Trophic Structure of the Northwest Hawaiian Islands and Resident Monk Seals (Monachus schaundslandi) During the Twentieth Century

Event Name/Location

18th Biennial Conference of the Society for Marine Mammalogy, Quebec City, Canada, October 12-16, 2009

Presentation Date

10-10-2009

Document Type

Poster

Presenters / Authors

Nina M. Thompson, Nova Southeastern University
Amy Hirons, Nova Southeastern UniversityFollow
Charles W. Potter, National Museum of Natural History - Smithsonian Institution
Charles Littnan, NOAA Pacific Island Fisheries Science Center

Description

The Hawaiian monk seal (Monachus schauinslandi) is an endangered species only found within the Hawaiian Archipelago. The majority of the breeding population for this seal is located around six islands in the Northwest Hawaiian Island chain (NWHI). Overall, both juvenile and adult seals have a wide range in δ¹³C and δ¹⁵N from 1912-2006 (δ¹³C: -12.5‰; δ¹⁵N: 12.6‰). Seals in the northern NWHI were enriched in δ¹³C by nearly 2‰ and depleted in δ¹⁵N by nearly 6‰ during the 96 years. Meanwhile, seals within the middle and southern extent of the NWHI showed little to very slight decreases in δ¹³C and δ¹⁵N. Preliminary comparison of modern monk seals with selected potential prey in the southern NWHI indicate possible trophic reliance on a mix of reef fish, eels, and lobster. Commercial fishery data post-WWII indicate an overlap between fisheries and monk seal diets in lobster, squirrelfish, and goatfish.

NSUWorks Citation

Thompson, Nina M.; Hirons, Amy; Potter, Charles W.; and Littnan, Charles, "Trophic Structure of the Northwest Hawaiian Islands and Resident Monk Seals (Monachus schaundslandi) During the Twentieth Century" (2009). Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures. 430.
https://nsuworks.nova.edu/occ_facpresentations/430