0.0 NA 100.0

Figure 2

Figure 2. Temporal variation of the pressure indicators I‒1, I‒3 and I‒4 in the South-Iberian Atlantic subdivision. Descriptions of the pressure indicators are provided in the ‘Essential Information’ Table E1 in this document.

**Figure 2. Temporal variation of the pressure indicators I‒1, I‒3 and I‒4 in the South-Iberian Atlantic subdivision. Descriptions of the pressure indicators are provided in the ‘Essential Information’ Table E1 in this document.**

Fishing by métier

Table 4

Table 4. Landings weight and value by métier and their relationship with swept area in the South-Iberian Atlantic subdivision.

OT_CRU OT_DMF OT_MI
Area swept (×1000 km2) 7.8 5.94 0.09
Landings (×1000 tonnes) 0.6 0.88 0.06
Value (×106 euro) NA NA NA
Landings / Area swept (kg/km2) 77.4 147.65 666.41
Value / Area swept (euro/km2) NA NA NA

Core fishing grounds

Core fishing grounds could not be identified in this subdivision.

Impact

Figure 5

Figure 5. The spatial distribution of MBCG fisheries impact in the South-Iberian Atlantic subdivision, as assessed with the PD indicator (I‒6a) and PD-sens indicator (I‒6b), shown as annual means for the assessment period, evaluated at the c-square scale. Descriptions of the impact indicators are provided in the ‘Essential Information’ Table E1 in this document.

**Figure 5. The spatial distribution of MBCG fisheries impact in the South-Iberian Atlantic subdivision, as assessed with the PD indicator (I‒6a) and PD-sens indicator (I‒6b), shown as annual means for the assessment period, evaluated at the c-square scale. Descriptions of the impact indicators are provided in the ‘Essential Information’ Table E1 in this document.**

Figure 6

Figure 6. Temporal variation in values of the PD indicator (I‒6a), PD-sens indicator (I‒6b), proportion of the extent with PD impact < 0.2 (I‒7a) and proportion of extent with PD-sens impact < 0.2 (I‒7b), shown for the overall area and for the four most extensive broad habitat types separately in the South-Iberian Atlantic subdivision. Descriptions of the impact indicators are provided in the ‘Essential Information’ Table E1 in this document.

**Figure 6. Temporal variation in values of the PD indicator (I‒6a), PD-sens indicator (I‒6b), proportion of the extent with PD impact < 0.2 (I‒7a) and proportion of extent with PD-sens impact < 0.2 (I‒7b), shown for the overall area and for the four most extensive broad habitat types separately in the South-Iberian Atlantic subdivision. Descriptions of the impact indicators are provided in the ‘Essential Information’ Table E1 in this document.**

Table 5

Table 5. Métier-specific landings weight and value per unit PD or PD-sens impact in the South-Iberian Atlantic subdivision.

OT_CRU OT_DMF OT_MI
Landings (tonnes)/PD impact 7.3 29.4 29.6
Value (×1000 euro)/PD impact NA NA NA
Landings (tonnes)/PD-sens impact 7.0 27.7 28.5
Value (×1000 euro)/PD-sens impact NA NA NA

Figure 7

Figure 7. Métier-related impacts, reported as annual means of the PD indicator (I‒6a, top) and PD-sens indicator (I‒6b, bottom), on the four most extensive broad habitat types in the South-Iberian Atlantic subdivision.

**Figure 7. Métier-related impacts, reported as annual means of the PD indicator (I‒6a, top) and PD-sens indicator (I‒6b, bottom), on the four most extensive broad habitat types in the South-Iberian Atlantic subdivision.**

Scenarios

Footprint reduction

Table 6: Effort

Table 6. The effects of stepwise exclusion of all MBCG fisheries from a specified proportion of a MSFD broad habitat type within the South-Iberian Atlantic subdivision, on swept area (presented as % of total swept area within that habitat type). The stepwise exclusion is conducted in 10% increments, and within each successive increment from 10% to 90% the c-squares with the lowest recorded rank MBCG swept area are excluded. Note that the top row shows the total estimate for all habitats combined.

MSFD broad habitat type Extent of habitat (×1000 km2) Total area swept (×1000 km2 10% 20% 30% 40% 50% 60% 70% 80% 90%
total 36.87 100 0.0 0.0 0.0 <0.1 0.3 1.7 5.6 14.0 32.7
Offshore circalittoral mud 8.72 3.44 0.0 0.0 0.0 0.0 0.0 <0.1 1.7 7.2 23.9
Upper bathyal sediment or Upper bathyal rock and biogenic reef 6.93 3.54 0.0 0.0 0.0 0.0 0.2 1.3 4.9 12.0 32.1
Upper bathyal sediment 6.04 5.07 0.0 0.0 0.0 <0.1 0.6 2.4 6.7 15.8 34.2
Circalittoral sand 2.95 0.02 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Circalittoral mixed sediment 2.49 0.02 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Offshore circalittoral sand 2.26 1.09 0.0 0.0 0.0 0.0 0.3 4.0 14.1 33.9 58.5
Offshore circalittoral rock and biogenic reef 1.95 0.33 0.0 0.0 0.0 0.0 0.8 4.6 11.5 22.8 46.0
Circalittoral mud 1.77 0.02 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Circalittoral rock and biogenic reef 1.64 0.02 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Offshore circalittoral mixed sediment 0.64 0.22 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.8 7.4
Infralittoral sand 0.62 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Upper bathyal rock and biogenic reef 0.24 0.03 0.0 0.0 0.0 0.0 0.0 0.0 0.3 10.9 54.8
Infralittoral rock and biogenic reef 0.21 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Unknown 0.15 0.01 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Lower bathyal sediment or Lower bathyal rock and biogenic reef 0.1 0.01 0.0 0.0 0.0 3.5 6.5 6.5 10.4 41.9 78.9
Infralittoral mixed sediment 0.06 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Offshore circalittoral coarse sediment 0.05 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 34.5
Infralittoral mud 0.05 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Abyssal 0 0 0.0 0.0 0.0 0.0 0.0 100.0 100.0 100.0 100.0
Circalittoral coarse sediment 0 0 NaN NaN NaN NaN NaN NaN NaN NaN NaN
Lower bathyal sediment 0 0 NaN NaN NaN NaN NaN NaN NaN NaN NaN
Table 7: Landings weight

