Stoichiometry, growth, and fecundity responses to nutrient enrichment by invertebrate grazers in sub-tropical turtle grass (Thalassia testudinum) meadows

Although the effectiveness of herbivores in mitigating the effects of nutrient enrichment is well documented, few studies have examined the effects of nutrient enrichment on components of consumer fitness. Enclosures were deployed in shallow turtle grass (Thalassia testudinum) beds in Florida Bay, Florida in fall 2003, spring 2004, and fall 2004 to measure the effects of nitrogen and phosphorous enrichment on the growth, fecundity, and stoichiometry of three invertebrate epiphyte grazers commonly associated with T. testudinum. The gastropod Turbo castanea exhibited significantly greater wet weight gain and lower C:P and N:P in enriched than in ambient treatments. Although nutrient enrichment did not have any significant effects on the growth of caridean shrimp (treatment consisted of several different caridean shrimp species), their C:N was significantly lower in enriched treatments. The final size and stoichiometry of the hermit crab Paguristes tortugae was not significantly affected by nutrient enrichment, nor did nutrient enrichment significantly affect the fecundity of P. tortugae, the only grazer in which gravid individuals or egg masses were present. Our study demonstrated that nutrient enrichment of primary producers can positively affect the growth of marine invertebrate grazers and alter their stoichiometry; however, these effects were species-specific and may be dependent upon the life stage, specific diets, and/or compensatory feeding habits of the grazers.

Anatomy and variability of "Cuvierichelys parisiensis", a geoemydid turtle that crosses the Eocene-Oligocene boundary in Belgium

Abundant material of turtles from the early Oligocene site of Boutersem-TGV (Boutersem, Belgium), is presented here. No information on the turtles found there was so far available. All the turtle specimens presented here are attributable to a single freshwater taxon that is identified as a member of Geoemydidae, Cuvierichelys. It is the first representative of the ‘Palaeochelys s. l.–Mauremys’ group recognized in the Belgian Paleogene record. This material, which allows to know all the elements of both the carapace and the plastron of the taxon, cannot be attributed to the only species of the genus Cuvierichelys so far identified in the Oligocene, the Spanish form Cuvierichelys iberica. The taxon from Boutersem is recognized as Cuvierichelys parisiensis. Thus, both the paleobiogeographic and the biostratigraphic distributions of Cuvierichelys parisiensis are extended, its presence being confirmed for the first time outside the French Eocene record. The validity of some European forms is refuted, and several characters previously proposed as different between Cuvierichelys iberica and Cuvierichelys parisiensis are recognized as subjected to intraspecific variability.

Monitoring and conservation of the largest loggerhead turtle (Caretta caretta) nesting population in Africa: successes and challenges.

[EN] The Republic of Cape Verde is situated about 500 km off the coast of Senegal, West Africa. The islands of Sal, Boa Vista and Maio constitute the Eastern group and harbour the most important nesting beaches for loggerhead turtles in the Archipelago. During 1998-2004 nesting seasons, fieldwork has been focused on the eastern beaches of Boa Vista and, occasionally, in other beaches of Boa Vista and in the islands of Maio, Sal and Santa Luzia. The main study area includes a total extension of 3.1 km of suitable nesting beaches. All through these years, a tagging program has been carried out, alongside recording of biological data and monitoring of nests.

Fusarium solani is responsible for mass mortalities in nests of loggerhead sea turtle, Caretta caretta, in Boavista, Cape Verde

[EN] The fungus Fusarium solani (Mart.) Saccardo (1881) was found to be the cause of infections in the eggs of the sea turtle species Caretta caretta in Boavista Island, Cape Verde. Egg shells with early and severe symptoms of infection, as well as diseased embryos were sampled from infected nests. Twenty-five isolates with similar morphological characteristics were obtained. Their ITS rRNA gene sequences were similar to the GenBank sequences corresponding to F. solani and their maximum identity ranged from 95% to 100%.

Population structure and conservation implications for the loggerhead sea turtle of the Cape Verde Islands

[EN] The Cape Verde Islands harbour the second largest nesting aggregation of the globally endangered loggerhead sea turtle in the Atlantic. To characterize the unknown genetic structure, connectivity, and demographic history of this population, we sequenced a segment of the mitochondrial (mt) DNA control region (380 bp, n = 186) and genotyped 12 microsatellite loci (n = 128) in females nesting at three islands of Cape Verde. No genetic differentiation in either haplotype or allele frequencies was found among the islands (mtDNA FST = 0. 001, P > 0. 02; nDNA FST = 0. 001, P > 0. 126). However, population pairwise comparisons of the mtDNA data revealed significant differences between Cape Verde and all previously sequenced Atlantic and Mediterranean rookeries (FST = 0. 745; P < 0. 000).

Twelve new polymorphic microsatellite markers from the loggerhead sea turtle (Caretta caretta) and cross-species amplification on other marine turtle species

[EN] We describe 12 new polymorphic dinucleotide microsatellite loci and multiplex Polymerase Chain Reaction conditions from the loggerhead sea turtle Caretta caretta. Levels of polymorphism were assessed in 50 individuals from the nesting population of the Cape Verde Islands.

