The Importance of the Northeastern Gulf of Mexico to Foraging Loggerhead Sea Turtles

Identification of high-use foraging sites where imperiled sea turtles are resident remains a globally-recognized conservation priority. In the biodiverse Gulf of Mexico (GoM), recent telemetry studies highlighted post-nesting foraging sites for federally threatened loggerhead turtles (Caretta caretta). Our aim here was to discern loggerhead use of additional northern GoM regions that may serve as high-use foraging sites. Thus, we used satellite tracking and switching state-space modeling to show that the Big Bend region off the northwest Florida coast is a coastal foraging area that supports imperiled adult female loggerhead turtles tracked from different nesting subpopulations. From 2011 to 2016, we satellite-tagged 15 loggerheads that nested on four distinct beaches around the GoM: Dry Tortugas National Park, FL; Everglades National Park, FL; St. Joseph Peninsula, FL; and Gulf Shores, AL. Turtles arrived at their foraging ground in the Big Bend region between June and September and remained resident in their respective foraging sites for an average of 198 tracking days, where they established mean home ranges (95% kernel density estimate) 232.7 km2. Larger home ranges were in deeper water; 50% kernel density estimate centroid values were a mean 26.4 m deep and 52.7 km from shore. The Big Bend region provides a wide area of suitable year-round foraging habitat for loggerheads from at least 3 different nesting subpopulations. Understanding where and when threatened loggerheads forage and remain resident is key for designing both surveys of foraging resources and additional protection strategies that can impact population recovery trajectories for this imperiled species

δ13C and δ15N in the endangered Kemp’s ridley sea turtle Lepidochelys kempii after the Deepwater Horizon oil spill

The Deepwater Horizon explosion in April 2010 and subsequent oil spill released 3.19 × 106 barrels (5.07 × 108 l) of MC252 crude oil into important foraging areas of the endangered Kemp’s ridley sea turtle Lepidochelys kempii (Lk) in the northern Gulf of Mexico (GoM). We measured δ13C and δ15N in scute biopsy samples from 33 Lk nesting in Texas during the period 2010 to 2012. Of these, 27 were equipped with satellite transmitters and were tracked to traditional foraging areas in the northern GoM after the spill. Differences in δ13C between the oldest and newest scute layers from 2010 nesters were not significant, but δ13C in the newest layers from 2011 and 2012 nesters was significantly lower compared to 2010. δ15N differences were not statis- tically significant. Collectively, the stable isotope and tracking data indicate that the lower δ13C values reflect the incorporation of oil rather than changes in diet or foraging area. Discriminant analysis indicated that 51.5% of the turtles sampled had isotope signatures indicating oil exposure. Growth of the Lk population slowed in the years following the spill. The involvement of oil exposure in recent population trends is unknown, but long-term effects may not be evident for many years. Our results indicate that C isotope signatures in scutes may be useful biomarkers of sea turtle exposure to oil

Mitigating By-Catch of Diamondback Terrapins in Crab Pots

ABSTRACT Chronic by-catch of diamondback terrapins (Malaclemys terrapin) in blue crab (Callinectes sapidus) pots is a concern for terrapin conservation along the United States Atlantic and Gulf of Mexico coasts. Despite the availability of by-catch reduction devices (BRDs) for crab pots, adoption of BRDs has not been mandated and by-catch of terrapins continues. We conducted experimental fishing studies in North Carolina's year-round blue crab fishery from 2000 to 2004 to evaluate the ability of various BRDs to reduce terrapin by-catch without a concomitant reduction in the catch of blue crabs. In 4,822 crab pot days fished, we recorded only 21 terrapin captures. Estimated capture rates were 0.003 terrapins/pot per day in hard crab experimental fishing and 0.008 terrapins/pot per day in peeler experimental fishing. All terrapin captures occurred from April to mid-May within 321.4 m of the shoreline. Longer soak times produced more dead terrapins, with 4 live and 4 dead during hard crab experimental fishing and 11 live and 2 dead during peeler experimental fishing. The 4.0-cm BRDs in fall and 4.5-cm and 5.0-cm BRDs in spring reduced the catch of legal-sized male hard crabs by 26.6%, 21.2%, and 5.7%, respectively. Only the 5.0-cm BRDs did not significantly affect the catch of legal-sized hard male crabs. However, BRDs had no measurable effect on catch of target crabs in the peeler crab fishery. Our results identify 3 complementary and economically feasible tools for blue crab fishery managers to exclude terrapins from commercially fished crab pots in North Carolina: 1) gear modifications (e.g., BRDs); 2) distance-to-shore restrictions; and 3) time-of-year regulations. These measures combined could provide a reduction in terrapin by-catch of up to 95% without a significant reduction in target crab catch. ß 2011 The Wildlife Society

