The fishing pattern of individual beam trawl vessels comprises alternating searching and exploitation phases during a fishing trip. The searching phase is characterized by a below-average catch rate and a long distance between the midpoints of hauls. The exploitation phase is characterized by an above average-catch rate and a small inter-haul distance. During the exploitation of a local concentration of flatfish, the catch rate decreases on average by 10% over a period of 48 h. The rate of decline is a function of the engine power. Powerful vessels experience a small or no decline in catch rate, whereas less powerful vessels experience a decline of up to 16%. It is inferred that the decline in catch rate may be due to interference competition among vessels through a change in the behaviour of flatfish in response to fishing disturbance, although a reduction in local abundance may also have contributed to the decline. Areas with above-average catch rates may change on a weekly basis. (C) 2000 International Council for the Exploration of the Sea.
CITATION STYLE
Rijnsdorp, A. D., Van Mourik Broekman, P. L., & Visser, E. G. (2000). Competitive interactions among beam trawlers exploiting local patches of flatfish in the North Sea. ICES Journal of Marine Science, 57(4), 894–902. https://doi.org/10.1006/jmsc.2000.0576
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