Commission Decision of 25 February 2016 setting up a Scientific, Technical and Economic Committee for Fisheries, C(2016) 1084, OJ C 74, 26.2.2016, p. 4–10. The Commission may consult the group on any matter relating to marine and fisheries biology, fishing gear technology, fisheries economics, fisheries governance, ecosystem effects of fisheries, aquaculture or similar disciplines.
This report is the fifth of a suite of STECF EWG reports dedicated to the fishing effort regime in the Western Mediterranean Sea, following EWG reports 18-09, 18-13, 19-01 and 19-14.
The group was requested to progress to update mixed fisheries models and F-E analyses with the most recent data and the most recent stock assessments, to run a number of effort scenarios until 2025, to draft a mixed-fisheries advice including relevant scenarios and displays, and to discuss next steps.
In EMU 1, good progresses were achieved in combining effort and catch data from both France and Spain into the bioeconomic multifleet model IAM. The model is now able to run and perform management simulations on the stocks of hake (combined assessment in GSAs 1-2-5-6-7), red mullet (in GSA 1, GSA 6 and GSA 7), striped red mullet (in GSA 5), Norway lobster (in GSA 6), and blue and red shrimp (combined assessement in GSAs 6-7).
The updates of the F-E analyses performed in previous years with the most recent time series did not change the perception of the lack of relationship between fishing effort and fishing mortality. For many stocks and fleet segments, the relationship using effort expressed as fishing days has no obvious slope, indicating that the limited reduction of effort observed in the recent years did not have any visible effect on reducing fishing mortality yet.
Extended simulation work was performed regarding management scenarios in EMU 2 (GSAs 8-9-10-11). The multi-fleet BEMTOOL model was updated with latest data and extended, and 8 scenarios involving effort reductions, combined with spatial closures, were simulated in a stochastic approach, where the area closure was implemented using the proportion of effort at spatial sub-unit, to calibrate an improvement of the exploitation pattern, based on an increase of the size at first capure. Also, the individual-based spatial model SMART was updated with 2019 data and the results of the two models were compared.
Finally, a synthetic advice is proposed, summarising the key findings of the simulations. For most of the stocks in the two management units, none of the scenarios investigated allows reaching Fmsy (nor Fmsy upper) in 2025. Nevertheless, all scenarios involving substantial effort reductions foresee some positive effects on the biomass of the stocks even under the current poor levels of recruitment. Some economic results are presented, although it is acknowledged that given the large number of other species exploited beyond the key ones included in the management plan and in the simulation models, the actual socio-economic impact of the plan remains uncertain. Also, the economic results are presented considering a constant number of vessels, and would differ if the number of vessels is reduced.
In the light of the F-E relationships analyses, all results presented in this report are considered to be overoptimistic since they assume a true reduction in F if effort decreases, which may in reality be more limited during the first years of effort reductions.
ULRICH Clara;
PINTO Cecilia;
2020-12-18
Publications Office of the European Union
JRC122924
978-92-76-27701-9 (online),
1831-9424 (online),
2467-0715,
EUR 28359 EN,
OP KJ-AX-20-020-EN-N (online),
https://publications.jrc.ec.europa.eu/repository/handle/JRC122924,
10.2760/143313 (online),
