Reef Fish Spatial Distribution And Benthic Habitat Associations On The Southeast Florida Reef Tract

The Florida Reef Tract (FRT) extends from the tropical Caribbean up the southeast coast of Florida into a temperate environment where tropical reef assemblages diminish with increasing latitude. This study used data from a three-year comprehensive fishery-independent survey to quantify reef fish spatial distribution along the Southeast FRT and define where the assemblage shifts from tropical to temperate. A total of 1,676 reef fish visual census samples were conducted to assess the populations on a stratified-random selection of sites of marine hardbottom habitats between the Miami River and St. Lucie inlet. Multivariate analyses were used to investigate differences in assemblages among sites. Depth (m), general habitat (reef or hardbottom), and slope (high or low) strata were examined to explain the dissimilarities between assemblages. A general trend of cold-tolerant temperate fish dominated the northern assemblages and more tropical species dominated further south. Seven reef fish assemblage biogeographic regions were determined. In shallow habitats the data clustered in three spatial regions: One south of Hillsboro inlet, one in Northern Palm Beach south of Lake Worth inlet, and one north of Lake Worth inlet. The assemblage in deep habitats mainly split in close proximity to the Bahamas Fracture Zone south of Lake Worth Inlet. The presence of reef habitat aided in splitting the southern assemblage regions from the northern all-hardbottom assemblage regions in both the shallow and deep habitats. Substrate relief was significantly correlated with the differences in the northernmost deep assemblages but did not appear to affect the remainder of the shallow and deep assemblages. This bioregional study creates a baseline assessment of reef fish assemblages of the Southeast FRT for future analyses.

[Truncated abstract] The goal of this work was to investigate the finescale habitat associations and determine the effect of human impacts on coral reef fish assemblages. Initially I investigate how finescale spatial habitat variation influences the distribution and abundance of coral reef fishes. Significant variation in the reef fish assemblage was driven by variation in habitat. Consequently finescale habitat variation needs be accounted for in spatial or temporal surveys of coral fish assemblages. My second question investigated how protection from fishing influences the overall variation in coral reef fish assemblages, while my third question investigated how consistent the differences in protected fish assemblages are through time. Protection from fishing accounted for significantly more variation in fish assemblages than that explained by finescale habitat alone. This was driven by an average abundance and length of target species being higher inside sanctuaries and a response in non-target species indicating that there are some trophic interactions occurring between fishes. I found that both target and non-target species can be more abundant at protected reefscapes through time, consistent with the theory that protected areas can achieve recovery and lasting maintenance of fish assemblage structure relative to adjacent fished locations. I also investigated how fish assemblages within shallow coral reef habitats differ to those of adjacent continental shelf habitats to a depth of 100m. Cross-shelf sampling produced significant new knowledge on the depth and habitat specificity of many species previously only known from shallow coral reef environments. Many target species protected by shallow water protected areas are found as adults in unpotected shelf waters suggesting shallow water protected areas alone may not be effective for all species equally. Expanded depth distributions for many species revealed some refuge at depth from shallow water climate related impacts, though it is uncertain how this might contribute to persistence in populations at a local or regional scale. Many species are confined to one or a few shallow water habitats for their entire post recruitment lifehistory as opposed to others that can range across many. Fish assemblages associated with deeper water habitats are composed of higher order predators and high numbers of unique species, suggesting they will respond very differently to shallow waters when impacted by fisheries. Diversity and unique species associated with deep water habitats approached those found at shallow coral reef habitats. Habitat specialization changes dramatically from species to species and was not easily predicted. This research holds a number of key implications. Firstly the design of coral reef marine protected areas and associated monitoring programs should account for variation in benthic habitat. Fishing and other human impacts affect significantly different elements of coral reef fish assemblages depending upon the biological and physical parameters of the benthic habitat found. Marine protected areas should incorporate this habitat variability wherever practical, as discrete elements of trophic structure were significantly associated with different habitats...

