Temporal trends (2000–2011) and influences on fishery-independent catch rates for loggerhead sea turtles (Caretta caretta) at an important coastal foraging region in the southeastern United States

Seasonal trawling was conducted randomly in coastal (depths of 4.6–17 m) waters from St. Augustine, Florida, (29.9°N) to Winyah Bay, South Carolina (33.1°N), during 2000–03, 2008–09, and 2011 to assess annual trends in the relative abundance of sea turtles. A total of 1262 loggerhead sea turtles (Caretta caretta) were captured in 23% (951) of 4207 sampling events. Capture rates (overall and among prevalent 5-cm size classes) were analyzed through the use of a generalized linear model with log link function for the 4097 events that had complete observations for all 25 model parameters. Final models explained 6.6% (70.1–75.0 cm minimum straight-line carapace length [SCLmin]) to 14.9% (75.1–80.0 cm SCLmin) of deviance in the data set. Sampling year, geographic subregion, and distance from shore were retained as significant terms in all final models, and these terms collectively accounted for 6.2% of overall model deviance (range: 4.5–11.7% of variance among 5-cm size classes). We retained 18 parameters only in a subset of final models: 4 as exclusively significant terms, 5 as a mixture of significant or nonsignificant terms, and 9 as exclusively nonsignificant terms. Four parameters also were dropped completely from all final models. The generalized linear model proved appropriate for monitoring trends for this data set that was laden with zero values for catches and was compiled for a globally protected species. Because we could not account for much model deviance, metrics other than those examined in our study may better explain catch variability and, once elucidated, their inclusion in the generalized linear model should improve model fits.

Strandings as indicators of marine mammal biodiversity and human interactions off the coast of North Carolina

The adjacency of 2 marine biogeographic regions off Cape Hatteras, North Carolina (NC), and the proximity of the Gulf Stream result in a high biodiversity of species from northern and southern provinces and from coastal and pelagic habitats. We examined spatiotemporal patterns of marine mammal strandings and evidence of human interaction for these strandings along NC shorelines and evaluated whether the spatiotemporal patterns and species diversity of the stranded animals reflected published records of populations in NC waters. During the period of 1997–2008, 1847 stranded animals were documented from 1777 reported events. These animals represented 9 families and 34 species that ranged from tropical delphinids to pagophilic seals. This biodiversity is higher than levels observed in other regions. Most strandings were of coastal bottlenose dolphins (Tursiops truncatus) (56%), harbor porpoises (Phocoena phocoena) (14%), and harbor seals (Phoca vitulina) (4%). Overall, strandings of northern species peaked in spring. Bottlenose dolphin strandings peaked in spring and fall. Almost half of the strandings, including southern delphinids, occurred north of Cape Hatteras, on only 30% of NC’s coastline. Most stranded animals that were positive for human interaction showed evidence of having been entangled in fishing gear, particularly bottlenose dolphins, harbor porpoises, short-finned pilot whales (Globicephala macrorhynchus), harbor seals, and humpback whales (Megaptera novaeangliae). Spatiotemporal patterns of bottlenose dolphin strandings were similar to ocean gillnet fishing effort. Biodiversity of the animals stranded on the beaches reflected biodiversity in the waters off NC, albeit not always proportional to the relative abundance of species (e.g., Kogia species). Changes in the spatiotemporal patterns of strandings can serve as indicators of underlying changes due to anthropogenic or naturally occurring events in the source populations.

Spatial and temporal variability in the distribution and abundance of larval and juvenile fishes associated with pelagic Sargassum

A survey of the larval and juvenile fishes associated with the pelagic Sargassum habitat in the South Atlantic Bight and adjacent western Atlantic Ocean was conducted from July 1991 through March 1993. Fishes representing 104 taxonomic categories were identified, including reef fishes, coastal demersal, coastal pelagic, epipelagic and mesopelagic species. The most important families were Balistidae and Carangidae, each represented by 15 species. Species composition, species diversity and abundance varied both seasonally and regionally. Diversity was highest during spring through fall over the outer continental shelf and in the Gulf Stream. Abundance decreased from spring through winter and from the continental shelf into offshore waters. The numbers of fishes and fish biomass were found to be positively correlated with the wet weight of algae in most cases examined. The results of this study will be useful to fisheries managers assessing the potential impacts of commercial Sargassum harvesting in the region.

