Kathleen Sullivan Sealey

Population Structure and Phylogeography in Nassau Grouper (Epinephelus striatus), a Mass-Aggregating Marine Fish

To address patterns of genetic connectivity in a mass-aggregating marine fish, we analyzed genetic variation in mitochondrial DNA (mtDNA), microsatellites, and single nucleotide polymorphisms (SNPs) for Nassau grouper (Epinephelus striatus). We expected Nassau grouper to exhibit genetic differentiation among its subpopulations due to its reproductive behavior and retentive oceanographic conditions experienced across the Caribbean basin. All samples were genotyped for two mitochondrial markers and 9 microsatellite loci, and a subset of samples were genotyped for 4,234 SNPs. We found evidence of genetic differentiation in a Caribbean-wide study of this mass-aggregating marine fish using mtDNA (FST = 0.206, p<0.001), microsatellites (FST = 0.002, p = 0.004) and SNPs (FST = 0.002, p = 0.014), and identified three potential barriers to larval dispersal. Genetically isolated regions identified in our work mirror those seen for other invertebrate and fish species in the Caribbean basin. Oceanographic regimes in the Caribbean may largely explain patterns of genetic differentiation among Nassau grouper subpopulations. Regional patterns observed warrant standardization of fisheries management and conservation initiatives among countries within genetically isolated regions.

Characterization of tropical near-shore fish communities by coastal habitat status on spatially complex island systems

SynopsisWe present a protocol for characterizing near-shore fish habitat as well as fish communities for Andros Island, Bahamas, a complex coastal-reef island system. Benthic assessments and beach seine surveys were carried out at sites varying in coastal and benthic characteristics. Temporal variability affected fish community composition, indicating that attempts to characterize a fish community should include sampling evenly across tides, times of day, and seasons. Univariate and multivariate analyses revealed that each site harbored a unique fish community, with the greatest variability within each site attributed to seasonal changes. Measures of diversity (Shannon–Weiner Index and number of species) were markedly different at sites with varying coverage of seagrass and macro-algae and extents of disturbance. Total abundance of fishes was positively related to the percent of bare sand. We suggest that thorough sampling of coastal fish communities can be applied to comparative and long-term studies. This protocol for the characterization of complex island habitats can be applied to ecological studies aimed at understanding the responses of fishes to small-scale changes in coastal areas and habitat structure due to land use and shoreline alterations.

Fish-environment associations in the coastal waters of Andros Island, The Bahamas

SynopsisWe surveyed fish communities and corresponding environmental conditions at three broadly similar coastal sites of eastern Andros Island, The Bahamas over a summer–winter–summer sequence to assess the relationship between detailed environmental features and fish species patterns. Environmental variables included covers of various benthic flora components, benthic flora diversity, floral canopy height, micro-crustacean diversity and density, water temperature, extent of destructive land-use and extent of invasion by human-introduced exotic terrestrial plants. Correspondence analysis (CA) indicated that spatial (site) differences in environmental characteristics were greater than temporal (seasonal) differences. Detrended canonical correspondence analysis (DCCA) was used to assess the strength of relationships between the environmental characteristics and the distribution patterns of 25 fish species. Environmental features deemed to be most important in influencing fish species patterns included benthic flora canopy height, extent of invasion by exotic terrestrial plants, cover of Batophora oerstedii, cover of Thalassia testudinum, turf cover, water temperature, micro-crustacean diversity, and micro-crustacean density. Based upon similarities in distribution patterns, fish species formed four clusters which, ultimately, reflected similarities in species’ feeding habits and preferences for habitats that likely maximize foraging success. We conclude that fish distribution patterns are related to environmental characteristics, and that anthropogenic coastal activity, by influencing coastal benthic characteristics, may influence the distribution and abundances of fish species in coastal habitats.

The Commonwealth of the Bahamas

Abstract The Commonwealth of The Bahamas covers a vast archipelago of low-lying carbonate islands and broad shallow banks. Although the bulk of the bank and island system occurs north of the Tropic of Cancer, the waters are warm, tropical, and largely oligotrophic. This unique ecosystem has a concentration of biological diversity along the bank platform margins and island environs, leaving marine resources vulnerable to land-based sources of pollution. The state of the marine and coastal resources of the country depends on detailed characterization and assessment focused on responses to storm events and the sea-level rise. The future of low-lying carbonate islands depends on careful biodiversity management and planning for resilience to climate change-related disturbances. The combination of applied research, outreach, and community engagement along with thoughtful policies and regulations will reduce impacts of disturbances and sustain resource use for future generations.

