H. wrightii from Florida Bay was used for comparison. H. wrightii with a high level of genetic diversity has the best chance of adapting to a recipient site after being transplanted to Galveston Bay, Texas, which has lost over 90 percent of its seagrass since 1956. Seagrass beds are economically important because they provide a nursery habitat for 28 percent of commercial fish species and 30 percent of blue crab and shrimp populations in Galveston Bay. Isozyme analysis had shown that H. wrightii populations in Texas had low genetic diversity. RAPD is more sensitive to detecting genetic diversity than isozymes because it samples coding and noncoding sections of the genome.
Genetic diversity is determined by the presence or absence of a band at a particular locus.
RAPD revealed a high level of genetic diversity. All individuals appeared to have unique genotypes. Corpus Christi clustered more closely to Florida Bay than to Christmas Bay. These results were not expected since Corpus Christi and Florida Bay are separated by 1600 km whereas Corpus Christi is only 400 km from Christmas Bay. The similar habitats of Corpus Christi and Florida Bay may be acting as a selection agent or mating time may differ between Christmas Bay and Corpus Christi thus preventing gene flow.