Sea Turtles

Population of loggerhead turtles nesting in the Mediterranean Sea has probably evolved from the North Atlantic (NA) population, but is geographically and genetically distinct. We aggregated previously published and new unpublished data, and took two approaches to comparing these populations: an empirical one based on statistical analyses of morphological data, and a physiological one based on a Dynamic Energy Budget (DEB) model. We then analyzed causes of faster growth and maturation, but smaller size at puberty and ultimate size of the Mediterranean (MED) loggerhead turtles relative to their NA conspecifics. The empirical analysis showed that young juvenile, sexually mature, and fully grown MED individuals were consistently smaller in terms of length and mass. The physiological approach suggested physiological adaptations of the MED population to higher salinity and scarcer food availability. In particular, these adaptations included an increase in somatic maintenance needs, and a decrease in energy investment to reach and maintain sexual maturity. Our study therefore offers a mechanistic underpinning of previously observed but unexplained life-history traits, and showcases an application of DEB theory as a tool for comparative analysis of two distinct populations of the same species.

There is little doubt that marine turtles are a flagship species for wildlife tourism.  In some cases, this has turned out to be liability for sea turtle conservation, but in other cases, where for example turtle-based ecotourism has been developed, it has made a positive contribution to turtle conservation.  Examples of both cases are given.  Particular attention is given to the development of turtle-based ecotourism at Mon Repos Beach near Bundaberg, Australia.  This development is set in its historical context and its contribution to conservation is discussed.  Headstart projects for sea turtles in Sri Lanka are a tourist attraction.  While they are promoted as having positive conservation consequences and a survey indicates that visitors are on the whole convinced of this, their effects on turtle conservation is uncertain.  The farming of sea turtles provides a basis for tourism and can contribute to turtle conservation in ways outlined.  It is argued that insufficient attention has been given to legends, culture and history associated with sea turtles in the promotion of turtle-based tourism.  This is supported by Australian evidence.  Insufficient use has been made of the connections of indigenous Australians with sea turtles in turtle-based tourism.  Beneficial scope exist for developing connections between man and turtles further than at present in promoting turtle-based tourism.  This could add further to the role of turtle-based tourism in promoting turtle conservation.

This study presents a comprehensive genetic
analysis of stock structure for leatherback turtles (Dermochelys
coriacea), combining 17 microsatellite loci and
763 bp of the mtDNA control region. Recently discovered
eastern Atlantic nesting populations of this critically endangered
species were absent in a previous survey that found
little ocean-wide mtDNA variation. We added rookeries in
West Africa and Brazil and generated longer sequences for
previously analyzed samples. A total of 1,417 individuals
were sampled from nine nesting sites in the Atlantic and SW Indian Ocean. We detected additional mtDNA variation with
the longer sequences, identifying ten polymorphic sites that
resolved a total of ten haplotypes, including three new variants
of haplotypes previously described by shorter sequences.
Population differentiation was substantial between all but two
adjacent rookery pairs, and FST values ranged from 0.034 to
0.676 and 0.004 to 0.205 for mtDNA and microsatellite data
respectively, suggesting that male-mediated gene flow is not
as widespread as previously assumed. We detected weak
(FST = 0.008 and 0.006) but significant differentiation with
microsatellites between the two population pairs that were
indistinguishable with mtDNA data. POWSIM analysis
showed that our mtDNA marker had very low statistical
power to detect weak structure (FST\0.005), while our microsatellite marker array had high power. We conclude that
the weak differentiation detected with microsatellites reflects
a fine scale level of demographic independence that warrants
recognition, and that all nine of the nesting colonies should be
considered as demographically independent populations for
conservation. Our findings illustrate the importance of evaluating
the power of specific genetic markers to detect structure
in order to correctly identify the appropriate population
units to conserve.

Loggerhead sea turtles (Caretta caretta) are a species of endangered sea turtle, whose nesting and hatching success can be hindered by light pollution. We hypothesize that beaches with lower light pollution levels will have higher nesting success, i.e. higher number of nests, higher ratio of nests to false crawls, higher nest success, higher beach success, and lower nest relocation percentage. Using data from SeaTurtle.org and the 2015 VIIRS light data, we analyzed the effects of light pollution on loggerhead sea turtle nesting behavior. We performed a series on linear regressions to examine the relationship between light pollution and six sea turtle nesting success variables. We found a significant positive relationship between light pollution and the ratio of nests to false crawls, and a significant positive relationship between light pollution and the nest relocation percentage. The other four linear regressions were not statistically significant. However, low R 2 values indicate that light pollution does not explain much of the variation in these nesting success variables, and further studies should be conducted to investigate sea turtle nesting behavior.

