Life Sciences Commons^™

A Decade Of Changes For Virginia Freshwater Aquaculture (1993-2003), Scott H. Newton

Virginia Journal of Science

Aquaculture surveys were designed and initiated along with the writing of the State Aquaculture Plan during 1993 to 1995. The first Virginia Aquaculture Survey, conducted for the production year 1993, established the status of both freshwater and marine commercial industries. Subsequent surveys were conducted to trace industry developments relevant to production aspects and economic impacts. Survey data from Virginia Agricultural Statistics Service Reports for 1993, 1995, 1997, and 2003 summarize a decade of Virginia freshwater aquaculture information. Significant changes in sales among the principal aquaculture species occurred over the 10-year period. The 1993 freshwater aquaculture value of $2.8 million increased …

Gis And 3d Analysis Applied To Sea Turtle Mortalities And Navigation Channel Dredging, Bradley A. Shellito, Keith B. Lockwood

Virginia Journal of Science

Between 2000 and 2003 there were an increased number of documented sea turtle mortalities related to hopper dredging in the channels of the Chesapeake Bay. A pilot study was undertaken to create a bathymetric surface and three-dimensional model of the Cape Henry Channel using Geographic Information Systems (GIS) as a visualization tool to examine sea turtle mortalities in relation to the dredging. In Fall 2003, the US Army Corps of Engineers dredged the Thimble Shoals Federal Navigation Channel, and a more refined model was developed using this data. This project examines the growing concerns over sea turtle mortality rates and …

Benthic Nutrient Flux In A Small Estuary In Northwestern Florida (Usa), Guy T. Didonato, Emile M. Lores, Michael C. Murrell, Lisa M. Smith, Jane M. Caffrey

Gulf and Caribbean Research

Benthic nutrient fluxes of ammonium (NH₄⁺), nitrite/nitrate (NO₂^- + NO₃^-), phosphate (PO₄^-3), and dissolved silica (DSi) were measured in Escambia Bay, an estuary within the larger Pensacola Bay system of northwestern Florida (USA). Our study occurred during a severe drought which reduced riverine inputs to Escambia Bay. Laboratory incubations of field-collected cores were conducted on 8 dates between June and October 2000 to estimate nutrient flux, and cores were collected from locations exhibiting a range of sediment organic matter content. NH₄⁺ flux ranged from – 48.1 to …

Feeding Habits Of Common Snook, Centropomus Undecimalis, In Charlotte Harbor, Florida, David A. Blewett, Rebecca A. Hensley, Philip W. Stevens

Gulf and Caribbean Research

We examined the feeding habits, ontogenetic and seasonal diet variations, and predator size–prey size relationships of common snook, Centropomus undecimalis, in Charlotte Harbor, Florida, through stomach contents analysis. A total of 694 stomachs were extracted from common snook (300–882 mm standard length [SL]) during a 24-month period (March 2000–February 2002); 432 stomachs contained prey items. At least 37 prey taxa were identified, including 19 that had not been previously reported. Fishes made up 71% of the prey by number and 90% by weight. Three prey items made up almost 50% of the diet numerically—Lagodon rhomboides, Anchoa spp., …

Comparison Of Fish Assemblages And Water Quality In Two Marinas In The British Virgin Islands, Brian Gratwicke, Martin R. Speight

Gulf and Caribbean Research

Eutrophication is a widespread problem in tropical marine environments that leads to the increase of nutrients in a water body, usually nitrate and phosphate, and is usually associated with the discharge of untreated sewage, intensive farming or fertilizer-enriched agricultural runoff (Wu 1999). Common symptoms are increased N and P levels, increased macroalgal production in shallow areas, reduced dissolved oxygen, loss of seagrass and coral habitats and changes in the fish community (Hallock and Schlager 1986, Granelli et al. 1990, Valiela 1995, Hemminga and Duarte 2000). Direct chemical testing to establish pollution levels can be difficult because of sharp pollution gradients, …

Body Size Of The Endosymbiotic Pea Crab Tumidotheres Maculatus: Larger Hosts Hold Larger Crabs, Karen Kane, Gregory S. Farley

Gulf and Caribbean Research

The endosymbiotic pea crab, Tumidotheres maculatus, uses a broad range of host taxa, including several bivalve species, in the northern Gulf of Mexico. Because shelter size affects the size of other, free-living crab species, we hypothesized that pea crabs living in larger bivalve hosts should attain larger sizes. Crabs and hosts collected from 3 field sites in northern Florida show this trend. We examined crabs living in a large host, the pen shell Atrina rigida, and found them to be larger than pea crabs living in a small host, the bay scallop Argopecten irradians. Moreover, this trend …

Marionia Tedi Ev. Marcus, 1983 (Nudibranchia, Tritoniidae) In The Gulf Of Mexico: First Record Of An Opisthobranch Mollusk From Hydrocarbon Cold Seeps, Angel Valdes

Gulf and Caribbean Research

Cold seeps in the Gulf of Mexico contain relatively diverse molluscan assemblages primarily composed of species that support chemoautotrophic symbionts, such as vesicomyid and mytilid bivalves, but also numerous species of shelled gastropods, bivalves, monoplacophorans, and polyplacophorans (Cordes 2004).

Recent exploration of hydrocarbon seep sites in the Mississippi Canyon and the Vioska Knoll revealed the presence of an unidentified species of nudibranch. The present paper describes the single specimen collected, which constitutes the first published record of an opisthobranch mollusk from a cold seep. The material examined is deposited at the Field Museum of Natural History (FMNH).

New Records For Cubanocuma Gutzui Băcescu And Muradian, 1977 (Crustacea: Cumacea: Nannastacidae) From The Western Atlantic, Richard W. Heard, Joel W. Martin, Thomas J. Hansknecht, Donald B. Cadien

Gulf and Caribbean Research

Because the original description and many subsequent records for Cubanocuma gutzui have appeared in a Romanian journal, Travaux du Muséum d’Histoire naturelle “Grigore Antipa,” which has limited distribution in the west, many workers studying tropical western Atlantic crustaceans still remain unaware of both the genus and species. Also, the species may have gone unrecognized (recorded as an odd specimen of Campylaspis, for instance) or may have been overlooked because of its small size. As part of an ongoing survey of the marine invertebrates of Guana Island, British Virgin Islands (BVI) (led by T.L. Zimmerman and J.W. Martin), numerous specimens …