100 years in the North Sea: fundamental changes in the distribution and diet of commercial fish species
Friday seminar by John K. Pinnegar
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).