Joseph Hall
I received a BS in Marine Biology from the College of Charleston in 1995. I gained my first field experience working as an intern at the Grice Marine Laboratory. Most of my time was spent working with the South Carolina Department of Environmental Protection gathering age related fecundity data on the inshore populations of Red Drum (Sciaenops ocellatus) and Spotted Sea Trout (Cynoscion nebulosus).
After a brief (9 year) 'tour of duty' in the business world, I returned to academia in 2007 and earned my MS in Marine Biology at Nova Southeastern University - Oceanographic Center. While working in the amphipod taxonomy lab, under the guidance of Dr. J.D. Thomas, I solidified my love for field biology through numerous collection trips to Belize, Florida Keys, and Australia. The research for my thesis, titled “Ecology, Distribution, and Systematics of Leucothoid Amphipods of the West Florida Shelf Benthic Ecosystem” involved the examination of a collection of amphipods from the Hourglass cruises of 1965-1967.
I was accepted into the CMSS Ph.D. program here at TAMUCC in the Fall of 2007. Working with Dr. Frank Pezold I have identified a research project that not only has important implications for the conservation and management of a unique family of gobioid fishes, it may result in the development of new management tools for a variety of marine fish stocks.
Web site: http://www.tropicalmarineecology.org
Research Interests
- I am interested in all areas of marine conservation biology. Currently I am evaluating the effect of an amphidromous life-history strategy on the persistence of metapopulations of tropical freshwater gobies. Amphidromy refers to a type of diadromy where juveniles and adults live and breed in freshwater while the larval stage is completed in marine waters. Amphidromous species often exist in metapopulations that are comprised of semi-isolated adult sub-populations (streams) that only achieve connectivity via larval dispersal in marine waters and the subsequent post-larval recruitment back to fresh water.
- Specifically, my research is focused on the dispersal capability of the larvae of two Sicydiine gobies (Stiphodon cf. elegans and Stiphodon caeruleus) while in marine waters around the island of Pohnpei, Micronesia. After documenting the genetic structure of adult subpopulations in different streams I will use nDNA microsatellite data from post-larval recruits to estimate their natal origin. Comparison of the location of the genetically determined natal population and the actual stream of capture of the post-larval recruits will result in a better understanding of Sicydiine goby larval dispersal patterns. In an effort to estimate the long distance dispersal capability of the marine larvae I will examine the stable isotope signatures of 15N and 13C in the muscle tissue of each recruit. Specimens that spent a significant amount of time outside of the lagoon in the open ocean will have distinctly different isotopic ratios than those that stayed in estuarine waters. The mean pelagic larval duration of S. cf. elegans and S. caeruleus is 65 and 88 days respectively. If larvae reach the open ocean then they could potentially be transported 100s of kilometers.
- Understanding larval dispersal and connectivity within an amphidromous metapopulation is critical in making conservation decisions. As with many of the high islands of Oceania the watershed ecosystems of Pohnpei are under increasing pressure from farming activities. Maintaining the water quality of insular streams is critical to protecting the biodiversity of these unique habitats and this type of research will give natural resource managers additional tools for establishing effective land use regulations.
- Advisors: Dr. Frank Pezold, Dr. Thomas Shirley, Dr. Greg Stunz
Presentations and Publications
Hall, J. D. 2008. Systematics and ecology of leucothoid amphipods (Gammaridea) of the West Florida Shelf benthic ecosystem. (Submitted for consideration to the Journal of Crustacean Biology).
Texas A&M University - Corpus Christi, Graduate Scholarly Works Symposium 2008. Presentation: Ecology, Distribution, and Systematics of Leucothoid Amphipods of the West Florida Shelf Benthic Ecosystem.