Fishing Down Marine Food Webs Project of The Fisheries Centre, University of British Columbia

Many authors - fisheries scientists and others- have pointed out that modern marine fisheries tend to operate lower in the food web and had given various names to this trend ("biomass fishing", "industrial fishing", "exploiting forage fish", etc).

This trend was recently quantified, and given what might become its definite name - "fishing down marine food webs" (FDMFW) in a report of the same name published in Science on February 6, 1998.

FDMFW, authored by Daniel Pauly and Johanne Dalsgaard of the Fisheries Centre, and V. Christensen, R. Froese and F. Torres Jr. of ICLARM relied on two sets of data:

1) Estimates of trophic levels of major species groups in global fisheries landings; and

2) Global fisheries catches, as compiled by the Food and Agriculture Organization of the United Nations as also incorporated in FishBase , the global database on fish.

The trophic levels in (1) were estimated from 60 ECOPATH models, one of these models is illustrated on figure below (click on image to see full size version), representing both the North Sea (see Footnote 3 in FDMFW) and the "food triangle" discussed in FDMFW (see also footnote 21 and 22).

Colleagues interested in replicating the results on FDMFW are free to use the trophic levels on the file linked with this text, while the required catch statistics may be obtained from FAO or from FishBase 97. Our trophic level estimate may be also used for more local studies, in combination with national catch series. In either case, the trophic level estimate may be cited as:

Pauly, D. and V. Christensen. 1997. Trophic levels of fishes. Box 16, p. 127 In R. Froese and D. Pauly (eds) FishBase 97: concepts, design and data sources. ICLARM, Manila.