Raymond Carthy

United States Geological Survey | USGS · Cooperative Research Units Program

Little is known about the post-nesting migration and foraging areas of hawksbill turtles (Eretmochelys imbricata) nesting on St. Kitts and Nevis, an important nesting site for hawksbills in the eastern Caribbean. To elucidate internesting, migration and foraging patterns of hawksbills from Nevis, we satellite tagged 28 post-nesting turtles between...

Fibropapillomatosis (FP) is a neoplastic disease most often found in green turtles (Chelonia mydas). Afflicted turtles are burdened with potentially debilitating tumors concentrated externally on the soft tissues, plastron, and eyes and internally on the lungs, kidneys, and the heart. Clinical signs occur at various levels, ranging from mild diseas...

Context Sea turtle hatchlings generally emerge at night from nests on sand beaches and immediately orient using visual cues, which are believed to entail the difference in brightness between the light seen in the seaward direction and that seen in the duneward direction. Aim The aim of this study was to understand how dune proximity affected hatchl...

Emerging infectious diseases of wildlife have markedly increased in the last few decades. Unsustainable, continuous, and rapid alterations within and between coupled human and natural systems have significantly disrupted wildlife disease dynamics. Direct and indirect anthropogenic effects, such as climate change, pollution, encroachment, urbanizati...

Close to 19.6 million people live in Florida, and 76.5% of them, or approximately 15 million, live on the coast. Florida’s coasts are attractive despite the increasing risks from sea-level rise and more frequent climatic events such as hurricanes and coastal flooding. At particular risk from these erosive events are Florida’s 825 miles of sandy bea...

A unique drone-based system for underwater mapping (bathymetry) was developed at the University of Florida. The system, called the “Bathy-drone”, comprises a drone that drags, via a tether, a small vessel on the water surface in a raster pattern. The vessel is equipped with a recreational commercial off-the-shelf (COTS) sonar unit that has down-sca...

A unique drone-based system for underwater mapping (bathymetry) was developed at the University of Florida. The system, called the “Bathy-drone”, comprises a drone that drags, via a tether, a small vessel on the water surface in a raster pattern. The vessel is equipped with a recreational commercial off-the-shelf (COTS) sonar unit that has down-sca...

The recent developments of new deep learning architectures create opportunities to accurately classify high-resolution unoccupied aerial system (UAS) images of natural coastal systems and mandate continuous evaluation of algorithm performance. We evaluated the performance of the U-Net and DeepLabv3 deep convolutional network architectures and two t...

Dermatemys mawii is a critically endangered freshwater turtle endemic to Central America. In the wild, these turtles are thought to be wholly herbivorous as adults and feed on a variety of vegetation; however, no studies have quantitatively assessed potential dietary differences based on biotic and abiotic factors. The purpose of our study was to d...

Goforth, K.M. and Carthy, R.R., 2022. Tidally-driven gas exchanges in beaches: Implications for sea turtle nest success. Journal of Coastal Research, 38(3), 523537. Coconut Creek (Florida), ISSN 0749-0208. The success of individual sea turtle nests is influenced by nest location on the beach and the resulting incubation environment. Several abiotic...

Endangered leatherback sea turtles (Dermochelys coriacea) are wide‐ranging, long‐distance migrants whose movements are often associated with environmental cues. We examined the spatial distribution and habitat use for 33 satellite‐tracked leatherbacks from nesting beaches on the Caribbean coast of Costa Rica and Panama from 2004 to 2018, an importa...

On sea turtle nesting beaches, artificial lighting associated with human development interferes with hatchling orientation from nest to sea. Although hatchling disorientation has been documented for many beaches, data that managers can use in understanding, predicting, and managing the issue are of limited detail. The present study provides baselin...

The Central American river turtle Dermatemys mawii is a critically endangered species that has incurred substantial losses over the last several decades due to overhunting. This species is now being considered for head-starting programmes (i.e., captive breeding of turtles for wild release). However, relatively little is known about their life hist...

Management of imperiled species facing spatiotemporally dynamic threats is difficult. Systems thinking can inform their management by quantifying the impacts that they face. We apply systems thinking to the Northern Gulf of Mexico (NGM) loggerhead (Caretta caretta) Recovery Unit (RU), one of the smallest subpopulations of loggerheads nesting in the...

Sea turtle hatchlings emerge from nests at night on sand beaches and immediately orient using visual cues. These cues involve horizon brightness, and on beaches without artificial lighting, hatchling orientation is seaward. Although many studies have examined which visual cues influence hatchling orientation, we found no work focused on a compariso...

