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| Titel |
Putative fishery-induced changes in biomass and population size structures of demersal deep-sea fishes in ICES Sub-area VII, Northeast Atlantic Ocean |
| VerfasserIn |
J. A. Godbold, D. M. Bailey, M. A. Collins, J. D. M. Gordon, W. A. Spallek, I. G. Priede |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 10, no. 1 ; Nr. 10, no. 1 (2013-01-25), S.529-539 |
| Datensatznummer |
250017487
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| Publikation (Nr.) |
 copernicus.org/bg-10-529-2013.pdf |
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| Zusammenfassung |
| A time series from 1977–1989 and 2000–2002 of scientific trawl surveys in
the Porcupine Seabight and adjacent abyssal plain of the NE Atlantic was
analysed to assess changes in demersal fish biomass and length frequency.
These two periods coincide with the onset of the commercial deep-water
fishery in the late 1970s and the onset of the regulation of the fishery in
the early 2000's, which allowed us to investigate changes in the
relationship between total demersal fish biomass and depth between the pre-
and post commercial fishing periods, as well as changes in the biomass (kg km−2) depth distribution and length frequency distribution of the most
dominant fish species. Our results show a decline in total demersal fish
biomass of 36% within the depth range of the commercial fishery
(< 1500 m). Whilst there were significant declines in target (e.g. Coryphaenoides rupestris decreased by 57%)
and non-target (e.g. C. guentheri and Antimora rostrata) species, not all species
declined significantly. Changes in the overall length-frequency distribution
were detected for 5 out of the 8 dominant species occupying depth ranges
both within and outside the maximum depth for commercial trawling. This
suggests that whilst there is evidence for likely fishery impacts on the
biomass distribution of the demersal fish population as a whole,
species-specific impacts are highly variable. It is clear that changes in
population structure can extend beyond the depth at which fishing takes
place, highlighting the importance for also considering the indirect effects
on deep-sea fish populations. |
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