Table 7. The effects of stepwise exclusion of all MBCG fisheries from a specified proportion of a MSFD broad habitat type within the South-Iberian Atlantic subdivision, on landings weight (presented as % of total landings weight within that habitat type). The stepwise exclusion is conducted in 10% increments, and within each successive increment from 10% to 90% the c-squares with the lowest recorded rank MBCG swept area are excluded. Note that the top row shows the total estimate for all habitats combined.

MSFD broad habitat type Extent of habitat (×1000 km2) Total landings weight (×1000 kg) 10% 20% 30% 40% 50% 60% 70% 80% 90%
Total 36.87 1539.1 0.0 0.0 0.0 <0.1 0.3 1.8 6.4 15.5 38.6
Offshore circalittoral mud 8.72 352.5 0.0 0.0 0.0 0.0 0.0 0.1 2.0 8.8 29.8
Upper bathyal sediment or Upper bathyal rock and biogenic reef 6.93 347.6 0.0 0.0 0.0 0.0 0.2 1.7 6.2 14.2 37.9
Upper bathyal sediment 6.04 578 0.0 0.0 0.0 <0.1 0.5 2.3 7.3 16.3 42.7
Circalittoral sand 2.95 2.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Circalittoral mixed sediment 2.49 1.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Offshore circalittoral sand 2.26 183.9 0.0 0.0 0.0 0.0 0.2 3.4 12.2 28.6 46.6
Offshore circalittoral rock and biogenic reef 1.95 44.7 0.0 0.0 0.0 0.0 0.9 4.0 11.1 21.8 44.9
Circalittoral mud 1.77 1.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Circalittoral rock and biogenic reef 1.64 2.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Offshore circalittoral mixed sediment 0.64 17.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.1 9.4
Infralittoral sand 0.62 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Upper bathyal rock and biogenic reef 0.24 2.9 0.0 0.0 0.0 0.0 0.0 0.0 0.3 9.0 52.2
Infralittoral rock and biogenic reef 0.21 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Unknown 0.15 1.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Lower bathyal sediment or Lower bathyal rock and biogenic reef 0.1 1.6 0.0 0.0 0.0 2.7 5.9 5.9 9.3 42.6 76.2
Infralittoral mixed sediment 0.06 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Offshore circalittoral coarse sediment 0.05 0.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 26.8
Infralittoral mud 0.05 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Abyssal 0 0 0.0 0.0 0.0 0.0 0.0 100.0 100.0 100.0 100.0
Circalittoral coarse sediment 0 0 NaN NaN NaN NaN NaN NaN NaN NaN NaN
Lower bathyal sediment 0 0 NaN NaN NaN NaN NaN NaN NaN NaN NaN
Table 8: Landings value

Table 8. The effects of stepwise exclusion of all MBCG fisheries from a specified proportion of a MSFD broad habitat type within the South-Iberian Atlantic subdivision, on landings value (presented as % of total landings value within that habitat type). The stepwise exclusion is conducted in 10% increments, and within each successive increment from 10% to 90% the c-squares with the lowest recorded rank MBCG swept area are excluded. Note that the top row shows the total estimate for all habitats combined.