• Fisheries bycatch of non‐target species in the commercial fleet is a major source of anthropogenic injury and mortality for sea turtles and marine megafauna. • The Río de la Plata maritime front (RLPMF) and its adjacent international waters – comprising part of the Argentine and Uruguayan exclusive economic zones, is a highly important fishing gr...

The warming climate presents a challenge to conservation of all threatened and endangered species but particularly to those that exhibit temperature-dependent sex determination such as sea turtles. Changes in temperature may result in changes in the sex ratio of the population which can directly affect reproductive rate, abundance and population dy...

All five species of sea turtle that occur in Florida are in danger of extinction. This 4-page fact sheet written by Jessica E. Swindall, Holly K. Ober, Margaret M. Lamont, and Raymond R. Carthy and published by the UF/IFAS Department of Wildlife Ecology and Conservation discusses common human actions that are harmful to sea turtles and provides ins...

Lidar from small unoccupied aerial systems (UAS) is a viable method for collecting geospatial data associated with a wide variety of applications. Point clouds from UAS lidar require a means for accuracy assessment, calibration, and adjustment. In order to carry out these procedures, specific locations within the point cloud must be precisely found...

Florida’s dynamic beach-dune ecosystem and the structures built along the shore face threats from coastal (or shoreline) erosion, sea level rise, and inadequate regulatory protection efforts. In light of these threats, private property owners are choosing to install coastal armoring on their property to protect upland structures which can negativel...

The Archie Carr National Wildlife Refuge, Florida, USA (27.946°N, − 80.494°W) represents one of the largest loggerhead turtle (Caretta caretta) nesting sites in the Western Hemisphere. Surprisingly, little work has been conducted to determine females’ post-nesting migratory behavior and characteristics of their foraging areas. Between 2008 and 2017...

Most sea turtle (Cheloniidae) species worldwide are endangered or threatened, with threats causing harm to sea turtles predominantly human‐induced. Thus, prevention of further declines to these imperiled species will require alteration of human behaviors. Regulations, incentives, and environmental education are 3 strategies that could be used to al...

To determine the relationship between the intent of owners of homes located near sea turtle nesting beaches in the state of Florida to engage in coastal conservation easements (CCE), the theory of planned behavior (TPB), environmental identity (EI) and relevant demographics were analyzed. As CCEs are a novel application of a proven conservation too...

Shoreline changes affect functionality of a sandy beach as a wildlife habitat and coastal erosion is among the primary causes of the changes. We examined temporal shifts in locations where loggerheads placed nests in relation to coastal erosion along a barrier island beach in the northern Gulf of Mexico. We first confirmed consistency in long-term...

The use of satellite systems and manned aircraft surveys for remote data collection has been shown to be transformative for sea turtle conservation and research by enabling the collection of data on turtles and their habitats over larger areas than can be achieved by surveys on foot or by boat. Unmanned aerial vehicles (UAVs) or drones are increasi...

Somatic growth is an integrated, individual-based response to environmental conditions, especially in ectotherms. Growth dynamics of large, mobile animals are particularly useful as bio-indicators of environmental change at regional scales. We assembled growth rate data from throughout the West Atlantic for green turtles, Chelonia mydas, which are...

Grande Riviere beach, on the island of Trinidad, supports the largest nesting population of leatherback turtles in the Caribbean region. Throughout the nesting season, nests are naturally disturbed by newly nesting females, resulting in egg breakage and loss of some nest viability. This environment is ideal for the growth and proliferation of micro...

We developed a Kemp’s ridley (Lepidochelys kempii) stock assessment model to evaluate the relative contributions of conservation efforts and other factors toward this critically endangered species’ recovery. The Kemp’s ridley demographic model developed by the Turtle Expert Working Group (TEWG) in 1998 and 2000 and updated for the binational recove...

Erratum to: Mar Biol (2014) 161:2659–2668 DOI 10.1007/s00227-014-2537-0The Open Robust Model methods used for analysis in this study were developed by Kendall and Bjorkland (2001) and Kendall (2010). The language used in this manuscript to describe formatting and implementation of data for these analyses was derived heavily from Phillips et al. (20...

Background/Question/Methods Sandy beaches are dynamic environments inhabited by specific biota structured by physical forces. These environments are commonly exposed to natural and anthropogenic induced changes, such as storage, transport, exchange of sand, erosion and renourishment. The ghost crab, Ocypode quadrata has been used as a bio-indicat...

