The islands of Bonaire and Curacao, Dutch Caribbean, were both mapped along their leeward coasts for dominant coral community and other benthic cover in the early 1980s. This mapping effort offers a unique baseline for comparing changes in the benthic community of the two islands since that time, particularly given the marked differences between the two islands. Bonaire is well-protected and completely surrounded by a marine protected area (MPA), which includes two no-diving marine reserves; additionally, Bonaire's population is only around 15,000. In contrast, the island of Curacao is home to 140,000 inhabitants and marine protection is limited, with a reef area of 600 ha established as a "paper" park (i.e., little enforcement). Video transects collected by SCUBA over the reefs were collected on Bonaire in January of 2008; when compared to data from 1985, coral cover had declined in the shallowest portion of the reef (< 5 m) and was mostly the result of declines in Acropora spp., whereas head corals increased. Transects closest to the no-diving marine reserves showed higher coral cover and diversity than transects located farther from the reserves. Satellite remote sensing techniques were used to create landscape-scale reef maps along the leeward coasts of both islands, which could differentiate areas of high hard coral cover (> 20%), predominantly sand (> 50%) and areas where hard coral and sand were mixed with soft corals, sea whips and marine plants. These modern maps (2007-09) were groundtruthed using the video data collected on Bonaire for accuracy and then compared to the early 1980s maps of the reefs on both islands. Bonaire experienced declines in coral cover overall and the remaining coral was increasingly patchy; however, changes in patch characteristics were not significant over the time period, but status as a marine reserve and the sheltering of the shoreline did appear to buffer against coral loss. Surprisingly, the island of Curacao did not experience a decline in total coral cover, but did become increasingly patchy, significantly more so than Bonaire. The Curacao Underwater Park afforded no additional protection against coral loss or fragmentation than an adjacent unprotected area of reef. The difference between the two islands in coral loss versus fragmentation has the potential for a unique natural experiment to study the effects of habitat fragmentation in the absence of overall habitat loss at the landscape scale. The Bonaire National Marine Park could benefit by restricting visitors to its most frequented dive sites by increasing the cost of entry into a tiered pay system, thus generating more income for education and management of the park, as well as deterring some divers from these overused sites. Satellite remote sensing-derived maps are useful for rapid reef mapping and can be utilized for comparison to ancillary maps created by more traditional methods. Satellite-derived maps can only distinguish benthic habitats coarsely (3-4 habitat classes) and are only as reliable as their source data, they benefit greatly from fieldwork to determine depth, geographic location, and benthic habitat cover in real time.

No description available.

No description available.

The threat to biodiversity posed by increasing rates of anthropogenic habitat fragmentation necessitates an understanding of the consequences of spatial pattern for natural communities. Reduction of patch size, loss of habitat, changes in the quantity and proportion of habitat edge, and reduced connectivity among habitats can all shape ecological processes and faunal behavior. Seagrass habitats provide a natural model system for examining spatial inf1uences on marine fauna, but separating the effects of habitat structure, environmental conditions, and spatial pattern is difficult because shoot density, percent cover, and hydrodynamic regime often co-vary with patch size. This study used experimentally manipulated seagrass patches to measure the response of seagrass-associated fauna to patch size and bed fragmentation on the scale of meters. Replicate plots were created by transplanting eelgrass, Zostera marina, at two sites in the lower Chesapeake Bay, USA. Plots were designed to examine effects of patch size and bed fragmentation on the density of epibenthic decapod and peracarid crustaceans (crabs, shrimps, amphipods, and isopods), gastropods, and demersal fish. Densities of most species examined did not vary significantly among fragmented and unfragmented plots, or among plots with differing amounts of habitat area. Furthermore, seasonal edge effects were observed within both fragmented and unfragmented plots for five amphipod crustaceans (Atnpithoe longimana, A. valida, Caprella penantis, Elasmopus levis, and Microprotopus raneyi), the gastropod Mitrella lunata, and blue crab postlarvae, indicating that the processes regulating small-scale distribution within seagrass plots were insensitive to meter-scale habitat patchiness. In addition, two isopods (Edotea triloha and Erichsonella attenuata), the gastropod Nassarius vibex, and the amphipod Erichthonius brasiliensis exhibited edge effects within individual plot types, with few commonalities to suggest that any particular habitat configuration promotes edge effects. In 24 of 27 instances (species - plot type combinations) where effects of plot edges were detected, faunal densities were higher near plot edges than in their interiors. High densities in plot edges were not accompanied by higher overall densities in plots with greater proportions of habitat edges, suggesting that the processes regulating the distribution of individuals among plots are distinct from within-plot processes. Secondary production of epifauna, estimated from size distribution data, was not significantly affected by fragmentation treatments. Although commonly employed faunal categorizations such as body size, mobility, and trophic position did not completely predict response to fragmentation, all of the species exhibiting edge effects were among the smallest and least mobile of those studied. The results suggest that fragmented patches, which are common features of the Chesapeake Bay's seagrass habitat, support a dense faunal assemblage, and that seagrass habitat edges may be zones of enhanced faunal density. Far from supporting a positive influence of seagrass fragmentation, the results indicate that at the scale studied, there is little compensation for habitat loss via enhanced faunal densities in edges. Since fragmented and unfragmented plots support similar faunal densities, total abundances are lower in fragmented plots due to the loss of seagrass area. The mechanisms by which spatial pattern influences faunal dynamics, and the effects of fragmentation at larger scales remain subjects for future research.