Spatial and temporal analysis of bottlenose dolphin strandings in South Carolina, 1992-2005

This CD contains summary data of bottlenose dolphins stranded in South Carolina using a Geographical Information System (GIS) and contains two published manuscripts in .pdf files. The intent of this CD is to provide data on bottlenose dolphin strandings in South Carolina to marine mammal researchers and managers. This CD is an accumulation of 14 years of stranding data collected through the collaborations of the National Ocean Service, Center for Coastal Environmental Health and Biomolecular Research (CCEHBR), the South Carolina Department of Natural Resources, and numerous volunteers and veterinarians that comprised the South Carolina Marine Mammal Stranding Network. Spatial and temporal information can be visually represented on maps using GIS. For this CD, maps were created to show relationships of stranding densities with land use, human population density, human interaction with dolphins, high geographical regions of live strandings, and seasonal changes. Point maps were also created to show individual strandings within South Carolina. In summary, spatial analysis revealed higher densities of bottlenose dolphin strandings in Charleston and Beaufort Counties, which consist of urban land with agricultural input. This trend was positively correlated with higher human population levels in these coastal counties as compared with other coastal counties. However, spatial analysis revealed that certain areas within a county may have low human population levels but high stranding density, suggesting that the level of effort to respond to strandings is not necessarily positively correlated with the density of strandings in South Carolina. Temporal analysis revealed a significantly higher density of bottlenose dolphin strandings in the northern portion of the State in the fall, mostly due to an increase of neonate strandings. On a finer geographic scale, seasonal stranding densities may fluctuate depending on the region of interest. Charleston Harbor had the highest density of live bottlenose dolphin strandings compared to the rest of the State. This was due in large part to the number of live dolphin entanglements in the crab pot fishery, the largest source of fishery-related mortality for bottlenose dolphins in South Carolina (Burdett and McFee 2004). Spatial density calculations also revealed that Charleston and Beaufort accounted for the majority of dolphins that were involved with human activities. 1

Ecological condition of coastal ocean and estuarine waters of the U.S. South Atlantic Bight: 2000-2004

In March-April 2004, the National Oceanic and Atmospheric Administration (NOAA), U.S. Environmental Protection Agency (EPA), and State of Florida (FL) conducted a study to assess the status of ecological condition and stressor impacts throughout the South Atlantic Bight (SAB) portion of the U.S. continental shelf and to provide this information as a baseline for evaluating future changes due to natural or human-induced disturbances. The boundaries of the study region extended from Cape Hatteras, North Carolina to West Palm Beach, Florida and from navigable depths along the shoreline seaward to the shelf break (~100m). The study incorporated standard methods and indicators applied in previous national coastal monitoring programs — Environmental Monitoring and Assessment Program (EMAP) and National Coastal Assessment (NCA) — including multiple measures of water quality, sediment quality, and biological condition. Synoptic sampling of the various indicators provided an integrative weight-of-evidence approach to assessing condition at each station and a basis for examining potential associations between presence of stressors and biological responses. A probabilistic sampling design, which included 50 stations distributed randomly throughout the region, was used to provide a basis for estimating the spatial extent of condition relative to the various measured indicators and corresponding assessment endpoints (where available). Conditions of these offshore waters are compared to those of southeastern estuaries, based on data from similar EMAP/NCA surveys conducted in 2000-2004 by EPA, NOAA, and partnering southeastern states (Florida, Georgia, South Carolina, North Carolina, Virginia) (NCA database for estuaries, EPA Gulf Ecology Division, Gulf Breeze FL). Data from a total of 747 estuarine stations are included in this database. As for the offshore sites, the estuarine samples were collected using standard methods and indicators applied in previous coastal EMAP/NCA surveys including the probabilistic sampling design and multiple indicators of water quality, sediment quality, and biological condition (benthos and fish). The majority of the SAB had high levels of DO in near-bottom water (> 5 mg L-1) indicative of "good" water quality. DO levels in bottom waters exceeded this upper threshold at all sites throughout the coastal-ocean survey area and in 76% of estuarine waters. Twenty-one percent of estuarine bottom waters had moderate levels of DO between 2 and 5 mg L-1 and 3% had DO levels below 2 mg L-1. The majority of sites with DO in the low range considered to be hypoxic (< 2 mg L-1) occurred in North Carolina estuaries. There also was a notable concentration of stations with moderate DO levels (2 – 5 mg L-1) in Georgia and South Carolina estuaries. Approximately 58% of the estuarine area had moderate levels of chlorophyll a (5-10 μg L-1) and about 8% of the area had higher levels, in excess of 10 μg L-1, indicative of eutrophication. The elevated chlorophyll a levels appeared to be widespread throughout the estuaries of the region. In contrast, offshore waters throughout the region had relatively low levels of chlorophyll a with 100% of the offshore survey area having values < 5 μg L-1.

