Discipline: Ecology Environmental and Earth Sciences
Subcategory: Geosciences and Earth Sciences
Lauren Arnold - University of the Virgin Islands
Co-Author(s): Brian C. Stock, Lynn Waterhouse, Ron Burton, and Brice X. Semmens, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA Croy M. McCoy, Department of Environment, Cayman Islands Government, Grand Cayman, Cayman Islands Christy V. Pattengill-Semmens, Reef Environmental Education Foundation (REEF), Key Largo, FL
Nassau grouper are an important species in the Caribbean both in a fisheries context and because they contribute to tourism through enhanced diving experiences. However, the species has suffered dramatic declines through it range due to overfishing on fish spawning aggregations (FSAs) for the species. These spawning aggregations, occurring during the winter months in the central Caribbean, represent the total reproductive output for the species. It is thus important that we gain an understanding of the patterns of connectivity generated by FSA sites, and characterize the processes of egg/larval advection, diffusion, and planktonic ecology (feeding and predation). To do this, we evaluated the ability of a novel plankton sampler, the NetCam, to map the dispersal of Nassau grouper eggs from the FSA immediately post-spawning. The NetCam captures images of items passing through the cod-end of a plankton net. However, it is not clear what proportion of the eggs imaged by the NetCam are Nassau grouper. Using eggs from preserved samples taken during the NetCam deployment, we demonstrate at least 3 distinct size classes of eggs. Based on genetic analysis, these distinct classes belong to separate species. These findings suggest that images of fish eggs captured by the NetCam can reliably be identified to species, and are thus useful in characterizing the spatial ecology and early life history of Nassau grouper eggs.
Funder Acknowledgement(s): Lauren was funded by the UC Office of the President through the UC-HBCU Oceans as a Bridge Program. The NetCam deployment was funded by NSF INSPIRE grant #1344291.
Faculty Advisor: Brice Semmens, email@example.com
Role: I went through the plankton samples they collected previously this year, and separated out all of the eggs. I then photographed, measured and counted all the eggs. Once that was done, I used a computer program called R, to run statistical tests and create the graphs. I was able to identify the Nassau grouper range and compare it to the DNA testing the lab previously did, as well as to other studies. For further evidence that size is a valid metric, I remeasured and photographed a previous years known species eggs to compare the size distributions.