Seascape Ecology provides a comprehensive look at the state-of-the-science in the application of landscape ecology to the seas and provides guidance for future research priorities. The first book devoted exclusively to this rapidly emerging and increasingly important discipline, it is comprised of contributions from researchers at the forefront of seascape ecology working around the world. It presents the principles, concepts, methodology, and techniques informing seascape ecology and reports on the latest developments in the application of the approach to marine ecology and management. A growing number of marine scientists, geographers, and marine managers are asking questions about the marine environment that are best addressed with a landscape ecology perspective. Seascape Ecology represents the first serious effort to fill the gap in the literature on the subject. Key topics and features of interest include: The origins and history of seascape ecology and various approaches to spatial patterning in the sea The links between seascape patterns and ecological processes, with special attention paid to the roles played by seagrasses and salt marshes and animal movements through seascapes Human influences on seascape ecology—includes models for assessing human-seascape interactions A special epilogue in which three eminent scientists who have been instrumental in shaping the course of landscape ecology offer their insights and perspectives Seascape Ecology is a must-read for researchers and professionals in an array of disciplines, including marine biology, environmental science, geosciences, marine and coastal management, and environmental protection. It is also an excellent supplementary text for university courses in those fields.

Understanding the biogeography of reef fish assemblages is paramount to reef conservation, management, and conducting appropriate population survey designs. Reef fish assemblages are a multispecies complex of reef-associated fish and are shaped by multiple environmental and biological factors (e.g. temperature, depth, benthic habitat, and topographic relief), which determine the species constituents residing in an area. Assemblages typically change with latitude where the number of families, genera, and/or densities of species specific to warmer climates decrease poleward into colder climate regimes. The Florida Reef Tract (FRT) extends for 595 km from the Dry Tortugas in the south-west to Martin County in the north, crossing a sub-tropical to temperate climate transition. This study investigates the biogeography of reef fish assemblages throughout the FRT to determine if they correspond to previous regional delineations that were primarily based on coastal geomorphology. Multivariate density analyses show that depth, habitat, relief, and region are major factors in determining the assemblages. Four main ecoregions were evident based on depth, benthic habitat, relief and latitudinal region: Dry Tortugas (DT), Florida Keys (FK), Southeast mainland (SE), and Bahamas Fracture Zone (BF). DT split into four biogeographic assemblage regions primarily based on depth, and relief. FK split into five biogeographic assemblage regions with a sixth extending through Broward County primarily based on depth, habitat type, and relief. SE split into four biogeographic assemblage regions primarily based on depth, and region. BF split into three biogeographic assemblage regions primarily based on depth, and region. These sixteen assemblages represent the current composition of reef fish based on four factors. Numerous other factors also affect reef fish assemblages (e.g. past and present fishing pressure, mangrove nursery habitat, and coral death) that were not part of the analysis but are discussed. The final reef fish assemblage regions were associated with previous benthic habitat maps in order to view their spatial extent. Having a map of current biogeographic reef fish assemblages serves as a baseline and allows more accurate management and monitoring of future reef fish populations.

"This document provides the background behind and descriptions of the protocols developed for a collaborative, multi-agency effort to monitor reef fish populations in the Florida Keys and Dry Tortugas. Agencies involved include the National Oceanic and Atmospheric Administration Southeast Fisheries Science Center (NOAA Fisheries), Florida Fish and Wildlife Conservation Commission's Florida Fish and Wildlife Research Institute (FWRI), the University of Miami's Rosenstiel School of Marine and Atmospheric Science (UM-RSMAS), and the National Park Service (NPS). This collaborative effort is the culmination of nearly three decades of independent Florida Keys monitoring programs aimed at fish populations in the region"--Executive summary.

As marine protected areas (MPAs) become an increasingly popular method to address global declines of coral reef ecosystems, understanding how to gauge no-take reserve effectiveness through both simple metrics and spatially quantitative methods is imperative for robust design and management. In order to be an effective fisheries management tool, it must be shown that MPAs do not simply displace fishing effort, but can actually increase the biomass or density of fish in adjacent fisheries. Net export of adult fish to surrounding waters, termed the spillover effect, is one way MPAs may function to replenish fish stocks. The ability to detect the spillover effect using simple metrics of abundance and biomass for five highly targeted species was tested for an MPA in the US Virgin Islands. Moreover, it is equally important for managers to understand linkages between reef fish biomass patterns and associated habitat at multiple scales. Habitat characteristics that influence distribution patterns of targeted reef fish can be explored through spatial statistics and spatial multivariate models. In this study, the specific aim was to further evaluate seascape and local site habitat metrics to find how spatial scales of habitat composition and configuration can be used together cohesively to understand reef fish distribution patterns. In addition, global and local spatial regression models were compared to determine if there is non-stationarity of ecological processes across management zones. Results of this study reinforce the complexities of fish-habitat interactions, which make detection of spillover difficult using simple metrics. However, using a combination of both multi-scale spatial habitat metrics and local regression methods can aid in MPA management and design.