Integrated conceptual ecosystem model development for the Florida Keys/Dry Tortugas coastal marine ecosystem: MARine Estuarine goal Setting (MARES) for South Florida

The overall goal of the MARine and Estuarine goal Setting (MARES) project for South Florida is “to reach a science-based consensus about the defining characteristics and fundamental regulating processes of a South Florida coastal marine ecosystem that is both sustainable and capable of providing the diverse ecosystem services upon which our society depends.” Through participation in a systematic process of reaching such a consensus, science can contribute more directly and effectively to the critical decisions being made by both policy makers and by natural resource and environmental management agencies. The document that follows briefly describes the MARES project and this systematic process. It then describes in considerable detail the resulting output from the first two steps in the process, the development of conceptual diagrams and an Integrated Conceptual Ecosystem Model (ICEM) for the first subregion to be addressed by MARES, the Florida Keys/Dry Tortugas (FK/DT). What follows with regard to the FK/DT is the input received from more than 60 scientists, agency resource managers, and representatives of environmental organizations beginning with a workshop held December 9-10, 2009 at Florida International University in Miami, Florida.

Integrated conceptual ecosystem model development for the southwest Florida shelf coastal marine ecosystem: MARine Estuarine goal Setting (MARES) for South Florida

The overall goal of the MARine and Estuarine goal Setting (MARES) project for South Florida is “to reach a science-based consensus about the defining characteristics and fundamental regulating processes of a South Florida coastal marine ecosystem that is both sustainable and capable of providing the diverse ecosystem services upon which our society depends.” Through participation in a systematic process of reaching such a consensus, science can contribute more directly and effectively to the critical decisions being made by both policy makers and by natural resource and environmental management agencies. The document that follows briefly describes the MARES project and this systematic process. It then describes in considerable detail the resulting output from the first two steps in the process, the development of conceptual diagrams and an Integrated Conceptual Ecosystem Model (ICEM) for the second subregion to be addressed by MARES, the Southwest Florida Shelf (SWFS). What follows with regard to the SWFS is the input received from more than 60 scientists, agency resource managers, and representatives of environmental organizations beginning with a workshop held August 19-20, 2010 at Florida Gulf Coast University in Fort Myers, Florida.

Report of 2009 Bottlenose Dolphin (Tursiops truncatus) Life History Workshop: expanding network capabilities

The Virginia Aquarium & Marine Science Center Foundation’s Stranding Response Program (VAQS) was awarded a grant in 2008 to conduct life history analysis on over 10 years of Tursiops truncatus teeth and gonad samples from stranded animals in Virginia. A major part of this collaborative grant included a workshop involving life historians from Hubbs-Sea World Research Institute (HSWRI), NOS, Texas A & M University (TAMU), and University of North Carolina Wilmington (UNCW). The workshop was held at the NOAA Center for Coastal Environmental Health & Biomolecular Research in Charleston, SC on 7-9 July 2009. The workshop convened to 1) address current practices among the groups conducting life history analysis, 2) decide on protocols to follow for the collaborative Prescott grant between VAQS and HSWRI, 3) demonstrate tissue preparation techniques and discuss shortcuts and pitfalls, 4) demonstrate data collection from prepared testes, ovaries, and teeth, and 5) discuss data analysis and prepare an outline and timeline for a future manuscript. The workshop concluded with discussions concerning the current collaborative Tursiops Life History Prescott grant award and the beginnings of a collaborative Prescott proposal with members of the Alliance of Marine Mammal Parks and Aquariums to further clarify reproductive analyses. This technical memorandum serves as a record of this workshop.

