Scientific, Technical and Economic Committee for Fisheries - 73rd plenary report (STECF-PLEN-23-02)

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. The Scientific, Technical and Economic Committee for Fisheries held its 73 rd plenary from 10 to 14 July 2023

Occurrence of sharks, rays and rabbit fish in the Greater North Sea – and catches in Swedish fisheries

This report was written in response to a request from the Swedish Agency for Marine and Water Management to update an earlier technical note from SLU Aqua “Occurrence of skates and rays in northern European waters and catches in Swedish fisheries in the Skagerrak/Kattegat and the eastern North Sea”. The aim was to provide a comprehensive overview of elasmobranchs present in Swedish waters and to what extent these species are caught in Swedish fisheries. To describe the occurrence and spatial distribution of sharks, rays and rabbit fish we used fisheries-independent survey data from 1967–2020, as well as data from the national on-board observer program and official landing data. During this time a total of 21 species of sharks, rays and rabbit fish were reported from the Skagerrak, Kattegat and the Sound. Seven of the species were common in both the fishery independent and the commercial data supporting that they are native to Swedish waters. These species included three shark species; velvet belly (Etmopterus spinax), lesser spotted dogfish (Scyliorhinus canicula) and spurdog (Squalus acanthias); three species of rays; starry ray (Amblyraja radiata), thornback ray (Raja clavata), and sailray (Rajella lintea); and the rabbit fish (Chimaera monstrosa). The round ray (Rajella fyllae) was also relatively common in survey catches from the deeper parts of the Skagerrak. All common species were present year round, but spurdog also showed a seasonal trend, being more common along the Norwegian coast and in offshore part of the Skagerrak in the first quarter, and closer to the Swedish coast in the third and fourth quarter. There are no longer any targeted fisheries for elasmobranchs by Swedish vessels but by-catches occur, predominantly in demersal trawl fisheries in the deeper parts (> 200 m) of Skagerrak and the Norwegian trench where a majority the observed hauls had by-catch of one or more species. Usage of a sorting device (grid) in the Nephrops and Pandalus trawl fisheries appear to reduce the amount of by-catches. Historical and anecdotal information suggest that by-catch of spurdog in gillnets could be significant, but as landing were prohibited in 2010, no data is available since then. Starry ray and spurdog represents > 75 % of the estimated total catch weight of shark and rays combined. More than 90 % of elasmobranchs was discarded, which is not surprising given that landing of spurdog, starry ray, common skate and thornback ray are prohibited in 3a. Sailray is the only species landed to some extent (few tonnes per year) by Swedish vessels during the last five years. Swedish landings of sailray mainly come from the Pandalus fishery and from demersal trawl fishing without grids in the deeper parts of Skagerrak

Scientific, Technical and Economic Committee for Fisheries (STECF) – Evaluation of the landing obligation joint recommendations (STECF-18-06)

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 contains reviews of joint recommendations from Member States regional groups for the implementation of the landing obligation in 2019

Scientific, Technical and Economic Committee for Fisheries (STECF) – 62nd Plenary Meeting Report (PLEN-19-03)

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. The Scientific, Technical and Economic Committee for Fisheries hold its 62nd plenary on 11-15 November 2019 at the Centre Borschette, Brussels

Ecological risk assessment of invertebrates caught in Swedish west-coast fisheries

Ecological risk assessments are important as scientific support for the implementation of ecosystem-based fisheries management. Marine invertebrates are important to ecosystem structure and function and may be sensitive to fishing pressure. Some are also of increasing commercial value – but have hitherto not been paid much attention to in ecological risk assessments. Here, catches of invertebrates in Swedish west-coast fisheries with demersal trawls and creels are examined from an ecological risk assessment perspective. It is found that few non-commercial invertebrate species have been regularly recorded in onboard observer programs. Furthermore, for being a comparatively well-studied area, it is striking to find that out of the 93 species included, 56% could be classified as data deficient in terms of known attributes needed to perform basic ecological risk assessments. This implies that there is little or no available information on the basic life history traits important for estimating productivity. Additionally, onboard observer data for invertebrates are inadequate beyond targeted commercial species for robust statistical analysis on volumes generated over time and between fisheries. However, over 18% of the studied species are categorized as red-listed on the Swedish IUCN Red List. Combined with the few records available in observer data programs, the study illustrates the need to pay more attention to marine invertebrates in fisheries monitoring programs and research, especially bycaught and non-commercial invertebrate species

Survival rates for Nephrops norvegicus discarded from Northern European trawl fisheries

When discarded from bottom trawl fisheries, survival of Nephrops norvegicus may be sufficiently high that this species can be exempted from the EU Landing Obligation. In three studies, Nephrops were sampled from trawlers in northern European waters, and the fate of individuals monitored for a minimum of 13 days in onshore tanks. Winter estimates of captive survival (means ± 95% confidence intervals), including immediate mortality during catch sorting, were 62 ± 2.8% for the West of Scotland, 57 ± 1.8% for the Farne Deeps (North Sea), and 67 ± 5.4% for the Skagerrak. The Farne Deeps fishery is not active in summer, but captive survival rates in summer in the other two areas were reduced to 47 ± 3.4% for West of Scotland and 40 ± 4.8% for the Skagerrak. Linear modelling of the West of Scotland and Skagerrak data suggested that higher survivals in winter were related to colder water or air temperatures, although temperatures during captive observation may also have had an impact. Net modifications in the Skagerrak study had an effect on survival, which was higher for Nephrops sampled from nets equipped with the more selective Swedish sorting grid compared to Seltra trawls