Core Sound Research Articles

Comparison of Visual Surveys Versus Dredging for Monitoring Bay Scallops (Argopecten irradians) in Seagrass Beds

Bay scallops (Argopecten irradians), once a profitable fishery species in North Carolina, have declined in population size following harmful algal blooms in the late 1980s. To prepare for future scallop restoration efforts, appropriate survey methods should be identified to evaluate the status of the population with respect to managing harvest. The North Carolina Division of Marine Fisheries monitors bay scallop populations in seagrass beds using a scallop dredge, though it is still unclear what the current natural densities of bay scallops are. In this study, visual surveys in three time treatments (5, 10, and 20 min) were compared with dredging in terms of quantifying scallop density and the catch per unit effort (CPUE) in seagrass beds in Core Sound, North Carolina. There was no significant difference in scallop density and the CPUE among visual survey time treatments. Scallop densities observed during visual surveys were three times higher than densities using a scallop dredge; however, the CPUE was five times higher using a scallop dredge compared with visual surveys. If visual surveys indicate the true natural density of bay scallops in this study system, then the dredge sampling efficiency for evaluating bay scallop density was 33%. Dredging for bay scallops can uproot seagrass and displace juvenile bay scallops. Visual surveys provide a low-impact method for identifying the distribution and abundance of bay scallops in seagrass bed habitats.

Molecular Assessment of Chelonid Alphaherpesvirus 5 Infection in Tumor-Free Green (Chelonia mydas) and Loggerhead (Caretta caretta) Sea Turtles in North Carolina, USA, 2015-2019.

Simple SummaryFibropapillomatosis is a debilitating tumor disease of sea turtles that is sometimes fatal. This disease is a key concern for sea turtle rehabilitation facilities due to its infectious nature, as it is associated with a virus called chelonid alphaherpesvirus 5. This is the first study to analyze antibodies to this virus in loggerhead sea turtles and represents the most complete dataset on viral detection in sea turtles encountered in the more northern latitudes of their habitat in the western Atlantic.Fibropapillomatosis is associated with chelonid alphaherpesvirus 5 (ChHV5) and tumor formation in sea turtles. We collected blood samples from 113 green (Chelonia mydas) and 112 loggerhead (Caretta caretta) turtles without fibropapillomatosis, including 46 free-ranging turtles (20 green turtles, 26 loggerheads), captured in Core Sound, North Carolina, and 179 turtles (93 green turtles, 86 loggerheads) in rehabilitative care in North Carolina. Blood samples were analyzed for ChHV5 DNA using quantitative polymerase chain reaction (qPCR), and for antibodies to ChHV5 peptides using an enzyme-linked immunosorbent assay (ELISA). None of the samples from foraging turtles tested positive for ChHV5 by qPCR; ELISA was not used for foraging turtles. Samples from 18/179 (10.1%) rehabilitating turtles tested positive for ChHV5 using qPCR, and 32/56 (57.1%) rehabilitating turtles tested positive for antibodies to ChHV5 using ELISA. Five turtles that tested positive by qPCR or ELISA at admission converted to being undetectable during rehabilitation, and five that initially tested negative converted to being positive. Both sea turtle species were significantly more likely to test positive for ChHV5 using ELISA than with qPCR (p < 0.001). There was no difference in the proportions of green turtles versus loggerheads that tested positive for ChHV5 using qPCR, but loggerheads were significantly more likely than green turtles to test positive for ChHV5 using ELISA. This finding suggests that loggerheads infected with ChHV5 at some point in their life may be more able than green turtles to mount an effective immune response against recrudescent infection, pointing to species-specific genetic differences in the two species’ immune response to ChHV5 infection. This is the first study to analyze antibodies to ChHV5 in loggerhead turtles and represents the most complete dataset on ChHV5 DNA detection in sea turtles encountered in the more northern latitudes of their western Atlantic habitat.