Effects of land use and physicochemical water quality on grass shrimp, Palaemonetes pugio, and its parasitic isopod, Probopyrus pandalicola, in South Carolina, USA tidal creeks

Grass shrimp, Palaemonetes pugio, are a common inhabitant of US East and Gulf coast salt marshes and are a food source for recreationally and economically important fish and crustacean species. Due to the relationship of grass shrimp with their ecosystem, any significant changes in grass shrimp population may have the potential to affect the estuarine system. Land use is a crucial concern in coastal areas where increasing development impacts the surrounding estuaries and salt marshes and has made grass shrimp population studies a logical choice to investigate urbanization effects. Any impact on tidal creeks will be an impact on grass shrimp populations and their associated micro-environment whether predator, prey or parasitic symbiont. Anthropogenic stressors introduced into the grass shrimp ecosystem may even change the intensity of infections from parasitic symbionts. An ectoparasite found on P. pugio is the bopyrid isopod Probopyrus pandalicola. Little is known about factors that may affect the occurrence of this isopod in grass shrimp populations. The goal was to analyze the prevalence of P. pandalicola in grass shrimp in relation to land use classifications, water quality parameters, and grass shrimp population metrics. Eight tidal creeks in coastal South Carolina were sampled monthly over a three year period. The occurrence of P. pandalicola ranged from 1.2% to 5.7%. Analysis indicated that greater percent water and marsh coverage resulted in a higher incidence of bopyrid occurrence. Analysis also indicated that higher bopyrid incidence occurred in creeks with higher salinity, temperature, and pH but lower dissolved oxygen. The land use characteristics found to limit bopyrid incidence were limiting to grass shrimp (definitive host) populations and probably copepod (intermediate host) populations as well.

Gulf of Mexico tidal creeks serve as sentinel habitats for assessing the impact of coastal development on ecosystem health

A study was conducted, in association with the Alabama and Mississippi National Estuarine Research Reserves (NERRs) in the Gulf of Mexico (GoM) as well as the Georgia, South Carolina, and North Carolina NERRs in the Southeast (SE), to evaluate the impacts of coastal development on tidal creek sentinel habitats, including potential impacts to human health and well-being. Uplands associated with Southeast and Gulf of Mexico tidal creeks, and the salt marshes they drain, are popular locations for building homes, resorts, and recreational facilities because of the high quality of life and mild climate associated with these environments. Tidal creeks form part of the estuarine ecosystem characterized by high biological productivity, great ecological value, complex environmental gradients, and numerous interconnected processes. This research combined a watershed-level study integrating ecological, public health and human dimension attributes with watershed-level land cover data. The approach used for this research was based upon a comparative watershed and ecosystem approach that sampled tidal creek networks draining developed watersheds (e.g., suburban, urban, and industrial) as well as undeveloped sites (Holland et al. 2004, Sanger et al. 2008). The primary objective of this work was to define the relationships between coastal development with its concomitant land cover changes, and non-point source pollution loading and the ecological and human health and wellbeing status of tidal creek ecosystems. Nineteen tidal creek systems, located along the Southeastern United States coast from southern North Carolina to southern Georgia, and five Gulf of Mexico systems from Alabama and Mississippi were sampled during summer (June-August) 2005, 2006 (SE) and 2008 (GoM). Within each system, creeks were divided into two primary segments based upon tidal zoning: intertidal (i.e., shallow, narrow headwater sections) and subtidal (i.e., deeper and wider sections), and watersheds were delineated for each segment. In total, we report findings on 29 intertidal and 24 subtidal creeks. Indicators sampled throughout each creek included water quality (e.g., dissolved oxygen, salinity, nutrients, chlorophyll-a levels), sediment quality (e.g., characteristics, contaminant levels including emerging contaminants), pathogen and viral indicators (e.g., fecal coliform, enterococci, F+ coliphages, F- coliphages), and abundance and tissue contamination of biological resources (e.g., macrobenthic and nektonic communities, shellfish tissue contaminants). Tidal creeks have been identified as a sentinel habitat to assess the impacts of coastal development on estuarine areas in the southeastern US. A conceptual model for tidal creeks in the southeastern US identifies that human alterations (stressors) of upland in a watershed such as increased impervious cover will lead to changes in the physical and chemical environment such as microbial and nutrient pollution (exposures), of a receiving water body which then lead to changes in the living resources (responses). The overall objective of this study is to evaluate the applicability of the current tidal creek classification framework and conceptual model linking tidal creek ecological condition to potential impacts of development and urban growth on ecosystem value and function in the Gulf of Mexico US in collaboration with Gulf of Mexico NERR sites. The conceptual model was validated for the Gulf of Mexico US tidal creeks. The tidal creek classification system developed for the southeastern US could be applied to the Gulf of Mexico tidal creeks; however, some differences were found that warrant further examination. In particular, pollutants appeared to translate further downstream in the Gulf of Mexico US compared to the southeastern US. These differences are likely the result of the morphological and oceanographic differences between the two regions. Tidal creeks appear to serve as sentinel habitats to provide an early warning of the ensuing harm to the larger ecosystem in both the Southeastern and Gulf of Mexico US tidal creeks.

