Presence of Potential Nursery Habitat for the Lemon Shark in Mississippi Coastal Waters

Advection of Karenia brevis blooms from the Florida Panhandle towards Mississippi coastal waters

Standards for the rapid detection of individual pathogens from environmental samples have not been developed, but in their absence, the use of molecular-based detection methods coupled with traditional microbiology techniques allows for rapid and accurate pathogen detection from environmental waters and sediment. The aim of this research was to combine the use of enrichment with PCR for detection of Salmonella in Mississippi coastal waters and sediment and observe if that presence correlated with levels of enterococci and climatological variables. Salmonella were primarily found in samples that underwent nutrient enrichment and were present more frequently in freshwater than marine waters. Salmonella were detected infrequently in marine and freshwater sediments. There was a significant positive correlation between the presence of detectable Salmonella and the average enterococcal count. An inverse relationship, however, was observed between the frequency of detection and the levels of salinity, turbidity and sunlight exposure. Results from this study indicated the presence of Salmonella in Mississippi coastal waters, and sediments are very low with significant differences between freshwater and marine environments. Using pathogenic and novel nonpathogenic molecular markers, Salmonella do not appear to be a significant pathogenic genus along the Mississippi Coast.

Bonefish (Albula spp.), Family Albulidae, occur worldwide in coastal waters of tropical and warm temperate seas (Crabtree et al. 1997), and 2 species, A. vulpes and A. nemoptera, are recognized from the western Atlantic Ocean (Rivas and Warlen 1967). The normal range of A. vulpes in the western Atlantic extends from Bermuda to Brazil, including the Bahamas, Cuba, Mexico, Central America and the Antilles (Hildebrand 1963), but in US waters, A. vulpes typically occurs off south Florida (Crabtree et al. 1997). In contrast, A. nemoptera has been reported from Panama, Colombia, Venezuela, Jamaica and Hispaniola (Uyeno et al. 1983). Published accounts of A. vulpes from the northcentral Gulf of Mexico (hereafter GOM) are rare. Ogren and Brusher (1977) collected a single specimen of A. vulpes from St. Andrew Bay, Florida but did not report its size. Thompson and Deegan (1982) reported the collection of 3 A. vulpes leptocephali (range: 34.8–53.5 mm standard length (SL)) from Louisiana coastal waters, and Boschung (1992) reported a single A. vulpes juvenile (37 mm SL) collected from Grand Bay, Alabama. We report the first record of A. vulpes from Mississippi.

Understanding the fundamental niche of invasive species facilitates our ability to predict both dispersal patterns and invasion success and therefore provides the basis for better-informed conservation and management policies. Here we focus on Nile tilapia (Oreochromis niloticus Linnaeus, 1758), one of the most widely cultured fish worldwide and a species that has escaped local aquaculture facilities to become established in a coastal-draining river in Mississippi (northern Gulf of Mexico). Using empirical physiological data, logistic regression models were developed to predict the probabilities of Nile tilapia survival, growth, and reproduction at different combinations of temperature (14 and 30°C) and salinity (0–60, by increments of 10). These predictive models were combined with kriged seasonal salinity data derived from multiple long-term data sets to project the species' fundamental niche in Mississippi coastal waters during normal salinity years (averaged across all years) and salinity patterns in extremely wet and dry years (which might emerge more frequently under scenarios of climate change). The derived fundamental niche projections showed that during the summer, Nile tilapia is capable of surviving throughout Mississippi's coastal waters but growth and reproduction were limited to river mouths (or upriver). Overwinter survival was also limited to river mouths. The areas where Nile tilapia could survive, grow, and reproduce increased during extremely wet years (2–368%) and decreased during extremely dry years (86–92%) in the summer with a similar pattern holding for overwinter survival. These results indicate that Nile tilapia is capable of 1) using saline waters to gain access to other watersheds throughout the region and 2) establishing populations in nearshore, low-salinity waters, particularly in the western portion of coastal Mississippi.

Movement patterns of spotted seatrout (Cynoscion nebulosus) were evaluated in Mississippi coastal waters by an angler-based tagging study from 1995 through 1999. During this period, 505 anglers tagged 15,206 spotted seatrout, the majority of which (84%) did not meet the state's legal minimum size limit of 14 inches (356 mm) total length. Overall, 408 (2.7%) tagged fish were recaptured and reported to project personnel. Over 90% of these recaptured fish moved less than 10 km from site of tagging to site of recapture (mean = 3.0 ± 0.41 km), and 82% moved less than 3 km. The greatest movement from tagging to recapture site by any fish was 60 km over a period of 200 d, and only three fish (0.7%) moved 50 km or more. Study results suggest that spotted seatrout in Mississippi waters comprise a nonmigratory fish stock, as has been found for this species in coastal waters of neighboring states along the U.S. Gulf of Mexico.