Oyster Density and Demographic Rates on Natural Intertidal Reefs and Hardened Shoreline Structures

The ubiquitous loss of natural intertidal oyster reefs and associated ecosystem services has fueled restoration efforts throughout the world. Effective restoration requires an understanding of the distribution, density, and demographic rates (growth and survival) of oysters inhabiting existing natural reefs and how these may vary as a function of landscape-scale factors, such as tidal range and fetch distances. Furthermore, natural intertidal habitats are increasingly being replaced with hardened shoreline structures that may be colonized by oysters, yet little is known about habitat quality (as indexed by oyster density and demographic rates) of these hardened structures relative to natural habitats. The present study sought to compare oyster density, demographic rates, and population estimates (1) across estuarine landscape settings to inform natural intertidal oyster reef restoration (i.e., comparing natural intertidal reefs within adjacent water bodies that vary in tidal regimes and fetch distances) and (2) across natural habitats and human-made structures to assess variation in habitat quality between natural reefs and hardened shorelines. Oyster density, growth rates, and population estimates on natural intertidal reefs were greatest within the smaller, more tidally influenced Core Sound versus the larger, wind-driven Pamlico Sound, with no significant difference in survivorship identified between the two water bodies. Natural intertidal reefs and hardened shoreline structures were compared within Pamlico Sound only, with natural intertidal reefs hosting three to eight times higher oyster densities than hardened shoreline structures. When mean oyster density/m2 was multiplied by reef area to estimate population size, natural intertidal reefs within Pamlico Sound hosted considerably greater populations of oysters relative to hardened shorelines. The present study fills an existing need to understand oyster density and demographic rates on natural intertidal reefs and hardened shorelines to better inform future restoration and shoreline management scenarios.

Clinical pathology reference intervals for an in-water population of juvenile loggerhead sea turtles (Caretta caretta) in Core Sound, North Carolina, USA.

The loggerhead sea turtle (Caretta caretta) is found throughout the waters of the Atlantic, Pacific, and Indian Oceans. It is a protected species throughout much of its range due to threats such as habitat loss, fisheries interactions, hatchling predation, and marine debris. Loggerheads that occur in the southeastern U.S. are listed as “threatened” on the U.S. Endangered Species List, and receive state and federal protection. As part of an on-going population assessment conducted by the National Marine Fisheries Service, samples were collected from juvenile loggerhead sea turtles in Core Sound, North Carolina, between 2004 and 2007 to gain insight on the baseline health of the threatened Northwest Atlantic Ocean population. The aims of the current study were to establish hematologic and biochemical reference intervals for this population, and to assess variation of the hematologic and plasma biochemical analytes by season, water temperature, and sex and size of the turtles. Reference intervals for the clinical pathology parameters were estimated following Clinical Laboratory Standards Institute guidelines. Season, water temperature, sex, and size of the turtles were found to be significant factors of variation for parameter values. Seasonal variation could be attributed to physiological effects of decreasing photoperiod, cooler water temperature, and migration during the fall months. Packed cell volume, total protein, and albumin increased with increasing size of the turtles. The size-related differences in analytes documented in the present study are consistent with other reports of variation in clinical pathology parameters by size and age in sea turtles. As a component of a health assessment of juvenile loggerhead sea turtles in North Carolina, this study will serve as a baseline aiding in evaluation of trends for this population and as a diagnostic tool for assessing the health and prognosis for loggerhead sea turtles undergoing rehabilitation.

The Workboats of Core Sound: Stories and Photographs of a Changing World

The Workboats of Core Sound: Stories and Photographs of a Changing World

Observations on spiny dogfish ( Squalus acanthias) captured in late spring in a North Carolina estuary.

Five spiny dogfish were captured in early-mid May during gillnet and longline sampling targeting juvenile coastal sharks in inshore North Carolina waters. Dogfish captures were made within Back Sound and Core Sound, North Carolina. All dogfish were females measuring 849-905 mm total length, well over the size at 50% maturity. Dogfish were caught at stations 1.8-2.7 m in depth, with temperatures 22.9-24.2 °C, 32.8-33.4 ppt salinity, and 6.9-8.0 mg/L dissolved oxygen. These observations are among the latest in the spring for spiny dogfish in the southeastern U.S. and occurred at higher temperatures than previously recorded for this species. It is unclear whether late-occurring spiny dogfish in this area represent a cryptic late-migrating or resident segment of the Northwest Atlantic population.