MSFD broad habitat type Extent of habitat (×1000 km2) Total landings value (×1000 euro) 10% 20% 30% 40% 50% 60% 70% 80% 90%
Total 36.87 NA NA NA NA NA NA NA NA NA NA
Offshore circalittoral mud 8.72 NA NA NA NA NA NA NA NA NA NA
Upper bathyal sediment or Upper bathyal rock and biogenic reef 6.93 NA NA NA NA NA NA NA NA NA NA
Upper bathyal sediment 6.04 NA NA NA NA NA NA NA NA NA NA
Circalittoral sand 2.95 NA NA NA NA NA NA NA NA NA NA
Circalittoral mixed sediment 2.49 NA NA NA NA NA NA NA NA NA NA
Offshore circalittoral sand 2.26 NA NA NA NA NA NA NA NA NA NA
Offshore circalittoral rock and biogenic reef 1.95 NA NA NA NA NA NA NA NA NA NA
Circalittoral mud 1.77 NA NA NA NA NA NA NA NA NA NA
Circalittoral rock and biogenic reef 1.64 NA NA NA NA NA NA NA NA NA NA
Offshore circalittoral mixed sediment 0.64 NA NA NA NA NA NA NA NA NA NA
Infralittoral sand 0.62 NA NA NA NA NA NA NA NA NA NA
Upper bathyal rock and biogenic reef 0.24 NA NA NA NA NA NA NA NA NA NA
Infralittoral rock and biogenic reef 0.21 NA NA NA NA NA NA NA NA NA NA
Unknown 0.15 NA NA NA NA NA NA NA NA NA NA
Lower bathyal sediment or Lower bathyal rock and biogenic reef 0.1 NA NA NA NA NA NA NA NA NA NA
Infralittoral mixed sediment 0.06 NA NA NA NA NA NA NA NA NA NA
Offshore circalittoral coarse sediment 0.05 NA NA NA NA NA NA NA NA NA NA
Infralittoral mud 0.05 NA NA NA NA NA NA NA NA NA NA
Abyssal 0 NA NA NA NA NA NA NA NA NA NA
Circalittoral coarse sediment 0 NA NA NA NA NA NA NA NA NA NA
Lower bathyal sediment 0 NA NA NA NA NA NA NA NA NA NA

Gear modifications

Figure 8: Habitat 1

Figure 8. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the South-Iberian Atlantic subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).

**Figure 8. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the South-Iberian Atlantic subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).**
Figure 9: Habitat 2

Figure 9. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the South-Iberian Atlantic subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).

**Figure 9. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the South-Iberian Atlantic subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).**
Figure 10: Habitat 3

Figure 10. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the South-Iberian Atlantic subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).

**Figure 10. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the South-Iberian Atlantic subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).**
Figure 11: Habitat 4

Figure 11. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the South-Iberian Atlantic subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).

**Figure 11. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the South-Iberian Atlantic subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).**

Gulf of Cadiz

Summary

Table 1

Table 1. Values of pressure and impact indicators for 2017‒2022 for three depth strata in the Gulf of Cadiz subdivision. Values of I‒1, I‒2, I‒3, I‒4, I‒6a, I‒6b, I‒7a and I‒7b are annual means and I‒5 is evaluated over the six years. Descriptions of the pressure and impact indicators are provided in the ‘Essential Information’ Table E1 in this document.

Indicators 0 to 200 m 200 to 400 m 400 to 800 m
I‒1: Average fishing intensity 8.51 9.0 1.06
I‒2: Proportion of area fished, evaluated at c-square scale (%) 85.40 100.0 52.70
I‒3: Proportion of area fished (%) 67.60 90.7 39.10
I‒4: Smallest proportion of area with 90% of fishing intensity, evaluated at c-square scale (%) 39.30 46.9 28.30
I‒5: Proportion of area persistently unfished, evaluated at c-square scale (%) 14.60 0.0 47.30
I‒6a: Average PD impact 36.60 47.3 11.80
I‒6b: Average PD-sens impact 40.20 51.7 14.60
I‒7a: Proportion of area with PD impact < 0.2, evaluated at c-square scale (%) 50.10 33.4 78.80
I‒7b: Proportion of area with PD-sens impact < 0.2, evaluated at c-square scale (%) 51.10 29.5 74.10

Figure 1

Figure 1. Geographic distribution of fishing intensity (swept area ratio), seabed sensitivity (community longevity), total landings value, and total landings weight from mobile bottom-contacting gear (MBCG) in the Gulf of Cadiz subdivision. The maps of swept area ratio, landings value, and landings weight show annual means evaluated at the c-square scale.

**Figure 1. Geographic distribution of fishing intensity (swept area ratio), seabed sensitivity (community longevity), total landings value, and total landings weight from mobile bottom-contacting gear (MBCG) in the Gulf of Cadiz subdivision. The maps of swept area ratio, landings value, and landings weight show annual means evaluated at the c-square scale. **

Table 2

Table 2. Contribution of small-scale fisheries (vessels < 12 m overall length) to total fishing effort (kW × fishing days) in the Gulf of Cadiz subdivision. The table shows the total fishing effort (kW × fishing days) by FAO region over the assessment period, and the mean contribution (%) and observed range in contribution (%) of small-scale MBCG fisheries’.

FAO region code FAO region name Total fishing effort (kW × Fishing days) Mean contribution SSF (%) Observed range SSF contribution (%) [min - max]
27.9.a Portuguese Waters - East 7567817 23.2 [2 - 34]

Fishing intensity

Table 3

Table 3. Extent (in km2 and %) of broad habitat types in the Gulf of Cadiz subdivision, and mean annual estimates of MBCG fishing intensity, landings weight, and landings value. In addition, estimates of the average annual proportion of the fished extent, the smallest proportion of the habitat extent affected by 90% of the fishing effort, and the proportion of extent persistently unfished are provided.

