STECF EXPERT WORKING GROUP EWG 16-13

Transcription

1 STECF EXPERT WORKING GROUP EWG Stock assessments in the Mediterranean Sea, Part I September 2016, Barza di Ispra, Italy DG MARE focal persons: Xavier Vazquez & Amanda Perez Chair: John Simmonds GENERAL GUIDELINES: unless the data used and information provided comes from the official DCF data calls, the experts are requested to indicate the data source from where certain information has been taken (e.g. L-W relationships, prices) or if it is an experts' reasoned deduction. Data collected outside the DCF shall be used as well and merged with DCF data following quality check whenever necessary. Due account shall also be taken of data used and assessments carried out within the Member States in particular when using data collected through the DCF/DCR and EU funded research projects, studies and other types of EU funding. The raw data used to generate the input data, assessment scripts and all input files should be made available to the JRC before the end of the meeting to ensure reproducibility of the assessments and documentation. TERM OF REFERENCE: ToR 1. Data gathering For the stocks given in Annexes I and II, the STECF-EWG is requested to: 1.1. Compile and provide the most updated information on stock identification, age and growth, maturity, feeding, habitat, and natural mortality Compile and provide complete sets of annual data on landings and discards for the longest time series available up to and including This should be presented by fishing gear as well as by size/age structure (see Annex III for more details) Compile and provide complete sets of annual data on fishing effort for the longest time series available up to and including This should be described in terms of amount of vessels, time (days at sea, soaking time, or other relevant parameter) and fishing power (gear size, boat size, horse power, etc.) by Member State and fishing gear. Data shall be the most detailed possible to support the establishment of a fishing effort or capacity baseline (see Annex III for more details) Compile and provide indices of abundances and biomass by year and size/age structure for the longest time series available up to and including 2015 (see Annex III for more details).

2 ToR 2. Stock assessments (Level 1) For the stocks given in Annex I-A, or combinations thereof, the STECF-EWG is requested to: 2.1. Assess trends in fishing mortality, stock biomass, spawning stock biomass, and recruitment. Different assessment models should be applied as appropriate. Models should be compared using model diagnostics including retrospective analyses when the models can produce one. The selection of the most reliable assessment should be justified. Assumptions and uncertainties should be reported Propose and evaluate candidate MSY value, range of values and safeguard points in terms of fishing mortality and stock biomass. The proposed values shall be related to long-term high yields and low risk of stock/fishery collapse and ensure that the exploitation levels restore and maintain marine biological resources at least at levels which can produce the maximum sustainable yield Provide short and medium 1 term forecasts of spawning stock biomass, stock biomass and catches. The forecasts shall include different management scenarios, inter alia: zero catch, the status quo fishing mortality, and target to F MSY or other appropriate proxy by 2018 and 2020 (by means of a proportional reduction of fishing mortality as from 2017). In particular, predict the level of fishing effort exerted by the different fleets which is commensurate with the short- and medium-term forecasts of the proposed scenarios Make any appropriate comments and recommendations to improve the quality of the assessments. Furthermore, advise on the ideal assessment frequency. ToR 3. Stock assessments (Levels 2-4) For the stocks given in Annex I-A, or combinations thereof, the STECF-EWG is requested to: 3.1. Assess trends in fishing mortality, stock biomass, spawning stock biomass, and recruitment. Based on the precautionary approach, determine proxies MSY reference points on the exploitation level and the status of the stocks. Different assessment models should be applied as appropriate, including retrospective analyses when the models can produce one. The selection of the most reliable assessment should be explained. Assumptions and uncertainties should be specified Make any appropriate comments and recommendations to improve the quality of the assessment and/or to upgrade the assessment level and/or improve the quality of the data. Furthermore, advise on the ideal assessment frequency. 1 Medium term forecast only when an acceptable stock-recruitment relationship is identifiable. 2