Observations on spiny dogfish ( Squalus acanthias) captured in late spring in a North Carolina estuary

Five spiny dogfish were captured in early-mid May during gillnet and longline sampling targeting juvenile coastal sharks in inshore North Carolina waters. Dogfish captures were made within Back Sound and Core Sound, North Carolina. All dogfish were females measuring 849-905 mm total length, well over the size at 50% maturity. Dogfish were caught at stations 1.8-2.7 m in depth, with temperatures 22.9-24.2 °C, 32.8-33.4 ppt salinity, and 6.9-8.0 mg/L dissolved oxygen. These observations are among the latest in the spring for spiny dogfish in the southeastern U.S. and occurred at higher temperatures than previously recorded for this species. It is unclear whether late-occurring spiny dogfish in this area represent a cryptic late-migrating or resident segment of the Northwest Atlantic population.

Observations on spiny dogfish (Squalus acanthias) captured in late spring in a North Carolina estuary

Five spiny dogfish were captured in early-mid May during gillnet and longline sampling targeting juvenile coastal sharks in inshore North Carolina waters. Dogfish captures were made within Back Sound and Core Sound, North Carolina. All dogfish were females over the size at maturity, and were caught at stations 1.77-2.74 m in depth, with temperatures 22.9-24.2 °C, 32.8-33.4 ppt salinity, and 6.9-8.0 mg/L dissolved oxygen. Stations where dogfish were captured were approximately 6.5-15.7 km from the nearest inlet and 43.4-247.1 m from the nearest seagrass bed. These observations are among the latest in the spring for spiny dogfish in the southeastern U.S. and occurred at higher temperatures than previously recorded for this species. It is unclear whether late-occurring spiny dogfish in this area represent a cryptic late-migrating or resident segment of the Northwest Atlantic population.

Using stable isotope analysis to validate effective trophic levels from Ecopath models of areas closed and open to shrimp trawling in Core Sound, NC, USA

We used stable isotope ratios of nitrogen (15N/14N) as a validation tool for determining the accuracy of the effective trophic levels computed in network analysis models for Core Sound, North Carolina, USA. Ecological network models (using Ecopath) were assembled for two trawling management areas, closed areas where shrimp trawling has been restricted for 30 years, and open trawling areas within the estuary. Effective trophic levels (ETLs) were computed from the two Ecopath models and compared with δ15N values measured from the same species at the same time in the two areas. Comparisons of ETLs between species compartments of the two models were very similar, and ETLs were positively related to δ15N values. Linear regression of ETL as a predictor of δ15N value was highly significant (R2=0.50, p>0.00001), suggesting that δ15N values increase by 2.52‰ per trophic level. This increase in δ15N value agrees well with a recent global meta-analysis of nitrogen fractionation estimates. There was no significant difference in δ15N values between trawling zones over all species examined, although there were significantly higher δ15N values in the areas open to trawling for certain species of fish (pinfish, spot) and invertebrate (blue crabs). Atlantic menhaden, which feed on detritus and zooplankton, had much higher δ15N values than the Ecopath ETL and δ15N regression model predicted (large studentized residuals), suggesting that Ecopath incorrectly computes the trophic level of animals that consume dead material (in our model, detritus and shrimp trawl bycatch species). Shrimp trawl bycatch species are mostly pinfish, spot and blue crabs, with ETLs of 2.5 or higher, but are inappropriately assumed to be at trophic level 1 when dead in Ecopath. Despite this discrepancy for some species of detritivores and scavengers, we conclude that this Ecopath network model of Core Sound is reliable and predicts with good accuracy the shifts and changes in trophic level and diet as measured by stable isotopes and observed in diet studies. The Core Sound network model will be a useful approach when predicting impacts in the ecosystem due to changes in trawling or other fisheries management decisions.

