Pollock Conservation Cooperative Research Center
2009 Awarded Research Projects
Project Title: Consummate and consumed predators: assessing killer whale predation on juvenile Steller sea lions in the Gulf of Alaska.
Principal Investigator: Jo-Ann Mellish
Award: $5,000
Abstract
This project addresses PCCRC Priority #1, and will allow us to directly quantify
predation on juvenile Steller sea lions in the Gulf of Alaska. We have deployed newly
developed, satellite linked Life History Transmitters in 15 juvenile Steller sea lions
to date, with an additional 12 animals scheduled for 2008 / 2009 under existing funding.
Life History Transmitters allow the determination of individual animal survival and allow
distinction of predation from non-traumatic causes of mortality, from satellite transmitted
post-mortems. Data returns from four of 15 initial deployments prove the viability of the
concept, and suggest that predation by killer whales may be the single greatest cause
of juvenile sea lion mortality, and that more than 50% of females may be consumed by
predators before primiparity.
Placing our preliminary findings into the context of a conceptual framework we have
developed to integrate bottom up and top down effects, suggests that implications
of this level of predation on recovery of the species may be profound, and may require
changes more substantial than those that in the past likely contributed to current
population status. Here we request support for the vital continuation of satellite
monitoring for LHX tag data returns.
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