Sea turtles, particularly green turtles (Chelonia mydas) are increasingly suffering from fibropapillomatosis, a disease that results in tumours that can severely inhibit normal movement and behaviour, leading to difficulty in feeding, obstructed vision, inhibited movement and inhibited internal organ functioning. The routine surgical removal of fibropapillomatosis tumours at rehabilitation facilities undoubtedly alleviates these behavioural and physiological burdens, but the immediate behavioural effects of removing tumours are not known. This study describes the activity budget of nine green turtles prior to undergoing surgical fibropapillomatosis tumour removal, one week after surgery, and one month after surgery. There were some significant changes in behaviour observed in each of the turtles one week after undergoing surgery. Turtles increased the time spent resting. Four turtles decreased and one increased the time spent investigating. Two turtles decreased the time spent swimming in repetitive patterns. Two decreased their time spent swimming randomly. Some behavioural changes were still present one month after surgery, and some behaviours that were significantly different one week after surgery reverted to pre-surgery levels after one month. A trend towards some more desirable behaviours (e.g. random swimming) and away from less beneficial behaviours (e.g. prolonged resting) was observed one month after surgery. This study highlights that surgery may result in behavioural changes in turtles, that the behavioural effect of surgery varies amongst individuals, and that the duration of the effects of surgery may also vary. We suggest that periodic behavioural monitoring of turtle behaviour before and after surgery would be helpful in tailoring husbandry practices to the needs of each individual, and increase our understanding of the immediate and longer-term effects of surgical tumour removal. Optimised post-operative care would promote recovery and encourage natural behaviour, thus contributing to the successful rehabilitation and long-term survival of endangered sea turtles in the wild.

Presentamos esta estrategia didáctica con información básica sobre las distintas especies de Tortugas Marinas, los problemas que enfrentan y algunas sencillas acciones que pueden ayudar a estos bellos reptiles que han surcado el océano desde los tiempos en que los dinosaurios reinaban sobre la tierra.

There are seven species of marine turtles living in the world and five come ashore to nest in Sri Lanka. All those five species are nesting on Rekawa beach and they are under threat of egg poaching. For a long time Rekawa villagers have collected all the turtle eggs for sale or local consumption. The main objective of this programme was conserving the marine turtle population nesting on Rekawa while providing alternative income for the villagers. At the same time we have conducted research on the turtles and observed their nesting frequencies. Over approximately four years, grants to the project provided employment to villagers that resulted in protection of 827 nesting female marine turtles and to the resulting 3328 nests containing 372,107 eggs. Successful incubation resulted in 305,128 hatchlings being released to the sea.

Rehabilitation is an important part of sea turtle conservation, and post-release tracking of the animals is both a way of obtaining information on their movements and behaviour and, at least temporarily, monitoring the success of the rehabilitation process. Two green turtles, Chelonia mydas, and one loggerhead turtle, Caretta caretta, were rehabilitated after long periods in captivity, and their movements followed by satellite tracking after their release near the south of Portugal. Location data were obtained for an average of 688 days after release. All three animals showed a directional movement and the last observed locations coincided with known feeding areas for both species, near the coasts of Mauritania and the state of Ceará, Brazil, for the green turtles, and near Cuba for the loggerhead. Bathymetry, surface currents, wind, sea surface temperature, chlorophyll-a concentration and geomagnetic field were analysed as spatial and environmental variables potentially affecting movement. Only bathymetry, sea surface temperature and geomagnetic variables showed significant association with the path choice. This project supports the notion that sea turtles have the ability to survive in the wild after long periods in captivity and to return to the species' known feeding areas, justifying the effort in their rehabilitation and post-release tracking.