Pugheaded Spotted Sea Trout in North Carolina

Pugheadedness was first reported in the fresh water fish, carp (Cyprinus carpio Linnaeus, 1758, family Cyprinidae) in 1554 (Fig. 1) (Gudger 1928). Other species have exhibited pugheadedness (Gudger 1930), most notably the marine fish, Striped Bass (Morone saxatilis Walbaum, 1796, family Moronidae) Gudger 1930; Manuseti 1960; Lyman 1960; Cheek 1966).Pugheadedness, to date, has been reported for two female spotted Sea Trout (Cynoscion nebulosus Linnaeus, 1830, family Sciaenidae) caught by hook and line in Louisiana (Rose and Harris 1968; Hine and Shepard 1980; Overstreet 1983). Sizes were: 392 mm SL caught by Rose and Harris (1968) 396 mm SL, 841 g. caught by Hine and Shepard 1980).Cheek (1966) reported the only pugheaded fish caught in North Carolina, a Striped Bass. A Spotted Sea Trout (NCMS 74131), that ranges from New York south to the Gulf of Mexico (McEachran and Fechhelm 1989) exhibiting pugheadedness was caught 14 January 2013 on an artificial lure while fishing unpolluted Smyrna creek, a short tributary that enters Core Sound, Carteret County, North Carolina. It was 323 mm SL, 358 mm Tl, weight 569 g.External and x-ray examination (Fig. 2) of the pugheaded Spotted Sea Trout found extreme shortening of the head, snout, small eyes, shortened upper jaws and greater inter-orbital distances (Table 1). Other features of the pugheaded Spotted Sea Trout were similar to “normal specimens” except for dorsal and ray fin counts (Table 1).Mansueti (1960) postulated that pugheadedness was the result of environmental conditions and heredity, not physical injury. Thus, the reasons pugheadednes occurred in the Spotted Sea Trout in North Carolina remains a mystery.J. Francesconi (NCDNR) appreciated the value of the pugheaded Spotted Sea Trout and called it to our attention. E. Fuge and C. Williams (Cartert County Community College) produced the x-ray of the pugheaded Spotted Sea Trout; G. Hogue (NCMS) provided the catalog number for the spotted seatrout now housed in Raleigh, North Carolina. A. Rodriguez (IMS) produced Figure 1 photograhphically.

3D Impulse Response Measurements of Spaces Using an Inexpensive Microphone Array

The acoustical characteristics of a room are traditionally determined using omnidirectional impulse response measurements, yielding information about sound reflections in terms of magnitude and time, but not direction. However, the direction of reflections is often important, and thus the need for a practical, low cost measurement system for determining this. In this paper we present the performance of a low cost measurement system utilising an inexpensive microphone array, namely the Core Sound TetraMic, for the determination of 3D room impulse responses. These can then be visualised, for example, as a “hedgehog pattern”. Experiments undertaken in an anechoic chamber indicate that the accuracy of directional estimation of this system is in the region of ±7.5°.

MODERN FORAMINIFERAL DISTRIBUTION AND RECENT ENVIRONMENTAL CHANGE IN CORE SOUND, NORTH CAROLINA, USA

Core Sound, a shallow, narrow estuarine lagoon located behind North Carolina’s southern Outer Banks, was studied to document modern foraminiferal distributions and identify environmental changes during the past ca. 90 years. Seventy-six samples collected in 2004 were analyzed to establish the modern distribution and abundance of foraminifera. Cluster analysis defined four modern biofacies: Marsh (dominated by Trochammina inflata and Haplophragmoides wilberti ), Estuarine High Salinity A (dominated by Ammonia parkinsoniana and Elphidium mexicanum ), Estuarine High Salinity B (dominated by Ammonia parkinsoniana and Elphidium excavatum ), and Estuarine Low Salinity (dominated by Ammotium salsum , Ammonia parkinsoniana and Elphidium gunteri ). The four biofacies were also recognized by discriminant analysis. Comparison of the 2004 distributional data with those derived from samples collected in 1959 from central and eastern Core Sound revealed that Elphidium decreased while Ammonia increased in relative abundance. Other researchers have suggested that such a trend reflects increased eutrophication, although there is no independent evidence for this in Core Sound. The temporal comparison also showed that Quinqueloculina has become more widespread immediately adjacent to barrier islands, which might relate to an increase in subaquatic vegetation. Five short cores were taken in mainland bays on the western margin of Core Sound. Analysis of radionuclides ( 210 Pb and 137 Cs) provided a chronostratigraphic framework for two of the cores. To aid paleoenvironmental interpretations, foraminiferal data from core sediments dated as ca. 90 yr were entered as unknowns into the modern distribution discriminant analysis. Samples from mainland bay cores were classified with modern biofacies and indicated no significant foraminiferal change in the mainland bays over the last ca. 90 years.

