Can otolith chemistry be used for identifying essential seagrass habitats for juvenile spotted seatrout, Cynoscion nebulosus, in Chesapeake Bay?
Emmanis Dorval A D E , Cynthia M. Jones A , Robyn Hannigan B and Jacques van Montfrans CA Center for Quantitative Fisheries Ecology, Old Dominion University, Norfolk, VA 23529, USA.
B Department of Chemistry, Arkansas State University, PO Box 419, State University, AR 72467, USA.
C Virginia Institute of Marine Science, College of William and Mary Gloucester Point, VA 23062, USA.
D Current address: National Marine Fisheries Service, Southwest Fisheries Science Center, 8604 La Jolla Shore Drive, La Jolla, CA 92037, USA.
E Corresponding author. Email: emmanis.dorval@noaa.gov
Marine and Freshwater Research 56(5) 645-653 https://doi.org/10.1071/MF04179
Submitted: 23 July 2004 Accepted: 17 February 2005 Published: 21 July 2005
Abstract
We investigated the variability of otolith chemistry in juvenile spotted seatrout from Chesapeake Bay seagrass habitats in 1998 and 2001, to assess whether otolith elemental and isotopic composition could be used to identify the most essential seagrass habitats for those juvenile fish. Otolith chemistry (Ca, Mn, Sr, Ba, and La; δ13C, δ18O) of juvenile fish collected in the five major seagrass habitats (Potomac, Rappahannock, York, Island, and Pocomoke Sound) showed significant variability within and between years. Although the ability of trace elements to allocate individual fish may vary between years, in combination with stable isotopes, they achieve high classification accuracy averaging 80–82% in the Pocomoke Sound and the Island, and 95–100% in the York and the Potomac habitats. The trace elements (Mn, Ba, and La) provided the best discrimination in 2001, a year of lower freshwater discharge than 1998. This is the first application of a rare earth element measured in otoliths (La) to discriminate habitats, and identify seagrass habitats for juvenile spotted seatrout at spatial scales of 15 km. Such fine spatial scale discrimination of habitats has not been previously achieved in estuaries and will distinguish fish born in individual seagrass beds in the Bay.
Extra keywords: estuarine-dependent fish, natural tag, otolith microchemistry, seagrass bed discrimination.
Acknowledgments
We thank Mr David Combs, whose assistance in the field was invaluable. We also thank Dr Jay Kaufman for his assistance with stable isotope analysis, Dr Zhongxing Chen for his assistance with trace-element analysis, and D. Combs and Henry Orr for their assistance with the graphics. We modified a SAS program provided by Dr Dayanand N. Naik to transform the data. The comments of two reviewers significantly improved the manuscript. This project was funded by Virginia Sea Grant (R-CF/37) and the Virginia Marine Resources Commission. Some of C. Jones’ time was provided by a NSF grant: OCE-9876565. The present study is a part of a PhD dissertation thesis for an Ecological Science Program at Old Dominion University (Dorval).
Dorval, E. , Jones, C. M. , and Hannigan, R. (2005). Chemistry in surface waters: distinguishing fine scale differences in seagrass habitats of Chesapeake Bay. Limnology and Oceanography 50, 1073–1083.
Hannan, J. C. , and Williams, R. J. (1998). Recruitment of juvenile marine fishes to seagrass habitats in a temperate Australian estuary. Estuaries 21, 29–51.
Kimura, R. , Secor, D. H. , Houde, E. D. , and Piccoli, P. M. (2000). Up-estuary dispersal of young-of-the-year bay anchovy Anchoa mitchilli in the Chesapeake Bay: inference from microprobe analysis of strontium in otoliths. Marine Ecology Progress Series 208, 217–227.
Paucot, H. , and Wollast, R. (1997). Transport and transformation of trace metals in the Scheldt estuary. Marine Chemistry 58, 229–244.
| Crossref | GoogleScholarGoogle Scholar |
Rooker, J. R. , Holt, S. A. , Soto, M. A. , and Holt, G. J. (1998). Postsettlement patterns of habitats use by sciaenid fishes in subtropical seagrass meadows. Estuaries 21, 318–327.
Secor, D. H. , Henderson-Arzapalo, A. , and Piccoli, P. M. (1995). Can otolith microchemistry chart patterns of migration and habitat utilization in anadromous fishes? Journal of Experimental Marine Biology and Ecology 192, 15–53.
| Crossref | GoogleScholarGoogle Scholar |
Thorrold, S. R. , Jones, C. M. , Swart, P. K. , and Targett, T. E. (1998). Accurate classification of juvenile weakfish, Cynoscion regalis, to estuarine nursery areas based on chemical signatures in otoliths. Marine Ecology Progress Series 173, 253–265.