During the last 70-100 years we have seen trends of decline in the world’s sea turtles populations.  This is due to high levels of turtle harvest and egg poaching. Both legal and illegal harvesting of adult and juvenile sea turtles has drastically impacted the population dynamics of Caribbean species. The hawksbill (Eretmochelys imbricata) and green turtles (Chelonia mydas) of the Turks and Caicos Islands have suffered massive population declines since the 1900s mostly due to over-harvesting (Stingell et al., 2013). Costa Rica’s history of egg poaching has had a huge impact on population dynamics of the leatherback sea turtle (Dermochelys coriacea) with estimates of total extinction within 50 years (Tomillo et al. 2008).  This literature review seeks to illuminate the current problems attributed to the population decline of Caribbean sea turtles and the relevant conservation strategies that are/should be implemented through the critically analysis of a variety of previous studies.

The story of the long-running Key West turtling industry is examined through historical research, the archaeological excavation of the Key West Turtle Kraals, and oral history. The turtling business helped to shape the island’s economy and development but at an unsustainable cost to the region’s sea turtles, especially the Green turtle (Chelonia mydas). The body of this paper, originally written in 2009, serves as the basis of the exhibit “The Rise and Fall of the Key West Turtle Fishing Industry” at the Key West Turtle Museum, Key West, Florida.

Latest information(2013) on the present status of sea turtles along India's mainland. A 2010-12 project initiative by WWF-India.Compiled and Edited by Annie Kurian.

(This survey is after a decadal gap since the last GOI-UNDP survey carried out between 2000-2002.And editors of this report-Marine Turtles of the Indian Subcontinent-were Kartik Shanker and BC Choudhury)

P.S  Included in the 2013 report is comprehensive chapter contribution by  Dr.Chandrashekar Kar, and a good review effort Dr.S.Bhupathy- predecessors and among the foremost in sea turtle research and conservation in India. It is sad that both of them passed away in April 2014, and this report probably constitutes among the last of their visible efforts!My deep gratitude and respect to both these wonderful people who enlightened other lives!

NOAA NMFS - 443

PP. 101-103

"The first described fossilized sea turtle nests occur as sedimentary structures preserved in the Fox Hills Sandstone, Elbert County, Colorado. They are Cretaceous analogs to Recent loggerhead sea turtle nests studied on St. Catherines Island, GA (Marsh and Bishop, 1993). Although sea turtles have an extensive geological record extending at least  into the Jurassic and Early Cretaceous (Nicholls, 1997; Hirayama, 1997), traces of their terrestrial nesting activities (Caldwell, Carr, and Ogren, 1959; Witherington [and Witherington, 2016]; Hailman and Elowson, 1992) have not been well documented in the literature and fossil traces have only recently been described (Bishop et al., 1997, [ 2011])."

N.B. Abstract slightly modified to new literature.

The study examines the economic educational and conservation values of sea turtle- based ecotourism in Australia. The centre-piece of this research is a case study undertaken at the Mon Repos Conservation Park located near the town of Bundaberg, Queensland. Each year from mid-November to end of March, thousands of visitors visit Mon Repos Conservation Park to view sea turtles either nesting on the 1 km stretch of beach or to see hatchlings emerge from their nests and march on to the sea or both. As a result of this activity there are considerable economic benefits to the Bundaberg region during the sea turtle season. The study examines the economic impact of sea turtle viewing at Mon Repos to the region. The study assesses the recreational value of sea turtle viewing. Furthermore, sea turtle-based ecotourism also provides educational and conservation benefits which are important for the protection and conservation of sea turtles especially in Australia. The study specifies the extent of the educational impact and conservation appreciation of sea turtle viewing at Mon Repos Conservation Park. As a background to the study, Mon Repos visitors' profile and socio-economic data of visitors are provided. In order to conduct this study, 1,200 survey forms were distributed, out of which 519 usable responses were obtained.

During the last half of the 20th century, the southern Mexican state of Oaxaca was home to one of the world’s largest sea turtle slaughterhouses which provided Olive Ridley turtle skins to the global leather market. Although the international demand for turtle leather led to a rapid depletion of Olive Ridley stocks, from the 1960’s to 1990 the Mexican turtle fishery went hand in hand with conservation measures and research programs which included beach monitoring, fishing restrictions, and breeding programs. Thanks in part to these controversial efforts to preserve the fishery, Mexico has some of the most complete historical records of sea turtle captures. After the Mexican federal government banned all
sea turtle captures in 1990, the region underwent profound changes as the main source of income for the vast majority of the population became illicit. In spite of efforts by government agencies and NGOs to convert the area to ecotourism, shark fishing soon became an important source of income, primarily due to the increase in demand for shark fins in East Asian markets. Although Olive Ridley Sea Turtles enjoyed a quick recovery
after the ban (partly due to conservation efforts during the fishery years), shark populations rapidly declined. Both the shark and sea turtle fisheries in the region appeared and grew as a result of growing demands in the global market. In this case study, the analysis of historical and ethnographic data allows for a deeper understanding of the relationship between economics and socio-economic adaptation with marine animal and ecosystem exploitation.

