Ph.D.-project by Bo Poulsen
Supervisors: Professor Poul Holm
Project period: July 2002 – June 2005
In this period the herring fisheries were the most profitable and important natural resource in the North Sea area, and the ups and downs of those fisheries have been explained previously from national and economic points of views. A comparative study of the fishing effort around the North Sea, with the aim of testing a number of biological hypotheses, will further qualify these explanations.
The Scottish, English, French, Norwegian and Swedish herring fisheries were conducted close to the shore, and therefore very vulnerable to changes in stock abundance and migration patterns of the herring. For these fisheries, estimates based on, for instance, “catch per boat” are viable ecological detectors, and I have been researching into published source material for these fisheries.
The Dutch “Groote Visserij” however was conducted through large-scale high sea operations with herring buses, which enabled the processing of the fish on board, and journeys of more than one month's duration at a time. In order to detect ecological patterns from this fishery it is therefore necessary to know not only of the catch per boat, but also to correlate this with the length of the actual fishing time, the place of fishing and the quality of the fish.
Large amounts of primary source material from the Dutch fisheries can reveal the answer to such questions, and they have not to my knowledge been extensively exploited in this way before. Therefore, and since these were the economically most important herring fisheries in the North Sea, I have decided to focus on the “Groote Visserij” as the first case study of my project.