Biological oceanography and fisheries management: perspective after 10 years

Despite 100 years of research into the relationship between oceanographic factors and fish recruitment, it has proved very difficult to demonstrate causal connections between properties of the marine ecosystem and the success of fisheries. Some authors have been led to conclude that such causal connections, therefore, do not exist: a corollary would be that biological oceanography is of limited relevance to fisheries issues. However, it would be premature to dismiss biological oceanography as a tool in fisheries management. If we have not been able to implicate ecosystem factors as a significant source of variance in fish recruitment, it may be because the search has been conducted at an inappropriate scale, a consequence of the limitations of ships as oceanographic platforms. The advent of remotely sensed data from satellites greatly extends the scales of time and space at which synoptic oceanography can be carried out. Access to such data allows a wider range of hypotheses to be tested, than is possible with ships alone, on the relationship between ecosystem factors and recruitment. Applications in both the Atlantic and Pacific have demonstrated strong fluctuations between years in the timing and the intensity of phytoplankton dynamics, with implications for recruitment and growth of exploited populations of fish and invertebrates. The results provide essential intelligence for those charged with stewardship of the marine environment.