Ommastrephid squid paralarvae potential nursery habitat in the tropical-subtropical convergence off Mexico

Natural and Artificial Reefs in Mississippi Coastal Waters: Sport Fishing Pressure and Economic Considerations. Donnie L. Daniel and Joe E. Seward, Jr. Bureau of Business Research, School of Business Administration, University of Southern Mississippi, Hattiesburg, Mississippi 39401. Spring 1975. 27p

Diet of Tripletail, Lobotes surinamensis, from Mississippi Coastal Waters

New Observations of Common Snook, Centropomus undecimalis, in Mississippi Coastal Waters, with a Summary of Local Records

The effects of algae species and densities on the population growth of the marine rotifer, Colurella dicentra

Observations on the distribution and seasonality of common coastal portunid megalopae are presented. Callinectes sapidus megalopae were abundant from May through November. The megalopae of C. similis, though present throughout the year, peaked in numbers from February through April. With the exception of January, Portunus spp. megalopae occurred in all months, with maximum numbers collected in April. Callinectes sapidus megalopae commonly occurred at all stations, whereas, the megalopae of C. similis and Portunus spp. appeared to be limited by salinity.

Stomach contents analysis was used to quantitatively describe the diets of juvenile lane snapper, Lutjanus synagris, and juvenile gray snapper, Lutjanus griseus, from the northern Gulf of Mexico. Juvenile snapper were collected by trawling at two estuarine, deep channel sites in Mississippi coastal waters from September 1996 to January 1997. Lane snapper (n = 53) and gray snapper (n = 12) both consumed a variety of prey organisms, but primary prey were amphipods, decapods (shrimp and crabs), and fishes. The most important prey items for lane snapper based on percent Index of Relative Importance (%IRI) were shrimp remains (44%IRI), the shrimp Latreutes parvulus (23%IRI) and fish remains (13%IRI). Fishes of the genus Anchoa (43%IRI), shrimp remains (21%IRI) and the amphipod Corophium sp. (13%IRI) dominated the gray snapper diet. Intraspecific comparisons of lane snapper diet revealed significant overlap between collection sites, seasons and fish sizes.

Hermit crabs, the gastropod shells that they inhabit, and associated epifauna constitute a motile microhabitat. Twenty-three macroscopic. epifaunal invertebrates were associated with the diogenid crab Clihanarius vittatus in Mississippi coastal waters. Epibiotic growth may discourage predation of the crab, reduce competition for the shells, or provide an advantage in agonistic shell interaction. In addition, the shell provides a hard substrate for settling and attachment of epifauna in an area that is largely devoid of hard substrate. Reduced sedimentation and prevention of shell burial, improved food availability, transport, and protection from predation may also be advantageous to the epizoans.

The Spotted Seatrout Cynoscion nebulosus is the most popular target of recreational inshore fisheries in Mississippi coastal waters. The Gulf of Mexico (GOM) stock of Spotted Seatrout is composed of spatially distinct substocks, and each state imposes unique bag and size limits. In Mississippi, the stock is managed using minimum length limits and daily bag limits. We used two methods to evaluate the efficacy of length restrictions and fishing mortality (F) levels: (1) a per-recruit model simulation to evaluate the effects of proposed management actions on reproductive output and yield, and (2) an evaluation of how management regimes impact relative stock density (RSD). Relative stock density has been widely used as a management tool in recreational and generally freshwater fisheries but has not been widely employed in informing management of marine stocks. We used demographic information from fisheries-independent sampling and length-specific natural mortality estimates to construct both models. Our analysis suggested that decreased F, increased minimum length limits, and slot limits that include intermediate upper length limits could increase RSD measures for GOM Spotted Seatrout. We found that for all management regimes examined, local demographic properties of Spotted Seatrout may preclude large proportions of trophy-length (≥686 mm TL) individuals. Per-recruit modeling and RSD analysis are complementary approaches to inform management, as they consider spawning stock biomass, yield, and the maximization of angler satisfaction. Received October 6, 2015; accepted June 8, 2016 Published online September 13, 2016

Temporal and spatial distributions of nutrients and trace elements (Ba, Cs, Cr, Fe, Mn, Mo, U, V and Re) in Mississippi coastal waters: Influence of hypoxia, submarine groundwater discharge, and episodic events