Fishing down marine food web: it is far more pervasive than we thought
Pauly, D.; Palomares, M.L.D. (2005). Fishing down marine food web: it is far more pervasive than we thought. Bull. Mar. Sci. 76(2): 197-212
In: Bulletin of Marine Science. University of Miami Press: Coral Gables. ISSN 0007-4977; e-ISSN 1553-6955, more
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Authors | | Top |
- Pauly, D., more
- Palomares, M.L.D.
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Abstract |
The widespread call for a transition toward "ecosystem-based" fisheries management implies the development and testing of sustainability indicators suitable for inferences on the status of the ecosystems within which fisheries resource species are embedded. The mean trophic level (TL) of fisheries catches has been shown to allow for such inferences, leading in the process to the identification of global trends toward catches being increasingly dominated by low-TL species, a process now known as "fishing down marine food webs." However, for inferences from TL trends to be accurate, taxonomic and especially geographic over-aggregation of the underlying catch data must be avoided. Accounting for these strong sources of bias suggests that the fishing down effect is far more pervasive than previously thought, and in fact occurs in areas where initial analyses failed to detect it. This confirms the common verdict of absent sustainability for most fisheries of the world. This is illustrated here by five brief case studies, of which three also document a new method for estimating ecosystem transfer efficiency, under a set of specific conditions, from time series of catches and their corresponding mean TL. Some suggestions are given on how work in this area might proceed. |
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