Reptilien gehören in der sächsischen Kreide (Elbtal-Gruppe) zu den Seltenheiten. Die wenigen bekannten Reste sind historische Funde, die erstmals im 19. Jahrhundert von Hanns Bruno Geinitz bearbeitet wurden. Sie stammen aus zwei stratigraphischen Einheiten, der Dölzschen-Formation (oberes Obercenomanium) sowie dem Strehlener und Weinböhlaer Kalk der unteren Strehlen-Formation (mittleres Oberturonium) und wurden fast ausschließlich im heutigen Stadtgebiet von Dresden gesammelt. Die Exemplare aus der Dölzschen-Formation sind sehr fragmentarisch erhalten und konnten keiner Gruppe mit Sicherheit zugeordnet werden. Das Material aus dem Strehlener Kalk hingegen zeigt, dass zwei Plesiosaurier-Familien (Elasmosauridae und ?Polycotylidae) sowie verschiedene marine Schildkröten der Familie Protostegidae im sächsischen Kreidebecken vorkamen. Hinweise auf Squamaten (Mosasauridae und Dolichosauridae), wie von Geinitz (1875a) postuliert, fehlen hingegen.

Reptilian fossils are rare in the Saxonian Cretaceous (Elbtal Group). The few known specimens are historical finds, first described by Hanns Bruno Geinitz in the 19th century. They derive from two stratigraphical units, the Dölzschen Formation (upper Upper Cenomanium) and the Stehlen and Weinböhla Limestone of the lower Strehlen Formation (mid-Upper Turonian) and were collected almost exclusively within the current city limits of Dresden. Remains from the Dölzschen Formation are very fragmentary and cannot be referred to any taxonomic group with certainty. On the other hand, better preserved material from the Strehlen and Weinböhla Limestone reveals the presence of at least two different plesiosaurian families (Elasmosauridae and ?Polycotylidae) as well as different marine turtles of the family Protostegidae. However, evidence of mosasaurid and dolichosaurid marine squamates, as suggested by Geinitz (1875a), is missing.

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Some of the most basic questions of sea turtle life history are also the most elusive. Many uncertainties surround lifespan, growth rates, maturity and spatial structure, yet these are critical factors in assessing population status. Here we examine the keratinized hard tissues of the hawksbill (Eretmochelys imbricata) car-apace and use bomb radiocarbon dating to estimate growth and maturity. Scutes have an established dietary record, yet the large keratin deposits of hawksbills evoke a reliable chronology. We sectioned, polished and imaged posterior marginal scutes from 36 individual hawksbills representing all life stages, several Pacific populations and spanning eight decades. We counted the apparent growth lines, microsampled along growth contours and calibrated D 14 C values to reference coral series. We fit von Bertalanffy growth function (VBGF) models to the results, producing a range of age estimates for each turtle. We find Hawaii hawksbills deposit eight growth lines annually (range 5–14), with model ensembles producing a somatic growth parameter (k) of 0.13 (range 0.1–0.2) and first breeding at 29 years (range 23–36). Recent bomb radio-carbon values also suggest declining trophic status. Together, our results may reflect long-term changes in the benthic community structure of Hawaii reefs, and possibly shed light on the critical population status for Hawaii hawksbills.

Excavations at Kavuşan Höyük (southeastern Turkey) have revealed evidence of the use of turtles, tortoises and terrapins in post-Assyrian funerary practices. Of particular significance are the remains of the Euphrates soft-shelled turtle (Rafetus euphraticus), distinguished from other species of turtle by their quantity and treatment in the burial pit under investigation here. The unique finds from Kavuşan Höyük, coupled with archaeological and textual records, underline the economic and symbolic significance of these animals for communities in prehistoric and early historical Mesopotamia.