Temporal and Spatial Trends of Perfluorinated Compounds in Juvenile Loggerhead Sea Turtles (Caretta caretta) along the East Coast of the United States

Perfluorinated compounds (PFCs) are globally distributed persistent environmental contaminants. This study provides temporal trends as well as large-scale spatial trends of PFC concentrations in threatened juvenile loggerhead sea turtles near or from Florida Bay (FL Bay), Cape Canaveral (FL), Charleston (SC), Core Sound (NC), and Chesapeake Bay (MD). PFCs were extracted from 163 plasma and serum samples using solid-phase extraction and quantified with LC-MS/MS. Concentrations of six compounds significantly varied by site, with MD or FL Bay turtles having the highest concentrations. Perfluorooctane sulfonate (PFOS) was the predominant PFC at all sites (range: 0.31 ng/g to 39.0 ng/g). FL Bay turtles, compared to other sites, accumulated a unique PFC pattern with a higher proportion of perfluorocarboxylates compared to PFOS. Furthermore, this study was the first to statistically correlate wildlife PFC concentrations with human population, used as a proxy for urbanization and sources of PFCs to the environment. Positive relationships were found in which human population accounted for 75 and 81% of the variance in turtle PFOS and perfluoroundecanoate (PFUnA) concentrations (p = 0.06 and 0.04), respectively. PFOS and perfluorononanoate (PFNA) significantly decreased from 2000-2008 in SC turtles annually by 20 and 11%, respectively (p </= 0.02). Future investigations should continue temporal assessments as PFC regulations change, attempt to pinpoint specific sources and transport pathways in areas with unique PFC patterns, and assess turtle health at sites with higher PFC concentrations.

The Effect of Cull Rings on Catch Rates of Blue Crabs Callinectes sapidus in the North Carolina Trap Fishery

AbstractWe sampled seven North Carolina estuaries (Currituck, Core, Albemarle, Bogue, and eastern Pamlico sounds and the Cape Fear and Pamlico rivers) to determine the separate and interacting effects of cull ring size and the number of cull rings per trap on the catch rate (catch per trap) of blue crabs Callinectes sapidus. Since a single minimum cull ring size is required in North Carolina and regional differences in blue crab shape may mediate its effectiveness, we also measured subsamples of male and mature female blue crabs to determine whether there were shape differences among estuaries. The cull ring sizes tested in Currituck and Core sounds were 58.7, 60.3, and 61.9 mm. The smallest two sizes were tested in the other five estuaries. We also varied the number of cull rings from two to four per trap. Thus, there were nine treatments in Currituck and Core sounds and six in the other estuaries. Three blue crab types dominated the catches: legal males (≥127 mm), sublegal males, and mature females. Increasing ring size and number did not significantly affect the catch per unit effort (CPUE) of legal males except in Currituck Sound, where they positively affected CPUE. Increasing ring size negatively affected the CPUE of sublegal males in all estuaries except eastern Pamlico Sound, where if had no effect. Increasing ring number negatively affected the CPUE of sublegal males in two estuaries: Currituck and Albemarle sounds. Increasing ring size negatively affected the CPUE of mature females in two pairwise cases in one estuary (Core Sound); ring size and number did not impact the CPUE of mature females in other estuaries. Despite the apparent differences in the shapes of blue crabs among estuaries, the influences of cull ring size and number were consistent. Our data indicate that a 1.6‐ or 3.2‐mm increase in cull ring size would not negatively impact the catch rates of legal blue crabs but would increase the escapement of sublegal blue crabs.

The Common Core Sound: Short Notes on Themes, Harmonies and Disharmonies in European Tort Law

The aims, methods, key aspects and features of the research carried out by the 'Common Core of European Private Law' project in the field of tort law are discussed. The distinctive tenets of the Common Core approach as applied to tort law issues and the scenarios that such an approach is bound to open are highlighted.

