Working Group 3

Linking biology and assessment: Improving stock assessment through implementation of stock reproductive potential

Using the  information generated by Working Group 1 and methodologies implemented in Working Group 2, Working Group 3 will identify the most influential aspects of stock reproductive potential relevant for the assessment of commercially exploited fish stocks. The Working Group will incorporate the important aspects of SRP into existing stock assessment models and where feasible explore the use of novel assessment models that can incorporate SRP and environmental variables. The Working Group will also focus on the use of SRP in the development of biological reference points. Several studies illustrate there are no technical obstacles to determining analogous reference points for the alternative measures of spawning stock size. Furthermore, software tools have been or are being developed to facilitate both the estimation of these alternative measures and their application in standard techniques. More fundamentally, it is apparent that there are large differences between regional fisheries bodies in their capacity to adopt new approaches. This WG will be programmed not only to implement SRP in assessment but also to reduce differences in assessment standards between regions via implementation of new tools.

WG 3 will have five objectives to help address the overall issue of implementing Stock Reproductive Potential into stock assessment with the intention of improving advice for fish stock management.

This WG has the following deliverables:

  1.  Document detailing how current assessment techniques can incorporate SRP
  2.  Evaluation of current assessments versus assessments incorporating SRP
  3.  Document  of new techniques for the assessment of fish stocks that fully integrate the concepts of SRP
  4.  Document that details the interrelationship between environment and SRP influences on stock assessment and management advice.

Three workshops will be developed within this Working Group to address scientific issues such as :

  • Identifying assessment models that can incorporate SRP and ‘hands-on’ workshop to examine how SRP parameters are incorporated in to current stock assessments. This meeting will be designed to identify which assessments currently incorporate Stock reproductive Potential into the assessment procedure and also identify where, e.g., setting of biological reference points etc. In addition the various methods currently in use for stock assessment will be identified and their potential for incorporation of further parameters to be incorporated to be evaluated. The Working Group will identify what SRP parameters are available and which are most likely to be useful for improving the perception of stock status and potential management scenarios. Further, current state of the art for including SRP will be demonstrated and discussion on the shortfalls and potential ways forward for the inclusion of SRP in to all assessments will be stimulated.
  • Developing potential new models that incorporate SRP including an evaluation of traditional assessments versus assessments incorporating SRP. The workshop will bring together users of a wide range of techniques for stock assessment and modellers who are willing to consider new and novel techniques that can incorporate biological parameters such as SRP. Further the workshop will serve as a testing ground for models that do and do not incorporate SP. The objective is to provide realistic tests of the value in incorporating these parameters in to assessments.
  • Studying interrelationships between environment and SRP and implications for stock assessment. It is recognised that SRP will also vary due to environmental parameters i.e. ecosystem effects e.g. through predator-prey interactions, shifts in productivity etc. This Workshop is designed to explore the potential impact of environmental factors on the estimation of SRP and hence the value to incorporating SRP in to assessments. It will further provide a forum for the state of the art and any potential ways forward in the use of assessments that could use parameters that describe populations and realistically suggest their reactions to shifts in environment and management regimes.