Variation in home range size and patterns in adult female American crocodiles Crocodylus acutus

The American crocodile Crocodylus acutus is a threatened species that uses relatively deep, open-water habitats with low salinity. Adult female American crocodiles nest on sandy coastal beaches, islands or human-made berms, assist in the hatching process, and can travel long distances to nesting habitat. We satellite-tracked 15 adult female American crocodiles in 2 hydrologically distinct areas in Everglades National Park, Florida, USA, to quantify the home range sizes, test for intraspecific differences in home range and core area size and structure, and identify important crocodile high-use areas. Overall home ranges (95% kernel density estimate; KDE) for adult female crocodiles in South Florida ranged from 30.0 to 141.9 km2 (mean ± SD, 84.4 ± 32.3 km2), and core areas (50% KDE) ranged from 4.7 to 27.4 km2 (17.8 ± 7.3 km2). We identified patterns in home range and core area overlap, seasonally shifting patterns in core area use, and the Fox Lake complex as an important crocodile high-use area. As the population of American crocodiles continues to grow and expand into new areas, it is important for conservation managers to understand individual crocodile habitat-use patterns and spatial resource requirements

The effect of host structure on the selectivity and mechanism of supramolecular catalysis of Prins cyclizations.

The effect of host structure on the selectivity and mechanism of intramolecular Prins reactions is evaluated using K12Ga4L6 tetrahedral catalysts. The host structure was varied by modifying the structure of the chelating moieties and the size of the aromatic spacers. While variation in chelator substituents was generally observed to affect changes in rate but not selectivity, changing the host spacer afforded differences in efficiency and product diastereoselectivity. An extremely high number of turnovers (up to 840) was observed. Maximum rate accelerations were measured to be on the order of 105, which numbers among the largest magnitudes of transition state stabilization measured with a synthetic host-catalyst. Host/guest size effects were observed to play an important role in host-mediated enantioselectivity

Marine Threats Overlap Key Foraging Habitat for Two Imperiled Sea Turtle Species in the Gulf of Mexico

Effective management of human activities affecting listed species requires understanding both threats and animal habitat-use patterns. However, the extent of spatial overlap between high-use foraging areas (where multiple marine species congregate) and anthropogenic threats is not well-known. Our modeling approach incorporates data on sea turtle spatial ecology and a suite of threats in the Gulf of Mexico to identify and map “hot spots” of threats to two imperiled turtle species. Of all 820 “high” threats grid cells, our tracked turtles foraged at least 1 day in 77% of them. Although threat data were not available outside the U.S. Exclusive Economic Zone, our map of turtle and threat “hot spots” can be incorporated in future more comprehensive threat analyses for the region. Knowledge of these shared foraging- and threat-areas can assist managers charged with designing effective conservation and population recovery strategies, in future habitat modeling efforts, and in designations of Gulf of Mexico habitat with high conservation value

Stable isotopes used to infer trophic position of green turtles (Chelonia mydas) from Dry Tortugas National Park, Gulf of Mexico, United States