Lessons of Core Sound Workboats

Lessons of Core Sound Workboats Lawrence S. Earley (bio) Click for larger view View full resolution "Haul Boat and Shack, 2006." [End Page 86] Core Sound is a shallow body of water in eastern North Carolina that carries the Core Sound National Seashore on its eastern shoulder and the Carteret County peninsula on its west. Between Beaufort, the mainland town that has prettied itself up over recent decades, and Cedar Island, a jumping-off point by ferry for the tourist destination of Ocracoke, a handful of small fishing villages comprise the area locally known as "Down East." For more than two centuries the people of Core Sound have lived off the bounty of the Sound and the sea. To negotiate Core Sound's notorious shoals and exploit its rich fisheries, they built shallow-draft vessels—versatile and adaptable boats that could be converted from haul boat to run boat and back again. In recent decades these boats could long-haul for trout from spring to fall, trawl for shrimp in summer, and kick clams or oysters in winter. When I talked with Core Sound residents, what I had often photographed as purely artistic compositions—boat, marsh, the Sound as landscape—became cultural documents loaded with significance and complexity. Primarily, of course, a boat is a physical object built and used for practical ends. A fisherman is rarely sentimental about his boat; it's useful for as long as it enables him to make a living. When the boat ceases to be useful, it can be sold or stripped of its assets and towed to a marsh where, in time, it "falls to pieces." Yet fishermen and their families also can be very tender about a boat. One woman recalled how her father would go to his boat every night after supper to wash it down, paint, mend net, or tinker with the engine. Her mother would smile as he went out and say, "He's got to go tell her goodnight." Another woman teared up when describing a boat her husband sold. "Selling a boat," she said, "is like a death in the family." Fishermen themselves size up a boat quickly and with an intrinsic aesthetic appreciation. Some boats are "pretty boats";" others are "ugly" or "awkward looking" if they don't seem to hit the mark. Harkers Island fishermen will often declare that their boats are "prettier" than Atlantic boats, and some Atlantic natives agree, although others offer a kind of backhanded compliment. "The Atlanticers, we weren't really concerned about how pretty [a boat] was," explained one boat-builder. "We were more concerned about how it worked." Indeed, a workboat is not only a distinctive expression of the builder but also of a community. In addition to Atlantic and Harkers Island styles of workboats, there also is a Marshallberg style, each defined by a master craftsman at some point in their community history, although there would be variations within that community. "I can look at a boat and tell where it was built," the boatbuilder told me. "Most of the time, I can look at a boat and tell who built it." Thus, a Core Sound workboat is a link in the social and historical web of Down East communities. This small social web widens over time with the addition of new owners, mechanics, painters, carpenters, captains, and crew members from several other communities, across three generations, and it seems to be part of the [End Page 87] Click for larger view View full resolution "Linda (detail), 2005." The rounded sterns of Core Sound boats, designed to enable fishermen to haul their nets in without getting snagged on corners, are fairly typical of the region. common memory, recalled with surprising ease. From these photographs, residents could identify a boat by name, owner, builder, and the boat's namesake. When I ask fishermen how they know so many of the same stories about a particular boat, they often refer to the closeness with which they work on the water. Although fishermen are independent sorts, leaving before dawn and returning after dark (sometimes remaining away for several days), they are very aware of each other. Peering across the sound in...

The diet composition of immature loggerheads: Insights on trophic niche, growth rates, and fisheries interactions

For immature animals, diet quality and composition influence expression of life history traits such as growth rates and ultimately life stage duration and age to maturity. Circumglobally distributed loggerhead turtles ( Caretta caretta) exhibit a multi-decade immature stage that generally occupies neritic habitats and is characterized by slow growth and an omnivorous diet. Although adult nesting populations are geographically distinct, foraging areas for immature loggerheads show a high degree of mixing of individuals that originate from multiple nesting stocks. Furthermore, despite their generalist foraging ecology, immature loggerheads have been observed to supplement their natural diets with fish from fishery discards and/or caught in fishing gear. However, whether trophic opportunism results in variation in loggerhead growth rates within or among feeding areas has not been investigated. In Core Sound, North Carolina (NC), USA, immature loggerheads demonstrate highly variable size-specific growth rates, in contrast to other studies that report discernible somatic growth functions in immature marine turtles. To determine whether inter-individual variation in growth rates at this site was due to variation in diet composition, and specifically variation in consumption of fish, we analyzed carbon and nitrogen stable isotope ratios of loggerhead blood plasma and of tissue samples of putative loggerhead prey, as well as commercially important fish species. Our results indicated that growth rates were not related to trophic levels at which individual turtles fed, but rather probably reflected inter-individual variation in overwintering or foraging behavior (i.e. nearshore vs. offshore). Furthermore, loggerhead diets were highly diverse, and comprised mainly blue crabs and/or whelks, as well as small proportions of cannonball jellies. Fish were unimportant dietary components for loggerheads. Although loggerheads in NC do not appear to feed on fish catch or discards, immature turtles showed dietary preferences for prey items that are also valuable to or are commonly taken as bycatch in commercial fisheries (e.g. blue crabs and whelks, respectively) in the region. Thus, the status of these prey items/fishery stocks as well as trends in loggerhead populations should be monitored to mitigate potential competitive interactions between fisheries activities and loggerhead turtles.