MSFD broad habitat type Extent of habitat (×1000 km2) Relative habitat extent (%) Landings (×1000 tonnes) Value (×106 euro) Swept area (×1000 km2) Average fishing intensity (I‒1) Average annual extent fished (%) Smallest proportion of extent with 90% of fishing effort (%) Percentage extent persistently unfished (%)
Upper bathyal sediment 4.08 37.1 0.96 NA 11.62 2.85 52.3 33.4 35.6
Circalittoral sand 1.79 16.3 0.80 NA 10.51 5.87 59.7 34.0 19.2
Circalittoral mud 1.72 15.6 1.71 NA 25.68 14.95 88.8 65.8 2.6
Offshore circalittoral mud 1.28 11.6 1.45 NA 20.81 16.28 100.0 77.1 0.0
Offshore circalittoral sand 0.57 5.2 0.08 NA 0.94 1.65 86.2 72.8 0.0
Infralittoral sand 0.44 4.0 0.07 NA 0.63 1.44 18.1 6.5 37.6
Circalittoral mixed sediment 0.15 1.4 0.14 NA 1.64 11.24 93.2 52.9 0.6
Infralittoral rock and biogenic reef 0.14 1.3 0.00 NA 0.01 0.05 4.6 9.2 89.1
Circalittoral rock and biogenic reef 0.13 1.2 0.01 NA 0.05 0.38 19.1 20.5 61.1
Infralittoral mixed sediment 0.13 1.2 0.02 NA 0.20 1.53 33.4 20.8 2.3
Upper bathyal rock and biogenic reef 0.12 1.1 0.01 NA 0.09 0.70 35.5 30.1 39.0
Infralittoral mud 0.12 1.1 0.02 NA 0.04 0.37 9.3 5.5 33.7
Infralittoral coarse sediment 0.10 0.9 0.02 NA 0.10 0.97 31.5 25.4 21.3
Circalittoral coarse sediment 0.10 0.9 0.03 NA 0.27 2.70 77.1 61.6 5.1
Offshore circalittoral coarse sediment 0.08 0.7 0.02 NA 0.25 3.10 66.3 40.3 0.0
Offshore circalittoral mixed sediment 0.06 0.5 0.10 NA 1.44 25.28 100.0 83.8 0.0
Unknown 0.00 0.0 0.00 NA 0.00 0.01 1.2 NA 61.3

Figure 2

Figure 2. Temporal variation of the pressure indicators I‒1, I‒3 and I‒4 in the Gulf of Cadiz subdivision. Descriptions of the pressure indicators are provided in the ‘Essential Information’ Table E1 in this document.

**Figure 2. Temporal variation of the pressure indicators I‒1, I‒3 and I‒4 in the Gulf of Cadiz subdivision. Descriptions of the pressure indicators are provided in the ‘Essential Information’ Table E1 in this document.**

Fishing by métier

Table 4

Table 4. Landings weight and value by métier and their relationship with swept area in the Gulf of Cadiz subdivision.

OT_CRU OT_DMF OT_MI DRB_MOL
Area swept (×1000 km2) 73.14 0.79 0.39 0.02
Landings (×1000 tonnes) 5.24 0.06 0.04 0.10
Value (×106 euro) NA NA NA NA
Landings / Area swept (kg/km2) 71.71 81.39 100.53 5274.40
Value / Area swept (euro/km2) NA NA NA NA

Core fishing grounds

Core fishing grounds could not be identified in this subdivision.

Impact

Figure 5

Figure 5. The spatial distribution of MBCG fisheries impact in the Gulf of Cadiz subdivision, as assessed with the PD indicator (I‒6a) and PD-sens indicator (I‒6b), shown as annual means for the assessment period, evaluated at the c-square scale. Descriptions of the impact indicators are provided in the ‘Essential Information’ Table E1 in this document.

**Figure 5. The spatial distribution of MBCG fisheries impact in the Gulf of Cadiz subdivision, as assessed with the PD indicator (I‒6a) and PD-sens indicator (I‒6b), shown as annual means for the assessment period, evaluated at the c-square scale. Descriptions of the impact indicators are provided in the ‘Essential Information’ Table E1 in this document.**

Figure 6

Figure 6. Temporal variation in values of the PD indicator (I‒6a), PD-sens indicator (I‒6b), proportion of the extent with PD impact < 0.2 (I‒7a) and proportion of extent with PD-sens impact < 0.2 (I‒7b), shown for the overall area and for the four most extensive broad habitat types separately in the Gulf of Cadiz subdivision. Descriptions of the impact indicators are provided in the ‘Essential Information’ Table E1 in this document.

**Figure 6. Temporal variation in values of the PD indicator (I‒6a), PD-sens indicator (I‒6b), proportion of the extent with PD impact < 0.2 (I‒7a) and proportion of extent with PD-sens impact < 0.2 (I‒7b), shown for the overall area and for the four most extensive broad habitat types separately in the Gulf of Cadiz subdivision. Descriptions of the impact indicators are provided in the ‘Essential Information’ Table E1 in this document.**

Table 5

Table 5. Métier-specific landings weight and value per unit PD or PD-sens impact in the Gulf of Cadiz subdivision.

OT_CRU OT_DMF OT_MI DRB_MOL
Landings (tonnes)/PD impact 36.0 57.7 59.7 36.6
Value (×1000 euro)/PD impact NA NA NA NA
Landings (tonnes)/PD-sens impact 32.3 45.1 63.1 47.9
Value (×1000 euro)/PD-sens impact NA NA NA NA

Figure 7

Figure 7. Métier-related impacts, reported as annual means of the PD indicator (I‒6a, top) and PD-sens indicator (I‒6b, bottom), on the four most extensive broad habitat types in the Gulf of Cadiz subdivision.

