Bay of Biscay and the Iberian Coast Ecoregion - Ecosystem Overview

Key Signals

• Climate change effects are evident within the ecoregion, notably in the Gulf of Cadiz, where warming has been observed over the last two decades.
• The distribution of warm‑water copepod species such as Temora stylifera and Calanoides carinatus has moved northwards across the ecoregion.
• Winters in recent years have seen more northerly winds coupled with strong upwelling events, which can influence the recruitment of commercially important species such as sardine (Sardina pilchardus), anchovy (Engraulis encrasicolus), southern hake (Merluccius merluccius), Norway lobster (Nephrops norvegicus), and horse mackerel (Trachurus trachurus).
• A marked decrease in the individual condition of several small pelagic fish, including anchovy and sardine, has been noted in the Bay of Biscay since the mid-2000s. Similar trends have been observed in some demersal species.
• Fishing, and to a lesser extent tourism and recreation, are the main activities contributing to direct, human‑induced pressures to the ecoregion. Fleet size and commercial fishing effort have been decreasing since the late 1990s/early 2000s. The importance of recreational fishing in coastal areas is increasing.
• The spawning-stock biomass (SSB) of benthic-demersal (since 2002) and pelagic (since 2010) fisheries guilds has been increasing, while some elasmobranchs remain well below the reference level (MSY B_trigger).
• Community-level changes include a reorganization of demersal fish species biodiversity in the southern Bay of Biscay. This is mainly related to an increased occurrence of deep-water species previously found further south and increased replacement of species in the northern Bay of Biscay.
• A decline in habitat-forming macroalgae has been observed in the northwestern Iberian Peninsula.
• Non-indigenous species introductions are increasing in the southernmost part of the ecoregion, the Gulf of Cadiz.
• A number of seabird species have experienced declines across the ecoregion, with the Iberian guillemot (a common guillemot subspecies, (Uria aalge ibericus)) considered extinct as a breeder in Iberia and the black-legged kittiwake (Rissa tridactyla) considered regionally extinct.
• In recent years, the very high numbers of common dolphin (Delphinus delphis) bycatch in fisheries in the Bay of Biscay are a cause for concern.