Related Experiment Videos
Fishing down marine food webs
Pauly1, Christensen, Dalsgaard
1D. Pauly and J. Dalsgaard, Fisheries Centre, 2204 Main Mall, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4. V. Christensen, R. Froese, F. Torres Jr., International Center for Living Aquatic Resources Management.
Science (New York, N.Y.)
|February 18, 1998
Summary
Global fisheries show a significant decline in the average trophic level of species caught. This trend indicates unsustainable fishing practices that deplete marine food webs.
Area of Science:
- Marine Biology
- Fisheries Science
- Ecology
Background:
- Global fisheries statistics reveal a historical shift in species composition.
- Trophic levels represent a species' position in the food web, influencing ecosystem dynamics.
Purpose of the Study:
- To analyze trends in global fisheries landings and their implications for marine food webs.
- To assess the sustainability of current fishing practices based on trophic level changes.
Main Methods:
- Analysis of Food and Agricultural Organization (FAO) global fisheries statistics from 1950 to 1994.
- Examination of shifts in species groups landed, focusing on trophic level and life history traits.
Main Results:
- A decline in the mean trophic level of landed species groups from 1950 to 1994.
- A transition from high trophic level, piscivorous fish to lower trophic level invertebrates and planktivorous fish.
- The effect is more pronounced in the Northern Hemisphere and also observed in inland fisheries.
Conclusions:
- Fishing down marine food webs initially increases catches but leads to unsustainable exploitation patterns.
- Current fishing practices pose a risk to marine ecosystem stability and long-term productivity.
- A need for revised fisheries management strategies to ensure sustainability.