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Dr. Sarah Helyar School of Biological Sciences, University of Bangor, Deiniol Road, Bangor, Gwynedd, LL57 2UW, UK |
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Unravelling the patterns of population structure for two deep-sea species, the onion-eye grenadier (Macrourus berglax) and the longnose velvet dogfish (Centroselachus crepidater), between the Azores and north-western Norway
Over-exploitation of traditional coastal stocks has resulted in the shift of commercial fishing towards less-known, deep-sea species in many parts of the world. Most of these "new" fisheries are now proving to be unsustainable.
A key to our ability to manage these fisheries and protect their ecosystem is the understanding of the underlying demographic and life-history characteristics of deep sea species, including their migratory behaviour and spatial population structure. My current project is part of a larger EU study of several economically important deep-sea fishes across the continental slopes, seamounts and trenches between the Azores and north-western Norway (DEECON). We will be combining population genetics with otolith microchemistry to detect population structure, and integrating this with bathymetric data, life-history traits, and oceanographic models of ocean currents to unravel mechanisms for population connectivity, such as passive larval drift and active migration. This fundamental biological knowledge can then be used to develop scientifically sound management plans for one of the world's most valuable ecosystems.
The DEECON project is focusing on five bathyal (deep sea) species that have different life-histories and that are all affected by commercial fisheries: the Black scabbardfish (Aphanopus carbo), the Roundnose grenadier (Coryphaenoides rupestris), the Onion-eye grenadier (Macrourus berglax), the ling (Molva molva), and the longnose velvet dogfish (Centroselachus crepidater).
My part of this work is to use microsatellites to unravel the patterns of population structure across the continental slopes, seamounts and trenches between the Azores and north-western Norway. I am focusing on two species, the onion-eye grenadier (Macrourus berglax) and the longnose velvet dogfish (Centroselachus crepidater), both of which have recently become subject to exploitation. While not the intended target of the fisheries, both M. berglax and C. crepidater are thought to occur as by-catch throughout the Northern Atlantic, and are particularly vulnerable to fishing pressure due to their life history.
The objective is to identify stocks that will react independently to exploitation, and so provide a platform for evidence-based management strategies, and evaluate the potential for biodiversity loss caused by deep-sea fisheries and other anthropogenic pressures.
This project is an opportunity to utilise modern techniques to advise on management strategies. Too often we have overlooked the risks of exploiting natural resources, without a clear understanding of the biological dynamics, resulting in some well known and at times irreversible consequences. This is a timely contribution to the conservation and sound management of deep sea ocean resources, before irreversible overexploitation occurs.
Publications
Telfer, S., Clough, H.E., Birtles, R.J., Bennett, M., Carslake, D., Helyar, S. & Begon, M. (2007) Ecological differences and coexistence in a guild of microparasites: Bartonella in wild rodents. Ecology 88 (7), 1841–1849.
Telfer, S., Bennett, M., Carslake, D., Helyar, S. & Begon, M. (2007) The dynamics of murine gammaherpes virus within wild, sympatric populations of bank voles and wood mice.
Journal of Wildlife Disease 43 (1), 32-39.
Barker, F. S., Helyar, S. J., Kemp, S. J. & Begon, M. (2005) Highly polymorphic microsatellite loci in the bank vole (Clethrionomys glareolus).
Molecular Ecology Notes 5 (2), 311-313.
Ilik J. Saccheri, Hywel D. Lloyd, Sarah J. Helyar, Paul M. Brakefield (2005) Inbreeding uncovers fundamental differences in the genetic load affecting male and female fertility in a butterfly. Proceedings of the Royal Society of London Series B-Biological Sciences 272 (1558), 39-46.
Lee, G. J., Archibald, A. L., Law, A. S., Lloyd, S., Wood, J. & Haley, C. S. (2005) Detection of quantitative trait loci for androstenone, skatole and boar taint in a cross between Large White and Meishan pigs. Animal Genetics 36 (1), 14-22.