3 ToR 4. Length-based analysis For the stocks given in Annex I-B, the STECF-EWG is requested to assess trends in catch length composition, survey indices and catch-per-unit effort, depending on the data availability. In addition, provide size-based indicators (e.g. proportion of mature fish in the catch) to be used as reference points of the population status. ToR 5. Summary sheets Provide a synoptic overview of: (i) the fishery; (ii) the most recent state of the stock (spawning stock biomass, stock biomass, recruits, and exploitation level by fishing gear); (iii) the source of data and methods and; (iv) the management advice, including MSY value or proxies, range of values and safeguard points. ToR 6. Data quality check Summarize and concisely describe all data quality deficiencies, including possible limitations with the surveys of relevance for stock assessments and fisheries. Such review and description are to be based on the data format of the official DCF data call for the Mediterranean Sea launched on the 28 April Identify further research studies and data collections which would be required for improved fish stock assessments. 3

4 ANNEX I (A) List of stocks given to assess Target assessment level * Proposed stock boundaries ** Common name Scientific name Level 1 GSA 6 Anchovy Engraulis encrasicolus Level 1 GSA 7 Anchovy Engraulis encrasicolus Level 1 GSAs Anchovy Engraulis encrasicolus Level 1 GSA 6 Sardine Sardina pilchardus Level 1 GSA 7 Sardine Sardina pilchardus Level 1 GSAs Sardine Sardina pilchardus Level 2 GSA Atlantic horse mackerel Trachurus trachurus Level 2 GSA Atlantic horse mackerel Trachurus trachurus Level 2 GSA Atlantic horse mackerel Trachurus trachurus Level 3 GSA 9 Anchovy Engraulis encrasicolus Level 3 GSA 10 Anchovy Engraulis encrasicolus Level 3 GSA 10 Sardine Sardina pilchardus Level 4 GSA 5 Sardine Sardina pilchardus Level 4 GSA 5 Anchovy Engraulis encrasicolus (B) List of stocks given to length-based analysis Target assessment level * Proposed stock boundaries ** Common name Scientific name Length analysis GSA 11 Sardine Sardina pilchardus Length analysis GSA 11 Anchovy Engraulis encrasicolus Length analysis GSA Atlantic mackerel Scomber scomber Length analysis GSA Atlantic mackerel Scomber scomber Length analysis GSA Atlantic mackerel Scomber scomber * The target assessment levels come from the report of the Scientific, Technical and Economic Committee for Fisheries (STECF) - Methodology for the stock assessments in the Mediterranean Sea (STECF-16-14) Publications Office of the European Union, Luxembourg, EUR XXXX EN, JRC XXXX, 166 pp. Some flexibility shall be allowed to increase/decrease the proposed assessment levels, on the basis of data availability and experts' knowledge. ** The group should consider the proposed stock boundaries as a starting point. They are based on past stock assessments, on the EU project STOCKMED and on the distribution of other species with similar fish population dynamics. For each stock assessment, it would be advisable to carry out a throughout discussion to agree on the most suitable stock boundaries. Thus, proposed stock boundaries could be merged with other GSAs or split in several GSAs when dully justified. 4

5 ANNEX II Guidance for the preparation of the final report (specific sections ) SECTION 1.5 FISHERIES Landings Total landings/year * Landings/fishing gear/year * Landings /fishing gear/year/size structure Landings /fishing gear/year/age structure Discards Total discards/year * Discards/fishing gear/year * Discards/fishing gear/year/size structure Discards/fishing gear/year/age structure Fishing effort Fishing effort (GT*days at sea)/year * Fishing effort (GT*days at sea)/fishing gear/year * Fishing effort (Days at sea)/year * Fishing effort (Days at sea)/fishing gear/year * SECTION 1.6 SECTION 1.7 SCIENTIFIC SURVEYS STOCK ASSESSMENT Abundance index/year Abundance index/year/size structure Abundance index/year/age structure Biomass index/year Biomass index/year/size structure Biomass index/year/age structure Results * Fishing mortality Fishing mortality/fishing gear Recruitment SSB TB Reference points * F MSY, F upper and F lower B MSY, B lim, B pa Predictions * For the different scenarios, Fishing mortality Fishing mortality/fishing gear Catches Catches/fishing gear Fishing effort/fishing gear SSB * Please provide these variables at least in values (not only figures). 5