In response to a call from the US National Research Council for research programs to combine their data to improve sea turtle population assessments, we analyzed somatic growth data for Northwest Atlantic (NWA) loggerhead sea turtles (Caretta caretta) from 10 research programs. We assessed growth dynamics over wide ranges of geography (9–33°N latit...

The foraging ecology and diet of the green turtle, Chelonia mydas, remain understudied, particularly in peripheral areas of its distribution. We assessed the diet of an aggregation of juvenile green turtles at the northern edge of its range during winter months using two approaches. Stomach content analyses provide a single time sample, and stable...

The southeastern USA hosts the largest nesting concentration of loggerhead turtles Caretta caretta in the Atlantic. Regionally significant nesting also occurs along the Caribbean coast of Mexico, in Cuba, and in the Bahamas. Previous studies of North Atlantic loggerhead turtle rookeries based on a 380 bp fragment of the mitochondrial control region...

Marine turtles in the Gulf of Mexico are at risk due to many anthropogenic threats including habitat degradation, commercial fishing, and petroleum activities. The severity of this risk was made apparent in 2010 with the occurrence of the Deepwater Horizon oil spill. The objectives of this study were to assess long-term trends in abundance and repr...

ABSTRACT: In numerous studies involving hatchling sea turtles, researchers have collected small numbers of hatchlings from nests a few hours before the turtles would otherwise have emerged naturally. This procedure makes it possible to do experiments in which the behavioral or physiological responses of numerous hatchlings must be tested in a limit...

Designing conservation strategies that protect wide-ranging marine species is a significant challenge, but integrating regional telemetry datasets and synthesizing modeled movements and behavior offer promise for uncovering distinct at-sea areas that are important habitats for imperiled marine species. Movement paths of 10 satellite-tracked female...

The southeastern United States supports one of two large loggerhead turtle (Caretta caretta) nesting aggregations worldwide and is therefore critical to global conservation and recovery efforts for the species. Previous studies have established the presence of four demographically distinct nesting populations (management units) corresponding to bea...

Green turtles spend most of their lives in coastal foraging areas where they face multiple anthropogenic impacts. Therefore, understanding their spatial use in this environment is a priority for conservation efforts. We studied the fine scale daily movements and habitat use of East Pacific green turtles (Chelonia mydas) at Laguna San Ignacio, a sha...

Caribbean Nicaragua has its own cultural logic that helps to explain the eating habits of indigenous communities that rely on sea turtle meat for nutrition and prefer its taste to that of other available meats. Nutritional costs and benefits form a fundamental part of this reliance, yet there are ecological, economic, cultural, and other factors th...

Hatching sea turtles may be at risk to fire ant predation during egg incubation, and especially at risk once pipped from the egg, prior to hatchling emergence from the nest. In addition to direct mortality, fire ants have the potential to inflict debilitating injuries that may directly affect survival of the young. The increased incidence of red im...

We studied the presence and distribution of 19 species at risk in northeastern Florida at the Camp Blanding Training Site (CBTS) during 2000–2001, seven years after the first major baseline surveys of CBTS were conducted. Much of the training conducted at CBTS deals with light infantry exercises, but the site is also used for mining, silviculture,...

There are multiple factors that may determine individual and population growth rates and understanding the impact of extrinsic factors, such as temperature, is important for successful recovery plan stock assessment and modelling. In January 2001 and January 2003, cold‐stunning events occurred along the northern Gulf of Mexico, in St Joseph Bay, Fl...

The Army is very concerned about the preservation of Threatened and Endangered Species (TES) that make their home on Army training lands. The gopher tortoise (Gopherus polyphemus) is one species that the Army is particularly concerned about. To ensure that the Army is able to execute its training mission requirements while mitigating adverse impact...

Estimates of abundance of threatened and endangered species are crucial for monitoring population status and recovery progress. For most wildlife species, multiple abundance estimation methods are available and the choice of method should depend on cost and efficacy. We field-tested the cost and efficacy of line transect, total count, sample count,...

Estimating threatened and endangered species (TES), population trends is essential to be able to track a species' recovery progress. Natural resources managers on military installations use a wide variety of survey and monitoring methods, with incomplete knowledge toward their accuracy. Using the gopher tortoise (Gopherus polyphemus) as the test ca...

A major difficulty in sea turtle conservation is the inability to nonlethally and noninvasively identify the sex of hatching sea turtles. Traditional sexing techniques such as plasma sex steroid quantification cannot be applied to hatchlings without sacrificing the hatchlings or utilizing invasive procedure. This paper presents a technique for sexi...

Thesis (Ph. D.)--University of Florida, 1996. Vita. Includes bibliographical references (leaves 113-121). Photocopy. s