"Baseline mapping and quantitative assessment data are required prior to future permitted or un-permitted impacts in order to determine the pre-existing state of the benthic resources; therefore, it is imperative that these data be collected on the ecologically sensitive and economically valuable shallow-water coral reef habitats in southeast Florida. In southeast Florida, the nearshore reef habitats are most vulnerable to coastal construction activities and other anthropogenic impacts, therefore these habitats were the focus for this study. The study goals were to provide a spatially appropriate map of increased resolution and a regional quantitative characterization of nearshore benthic resources to evaluate differences in benthic communities between habitats and with latitude for the southeast Florida region of the Florida Reef Tract. This study is a snapshot habitat characterization providing the current status of shallow-water coral reef community composition. Additionally, these data can be used to reduce un-permitted impacts by informing marine zoning efforts and aid in the creation of new no-anchor zones"--Executive summary.

High-latitude reefs have been postulated as refugia, centers for resilience or the first areas to undergo re-organization under climate change. The Southeast Florida Reef Tract (SEFRT) is a high-latitude reef system (>25 °N) running parallel to the highly urbanized coastline of southeast Florida. With a benthic community comprised of a mixture of coral reef associated assemblages, the SEFRT is towards the northern limit of stony coral cover due to temperature constraints. This study analyzed spatial variations in benthic cover, spatiotemporal changes in the benthic community and the impact of spatial and temporal fluctuations in temperature on benthic cover on the SEFRT, from 2007-2016. Photographic data from two long term monitoring projects was used to calculate the percent cover of taxonomic assemblages in the benthic community. In situ temperature data and modelled data from HYCOM were used in combination to assess the impact of temperature fluctuations and thermal stress events. Data was split on a latitudinal gradient into six defined ecosystem regions based on biogeographic boundaries and at major port channels. These accounted for any possible range expansion and spatiotemporal variations on the SEFRT. Statistical analysis via generalized linear models (GLM) identified significant changes in the major benthic taxa, stony coral, octocoral, sponges and macroalgae. Ecosystem regions showed strong clustering by their taxonomic composition and this was in part created by temperature variation. Stony coral cover significantly declined on the SEFRT and a concomitant significant increase in macroalgae cover may create a negative feedback loop which hinders recovery. Spatiotemporal variations in benthic cover were found between ecosystem regions and thermal stress events, both hot and cold, had immediate and latent impacts on benthic cover. This has resulted in biotic homogenization on the SEFRT with a retraction of outlier regions towards the mean. Anthropogenically influenced high-latitude reefs are significantly impacted by thermal stress. As oceans continue to warm, populations expand, coastlines continue to develop and pollutants persist, the benefits of potential thermal refugia are negated.

Nearshore hardbottom reefs of Florida’s east coast are used by over 1100 species of fishes, invertebrates, algae, and sea turtles. These rocky reefs support reproduction, settlement, and habitat use, and are energy sources and sinks. They are also buried by beach renourishment projects in which artificial reefs are used for mitigation. This comprehensive book is for research scientists and agency personnel, yet accessible to interested laypersons including beachfront residents and water-users. An unprecedented collection of research information and often stunning color photographs are assembled including over 1250 technical citations and 127 figures. These shallow reefs are part of a mosaic of coastal shelf habitats including estuarine seagrasses and mangroves, and offshore coral reefs. These hardbottom habitats are federally designated as Essential Fish Habitats - Habitats of Particular Concern and are important feeding areas for federally-protected sea turtles. Organismal and assemblage responses to natural and man-made disturbances, including climate change, are examined in the context of new research and management opportunities for east Florida’s islands in the sand.