Proceedings of the National Academy of Sciences of the United States of America

About the PNAS Member Editor
Name Estes, James A.
Location University of California, Santa Cruz
Primary Field Environmental Sciences and Ecology
Secondary Field Evolutionary Biology
 Election Citation
Estes' studies of interactions involving sea otters and killer whales provide the dynamic cornerstone for marine food web research. His field observations, unparalleled in spatial and temporal scope, have generated the most comprehensive evidence that cascading trophic effects structure feeding networks, revolutionizing appreciation for apex predators and top-down dynamics.
 Research Interests
James Estes' laboratory is interested in the behavioral ecology of large predators and the impacts of these animals on other species and ecological processes. They have explored the effects of sea otter predation on temperate reef ecosystems by first defining the food web's structure through observational studies and then documenting the dynamic consequences of various consumer-prey interactions by contrasting islands of the Aleutian archipelago as sea otter populations waxed and waned following their near-extinction by the Pacific maritime fur trade. They have shown that sea otters enhance kelp forests by limiting populations of herbivorous sea urchins; that the effects of this trophic cascade extend widely through coastal ecosystems to other species and ecological processes; that predation by sea otters and their recent ancestors decoupled the coevolution of defense and resistance by marine plants and their herbivores; and that North Pacific kelp forests have been further influenced by events in the open sea that caused killer whales to begin preying on sea otters, thus driving otter populations downward and altering their effects on coastal ecosystems through the otter-urchin-kelp trophic cascade. Using this system as a model, they have helped identify the ecological and evolutionary influences of large predators across global ecosystems and the resulting consequences of widespread losses of these species on numerous features of the world we live in.

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