**Figure 7. Métier-related impacts, reported as annual means of the PD indicator (I‒6a, top) and PD-sens indicator (I‒6b, bottom), on the four most extensive broad habitat types in the Gulf of Cadiz subdivision.**

Scenarios

Footprint reduction

Table 6: Effort

Table 6. The effects of stepwise exclusion of all MBCG fisheries from a specified proportion of a MSFD broad habitat type within the Gulf of Cadiz subdivision, on swept area (presented as % of total swept area within that habitat type). The stepwise exclusion is conducted in 10% increments, and within each successive increment from 10% to 90% the c-squares with the lowest recorded rank MBCG swept area are excluded. Note that the top row shows the total estimate for all habitats combined.

MSFD broad habitat type Extent of habitat (×1000 km2) Total area swept (×1000 km2 10% 20% 30% 40% 50% 60% 70% 80% 90%
total 11.01 100 1.3 4.1 8.1 12.6 17.8 27.0 37.5 50.8 69.9
Upper bathyal sediment 4.08 11.62 0.0 0.0 0.0 <0.1 1.4 5.5 13.0 23.2 41.2
Circalittoral sand 1.79 10.51 0.0 <0.1 <0.1 0.8 2.1 7.6 14.6 34.1 64.4
Circalittoral mud 1.72 25.68 <0.1 3.6 9.2 14.6 20.9 31.3 42.2 54.9 72.0
Offshore circalittoral mud 1.28 20.81 3.4 8.5 14.3 21.9 29.8 41.4 55.2 66.8 83.2
Offshore circalittoral sand 0.57 0.94 2.2 7.6 13.0 20.4 28.3 37.8 48.8 61.8 78.0
Infralittoral sand 0.44 0.63 0.0 0.0 0.0 <0.1 <0.1 0.2 1.1 3.2 6.5
Circalittoral mixed sediment 0.15 1.64 1.3 3.4 6.5 9.1 16.0 27.3 50.3 73.4 100.0
Infralittoral rock and biogenic reef 0.14 0.01 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 9.1
Circalittoral rock and biogenic reef 0.13 0.05 0.0 0.0 0.0 0.0 0.0 0.0 2.7 16.4 55.8
Infralittoral mixed sediment 0.13 0.2 <0.1 <0.1 <0.1 <0.1 0.2 0.3 12.5 21.1 37.1
Upper bathyal rock and biogenic reef 0.12 0.09 0.0 0.0 0.0 0.2 1.7 7.1 16.5 65.8 86.6
Infralittoral mud 0.12 0.04 0.0 0.0 0.0 <0.1 <0.1 0.7 2.1 4.9 10.8
Infralittoral coarse sediment 0.1 0.1 0.0 0.0 0.1 0.1 0.4 0.9 3.1 40.2 40.2
Circalittoral coarse sediment 0.1 0.27 <0.1 1.2 6.9 14.7 17.8 40.7 40.7 76.3 76.3
Offshore circalittoral coarse sediment 0.08 0.25 0.7 1.7 3.5 8.4 8.4 15.9 20.7 40.0 100.0
Offshore circalittoral mixed sediment 0.06 1.44 12.4 16.3 29.7 37.9 46.2 69.6 69.6 82.9 100.0
Unknown 0 0 0.0 0.0 0.0 0.0 0.0 0.0 33.1 33.1 33.1
Table 7: Landings weight

Table 7. The effects of stepwise exclusion of all MBCG fisheries from a specified proportion of a MSFD broad habitat type within the Gulf of Cadiz subdivision, on landings weight (presented as % of total landings weight within that habitat type). The stepwise exclusion is conducted in 10% increments, and within each successive increment from 10% to 90% the c-squares with the lowest recorded rank MBCG swept area are excluded. Note that the top row shows the total estimate for all habitats combined.

MSFD broad habitat type Extent of habitat (×1000 km2) Total landings weight (×1000 kg) 10% 20% 30% 40% 50% 60% 70% 80% 90%
Total 11.01 5438.9 1.7 4.6 8.8 13.1 18.4 27.8 39.0 52.9 71.3
Upper bathyal sediment 4.08 960.5 0.0 0.0 0.0 0.1 1.4 6.3 14.9 26.0 43.7
Circalittoral sand 1.79 797.8 0.0 <0.1 1.6 2.8 5.7 12.8 20.5 43.0 70.3
Circalittoral mud 1.72 1711.3 1.5 5.3 11.3 16.4 22.6 32.5 44.4 56.3 72.4
Offshore circalittoral mud 1.28 1451.9 3.4 8.6 14.3 22.0 30.2 42.2 55.8 67.3 84.2
Offshore circalittoral sand 0.57 77.8 3.3 12.6 20.0 28.5 36.2 44.9 55.5 65.3 82.2
Infralittoral sand 0.44 68.1 0.0 0.0 0.0 0.1 4.8 9.9 37.4 40.5 44.7
Circalittoral mixed sediment 0.15 140.6 1.8 4.4 9.0 12.5 19.0 26.4 47.5 73.0 100.0
Infralittoral rock and biogenic reef 0.14 1.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 7.2
Circalittoral rock and biogenic reef 0.13 7.7 0.0 0.0 0.0 0.0 0.0 0.0 2.9 15.9 60.3
Infralittoral mixed sediment 0.13 23.9 0.4 1.3 3.8 3.8 7.0 10.3 27.0 35.6 58.3
Upper bathyal rock and biogenic reef 0.12 7.6 0.0 0.0 0.0 0.2 1.8 8.8 18.7 68.5 87.9
Infralittoral mud 0.12 17.1 0.0 0.0 0.0 0.2 1.0 8.4 24.5 73.5 75.5
Infralittoral coarse sediment 0.1 17.2 0.0 0.0 5.8 5.8 11.5 30.8 32.7 69.8 69.8
Circalittoral coarse sediment 0.1 32.8 2.2 3.2 9.2 18.2 23.5 52.0 52.0 89.4 89.4
Offshore circalittoral coarse sediment 0.08 23.3 1.0 2.7 4.8 10.7 10.7 19.7 24.3 42.1 100.0
Offshore circalittoral mixed sediment 0.06 100.1 13.0 16.6 29.9 38.6 46.1 68.9 68.9 82.1 100.0
Unknown 0 0 0.0 0.0 0.0 0.0 0.0 0.0 48.2 48.2 48.2
Table 8: Landings value