At Loggerheads: Gear Damage in the Blue Crab Fishery Attributed to Loggerhead Sea Turtles

AbstractNorth Carolina's fishery for the blue crab Callinectes sapidus is experiencing problems with gear damage during the summer season. Individuals of a protected species, the loggerhead sea turtle Caretta caretta, are the likely culprits of crab pot damage, bait theft, and reduced crab catch, perhaps with important economic impacts. In summer 2005, we conducted a fishing study in cooperation with a pair of crabbers operating one commercial blue crab boat in Core Sound, North Carolina, to characterize location, timing, and extent of damage to crab pots. We examined spatial and temporal overlap of fishing activity with loggerhead sea turtle sightings and quantified blue crab catch. Eighty‐seven percent of pots were damaged throughout the course of the study, and gear damage peaked in late June to early July. We measured a 40% reduction in blue crab catch in crab pots that were damaged. Loggerhead sea turtle sightings were consistent with areas of high gear damage. Our results should be considered by managers, who may be able to guide crabbers to concentrate fishing effort at times and areas of reduced overlap with loggerhead sea turtles so as to minimize damage.

Summer Abundance Estimates of Caretta caretta (Loggerhead Turtles) in Core Sound, NC

Abstract We estimated summer abundance of juvenile Loggerhead Turtles at our study site in Core Sound, NC with a Horvitz-Thompson type estimator, which uses count data and recapture probability to estimate abundance. Abundance ranged from 192 (95% CI = 88–1047) to 633 (95% CI = 219–1047) turtles over the six years of this study. These results provide preliminary estimates of juvenile Loggerhead Turtle abundance during the summer in Core Sound.

Perfluorinated Compounds in the Plasma of Loggerhead and Kemp's Ridley Sea Turtles from the Southeastern Coast of the United States

Perfluorinated compounds (PFCs) have been measured in blood of humans and wildlife and are considered globally distributed contaminants. We examined 12 PFCs in the plasma of 73 loggerhead sea turtles (Caretta caretta) and 6 Kemp's ridley sea turtles (Lepidochelys kempii) captured from inshore waters of Core Sound, North Carolina (NC), and offshore waters of South Carolina, Georgia, and Florida (SC-FL). Perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA) were the dominant compounds, with respective mean concentrations of 11.0 ng/mL and 3.20 ng/mL for loggerhead turtles and 39.4 ng/mL and 3.57 ng/mL for Kemp's ridley turtles. Mean PFOS concentrations were 2- to 12-fold higher than typical mean sigmaPCB concentrations (approximately 5 ng/g wet mass) measured previously in sea turtle blood. More than 79% of the samples had detectable levels of perfluorocarboxylates (PFCAs) with 8-12 carbons, whereas only 17% or less of samples had detectable levels of PFCAs with 6 or 7 carbons. No samples had detectable levels of PFCAs with 4 or 5 carbons. In loggerhead turtles, sigmaPFC concentrations were not influenced by sex (p > 0.05), but were higher in turtles captured from inshore waters of NC than in turtles from offshore waters of SC-FL (p = 0.009). A backward stepwise multiple regression model showed that sigmaPFC concentrations were (1) significantly higher in Kemp's ridley turtles than loggerhead turtles (p < 0.0001), (2) higher in larger turtles (p = 0.018; carapace length used as a proxy for age), and (3) higher in turtles captured toward the north (p = 0.006). These findings suggest that bioaccumulation of PFCs in sea turtles is influenced by species, age, and habitat.