Foraging Ecology of Northern Elephant Seals

Annual research proposal for A%26#195;%26#177;o Nuevo: 2008 Costa Lab, UC Santa Cruz The Costa lab seeks to continue the ongoing elephant seal diving and tracking research program. The data generated in the proposed studies will directly benefit the research projects of seven graduate students, a post-doctoral researcher, an undergraduate, and many Tagging of Pacific Pelagics researchers: Dr. Dan Costa Cory Champagne Jason Hassrick Autumn-Lynn Harrison Melinda Fowler Sara Maxwell Patrick Robinson Samantha Simmons Dr. Yann Tremblay Nicole Teutschel TOPP researchers General project goals include: 1. Foraging in relation to oceanography; diet reanalysis. 2. Movement patterns and navigation at various temporal and spatial scales. 3. Predictive movement modeling. 4. Age-related differences in foraging behavior and success 5. Contaminant loading. 6. Creation of optimal foraging models from diving behavior. 7. Importance of seamounts to foraging success. 8. Incorporation of tag data into TOPP database for multi-species analyses. 9. Fasting physiology in pups and adults 10. Variation in diet over the first foraging trip to sea. Methodology: To address all of these questions while minimizing impacts on animals and the reserve, all researchers will be working in close collaboration with each other and sharing much of the data collected from each seal, thus overall sample sizes will be kept at a minimum while maximizing the amount of data collected and used. Following the breeding season and molt season of 2008; 20 known-aged, adult female seals will be instrumented with a satellite tag (to follow their movement patterns while at sea), a time-depth recorder (to examine their diving behavior as well as environmental parameters such as water temperature and light level) and a VHF tag (to relocate the animal after return to the rookery). 1 to 2 of these females will be instrumented with a crittercam and accelerometer to detect feeding events. Pending tag availability, up to five additional adult male elephant seals will be equipped with Conductivity-Temperature-Depth (CTD) tags to collect oceanographic-quality data. Additional procedures (and purposes) during instrument deployment/recovery: 1. Morphometric measurements (lengths and girths) ; Body composition 2. Ultrasound measurement of blubber thickness ; Body composition 3. Mass ; Body composition / Foraging success 4. Blood samples ; Oxygen storage capacity, contaminant analysis 5. Muscle/blubber biopsy ; Oxygen storage capacity, contaminant and diet analyses 6. Whisker collection ; long-term diet analysis In addition to the full deployments described above, up to 15 translocation experiments will be conducted. Juvenile seals will be captured at A%26#195;%26#177;o Nuevo, equipped with instrumentation, and released either in the Monterey Bay by boat or from Monterey. These experiments will provide insights to oxygen usage, aide in the movement and navigation studies and assist tag manufacturers with instrument design and testing. Wherever possible we will work before and after tour hours and out of the direct view of tourists to minimize impacts on the day-to-day operation of the reserve. Recent publications and tracking data will be available for public viewing at the following websites: http://www.toppcensus.org/ http://las.pfeg.noaa.gov/TOPP/ We welcome an open dialog with respect to our activities at A%26#195;%26#177;o Nuevo. Please let us know if you have any questions or concerns. Costa Lab: 831-459-2691