Table 8. The effects of stepwise exclusion of all MBCG fisheries from a specified proportion of a MSFD broad habitat type within the Gulf of Cadiz subdivision, on landings value (presented as % of total landings value within that habitat type). The stepwise exclusion is conducted in 10% increments, and within each successive increment from 10% to 90% the c-squares with the lowest recorded rank MBCG swept area are excluded. Note that the top row shows the total estimate for all habitats combined.

MSFD broad habitat type Extent of habitat (×1000 km2) Total landings value (×1000 euro) 10% 20% 30% 40% 50% 60% 70% 80% 90%
Total 11.01 NA NA NA NA NA NA NA NA NA NA
Upper bathyal sediment 4.08 NA NA NA NA NA NA NA NA NA NA
Circalittoral sand 1.79 NA NA NA NA NA NA NA NA NA NA
Circalittoral mud 1.72 NA NA NA NA NA NA NA NA NA NA
Offshore circalittoral mud 1.28 NA NA NA NA NA NA NA NA NA NA
Offshore circalittoral sand 0.57 NA NA NA NA NA NA NA NA NA NA
Infralittoral sand 0.44 NA NA NA NA NA NA NA NA NA NA
Circalittoral mixed sediment 0.15 NA NA NA NA NA NA NA NA NA NA
Infralittoral rock and biogenic reef 0.14 NA NA NA NA NA NA NA NA NA NA
Circalittoral rock and biogenic reef 0.13 NA NA NA NA NA NA NA NA NA NA
Infralittoral mixed sediment 0.13 NA NA NA NA NA NA NA NA NA NA
Upper bathyal rock and biogenic reef 0.12 NA NA NA NA NA NA NA NA NA NA
Infralittoral mud 0.12 NA NA NA NA NA NA NA NA NA NA
Infralittoral coarse sediment 0.1 NA NA NA NA NA NA NA NA NA NA
Circalittoral coarse sediment 0.1 NA NA NA NA NA NA NA NA NA NA
Offshore circalittoral coarse sediment 0.08 NA NA NA NA NA NA NA NA NA NA
Offshore circalittoral mixed sediment 0.06 NA NA NA NA NA NA NA NA NA NA
Unknown 0 NA NA NA NA NA NA NA NA NA NA

Gear modifications

Figure 8: Habitat 1

Figure 8. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the Gulf of Cadiz subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).

**Figure 8. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the Gulf of Cadiz subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).**
Figure 9: Habitat 2

Figure 9. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the Gulf of Cadiz subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).

**Figure 9. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the Gulf of Cadiz subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).**
Figure 10: Habitat 3

Figure 10. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the Gulf of Cadiz subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).

**Figure 10. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the Gulf of Cadiz subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).**
Figure 11: Habitat 4

Figure 11. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the Gulf of Cadiz subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).

**Figure 11. Effects of gear modifications (5%, 10%, and 20% lower depletion) on the quality-extent relationship for the most abundant MSFD habitat type in the Gulf of Cadiz subdivision. Habitat quality is defined as 1 - impact, with impact calculated as PD (I‒6a) or PD-sens (I‒7a). The dotted line represent the extent threshold of 75% for the proportion of a broad habitat type that should not be adversely affected (EU, 2024).**

Essential information

Content of this advice product

This interactive document presents information on the distribution, intensity, impact, landings weight, and landings value of mobile bottom-contacting gear (MBCG) fisheries within the Bay of Biscay and the Iberian Coast area and the estimated consequences and costs (expressed as loss of landings weight and value) of reducing the relative extent of areas fished with MBCG. The information is from an assessment for the Bay of Biscay and the Iberian Coast area for the period 2017‒2022. The six-year period was selected to include the latest available vessel monitoring system (VMS) and logbook data rather than to match a specific Marine Strategy Framework Directive (MSFD) assessment period (EU, 2008). The assessment describes fishing intensity and impact with five pressure indicators and four benthic impact indicators (Table E1).

Table E1. Pressure and impact indicators, including the spatial scale and period for which indicators are evaluated. C-square refers to a grid cell of dimensions 0.05° latitude × 0.05° longitude. Examples of the “defined area” referred to in the description would be an area within a specified depth range or an area with the same BHT.