Weighing your options: how to protect your property from shoreline erosion, a handbook for estuarine property owners in North Carolina

If you own property on one of North Carolina’s estuaries, you can use this guide as a tool to learn about the choices you have to control your shoreline erosion and help decide which approach may be right for you. In North Carolina, we make a distinction between waterfront property that is located on the estuary, referred to as estuarine, shoreline, soundfront or riverside property, and waterfront property located directly on the ocean, referred to as oceanfront. Why? State laws and regulations addressing estuarine and oceanfront property, and the available erosion control methods, are quite different. This guide focuses on estuarine property. We’ll introduce you to the six main erosion control options in use in North Carolina and give you information about the out-of-pocket costs and tangible benefits of each option. We’ll also give you information about “hidden” costs and benefits that you may want to factor into your decision-making. You are fortunate to have a piece of estuarine shoreline to call your own, whether it’s your year-round residence or a weekend getaway. And if you’ve noticed some shoreline erosion lately, you’re probably a little concerned. But there are ready solutions.

A GIS analysis of coastal development and trends in bottlenose dolphin strandings in Charleston, SC: implications for coastal marine spatial planning

Bottlenose dolphins (Tursiops truncatus) inhabit estuarine waters near Charleston, South Carolina (SC) feeding, nursing and socializing. While in these waters, dolphins are exposed to multiple direct and indirect threats such as anthropogenic impacts (egs. harassment with boat traffic and entanglements in fishing gear) and environmental degradation. Bottlenose dolphins are protected under the Marine Mammal Protection Act of 1972. Over the years, the percentage of strandings in the estuaries has increased in South Carolina and, specifically, recent stranding data shows an increase in strandings occurring in Charleston, SC near areas of residential development. During the same timeframe, Charleston experienced a shift in human population towards the coastline. These two trends, rise in estuarine dolphin strandings and shift in human population, have raised questions on whether the increase in strandings is a result of more detectable strandings being reported, or a true increase in stranding events. Using GIS, the trends in strandings were compared to residential growth, boat permits, fishing permits, and dock permits in Charleston County from 1994-2009. A simple linear regression analysis was performed to determine if there were any significant relationships between strandings, boat permits, commercial fishing permits, and crabpot permits. The results of this analysis show the stranding trend moves toward Charleston Harbor and adjacent rivers over time which suggests the increase in strandings is related to the strandings becoming more detectable. The statistical analysis shows that the factors that cause human interaction strandings such as boats, commercial fishing, and crabpot line entanglements are not significantly related to strandings further supporting the hypothesis that the increase in strandings are due to increased observations on the water as human coastal population increases and are not a natural phenomenon. This study has local and potentially regional marine spatial planning implications to protect coastal natural resources, such as the bottlenose dolphin, while balancing coastal development.

Developing alternative shoreline armoring strategies: the living shoreline approach in North Carolina

