Abstract
Much has changed in the North Sea over the past 100 or so years; particular fisheries have come and gone, certain species (e.g. blue-fin tuna, common skate and sturgeon) have virtually disappeared and at the same time environmental conditions have changed appreciably with a general warming of surface waters. We have made use of a unique dataset of catch and effort data for British North Sea trawlers; these cover nine decades (spanning the period 1913 to 2007) and are spatially detailed by ICES rectangle (0.5 degrees Latitude, by 1 degrees Longitude). Based on an analysis of these data we quantify, for the first time, long-term distribution shifts of North Sea sole, plaice, cod and haddock over a period approaching a century. We interpret the findings in the light of climate change, long-term changes in fishing pressure and changes in benthic habitats. In addition, considerable effort has been dedicated to the digitization of fish stomach content data spanning the period 1884-2010 to look for major changes in food-webs over the past 100 years. Analyses suggest that there have been fundamental changes in aquatic ecosystems with fish consuming a very different portfolio of prey types at the beginning of the 21st Century compared to the early 20th Century.
Dr John K. Pinnegar
Programme Director - Climate Change,
Centre for Environment, Fisheries &
Aquaculture Science (Cefas).
Pakefield Road,
Lowestoft,
Suffolk,
NR33 0HT