Phenotypically linked dichotomy in sea turtle foraging requires multiple conservation approaches

[EN] Marine turtles undergo dramatic ontogenic changes in body size and behavior, with the loggerhead sea turtle, Caretta caretta, typically switching from an initial oceanic juvenile stage to one in the neritic, where maturation is reached and breeding migrations are subsequently undertaken every 2-3 years [1-3]. Using satellite tracking, we investigated the migratory movements of adult females from one of the world's largest nesting aggregations at Cape Verde, West Africa. In direct contrast with the accepted life-history model for this species [4], results reveal two distinct adult foraging strategies that appear to be linked to body size. The larger turtles (n = 3) foraged in coastal waters, whereas smaller individuals (n = 7) foraged oceanically.

Natural colonization of loggerhead turtle eggs by the pathogenic fungus Fusarium oxysporum

[EN] Sea turtle nests are exposed to different environmental risks that may affect their hatching success. Human exploitation, predation by wild or domestic animals, nest flooding or severe beach erosion or accession are common causes of egg mortality. However, there is very little information about the impact of microorganisms on turtle eggs. We analyzed loggerhead turtle eggs from Boavista Island (Republic of Cabo Verde) which were incubated under different environmental conditions in order to evaluate the presence and impact of fungus. We have isolated Fusarium oxysporum from dead and live eggs after three days of incubation.

The international importance of the archipelago of Cape Verde for marine turtles, in particular the loggerhead turtle Caretta caretta

[ES] The shores of Cape Verde hosts one of the most important nesting populations of the loggerhead turtle Caretta caretta in the world, as well as important feeding grounds for hawksbill Eretmochelys imbricata and green turtles Chelonia mydas. In the past few years, a number of scientific studies have demonstrated the relevance of the waters and beaches of this archipelago for the conservation of these endangered marine megavertebrates. This article aims to bring together the most relevant scientific information published on the subject so far. In addition, we will provide an overview of the current situation of sea turtles in Cape Verde, their conservation status and their importance in an international context.

New records of the olive ridley sea turtle Lepidochelys olivacea (Eschscholtz, 1829) from the Cape Verde Islands

[ES] The olive ridley sea turtle Lepidochelys olivacea has been recorded in the Cape Verde Islands, but the most recent published data (1998-2000) are of stranded ndividuals and remains only. This article presents new data on olive ridleys recorded during the years 2001-2011 on Boavista and Sal islands. The presence of his species does not appear to be related to nesting activity. The possible geographical origin of these turtles is discussed. In addition, we propose some studies that could help to reinforce the conservation of sea turtles in West Africa.

Urban hazards : spatial ecology and survivorship of a turtle in an expanding suburban environment

Evaluating the Effects of Sea Level Rise on Sea Turtle Nesting Sites: A Case Study of the Archie Carr National Wildlife Refuge

The purpose of this thesis was to determine the extent of sea level rise (SLR) impact on sea turtle nesting beach habitat on Archie Carr National Wildlife Refuge (NWR) as well as impacts on management strategies. The Archie Carr NWR is of exceptional importance due to the high density of Loggerhead, Leatherback, and Green sea turtles that nest there in the summer months. GIS data provided by the Archie Carr NWR and various SLR scenarios, provided by both the Intergovernmental Panel on Climate Change (IPCC) as well as leading scholars, were used to determine inundation area loss across the Refuge as well as nearby parcels targeted for possible acquisition. Inundation losses for the six scenarios were calculated to be in the 20-25% range. Approximately 26% of current lower priority parcels are reclassified as high priority when integrating this information. Therefore, a significant revision to future acquisition strategies is recommended.

Novel insights into the dynamics of green turtle fibropapillomatosis

Outbreaks of fibropapillomatosis (FP), a neoplastic infectious disease of marine turtles, have occurred worldwide since the 1980s. Its most likely aetiological agent is a virus, but disease expression depends on external factors, typically associated with altered environments. The scarcity of robust long-term data on disease prevalence has limited interpretations on the impacts of FP on turtle populations. Here we model the dynamics of FP at 2 green turtle foraging aggregations in Puerto Rico, through 18 yr of capture-mark-recapture data (1997−2014). We observed spatiotemporal variation in FP prevalence, potentially modulated via individual site-fidelity. FP ex pression was residency dependent, and FP-free individuals developed tumours after 1.8 ± 0.8 yr (mean ± SD) in the infected area. Recovery from the disease was likely, with complete tumour regression occurring in 2.7 ± 0.7 yr (mean ± SD). FP does not currently seem to be a major threat to marine turtle populations; however, disease prevalence is yet unknown in many areas. Systematic monitoring is highly advisable as human-induced stressors can lead to deviations in host− pathogen relationships and disease virulence. Finally, data collection should be standardized for a global assessment of FP dynamics and impacts.