Continental shelf nurseries and recruitment variability in American plaice and yellowtail flounder on the Grand Bank: insights into stock resiliency
Walsh, S.J.; Simpson, M.R.; Morgan, M.J. (2004). Continental shelf nurseries and recruitment variability in American plaice and yellowtail flounder on the Grand Bank: insights into stock resiliency. J. Sea Res. 51(3-4): 271-286. https://dx.doi.org/10.1016/j.seares.2003.10.003
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:Geffen, A.J.; Nash, R.D.M.; van der Veer, H.W. (Ed.) (2004). Proceedings of the Fifth International Symposium on Flatfish Ecology, Part II. Port Erin, Isle of Man, 3-7 November 2002. Journal of Sea Research, 51(3-4). Elsevier: Amsterdam. 167-338 pp., more
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| Keywords |
Compensation
Compensation
Ecosystem resilience
Management > Resource management > Fishery management
Models
Nurseries
Nurseries
Nursery grounds
Population functions > Recruitment
Stocks
Topographic features > Submarine features > Continental shelves
Hippoglossoides platessoides (Fabricius, 1780) [WoRMS]; Limanda ferruginea (Storer, 1839) [WoRMS]
ANW, Grand Banks [Marine Regions]
Marine/Coastal |
| Author keywords |
American plaice; yellowtail flounder; recruitment; juveniles; nurseries;compensation; generalised additive models; stock recovery |
| Authors | | Top |
- Walsh, S.J.
- Simpson, M.R.
- Morgan, M.J.
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| Abstract |
In 1994, a directed fishing moratorium was declared for Grand Bank American plaice (Hippoglossoides platessoides) and yellowtail flounder (Limanda ferruginea) stocks because both stocks showed severe declines in abundance from heavy exploitation during the mid 1980s and early 1990s. Four years later, the fishery for yellowtail re-opened while the plaice stock has shown little recovery and the moratorium is still in effect. To assess the possible causes of the differences in recovery between species, we examined the spatial structure and environmental characteristics of the continental shelf nursery habitats of plaice and yellowtail, and their relationship to recruitment variability and overall population size. Depth plays a major influential role determining the spatial pattern and the abundance of juveniles of both species and in the case of plaice the spatial structure of the adult population also determines the amount of nursery area utilised by juveniles. Recruitment variability was higher in plaice than in yellowtail. We found year class synchrony in both species indicating that common environmental conditions and/or biological processes are affecting recruitment in a similar manner. Density-dependent regulation appears to be more severe in yellowtail and this should contribute to a more stable population when compared to plaice. These results are discussed in terms of resiliency of both stocks to over-exploitation. |
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