Search Results

By the 1960s, Carr's activities for international sea turtle conservation developed along several pathways. The Caribbean Conservation Corporation and support from the US Navy facilitated Operation Green Turtle which aimed to re-establish nesting colonies of green turtles all across the Caribbean. As chairman of the Marine Turtle Group of the IUCN, Carr envisioned an ambitious program of international activism on behalf of sea turtles worldwide, but IUCN followed a more conservative path and focused on smaller, regional initiatives. The long and arduous process of establishing Tortuguero National Park revealed the challenges of sea turtle conservation. Finally, despite his early support for sea turtle farming as a possible conservation strategy, Carr criticized efforts to develop the commercial turtle farming on the grounds that in the short run it would stimulate international demand for sea turtle products without significantly increasing supply to circumvent poaching of wild stocks.

Carr spent more than thirty years dedicated to the study of the ecology and migration of sea turtles. Many of the stories he had heard from the turtle captains had been confirmed through tag returns from all over the Caribbean. The riddle of the ridley had been solved and documented by an old, grainy film, but it virtually disappeared during the 1960s. Carr's research extended beyond Tortuguero and the Caribbean to include Ascension Island, and he collaborated with other scientists to produce ambitious theories regarding olfaction, vision, and the role of seafloor spreading. Carr and his students participated in the Western Atlantic Turtle Symposium, an event that suggested growing interest in the ecology and conservation of sea turtles. Nevertheless, questions still remained. Sargassum mats had initially seemed promising as a refuge for sea turtles during their lost year, but oceanic zones of convergence (including sargassum) seemed to be a more promising explanation.

The seven years following the Carrs return from Honduras proved to be highly productive and successful. Carr published High Jungles and Low and the Handbook of Turtles. He also inaugurated his study of the ecology and migration of sea turtles with funding from the American Philosophical Society, the National Science Foundation, and the Office of Naval Research. Carr's experiences during preliminary research trips provided fodder for another popular travel narrative, The Windward Road. Fortuitously, The Windward Road came to the attention of Joshua Powers, who rallied the support of his friends to form the Brotherhood of the Green Turtle and the Caribbean Conservation Corporation, an organization dedicated to the conservation of sea turtles. Thus, even as Carr's study of sea turtles was gaining momentum, he secured additional and unanticipated support for related conservation efforts.

This chapter examines the biology of sea turtles in the tropical dry forest beaches of Costa Rica. It first discusses the development of Parque Marino Las Baulas on the Guanacaste coast. It then describes the history of sea turtle conservation and examines its local, national, and international aspects. Finally, it presents lessons and recommendations for future conservation of sea turtles in Costa Rica.

Sea turtle populations are threatened globally due to anthropogenic and natural factors, including fisheries interactions, watercraft strike, hunting, habitat loss, pollution, climate change, and severe weather. Injured and ill sea turtles are often evaluated by wildlife rehabilitation centres, and many sea turtles can be returned to the wild after rehabilitation. Physiological evaluation of injured and ill sea turtles has revealed life-threatening physiological dysfunction such as acidosis, hypoxia, hypercarbia, dehydration, and hyperkalaemia. Recognition and management of such conditions has improved the outcome for these patients. In addition to clinical advancement, veterinary evaluation has improved our understanding of general sea turtle biology, and increased the safety of procedures such as anaesthesia and laparoscopy. These modalities, combined with emerging biotelemetry technologies, will continue to improve our understanding of sea turtle ecology and conservation physiology.

This chapter discusses experimental approaches used to study the ecology and physiology of the critically endangered leatherback sea turtle (Dermochelys coriacea). It describes the measurement of field metabolic rates (FMRs) of leatherbacks using the doubly-labeled-water (DLW) method. It also discusses how to estimate FMRs based on aerobic dive limits and similarities in the behavior and physiology of two different species.

This chapter discusses the diversity of turtles and tortoises in Baja California and the Gulf of California. It examines their characteristics, distribution, and natural history. The Emylidae (pond turtles and sliders) are represented by two genera and two species: Clemmys marmorata (Western Pond Turtle), Trachemys nebulosa (Baja California Slider). The Testudinae (land tortoises) has only one living Baja California representative, Gopherus agassizii (Desert Tortoise). The Gulf of California and the west coast of Baja California peninsula are important nesting sites for the Cheloniidae family (sea turtles), represented by four genera and four species. The Dermochelyidae (leatherbacks) family has the largest and most distinctive of all living turtles, Dermochelys coriacea. This species is rare in the Gulf of California. The Trionychidae family (soft-shell turtles) is represented by Apalone spinifera, a freshwater turtle occurring in Río Colorado and associated drainages of northeastern Baja California.

