International Council for the Exploration of the Sea
OSPAR_Implementation_of_MSFD_for_marine_mammals.pdf (615.75 kB)

OSPAR request on implementation of MSFD for marine mammals

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posted on 2022-07-18, 11:39 authored by ICESICES

ICES  advises  on  a  number  of  aspects  of  the  common  implementation  by  OSPAR  of  the  Marine  Strategy Framework Directive (MSFD).

ICES advises that “assessment unit” is a more appropriate term than “management unit” for subdivisions of the range of marine mammals under consideration by OSPAR. In OSPAR regions II, III,and IV, ICES advises that harbour seals be treated  within 17 units  and grey  seals  be  treated  within  two units.  ICES also advises  on assessment  units  for  the  five cetacean species being considered by OSPAR under MSFD.

ICES provides general advice on the need to understand the statistical power of monitoring programmes before targets are set under MSFD in relation to that monitoring. It is not advisable to set targets that demand a higher statistical precision than  can  be  metwithin a  feasible  monitoring  programme.  This  requires  that  thestatistical power  of amonitoring programme needs to be analysed prior to set targets.

ICES notes that several of the indicators proposed by OSPAR are compound indicators(e.g. indicators that cover more than  one  species),which do  not  include specific rules defininghow the  indicator should  operate.  ICES  recommends breaking  the  compound  indicators  down  to  specieslevel, before setting  rules for  their  use.  ICES  also  suggests  the simplification of the indicators ofcetacean abundance. ICES advice is based on these simplified indicators.

ICES advises that distributional range is a difficult concept to set MSFD targets for in relation to seals and cetaceans with the exception ofinshore assessment units of bottlenose dolphins. The number of regular sites for grey seal pupping and harbour seal moulting would be suitable for target setting in relation to the distribution of these species.

ICES advises also that the current technique for monitoring grey seal abundance is to survey pup numbers and therefore there is duplication in the currently suggested grey seal targets. ICES advises on technical aspects of target setting for the abundance of the two seal species and notes that further harmonization of monitoring methods will be required, as well as an upgrade on current data storage.

The decadal frequency of current surveys of cetaceans that range over wide areas mean that it isvery difficult to detect,with any statistical certainty,any change in abundance on a reasonable time scale (a six-year time scale is implied in some EU legislation). This implies that survey frequency needs to be increased –the (societal) choice of statistical power has implications  for  survey  frequency.ICES also  notes  that  IUCN  uses  a three-generationalapproach  to  the  detection  of changes in population abundanceand recommends that OSPAR might switch to such an approachin setting targets. ICES makes suggestions for the wording of targets using this approach.

ICES has provided advice to the European Commission under EU Regulation 812/2004on setting targets for limits on bycatch using an approach known as the Catch Limit Algorithm. Key choices need to be made at the societal/policy level for this advice to be further developedand ICES has offered to help organize a workshop to consider these choices.

ICES has provided a summary of existing monitoring schemes but cannot provide a full overview of future monitoring needs until societal and policy decisions have been taken in relation to targets and their statistical precision. ICES has not, on this occasion,been able to provide overviews of the monitoring of marine mammal bycatch


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