Predicting the locations of new biological invasions has become a high priority for biologists as well as trying to predict if newly introduced species will become damaging to native ecosystems. Reefs of the eastern oyster Crassostrea virginica in Mosquito Lagoon, Florida have been highly disturbed in recent years resulting in dead reefs (piles of dead, disarticulated shells) some of which have been restored. I conducted oyster reef surveys for non-native invertebrates to determine if disturbance on these oyster reefs might assist invasion by two species, Mytella charruana and Perna viridis, recently introduced to the southeastern coast of the United States. Next, I investigated if M. charruana's temperature and aerial exposure tolerance limits may allow for it to establish permanently on intertidal oyster reefs. Temperature and aerial exposure tolerance experiments were conducted and oyster reef temperatures were collected. Oyster reef surveys could not predict if reef disturbance is assisting in the invasion process because only two non-native individuals (P.viridis) were found, one on a restored reef and one on a natural (reference) reef. Tolerance experiments showed that some Mytella charruana survived even after 7 days of 8??C temperatures if the mussels are exposed to air for 4 hours or less per day. Mytella charruana had near 0% survival after 4 hours of 44??C. However, only disturbed reefs reached this temperature in the field. It is likely that M. charruana could survive in the low intertidal zone on restored or reference reefs. This information is important for understanding the introduction of M. charruana in Mosquito Lagoon and also provides a data set of temperature tolerances for better understanding of whether the species might be able to invade other areas.

Oyster reefs are biodiverse communities that provide many ecological and commercial benefits. However, oyster reefs have declined around the world from human activities. Oyster reef restoration programs have begun to limit some of the decline, but the need for determining the success of a program has been problematic. Passive acoustic techniques can use naturally occurring sounds produced by organisms to assess biodiversity. Passive acoustics was utilized to compare the sounds in natural and restored oyster reefs, with special attention on snapping shrimp (Alpheus spp.) snap sounds, in the St. Lucie Estuary, Florida over a one year period. Season, estuary region, habitat and day period had an effect on sound production. Passive acoustic monitoring of snapping shrimp sound production may be a useful non-destructive technique for monitoring the progress of oyster reef restoration projects once further correlations are established between environmental effects and sound production. / by Hilde P. Zenil Becerra. / Thesis (M.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2012. Mode of access: World Wide Web.

Oyster reefs support diverse estuarine communities and food webs. Factors controlling oyster reef community development were studied on restored reefs in the St. Lucie Estuary. Freshwater discharges create stresses that cause oyster mortality, habitat loss and reduction in reef community diversity. Using structural equation modeling, it was demonstrated that salinity, turbidity, and chlorophyll-a gradients influence oysters and some reef invertebrate species, but did not support the predictions of the Intermediate Disturbance Hypothesis. In contrast, diversity and species richness were greatest at low stress sites. A field experiment showed that topographic relief and architectural complexity enhanced colonization and growth of reef-building species (e.g.oysters and mussels). The relief by complexity interaction had a higher order, synergistic effect on oyster abundance. When considered separately, increasing relief further enhanced dominant sessile taxa (cirripeds and ascideans) ; while, increasing complexity supported greater species richness and the abundance of cirripeds. / by Elizabeth A. Salewski. / Thesis (M.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.