This paper reviews the scientific data on the ecosystem services provided by shoreline habitats, the evidence for adverse impacts from bulkheading on those habitats and services, and describes alternative approaches to shoreline stabilization, which minimize adverse impacts to the shoreline ecosystem. Alternative shoreline stabilization structures that incorporate natural habitats, also known as living shorelines, have been popularized by environmental groups and state regulatory agencies in the mid-Atlantic. Recent data on living shoreline projects in North Carolina that include a stone sill demonstrate that the sills increase sedimentation rates, that after 3 years marshes behind the sills have slightly reduced biomass, and that the living shoreline projects exhibit similar rates of fishery utilization as nearby natural fringing marshes. Although the current emphasis on shoreline armoring in Puget Sound is on steeper, higher-energy shorelines, armoring of lower-energy shorelines may become an issue in the future with expansion of residential development and projected rates of sea level rise. The implementation of regulatory policy on estuarine shoreline stabilization in North Carolina and elsewhere is presented. The regulatory and public education issues experienced in North Carolina, which have made changes in estuarine shoreline stabilization policy difficult, may inform efforts to adopt a sustainable shoreline armoring strategy in Puget Sound. A necessary foundation for regulatory change in shoreline armoring policy, and public support for that change, is rigorous scientific assessment of the variety of services that natural shoreline habitats provide both to the ecosystem and to coastal communities, and evidence demonstrating that shoreline armoring can adversely impact the provision of those services.

Contrasting seasonal patterns in dimethylsulfide, dimethylsulfoniopropionate, and chlorophyll a in a shallow North Carolina estuary and the Sargasso Sea

Time series measurements of dimethylsulfide (DMS), particulate dimethylsulfoniopropionate (DMSPp), chlorophyll a (chl a), algal pigments, major nutrients, and the potential activity of DMSP lyase enzymes were made over a 2 yr period (6 March 2003 to 28 March 2005) near the mouth of the shallow, tidally mixed Newport River estuary, North Carolina, USA. DMSPp had a mean of 43 ± 20 nM (range = 10.5 to 141 nM, n = 85) and DMS a mean of 2.7 ± 1.2 nM (range = 0.9 to 7.0 nM). The mean DMS in Gallants Channel was not significantly different from that measured in the Sargasso Sea near Bermuda during a previous 3 yr time series study (2.4 ± 1.5 nM), despite there being a 43-fold higher mean chl a concentration (4.9 ± 2.4 µg l–1) at the coastal site. In winter, DMS was low and chl a was high in the surface waters of the Sargasso Sea, while the opposite was true at the coastal site. Consequently, DMS concentrations per unit algal chl a were on average 170 times higher in the Sargasso Sea than at the coastal site during the summer, but only 7 times higher during the winter. The much higher chl a-specific DMS concentrations at the oceanic site during the summer were linked to higher ratios of intracellular DMSP substrate and DMSP lyase enzyme per unit chl a. These differences in turn appear to be linked to large differences in nutrient concentrations and solar UV stress at the 2 sites and to associated differences in the composition of algal assemblages and physiological acclimation of algal cells.

Boat wakes and their influence on erosion in the Atlantic Intracoastal Waterway, North Carolina

Boat wakes in the Atlantic Intracoastal Waterway (AIWW) of North Carolina occur in environments not normally subjected to (wind) wave events, making sections of AIWW potentially vulnerable to extreme wave events generated by boat wakes. The Snow’s Cut area that links the Cape Fear River to the AIWW is an area identified by the Wilmington District of the U.S. Army Corps of Engineers as having significant erosion issues; it was hypothesized that this erosion could be being exacerbated by boat wakes. We compared the boat wakes for six combinations of boat length and speed with the top 5% wind events. We also computed the benthic shear stress associated with boat wakes and whether sediment would move (erode) under those conditions. Finally, we compared the transit time across Snow’s Cut for each speed. We focused on two size classes of V-hulled boats (7 and 16m) representative of AIWW traffic and on three boat speeds (3, 10 and 20 knots). We found that at 10 knots when the boat was plowing and not yet on plane, boat wake height and potential erosion was greatest. Wakes and forecast erosion were slightly mitigated at higher, planing speeds. Vessel speeds greater than 7 knots were forecast to generate wakes and sediment movement zones greatly exceeding that arising from natural wind events. We posit that vessels larger than 7m in length transiting Snow’s Cut (and likely many other fetch-restricted areas of the AIWW) frequently generate wakes of heights that result in sediment movement over large extents of the AIWW nearshore area, substantially in exceedance of natural wind wave events. If the speed, particularly of large V-hulled vessels (here represented by the 16m length class), were reduced to pre-plowing levels (~ 7 knots down from 20), transit times for Snow’s Cut would be increased approximately 10 minutes but based on our simulations would likely substantially reduce the creation of erosion-generating boat wakes. It is likely that boat wakes significantly exceed wind wave background for much of the AIWW and similar analyses may be useful in identifying management options.