Trophic cascades in a formerly cod-dominated ecosystem.
Removal of top predators from ecosystems can result in cascading effects through the trophic levels below, completely restructuring the food web. Cascades have been observed in small-scale or simple food webs, but not in large, complex, open-ocean ecosystems. Using data spanning many decades from a once cod-dominated northwest Atlantic ecosystem, we demonstrate a trophic cascade in a large marine ecosystem. Several cod stocks in other geographic areas have also collapsed without recovery, suggesting the existence of trophic cascades in these systems.
Frank
Kenneth T
KT
Department of Fisheries and Oceans, Bedford Institute of Oceanography, Ocean Sciences Division, Post Office Box 1006, Dartmouth, Nova Scotia, B2Y 4A2, Canada. frankk@mar.dfo-mpo.gc.ca
Petrie
Brian
B
Choi
Jae S
JS
Leggett
William C
WC
D000818:Animals; D001267:Atlantic Ocean; D044822:Biodiversity; D018533:Biomass; D017753:Ecosystem; D005398:Fisheries; D005399:Fishes; D020387:Food Chain; D048389:Gadus morhua; D007448:Invertebrates; D010839:Phytoplankton; D011156:Population Density; D011157:Population Dynamics; D011235:Predatory Behavior; D025341:Principal Component Analysis; D046048:Seals, Earless; D012623:Seawater; D013997:Time Factors; D015048:Zooplankton