Macrofauna-based biocriteria to assess impairment in aquatic communities are well-developed and have been widely accepted as useful for coastal monitoring programs worldwide. Meiofauna-based methods are not as well developed, but meiofauna are intimately associated with sediments through their life cycles and are functionally important. Thus, an understanding of meiofauna relationships with environmental quality is also important. Relationships between the abundance and composition of major meiofauna taxa for two shallow water habitat types (protected, with muddy sediment; exposed, with sandy sediment) were investigated along gradients associated with changing land use, sediment contamination and environmental stressors in Chesapeake Bay. Principal component analysis shows that urbanization, eutrophication and sediment contamination affect shallow water sites in the lower Chesapeake Bay, Virginia ecosystem. Multidimensional scaling ordination of meiofauna community data reveals gradients associated with human activities and major habitat types. Both sediment enrichment (high percent organic carbon and percent nitrogen) and sediment toxicity were associated with shifts in meiofauna community composition in muddy sediment. Benthic Foraminifera, known to be pollution sensitive, were rare or absent in collections from sites with sediment enrichment or toxicity. Nematodes were abundant at a site with enrichment, but not at a site with significant sediment toxicity. Major meiofauna taxa also differed clearly between protected and exposed sites, with greater abundances in collections from mud versus sand sediment. Results of analyses matching biotic to environmental patterns point to the importance of regional historic salinity and chlorophyll-a levels in addition to other habitat properties, including sediment organic carbon, total nitrogen and sediment toxicity as predictors of meiofauna community structure. The Benthic Index of Biotic Integrity (B-IBI) developed for Chesapeake Bay based on macrofauna was negatively correlated with nematode abundance at muddy sites when a site with significant sediment toxicity was excluded. There were no other significant relationships between meiofauna metrics and the B-IBI. The ratio of nematodes to copepods was not effective for discriminating relationships among sites relative to anthropogenic effects.

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No description available.

Coastal habitats provide crucial nursery habitat for predatory fishes, but they are in decline worldwide, impacting economically important fisheries. Habitat restoration can simultaneously mitigate the effects of habitat loss and benefit predators (e.g., sportfish), although this relationship is understudied. Here, the response of juvenile sportfish to oyster reef and living shoreline restoration is compared to controls in the Indian River Lagoon, Florida prior to and following restoration for up to three years through examination of community (diversity, assemblage), population (abundance), biometric (size, body condition), ontogenetic, and trophic (gut contents, stable isotopes) dynamics. Stable isotopes were used to quantify dietary history, beyond the temporary record of gut content, using carbon (δ13C) and nitrogen (δ15N). This study found juvenile sportfish abundance and richness was higher at restored reefs compared to natural and degraded reefs and was comparable between stabilized and natural living shorelines. Biomass was higher at oyster reefs compared to living shorelines, which was likely driven by an ontogenetic shift of larger mangrove snapper Lutjanus griseus toward oyster habitat. Snappers and prey at live reefs were carbon (δ13C) enriched, with a smaller isotopic niche area compared to dead reefs, while restored reefs were intermediate and contracted over time. Therefore, sportfish at higher quality reefs likely exhibit greater site fidelity, particularly among less-mobile juveniles. Moreover, stabilized shorelines can achieve trophic equivalence to natural shorelines, as shown through their similar isotopic signatures and niche area. These responses were best predicted by benthic habitat (e.g., oyster density), prey abundances, and site location, demonstrating the connection between habitat quality and setting to provide prey that support sportfish populations. This study validates the benefits of habitat restoration to economically important fisheries, by augmenting various attributes of juvenile sportfish life history, which can improve their survival and recruitment into the adult population, and thus extend restoration outcomes.

Intraspecific phenotype diversity allows for local adaption and the ability for species to respond to changing environmental conditions, enhancing survivability. Phenotypic variation could be stochastic, genetically based, and/or the result of different environmental conditions. Mojave Rattlesnakes, Crotalus scutulatus, are known to have high intraspecific venom variation, but the geographic extent of the variation and factors influencing venom evolution are poorly understood. Three primary venom types have been described in this species based on the presence (Type A) or absence (Type B) of a neurotoxic phospholipase A2 called Mojave toxin and an inverse relationship with the presence of snake venom metalloproteinases (SVMPs). Individuals that contain both Mojave toxin and SVMPs, although rare, are the third, and designated Type A + B. I sought to describe the proteomic and transcriptomic venom diversity of C. scutulatus across its range and test whether diversity was correlated with genetic or environmental differences. This study includes the highest geographic sampling of Mojave Rattlesnakes and includes the most venom-gland transcriptomes known for one species. Of the four mitochondrial lineages known, only one was monophyletic for venom type. Environmental variables poorly correlated with the phenotypes. Variability in toxin and toxin family composition of venom transcriptomes was largely due to differences in transcript expression. Four of 19 toxin families identified in C. scutulatus account for the majority of differences in toxin number and expression variation. I was able to determine that the toxins primarily responsible for venom types are inherited in a Mendelian fashion and that toxin expression is additive when comparing heterozygotes and homozygotes. Using the genetics to define venom type is more informative and the Type A + B phenotype is not unique, but rather heterozygous for the PLA2 and/or SVMP alleles. Intraspecific venom variation in C. scutulatus highlights the need for fine scale ecological and natural history information to understand how phenotypic diversity is generated and maintained geographically through time.

Sea level rise (SLR) has become a serious threat for coastal communities in recent years. Many communities, including South Florida, are already having the security of their daily lives impacted as climate change causes SLR and other environmental impacts to worsen. This study reviews the Miami-Dade Sea Level Rise Task Force Report to determine how this coastal county government views SLR as a threat. Using mixed content analysis to analyze the report qualitatively and quantitatively, the Task Force's recommendations are categorized based on their focus on security, infrastructure, economics, and the environment. One finds the concerns of the people to maintain their property and infrastructure, as well as their access to water and other basic needs, as insurance costs spike and funding becomes more difficult to obtain. Policies will have to be revised using updated scientific studies, modeling, and mapping to mitigate against the worse-case scenarios.