El Área de Conservación Osa (ACOSA), tiene 245 km de longitud costera, 158,721 ha terrestres protegidas y únicamente 11,675 ha de extensión marina protegida. Contiene 17 áreas protegidas, incluidas el Parque Nacional Marino Ballena, el Humedal Nacional Térraba-Sierpe, la Reserva Biológica Isla del Caño y el Parque Nacional Corcovado, todas con un fuerte componente marino-costero. El Golfo Dulce en particular, es un cuerpo de agua de 50 km de longitud, con una superficie aproximada de 680 km2. Se caracteriza por poseer una cuenca interna de pendiente pronunciada con una profundidad máxima de 215 m y un umbral poco profundo en su entrada de 60 m, lo que hace que posea características oceanográficas excepcionales. Podría albergar el 23% de la diversidad marina de nuestra costa Pacífica, por lo que se conoce como un punto caliente para la diversidad marina de nuestro país. Estas zonas marinas del Pacífico Sur dentro de ACOSA y especialmente el Golfo Dulce, han sido seleccionadas como un área de importancia para la biodiversidad marina y costera por el proceso Ordenamiento Territorial para la Conservación de la Biodiversidad de Costa Rica (GRUAS II), en donde se destacan los sistemas estuarinos (manglares), sistemas intermareales (acantilados de roca dura, playas de arena gruesa y fina), sistemas submareales (formaciones coralinas, fondos rocosos, fondos de lodo bioclásticos y litoclásticos) y la fosa anóxica. De igual manera, toma importancia la presencia de playas de anidación de tortugas marinas y los hábitats que favorecen la presencia de cetáceos. El objetivo de GRUAS II fue optimizar los esfuerzos nacionales para la conservación in situ de la biodiversidad marina costera del país, a través de la orientación de las políticas nacionales de ordenamiento territorial con fines de conservación de la biodiversidad, utilizando el mejor conocimiento científico disponible y mediante un proceso participativo y transparente. En este sentido, el objetivo de este Volumen Especial es aportar conocimiento científico relevante para evaluar el estado de conservación de los elementos focales de manejo en ACOSA para estos sitios. Como sucede en muchas zonas marino costeras del paísla mayoría de las datos corresponden a descripciones generales de los principales ambientes marinos, pero poca información específica como, por ejemplo, patrones de corrientes, impacto de la actividad pesquera, ecología de las comunidades, entre otras. Es así como este suplemento aporta información actualizada sobre organismos de la costa rocosa, playas arenosas y fangosas, que habían sido poco estudiadas a la fecha. Se han descrito la estructura poblacional de la piangua para algunos sitios dentro del golfo, sin duda el molusco de mayor importancia comercial en la zona. Desde inicios de los años 80, las formaciones coralinas habían sido estudiadas solo en su cobertura; sin embargo, se presenta ahora información relevante complementaria a cobertura, como rugosidad, diversidad y densidad de macro invertebrados, así como la diversidad y biomasa de peces arrecifales. Se rescataron esfuerzos de más de 16 años de trabajo de monitoreo de playas de anidación de tortugas marinas dentro del Gofo Dulce, así como también nuevos datos sobre la caracterización de anidación y agregaciones de tortugas lora y sobre alimentación de tortugas carey. Al ser Golfo Dulce una de las cinco Áreas Marinas de Uso Múltiple (AMUM) del país y, simultáneamente, un Área Marina de Pesca Responsable (AMPR), es de especial importancia tomar en cuenta los datos acá presentados sobre abundancia y reproducción de tiburones así como la caracterización de las pesquerías de varias especies de tiburones y rayas. Es importante destacar la valiosa información que ha resultado de los estudios generados por el Instituto Costarricense de Electricidad, que con esta iniciativa permite el acceso de información relevante relacionada al Humedal Nacional Térraba-Sierpe. Ahora es posible contar con información relacionada a la distribución espacial de las especies de mangle, su asociación con los tipos de sedimentos y la dinámica oceanográfica frente a sus costas. Así como también, entender acerca de la distribución espacial y temporal de la salinidad en la columna de agua y la productividad primaria relacionada a este humedal. Ahora contamos con mejor información técnica confiable como insumo para la toma de decisiones de manejo. Es importante recalcar que muchos autores recomiendan medidas de manejo y conservación que deben ejecutarse para velar por la salud de la población o ecosistema de estudio. Alentamos respetuosamente a las autoridades y gobierno a tomar estas recomendaciones en cuenta, a través del fortalecimiento de las instituciones públicas que hoy en día velan por la perpetuidad de dichos ecosistemas y especies.