Report of the Workshop on Methods for Estimating Discard Survival (WKMEDS)

Research aimed at determining whether aquatic organisms, which have been caught and subsequently returned to the water, survive has been conducted over many dec- ades. Although there have been reviews of the outputs from this work (e.g. Davis, 2002; Broadhurst et al., 2006; Revill, 2012; Uhlmann and Broadhurst, 2013), to date, there has been no comprehensive assessment of all the scientific methods and ap- proaches that can be employed in meeting this aim. WKMEDS was initiated to estab- lish and describe the methods of best practice to quantify the survival of aquatic organisms caught and returned to the water.
Relevant work on discard survival has been conducted in commercial and recreation- al fisheries around the world and the content of this report is designed to have global applicability. The catalyst for the formation of WKMEDS was the recent change in European Union fisheries policy, which has meant that there is particular need for guidance on how to investigate levels of discard survival. Article 15 of the reformed Common Fisheries Policy (CFP) Basic Regulation, which came into force on January 1st 2014, introduced a phased discard ban or landing obligation for regulated species. The policy includes a number of exemptions and flexibility tools. In paragraph 2(b) an exemption from the landing obligation is described for “species for which scientific evidence demonstrates high survival rates, taking into account the characteristics of the gear, of the fishing practices and of the ecosystem”. To support any proposal for an exemption for selected species or fisheries, therefore, clear, defensible, scientific evidence for high discard survival rates are required. This has generated interest from various stakeholders in understanding the methods to generate discard survival estimates, and in the quality and robustness of the results from survival assessments.
There are practical and scientific limitations to all of the methods currently available for estimating discard survival (ICES, 1995, 1997, 2000, 2004 and 2005; Revill, 2012; Gilman et al., 2013). Consequently, there is a need for the provision of guidelines, and identification of best practice, for undertaking discard-survival assessments. In re- sponse to a request from the European Commission, through the Scientific, Technical and Economic Committee for Fisheries (STECF, 2014), to address this need for guid- ance, ICES established a Workshop on Methods for Estimating Discard Survival (WKMEDS), on 1st January 2014.
WKMEDS, chaired by Mike Breen (Norway) and Thomas Catchpole (UK), has been tasked to:
a) Develop guidelines and, where possible, identify best practice for under- taking discard survival studies (using the framework detailed in the re- port of STECF Expert Working Group EWG 13-16) (ICES WKMEDS, 17-21 February, 2014 workshop);
b) Identify approaches for measuring and reducing, or accounting for, the uncertainty associated with mortality estimates;
c) Critically review current estimates of discard mortality, with reference to the guidelines detailed in 1, and collate existing validated mortality esti- mates;
d) Conduct a meta-analysis, using the data detailed in 3, to improve the un- derstanding of the explanatory variables associated with discard mortality and identifying potential mitigation measures; and

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e) Based on ToR a) to d) a Cooperative Research Report (CRR) should be de- veloped for consideration by the ICES Advisory (ACOM) and Scientific (SCICOM) committees.
This group will work by correspondence and a series of workshops to be held in 2014–2016. The first meeting was held on 17–21 February, 2014, at the ICES HQ in Copenhagen.
Objectives for the Guidance Notes (ToR a):
The primary objective of this document is to provide the user with an overview and guidance on the currently available methods for estimating survival rates of fish (and other animals) that are discarded as part of commercial fishing operations. By provid- ing examples of best practice, it is expected that this guidance will enable the user to produce reliable estimates of discard survival.
This report will:
 describe the concepts behind assessing discard survival (Sections 2 and 3);
 describe three different approaches for estimating survival (vitality as- sessment, captive observation and tagging) (Sections 4, 5 and 6); and
 provide guidance on the selection of the most appropriate approaches and experimental designs, as well as how to integrate and utilize information from them, with respect to specific discard survival objectives (Sections 3, 7, 8 and 9).
Later versions of this report will cover in more detail:
 techniques for assessing survival using tagging and biotelemetry; and
 the most appropriate methods for analysing and reporting survival data.
It is assumed that the user of these guidance notes has sufficient scientific training, or at least access to suitable scientific support, to be able to conduct the techniques de- scribed in these notes in an appropriately systematic and disciplined manner. How- ever, these guidance notes are intended also to be informative for other stakeholders associated with fishing (primarily fishers and managers) who wish to support and understand discard survival estimates.
Note on high survival
As well as describing and recommending how best to estimate discard survival, it is also recognized that stakeholders will also require guidance on the second element of the exemption – what constitutes "high survival rates". However, this is not the remit of WKMEDS and readers are directed to STECF EWG 13–16 (STECF, 2013). The STECF EWG concluded that the term “high survival” is somewhat subjective and that defining a single value cannot be scientifically rationalized. Therefore it is ad- vised that assessing proposed exemptions on the basis of "high survival" need to be considered on a case-by-case basis, taking account the specificities of the species and fisheries under consideration.