Whales, whaling and ecosystem change in the Antarctic and Eastern Bering Sea: insights from ecosystem models

• Main Authors: Andrew W. Trites, Andrea P. Coombs, Emma L. Bredesen
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2004
• Subjects: Antarctic; Bering Sea; Gulf of Alaska; Myers; The Antarctic; Antarc*; Orca; Orcinus orca; Alaska; Aleutian Islands
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.666.8656; http://www.marinemammal.org/wp-content/pdfs/TritesCIESM2004.pdf

The question of whether species assemblages are controlled by food availability or by predators is a fundamental ecological question that has implications for biological conservation, mainte-nance of biodiversity, development of marine protected areas, and management of economically and culturally important marine resources (Worm and Duffy, 2003). Increases in prey popula-tions following the removal of predators by fisheries have been taken as proof that top-down processes control marine ecosystems (e.g., Worm and Myers, 2003). Similar arguments have been used to justify perceived benefits of whaling to fisheries (e.g., Tamura, 2003), or to account for large scale ecosystem changes noted in the northern and southern hemispheres following the cessation of whaling (e.g., Knox, 1994; Springer et al., 2003). There is considerable uncertainty about the role that whales play in the ecosystem. Many of the large-scale changes noted in marine ecosystems have been attributed to the effects of human activities, especially commercial whaling. One such example is the compelling and eloquently simple hypothesis proposed by Springer et al. (2003) to explain a cascading series of population declines that began in the late 1970s in the Gulf of Alaska, Aleutian Islands and Bering Sea. The core of their argument is that killer whales (Orcinus orca) were forced to eat smaller marine