Composition and fate of the catch and bycatch in the Farne Deep (North Sea) Nephrops fishery
Evans, S.M.; Hunter, J.E.; Wahju, E.; Wahju, R.I. (1994). Composition and fate of the catch and bycatch in the Farne Deep (North Sea) Nephrops fishery. ICES J. Mar. Sci./J. Cons. int. Explor. Mer 51(2): 155-168. http://dx.doi.org/10.1006/jmsc.1994.1017
In: ICES Journal of Marine Science. Academic Press: London. ISSN 1054-3139; e-ISSN 1095-9289, more
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Keywords |
Aquatic organisms > Marine organisms > Aquatic birds > Marine birds Eukaryotes > Animals > Chordata > Vertebrates > Birds > Aquatic animals > Sea birds Nephrops Leach, 1814 [WoRMS] ANE, North Sea [Marine Regions] Marine/Coastal |
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Authors | | Top |
- Evans, S.M., more
- Hunter, J.E.
- Wahju, E.
- Wahju, R.I.
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Abstract |
Landings of Nephrops in the North Sea Farne Deep Nephrops fishery represented only 12% of the original catch by weight. The bycatch included 34 species of fish and 23 invertebrate taxa, as well as undersized and unmarketable Nephrops. There were small landings of lemon sole, plaice, whiting, cod, haddock, and starry ray, but the large majority of the bycatch was of juvenile fish or species of no commercial value and they were discarded. Survival of discarded Nephrops and fish was probably minimal. The discards were usually on deck for several hours before they were thrown overboard, by which time the large majority of fish and a high proportion of Nephrops were dead. Nephrops and some fish sank when they were returned to seawater, but other species of fish floated on the surface. In all cases, seabirds took the majority of discards (<70%) when they were thrown overboard. Those Nephrops landing on the seafloor alive are likely to have suffered further mortality because: (1) the bycatch was often discarded distant from the fishing grounds (i.e. the natural habitat), at places where conditions were probably unsuitable for their survival; (2) a high proportion of Nephrops was injured in the trawl and it is evident from laboratory tests that such injuries may cause death several day later; and (3) laboratory studies suggest that injured Nephrops may have difficulty re-establishing themselves on the seafloor because they compete unsuccessfully with conspecifics for food or shelter. There is concern that, in addition to the impact of the Nephrops fishery on stocks of Nephrops and the commercially important fish (especially whiting) which are caught in large numbers in the bycatch, it may have profound effects on the ecology of the seabed. The fishery effectively transfers organic matter from the seafloor to the surface of the sea, where most of it is removed for human food or by seabirds. Little of the fish or Nephrops catch returns to the seabed, dead or alive. |
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