Changes in the spatial distribution of North Sea plaice (Pleuronectes platessa) and implications for fisheries management
Van Keeken, O.A.; van Hoppe, M.; Grift, R.E.; Rijnsdorp, A.D. (2007). Changes in the spatial distribution of North Sea plaice (Pleuronectes platessa) and implications for fisheries management. J. Sea Res. 57(2-3): 187-197. https://dx.doi.org/10.1016/j.seares.2006.09.002
In: Journal of Sea Research. Elsevier/Netherlands Institute for Sea Research: Amsterdam; Den Burg. ISSN 1385-1101; e-ISSN 1873-1414, more
Also appears in:Yamashita, Y.; Nash, R.D.M.; van der Veer, H.W. (Ed.) (2007). Proceedings of the Sixth International Symposium on Flatfish Ecology, Part 1, held at Maizuru, Kyoto, Japan from 20-25 October 2005. Journal of Sea Research, 57(Spec. Issue 2-3). Elsevier: Amsterdam. IV, 89-235 pp., more
|  |
| Keywords |
20th century
Catch rate
Distribution > Geographical distribution
Management > Resource management > Fishery management
Spatial distribution
Pleuronectes platessa Linnaeus, 1758 [WoRMS]
ANE, North Sea [Marine Regions]
Marine/Coastal |
| Author keywords |
plaice; spatial distribution; North Sea; Plaice Box; fisheriesmanagement |
| Authors | | Top |
- Van Keeken, O.A.
- van Hoppe, M., more
- Grift, R.E.
- Rijnsdorp, A.D., more
|
|
|
| Abstract |
To protect the main nursery area of plaice, an area called the ‘Plaice Box’ was closed to trawl fisheries with large vessels in 1989, with the expectation that recruitment, yield and spawning stock biomass would increase. However, since then the plaice population has declined and the rate of discarding outside the Plaice Box has increased, suggesting an offshore shift in spatial distribution of juvenile plaice. Using research vessel survey data collected since 1970, the change in distribution of juvenile age groups was analysed in relation to the distance to the coast. Further, a comparison of the distribution of different length classes of plaice between three historic periods was made (1902-1909; 1983-1987; 1999-2003). A shift towards deeper water of larger-sized plaice (20-39 cm) is apparent already before the 1980s and may be related to the decrease in the number of competitors or predators. An offshore shift in the distribution of young plaice occurred in the 1990s most likely in response to higher water temperatures that may have exceeded the maximum tolerance range or increased the food requirements above the available food resources. A decrease in competition with larger plaice offshore, possibly in combination with increased inshore predation by cormorants and seals, may also have played a role. The offshore shift in distribution has reduced the effectiveness of the Plaice Box as a technical measure to protect the under-sized plaice from discarding, since an increased proportion of the population of undersized plaice is moving to the more heavily exploited offshore areas. |
|