Evaluating resource use patterns for imperiled species is critical for understanding what supports their populations. Here we established stable isotope (δ13C, δ15N) values for the endangered green sea turtle (Chelonia mydas) population found within the boundaries of Dry Tortugas National Park (DRTO), south Florida, USA. There is little gene flow between turtles sampled at DRTO and in other rookeries in Florida, underscoring the need to study this distinct population. Between 2008 and 2015 we collected multiple sample types (skin [homogenized epidermis/dermis], whole blood, red blood cells, plasma, carapace) from 151 unique green turtles, including 43 nesting females and 108 in-water captures; some individuals were resampled multiple times across years to evaluate consistency of isotope signatures. Isotopic ratios ranged from -27.3 to -5.4 for δ13C and 3.7 to 10.6 for δ15N. Using linear mixed models, we evaluated covariates (sample type, turtle size and year) that best explained the isotope patterns observed in turtle tissues. Predictions from the top model for δ13C indicated a slight decrease over time and for δ15N a slight increase in the middle sampling years (2010–2012); results indicated that turtle size appeared to be the driver behind the range in δ13C and δ15N observed in turtle skin. We found a pattern in stable carbon isotope values that are indicative of an ontogenetic change from an omnivorous diet in smaller turtles to a seagrass-based diet in larger turtles. When we compared the stable carbon and nitrogen isotope values of the samples collected from turtles with that of seagrasses found in DRTO, we found that turtles \u3e 65 cm SCL had similar stable carbon isotope values to the seagrass species present. Results of this study suggest stable isotope analysis coupled with data for available resources can be useful for tracking and detecting future changes in green turtle resource shifts in DRTO

Prior history of traumatic brain injury among persons in the Traumatic Brain Injury Model Systems National Database

OBJECTIVE: To determine the association between demographic, psychosocial, and injury-related characteristics and traumatic brain injury (TBI) occurring prior to a moderate or severe TBI requiring rehabilitation. DESIGN: Secondary data analysis. SETTING: TBI Model System inpatient rehabilitation facilities. PARTICIPANTS: Persons (N=4464) 1, 2, 5, 10, 15, or 20 years after TBI resulting in participation in the TBI Model System National Database. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: History of TBI prior to the TBI Model System Index injury, pre-Index injury demographic and behavioral characteristics, Index injury characteristics, post-Index injury behavioral health and global outcome. RESULTS: Twenty percent of the cohort experienced TBIs preceding the TBI Model System Index injury-80% of these were mild and 40% occurred before age 16. Pre- and post-Index injury behavioral issues, especially substance abuse, were highly associated with having had a prior TBI. Greater severity of the pre-Index injury as well as occurrence before age 6 often showed stronger associations. Unexpectedly, pre-Index TBI was associated with less severe Index injuries and better functioning on admission and discharge from rehabilitation. CONCLUSIONS: Findings suggest that earlier life TBI may have important implications for rehabilitation after subsequent TBI, especially for anticipating behavioral health issues in the chronic stage of recovery. Results provide additional evidence for the potential consequences of early life TBI, even if mild

δ13C and δ15N in the endangered Kemp’s ridley sea turtle Lepidochelys kempii after the Deepwater Horizon oil spill

The Deepwater Horizon explosion in April 2010 and subsequent oil spill released 3.19 × 106 barrels (5.07 × 108 l) of MC252 crude oil into important foraging areas of the endangered Kemp’s ridley sea turtle Lepidochelys kempii (Lk) in the northern Gulf of Mexico (GoM). We measured δ13C and δ15N in scute biopsy samples from 33 Lk nesting in Texas during the period 2010 to 2012. Of these, 27 were equipped with satellite transmitters and were tracked to traditional foraging areas in the northern GoM after the spill. Differences in δ13C between the oldest and newest scute layers from 2010 nesters were not significant, but δ13C in the newest layers from 2011 and 2012 nesters was significantly lower compared to 2010. δ15N differences were not statis- tically significant. Collectively, the stable isotope and tracking data indicate that the lower δ13C values reflect the incorporation of oil rather than changes in diet or foraging area. Discriminant analysis indicated that 51.5% of the turtles sampled had isotope signatures indicating oil exposure. Growth of the Lk population slowed in the years following the spill. The involvement of oil exposure in recent population trends is unknown, but long-term effects may not be evident for many years. Our results indicate that C isotope signatures in scutes may be useful biomarkers of sea turtle exposure to oil