This chapter examines modified and unmodified archaeological remains of sea turtles from Nuʻalolo Kai. The 1958–1964 and 1990 archaeological excavations at Nuʻalolo Kai yielded only a small number of sea turtle remains relative to the total bone assemblage, but the sample represents the largest collection of sea turtle bones recovered from an archaeological site in the Hawaiian Islands. This collection is also unique in that it contains identified elements from both the green sea turtle and the hawksbill turtle. This chapter discusses the presence of sea turtle remains in the archaeological collection from Nuʻalolo Kai, with particular emphasis on the distribution of modified and unmodified elements in the stratified deposits. The results indicate that sea turtles were used extensively in the later occupations of Nuʻalolo Kai and that hunting focused on the subadult and adult portions of the population.

This chapter outlines methods most commonly used to gather management-relevant data on sea turtles from the study of nesting beaches. Nesting beach studies are implemented worldwide and provide a foundation from which to estimate reproductive output and population size and trend. Although monitoring nesting beaches via aerial surveys provides rapid access to remote and expansive beaches, ground-based patrols generally provide more reliable information. Among the key elements of a nesting beach monitoring programme are accurate species identification based on visual observation of the turtle or its crawl signs, location and confirmation of successful versus unsuccessful nesting attempts, and collection of metrics related to reproductive output. Tagging initiatives strengthen inferences and data analyses by facilitating the identification of individuals over time. Lastly, interviewing the local population can provide valuable information about sea turtle populations, including both historic and contemporary patterns of nesting, exploitation, and commerce.

Sea turtles are an endangered species, while shrimping is the most profitable U.S. fishery. Thus, the incidental death of sea turtles in shrimp trawls (a problem generally known as bycatch) became one of most controversial problems ever confronted by U.S. fisheries management. Each stakeholder—from politicians to schoolchildren, fishers to environmentalists, and scientists to fisheries managers—had differing opinions on how best to resolve the problem, and cooperation between groups was critical to a successful solution, which came in the form of a turtle excluder device (TED)—a type of turtle escape hatch in the shrimp net. This chapter describes examples of fractionated and enforced trading zones as they played out in the TED case study. It offers evidential support for the hypothetical portrayal of the evolution of a trading zone proposed by Collins, Evans, and Gorman (2007) by organizing the case study within the trading zone model, thus showing the evolution from institutional power to boundary object to interactional expertise.

This chapter focuses on magnetoreception in animals. It provides a brief overview of the physics of the Earth's magnetic fields, followed by a description of animals known to sense these fields. Magnetic sense is present in many invertebrates such as bees, mealworm beetles, termites, lobsters, and marine mollusk. Migratory vertebrates that respond to magnetic fields include elasmobranchs, salmon, trout, eels, and tuna. Amphibians, birds, and mammals such as the blind mole rat use magnetic cues for navigation. The chapter also identifies sea turtles and cetaceans as the only secondarily aquatic tetrapods that have magnetic sense.

Many migrations match life histories to special habitat requirements. One such requirement is that of refuges. Waterfowl are particularly vulnerable during molt, and many migrate to sites offering protection at this time. Other species require specific breeding sites. Included among these are amphibians that must return to water to breed and terrestrial crustaceans that must return to the sea to deposit their eggs. Sea turtles and oceanic birds return to localized beaches and islands for their breeding, requiring the ability to locate what are dots on the face of the earth. There is an extensive discussion of diadromy. This mostly occurs in fishes, many of which are important commercial species, but it is also present in snails and crabs. Diadromy includes many of the most interesting cases of both ancient and contemporary evolutionary pathways to specialized life histories.

This chapter outlines some of the ways in which migrants take advantage of perturbations in air and water to facilitate their journeys. The winds and currents considered range from those of planetary scale weather acting over thousands of kilometers to those of nanoscale events acting over distances of ≤10 m on small organisms. Following a brief introduction to weather and ocean circulation patterns, several examples are considered of migrants that use winds or currents to aid transport. Waterfowl, moths, sea turtles, and eels are but some of the migrants to enhance both the timing and routes of their journeys. Methods such as radar have produced major advances in understanding the use of atmospheric conditions, for instance thermals, and the ability to compensate for wind drift. The new tracking methods have provided much insight into the interactions between oceanic migrations and current systems like the Gulf Stream. Natural selection has produced often remarkable abilities to orient by selecting specific winds and currents of appropriate direction and velocity.