Relocate Verses Rebuild Decisions: Understanding the Importance of Coupled Systems

Weather-related events stress rich and poor neighborhoods alike, but flooding events in coastal ecosystems pose a greater financial and ecological disaster for low-income residents (see “Surging Seas” Submerged Risk Map that highlights the vulnerability of neighborhoods along the Miami River and west of the International Airport at http://ss2.climatecentral.org/#12/25.8268/-80.1509?show=sovi&level=5&pois=show). Flood disasters provide a special challenge for social, financial and ecological resilience. Fundamental decisions need to be made in a timely manner for the long-term viability of recovery: should residents rebuild or relocate? The resilience of a community to recover after flooding disaster depends very much on where the neighborhood is, and how the community is prepared for short-term and long-term prospects of recovery.

What Is Happening in Miami

Miami has been the center of recent discussions of sea level rise and its economic and environmental effects, but flooding events have always been part of Miami’s urban history. Much of the metropolitan mainland area was built upon lands reclaimed from the freshwater Everglades while significant portions of the coastal area are situated on land that was raised, or reclaimed, from Biscayne Bay. This Chapter describes how periodic hurricanes and nuisance flooding are reminders of the risks associated with selecting a location to build.

Will Miami Survive

Miami has been the center of recent discussions of sea level rise and its economic and environmental effects, but flooding events have always been part of Miami’s urban history. Much of the metropolitan mainland area was built upon lands reclaimed from the freshwater Everglades while significant portions of the coastal area are situated on land that was raised, or reclaimed, from Biscayne Bay. This Chapter describes how periodic hurricanes and nuisance flooding are reminders of the risks associated with selecting a location to build.

Paradise Lost: Environmental Change and Ecological Impacts

Miami Dade County is at the southern end of a large complex watershed from the central Florida Lake District to Florida Bay. Changes in the hydrology and water flow across the landscape allowed for the development of vibrant and expensive coastal real estate. Unfortunately, lessons learned on the role and value of ecosystems services came too late. The loss of valuable systems, like coastal dunes that sustain beaches, forced engineered solutions to protect the built environment. With sea level rise, the restoring of flood-regulating ecosystem services may be the key to survival for individual neighborhoods of MDC. This chapter outlines the ecological changes across South Florida, and examines the value of existing and restored wetlands in reducing flood risks. The value of ecosystems services changes across the built landscape, and these services require a source of funding to restore or expand freshwater and coastal wetlands.

Financial Drivers and Urban Coastal Development in Miami, Florida

Miami Dade County (MDC) urban centers have a unique geographic location between Biscayne Bay and the massive wetlands of the Everglades. Water can come from both sides of MDC as well as percolate up from the groundwater. Sea level rise (SLR) impacts all of these connected sources of water, meaning Miami will be faced with more severe and frequent flooding into the foreseeable future. This chapter will explain the connection between urban development, the expenditure of funds, and the role of financing. Financing is the underlying requirement to convert development planning into development action; thus, recovery from disasters requires linking environmental issues back to the financial system.

The Reefs of the Turks and Caicos Islands

The Turks and Caicos Islands lie at the southern end of the Bahamas archipelago and comprise six major islands around the northern edge of Caicos Bank and two west of the smaller Turks Bank. The margins of these banks are defined by sharp drop-offs into deep water on all sides and are fringed by coral reefs, mainly on their windward (eastern) sides. There are six ecotypes comprising true (accreting) coral reefs: bank patch reefs, near-shore patch reefs, channel reefs, near-shore fringing reefs, platform margin bank-barrier reefs, and platform margin deep reefs. Hard-bottom non-reefal habitats that contain corals but are not true accreting coral reefs are also present. Near-shore fringing and bank-barrier reefs have their crests close to sea-level, with Acropora and Millepora as the main reef builders, and have lagoonal environments in their lee, while deeper reefs are dominated by the corals Diploria, Montastrea, Porites and Agaricia. The narrow platform margin is characterized by two terraces, the shallow terrace sloping gradually from either the shoreline or fringing reef to about 8–10 m depth, where there is an appreciable increase in slope to about 15 m depth, coinciding with the seaward edge of spur-and-groove structure, where developed. The deep terrace has a depth of 15–20 m and consists of a narrow sand plain with isolated patch reefs and/or low-relief spur-and-groove reefs, beyond which there is a steep drop-off into deep water.