The dynamics of small-scale patchiness of plaice and sole as reflected in the catch rates of the Dutch beam trawl fleet and its implications for the fleet dynamics
Poos, J.-J.; Rijnsdorp, A.D. (2010). The dynamics of small-scale patchiness of plaice and sole as reflected in the catch rates of the Dutch beam trawl fleet and its implications for the fleet dynamics, in: Poos, J.-J. Effort allocation of the Dutch beam trawl fleet. pp. 29-51
In: Poos, J.-J. (2010). Effort allocation of the Dutch beam trawl fleet. PhD Thesis. Rijksuniversiteit Groningen: Groningen. ISBN 978-90-367-4412-6. 173 pp., meer
Is gerelateerd aan:Poos, J.-J.; Rijnsdorp, A.D. (2007). The dynamics of small-scale patchiness of plaice and sole as reflected in the catch rates of the Dutch beam trawl fleet and its implications for the fleet dynamics. J. Sea Res. 58(1): 100-112. https://dx.doi.org/10.1016/j.seares.2007.01.006, meer
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| Trefwoorden |
20th century
Catching methods > Net fishing > Trawling
Data > Fishery data > Catch/effort
Fisheries > Finfish fisheries > Flatfish fisheries
Patchiness
Spatial variations
Pleuronectes platessa Linnaeus, 1758 [WoRMS]; Solea solea (Linnaeus, 1758) [WoRMS]
ANE, Noordzee [Marine Regions]
Marien/Kust |
| Author keywords |
spatial variations; flatfish fisheries; catch/effort; North Sea |
| Abstract |
Catch rates of sole Solea solea and plaice Pleuronectes platessa in the Dutch beam trawl fleet operating in the North Sea show spatio-temporal variation. The variation in catch rates reflects differences in abundance of the species. Up to 45% of the variation in catch rates can be explained by the time of day of the catch, the engine power of the vessel and the migration cycles of the species. Also, spatial covariance was found in the residual variation for both species using variograms and covariance functions. The ranges of the spatial structure were found to be between approximately 20 to 45 nautical miles, indicating patchy distribution of the species. No differences in the ranges of the spatial structures were found between different seasons. Cross-covariance analysis shows the patches lasted up to two weeks. The implication of the spatial pattern in flatfish for the dynamics of effort allocation is discussed. |
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