Clique Analysis of North Sea Ecosystems

摘要

Fisheries management has steadily down-shifted gears over the last 100years from revolutionary dialectical industrialization of fisheries (Baranov, 1917; Beverton and Holt, 1957), through various forms of scientific realpolitik (e.g., Hutchings et al., 1997), to genuinely heart-felt green utopianism, often inspired by SoCal syncretism (e.g.World Wildlife Fund, 2002); all leading to what often appears from the outside to be paralysis by analysis. Much of this policy doctoring has gone on at the professorial level of mathematical modeling in fisheries management. Fashionable modeling stances come and go without much change at the basic data level that is dominated almost exclusively by various catch estimates (biomass measures) and the various analogues of age Frequencies that are recalculated to provide mortality estimates, etc. The fisheries themselves have also not taken much notice of the changes in modeling stance. Mostly, they have simply continued to decline. In the case of the North Sea fisheries of interest to us, the landings of commercially valuable species have declined, but the overall fish biomass appears to have increased; as has the biomass of sea birds, a likely indicator species for fish biomass.