Abstract
Spatial population dynamics of coral reef fish revealed by otolith stable isotopes
8th International Conference on Applications of Stable Isotope Techniques to Ecological Studies Program Book, p.59
International Conference on Applications of Stable Isotope Techniques to Ecological Studies, 8th (Brest, France, 20-Aug-2012 - 24-Aug-2012)
2012
Abstract
In tropical coastal ecosystems, several fish and invertebrate species utilize inshore seagrass beds and mangroves during their juvenile stage before migrating as adults to coral reefs. Measuring the actual contribution of these nursery habitats to reef populations remains a major challenge. Fish otoliths (earbones) are very useful as natural tags due to their permanent recordings of environmental factors. Signatures of stable carbon and oxygen isotopes that are incorporated into otoliths vary regionally in surface waters, and thus reflect differences in water composition among habitats, making them suitable to trace earlier residence areas of fish. In this study, we determined the stable carbon and oxygen isotope signatures in the juvenile margin of otoliths of adult yellowtail snappers (Ocyurus chrysurus) from coral reefs, and compared these to the signatures in otoliths of juvenile fish collected in different nursery embayments harboring seagrass beds, to trace the origin of individual reef fishes. Unique in our approach is that our experimental reef fish represent a complete population on the scale of an entire island, and that all potential nurseries were sampled. Of all adult reef fish caught, 97% were identified as having resided as juveniles in one of the seagrass nurseries, yet different bays contributed unequally to the adult population. Additionally, we combined these data with a spatial simulation model that showed that adult dispersal away from reef areas near the mouth of bays was limited. These findings show that the spatial distribution of nursery areas and their productivity are important drivers of population dynamics, and can lead to a source-sink structure in a closed demersal fish population on the reef. Understanding source-sink dynamics of marine animals is of major importance for the design and placement of marine reserves, especially when life stages utilize spatially different habitats and sourcesink dynamics occur within life stages.
Details
- Title
- Spatial population dynamics of coral reef fish revealed by otolith stable isotopes
- Authors
- Chantal M Huijbers (Author) - Griffith UniversityI Nagelkerken (Author) - University of AdelaideA O Debrot (Author) - WageningenE Jongejans (Author) - Radboud University Nijmegen, Netherlands
- Publication details
- 8th International Conference on Applications of Stable Isotope Techniques to Ecological Studies Program Book, p.59
- Conference details
- International Conference on Applications of Stable Isotope Techniques to Ecological Studies, 8th (Brest, France, 20-Aug-2012 - 24-Aug-2012)
- Organisation Unit
- University of the Sunshine Coast, Queensland; School of Science and Engineering - Legacy
- Language
- English
- Record Identifier
- 99450399002621
- Output Type
- Abstract
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