Indicator code Indicator name Indicator type Description Spatial scale Period
I‒1 Average fishing intensity Pressure Average number of times a defined area is swept by mobile bottom-contacting gears (MBCG). Estimated as the sum of swept area for all vessels using MBCG divided by the total area of the defined area Absolute extent (km2) One year
I‒2 Proportion of area fished, at c-square scale Pressure The sum of the area of c-squares fished at least once by MBCG in a defined area, divided by the sum of the area of all c squares in the defined area C-square One year
I‒3 Proportion of area fished Pressure The sum of MBCG swept area in all c-squares in a defined area (where any swept area > c square area is set to c-square area), divided by the sum of the area of all c-squares in the defined area Absolute extent (km2) One year
I‒4 Smallest proportion of area with 90% of fishing intensity, at c-square scale Pressure The sum of the area of the smallest set of c squares accounting for 90% of the total MBCG swept area in a defined area, divided by the sum of the area of all c-squares in the defined area C-square One year
I‒5 Proportion of area persistently unfished, at c-square scale Pressure The sum of the area of c-squares not fished with MBCG at any time in the assessment period in a defined area, divided by the sum of the area of all c-squares in the defined area C-square Six years (assessment period)
I‒6a Average PD impact Impact The annual mean PD impact (population dynamics method, impact indicator), evaluated for a defined area C-square One year
I‒6b Average PD-sens impact Impact The annual mean PD-sens impact (population dynamics method, impact indicator for sensitive species), evaluated for a defined area C-square One year
I‒7a Proportion of area with PD impact < 0.2, at c-square scale Impact The sum of the area of c-squares in a defined area with PD < 0.2 divided by the sum of the area of all c-squares in the defined area (values <0.2 define areas where predicted reductions in abundance of benthic fauna are <20%. The threshold of 0.2 is illustrative only) C-square One year
I‒7b Proportion of area with PD-sens impact < 0.2, at c-square scale Impact The sum of the area of c-squares in a defined area with PD-sens < 0.2 divided by the sum of the area of all c-squares in the defined area (values <0.2 define areas where predicted reductions in abundance of benthic fauna are <20%. The threshold of 0.2 is illustrative only) C-square One year

For each defined assessment area and subdivision, sections of this interactive document provide “summary” information and information on “fishing intensity”, “core fishing grounds”, “fishing by métier”, “impact”, and “scenarios” (Table E2).

Table E2. Information provided in the tabs for each assessment area.

Tab Description
Summary
  • Values of pressure indicators I‒1 to I‒5 and impact indicators I‒6a, I‒6b, I‒7a and I‒7b by depth strata (Table 1).
  • Maps of swept area ratio, median longevity of benthic fauna, and landings value and weight (Figure 1).
  • Estimates of the contribution of small-scale fisheries (MBCG vessels < 12 m overall length) to total fishing effort in kW × days (Table 2).
Fishing intensity
  • The extent of broad habitat types, and various estimates of MBCG fishing activity for these habitat types; fisheries landings, value, and intensity (Table 3).
  • Temporal variation of pressure indicators I‒1, I‒3, and I‒4 (Figure 2).
Fishing by métier
  • Estimates of swept area, landings weight, and landings value for the active métiers (Table 4).
Core fishing grounds
  • Spatial stability of core fishing grounds (smallest area responsible for 90% of the landings value) over time (Figure 3).
  • Spatial distribution of the stability of core fishing grounds (Figure 4).
Impact
  • Spatial distribution of MBCG fisheries impact indicator values (I‒6a) and (I‒6b) (Figure 5).
  • Temporal variation of impact indicators I‒6a, I‒6b, I‒7a, and I‒7b (Figure 6).
  • Landings weight and value per unit impact for the active métiers (Table 5).
  • Métier-specific impacts for the four most extensive broad habitat types (Figure 7).
Scenarios
  • A “Footprint reduction” scenario presenting effects of stepwise exclusion of MBCG fisheries in each broad habitat type, in terms of effort reduction (Table 6), landings value (Table 7), and landings weight (Table 8).
  • A “Gear modifications” scenario presenting the effects of gear modifications (assumed reduction in the depletion of benthic faunal biomass after a gear pass) on the quality-extent threshold for the four most extensive habitat types (Figures 8‒11).
Assessment area

Figure E1. Map of the assessment area, showing the water depth class distributions (left), and boundaries of the relevant (MSFD) divisions and FAO regions (right).

**Figure E1. Map of the assessment area, showing the water depth class distributions (left), and boundaries of the relevant (MSFD) divisions and FAO regions (right).**
Limitations of this advice

Data and analytical limitations are described in the “Limitations” section of the main advice text. This text should be consulted before viewing this interactive document.

How is fishing intensity evaluated?

Five pressure indicators were used to describe fishing intensity and distribution resulting from the use of MBCG (Table E1).

