Use of Multiple Chemical Tracers to Define Habitat Use of Indo-Pacific Mangrove Crab, <Emphasis Type="Italic">Scylla Serrata</Emphasis> (Decapoda: Portunidae) |
| |
| Authors: | Amanda W J Demopoulos Nicole Cormier Katherine C Ewel Brian Fry |
| |
| Institution: | 1.Department of Oceanography, SOEST,University of Hawaii,Honolulu,USA;2.Integrative Oceanography Division, Scripps Institution of Oceanography,University of California,La Jolla,USA;3.USDA Forest Service, Pacific Southwest Research Station,Institute of Pacific Islands Forestry,Hilo,USA;4.School of Forest Resources and Conservation,University of Florida,Gainesville,USA;5.Department of Oceanography and Coastal Studies, School of the Coast and Environment,Louisiana State University,Baton Rouge,USA;6.Florida Integrated Science Center,U.S. Geological Survey,Gainesville,USA |
| |
| Abstract: | The mangrove or mud crab, Scylla serrata, is an important component of mangrove fisheries throughout the Indo-Pacific. Understanding crab diets and habitat use should
assist in managing these fisheries and could provide additional justification for conservation of the mangrove ecosystem itself.
We used multiple chemical tracers to test whether crab movements were restricted to local mangrove forests, or extended to
include adjacent seagrass beds and reef flats. We sampled three mangrove forests on the island of Kosrae in the Federated
States of Micronesia at Lelu Harbor, Okat River, and Utwe tidal channel. Samples of S. serrata and likely food sources were analyzed for stable carbon (δ13C), nitrogen (δ15N), and sulfur (δ34S) isotopes. Scylla serrata tissues also were analyzed for phosphorus (P), cations (K, Ca, Mg, Na), and trace elements (Mn, Fe, Cu, Zn, and B). Discriminant
analysis indicated that at least 87% of the crabs remain in each site as distinct populations. Crab stable isotope values
indicated potential differences in habitat use within estuaries. Values for δ13C and δ34S in crabs from Okat and Utwe were low and similar to values expected from animals feeding within mangrove forests, e.g.,
feeding on infauna that had average δ13C values near −26.5‰. In contrast, crabs from Lelu had higher δ13C and δ34S values, with average values of −21.8 and 7.8‰, respectively. These higher isotope values are consistent with increased crab
foraging on reef flats and seagrasses. Given that S. serrata have been observed feeding on adjacent reef and seagrass environments on Kosrae, it is likely that they move in and out of
the mangroves for feeding. Isotope mixing model results support these conclusions, with the greatest mangrove ecosystem contribution
to S. serrata diet occurring in the largest mangrove forests. Conserving larger island mangrove forests (> 1 km deep) appears to support
crab foraging activities. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
