|Leatherback turtles as oceanographic indicators: stable isotope analyses reveal a trophic dichotomy between ocean basins|Wallace, B.P.; Seminoff, J.A.; Kilham, S.S.; Spotila, J.R.; Dutton, P.H. (2006). Leatherback turtles as oceanographic indicators: stable isotope analyses reveal a trophic dichotomy between ocean basins. Mar. Biol. (Berl.) 149(4): 953-960. hdl.handle.net/10.1007/s00227-006-0247-y
In: Marine Biology. Springer: Heidelberg; Berlin. ISSN 0025-3162, more
|Authors|| || Top |
- Wallace, B.P.
- Seminoff, J.A.
- Kilham, S.S.
- Spotila, J.R.
- Dutton, P.H.
Oceanographic sampling is often limited to local and temporally concise assessments of complex, transient, and widespread phenomena. However, long-lived, migratory pelagic vertebrates such as leatherback turtles (Dermochelys coriacea, Vandelli 1761) can provide important integrated information about broad-scale oceanographic processes. Therefore, the present study analyzed stable carbon and nitrogen isotope ratios (d13C and d15N) of egg yolk and red blood cells from nesting leatherback populations from Costa Rica in the eastern Pacific in 2003–2004 and 2004–2005 and from St. Croix in the North Atlantic in 2004 and 2005 to establish differences between nutrient sourcing and its influence on higher trophic level consumers in both ocean basins. Whereas d13C signatures were similar between Costa Rica (-19.1±0.7‰) and St. Croix (-19.4±1.0‰) leatherbacks, reflecting the pelagic foraging strategy of the species, Costa Rica leatherback d15N signatures (15.4±1.8‰) were significantly enriched relative to St. Croix leatherback d15N signatures (9.8±1.5‰). This d15N difference likely reflects inter-basin differences in nitrogen cycling regimes and their influence on primary productivity being transferred through several trophic levels. Thus, high-order marine consumer movements, habitat preferences, and stable isotope signatures can be combined with ocean sampling to elucidate interactions between oceanographic processes and marine megafauna.