These indicators are calculated, for any given area as defined in this document, from estimates of the swept area in each of the c-squares within a defined area of interest. The swept area is calculated as hours fished × average fishing speed × gear width. This requires that VMS location records are linked to logbook data to associate a location and speed with gear code and fishing activity (Data Collection Framework level 4 and 6 respectively). VMS locations are allocated to “fishing” and “not fishing” based on vessel speed and other filters (ICES, 2022). The gear width is estimated based on relationships between average gear widths and average vessel length or engine power (kW; Eigaard et al. 2016; ICES, 2022). The swept-area ratio (SAR) is calculated as the sum of the area swept by a defined set of MBCG in a defined area (usually one c-square) in a defined period (usually one year) divided by the area of the defined area. Therefore, when calculated at the c-square scale, the SAR indicates the theoretical number of times the c-square is swept per year, assuming that the MBCG fishing is evenly distributed over the c-square. For example, a SAR of 2 means that the entire c-square is fished two times over the year, a SAR of 0.5 means that the entire c-square is fished once in two years.

How is benthic impact evaluated?

Four indicators were used to describe benthic impacts. These indicators are generated from the assessment methods PD and PD-sens. PD (population dynamics method) is used to estimate the loss of benthic biomass, relative to carrying capacity, from a defined area if the current MBCG fishing intensity continues indefinitely (Pitcher et al., 2017; ICES, 2018; Hiddink et al., 2019; ICES, 2022). PD-sens (population dynamics method for sensitive fauna) is used to estimate the loss of biomass of sensitive benthic fauna (the 10% most long-lived biomass fraction), relative to carrying capacity, from a defined area if the current MBCG fishing intensity continues indefinitely (ICES, 2024). For this advice, PD and PD-sens are estimated at the c-square scale.

PD and PD-sens are estimated from SAR and parameters for depletion (proportional mortality) per pass of a MBCG and the intrinsic rate of increase of biomass of the benthic community (Pitcher et al. 2017). Estimates of depletion were métier-specific and taken from Rijnsdorp et al (2020). The intrinsic rate of increase is estimated from the predicted local distribution of maximum ages in an unimpacted benthic community (Rijnsdorp et al., 2018). When PD-sens rather than PD is calculated, only the 10% most long-lived biomass fraction of this community is used to estimate the intrinsic rate of increase, to address the component of the benthic biomass most sensitive to MBCG.

How are landings values evaluated?

VMS location records are linked to logbook data to associate a location with gear code and fishing activity (Data Collection Framework level 4 and 6 respectively), and with landings weight and landings value records. VMS location records are classified as “fishing” and “not fishing” based on vessel speed and other filters (ICES, 2022). Landings weight and value are then allocated to the VMS location records classified as fishing, based on the time interval between location records or an equal split among location records by day, by ICES rectangle or by trip. Total landings weight or value by c-square, in a given time-interval, are calculated as the sum of the allocations to each location record in that c-square.

References

Eigaard O. R., Bastardie F., Breen M. l., Dinesen G. E., Laffargue P., Mortensen, J., et al. 2016. Estimating seafloor pressure from trawls and dredges based on gear design and dimensions. ICES Journal of Marine Science 73(1): 27−43 https://doi.org/10.1093/icesjms/fsv099

EU. 2008. Directive 2008/56/EC of the European Parliament and of the Council of 17 June 2008 establishing a framework for community action in the field of marine environmental policy (Marine Strategy Framework Directive) (Text with EEA relevance). Official Journal of the European Union L164, 19−40. http://data.europa.eu/eli/dir/2008/56/oj

Hiddink, J. G., Jennings, S., Sciberras, M., Bolam, S. G., Cambiè, G., McConnaughey, R. A., Mazor, T., et al. 2019 Assessing bottom-trawling impacts based on the longevity of benthic invertebrates. Journal of Applied Ecology, 56: 1075–1083. https://doi.org/10.1111/1365-2664.13278

ICES. 2018. Interim Report of the Working Group on Fisheries Benthic Impact and Trade-offs (WGFBIT), 12–16 November 2018, ICES Headquarters, Copenhagen, Denmark. ICES CM 2018/HAPISG:21. 74 pp.

ICES. 2022. Working Group on Fisheries Benthic Impact and Trade-offs (WGFBIT; outputs from 2021meeting). ICES Scientific Reports. 4:9. 133 pp. http://doi.org/10.17895/ices.pub.10042

Pitcher, C. R., Ellis, N., Jennings, S., Hiddink, J. G., Mazor, T., Kaiser, M. J., Kangas, M. I., et al. 2017. Estimating the sustainability of towed fishing-gear impacts on seabed habitats: a simple quantitative risk assessment method applicable to data-limited fisheries. Methods in Ecology and Evolution. 8: 472–480. https://doi.org/10.1111/2041-210X.12705.

Rijnsdorp, A. D., Bolam, S. G., Garcia, C., Hiddink, J. G., Hintzen, N. T., van Denderen, D. P., and Van Kooten, T. 2018. Estimating sensitivity of seabed habitats to disturbance by bottom trawling based on the longevity of benthic fauna. Ecological Applications, 28: 1302–1312. https://doi.org/10.1002/eap.1731

Rijnsdorp, A. D., Hiddink, J. G., van Denderen, P. D., Hintzen, N. T., Eigaard, O. R., Valanko, S., Bastardie, F., et al. 2020. Different bottom trawl fisheries have a differential impact on the status of the North Sea seafloor habitats. ICES Journal of Marine Science. 77(5): 1772–86. https://doi.org/10.1093/icesjms/fsaa050