Sustainable exploitation of temperate fish stocks.
Marine Scotland, Marine Laboratory, PO Box 101, 375 Victoria Road, Aberdeen, AB11 9DB, UK.
The theory of Maximum Sustainable Yield (MSY) underpins many fishery management regimes and is applied principally as a single species concept. Using a simple dynamic biomass production model we show that MSY can be identified from a long time series of multi-stock data at a regional scale in the presence of species interactions and environmental change. It suggests that MSY is robust and calculable in a multispecies environment offering a realistic reference point for fishery management. Furthermore the demonstration of the existence of MSY shows that it is more than a purely theoretical concept. There has been an improvement in the status of stocks in the Northeast Atlantic but our analysis suggests further reductions in fishing effort would improve long term yields.
Genetic tools for the management of Mussel (Mytilus) species in Scotland.
1, 2, Piertney S2, Davies I M1 and Snow M1
1Marine Scotland Marine Laboratory, 375 Victoria Road, Aberdeen AB11 9DB, UK.
2Institute of Biological and Environmental Sciences, University of Aberdeen AB24 2TZ, UK.
Mussel cultivation is the most rapidly growing sector of the Scottish shellfish aquaculture industry, production having increased from 262 tonnes to 5869 tonnes (worth £5.9 million) in the last two decades. Until recently, mussel production in Scotland was considered to be based exclusively on Mytilus edulis, the native species. However, the sympatric occurrence of M. edulis, Mytilus trossulus, Mytilus galloprovincialis and their hybrids in cultivation has recently been reported, and significant production losses attributed to the presence of fragile shelled M. trossulus. In order to put in place effective management strategies towards minimizing M. trossulus impact, an understanding of these species abundance, distribution and origin is required.