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The physiological tolerances of invasive species can be important predictors of geographic range expansion. Further, determining salinity tolerances can inform natural resource managers as to the ability of a freshwater species to invade estuarine habitats. Native to South America, the island apple snail Pomacea maculata (family Ampullariidae) is an invasive freshwater gastropod that is currently established across much of the southeastern United States, including South Carolina. The island apple snail is considered an invasive species because of the negative impacts of its intense grazing, high fecundity, and ability to out-compete native species. Further, the island apple snail can also serve as a potential to host the rat lungworm nematode parasite (Angiostrongylus cantonensis), which can cause eosinophilic meningitis in humans. Despite these known potential impacts, knowledge of biology of P. maculata in South Carolina is limited. The objective of this study was to determine the salinity tolerance of P. maculata hatchlings. Although previous studies on the salinity tolerance of P. maculata have been conducted, physiological tolerances can often vary regionally. Because of this potential for regional differences in salinity tolerance, determining the salinity tolerance of P. maculata specific to South Carolina is important in improving the understanding of its invasion/dispersion potential among brackish habitats in South Carolina. This knowledge will help resource managers to develop more effective control and/or eradication strategies. Newly hatched P. maculata obtained from egg clutches deposited by adult snails in a biosecure laboratory were placed in each of five salinity treatments (0, 4, 8, 12, and 16), and mortality was assessed daily for 14 days. Intraspecific variation at the regional scale in salinity tolerance has been documented in other species; thus, the survival of hatchlings from four separate mating pairs was assessed. Kaplan-Meier survival analysis was conducted to determine median survival probabilities, and differences in mean survival were determined using Kruskal-Wallis tests with post hoc Dunn's tests. An L[D.sub.50] value was determined by conducting a logistic regression analysis. A survival of 100% was observed at 0 salinity and 0% survival was observed at salinities of both 12 and 16. Survival probabilities at salinities of 4 and 8 were 0.925 and 0.156, respectively. There were no differences in survival among hatchlings from the different mating pairs. In relation to salinity, an L[D.sub.50] value of 6.39 was calculated. These results demonstrate the ability of P. maculata to survive salinities as high as 8, suggesting that this species could be capable of becoming established in upstream estuarine habitats in coastal South Carolina. KEY WORDS: Pomacea maculata, gastropod, freshwater, non-native, Ampullariidae, INTRODUCTION The ability to predict accurately an invasive species' potential range of impact is paramount in risk assessment, monitoring, and overall management (Stohlgren & Schnase 2006). Further, the physiological tolerances [...]

After going unreported in the northwestern Atlantic Ocean for 18 years (1988 to 2006), the Asian tiger shrimp, Penaeus monodon, has recently reappeared in the South Atlantic Bight and, for the first time ever, in the Gulf of Mexico. Potential vectors and sources of this recent invader include: 1) discharged ballast water from its native range in Asia or other areas where it has become established; 2) transport of larvae from established non-native populations in the Caribbean or South America via ocean currents; or 3) escape and subsequent migration from active aquaculture facilities in the western Atlantic. This paper documents recent collections of P. monodon from the South Atlantic Bight and the Gulf of Mexico, reporting demographic and preliminary phylogenetic information for specimens collected between North Carolina and Texas from 2006 through 2012. The increased number of reports in 2011 and 2012, ranging from 102 mm to 298 mm total length, indicates that an adult population is present in densities sufficient for breeding, which is indicative of incipient establishment. Based on these reports of P. monodon, its successful invasion elsewhere, and its life history, we believe that this species will become common in the South Atlantic Bight and Gulf of Mexico in less than 10 years. Penaeus monodon is an aggressive predator in its native range and, if established, may prey on native shrimps, crabs, and bivalves. The impacts of an established P. monodon population are potentially widespread (e.g., alterations in local commercial fisheries, direct and indirect pressures on native shrimp, crab and bivalve populations, and subsequent impacts on the populations of other predators of those organisms) and should be considered by resource managers. The impacts of P. monodon on native fauna and the source(s) or vector(s) of the invasion, however, remain unknown at this time. [ABSTRACT FROM AUTHOR]

We examined the recovery of vegetation and salt marsh macrofauna in a pipeline construction corridor at two locations where it intersected intertidal salt marshes near Charleston, SC. The impacts of construction were evaluated prior to construction and for subsequent periodsof 34 and 46 months at the two sites using aerial photography and three field sampling methods. Quadrats were used to estimate densities of selected salt marsh invertebrates, as well as stem densities and aboveground wet-weight biomass of Spartina alterniflora; pit traps were employed to simulate natural tidal pools for sampling small, motileepibenthic macrofauna that remained on the marsh surface at low tide; and flume nets were used to sample the natant macrofauna that used the marsh edge at high tide. The analyses of vegetation by quadrat and aerial imagery clearly showed that the recovery of Spartina was more rapid and complete at the Ashley River site (88%) than at Wappoo Creek (48%). In contrast to this apparent, if partial, vegetative recovery, several salt marsh invertebrates, including Littorina irrorata and Geukensia demissa, were eliminated from the corridor during construction and showed scant recovery by the end of our study. Differencesin species composition and abundance of natant organisms in the flume net collections also supported the conclusion that faunal recovery was incomplete after 3--4 years at these sites. The recovery of functional equivalency of the excavations, compared with natural marshes, was not evaluated during our study, but we speculate that their functioning may equilibrate over time, since preexisting hydrologic conditions are more or less intact, seedstock for Spartina revegetation is nearby, and macrofauna will probably eventually reestablish themselves from adjacent areas. [ABSTRACT FROM AUTHOR]