Varo-Cruz N.,University of Las Palmas de Gran Canaria |
Hawkes L.A.,University of Exeter |
Hawkes L.A.,Bangor University |
Cejudo D.,Cabo Verde Natura 2000 |
And 4 more authors.
Journal of Experimental Marine Biology and Ecology | Year: 2013
In recent years, information about the movements and timing of migration by male sea turtles has begun to be unraveled. Here, we present the first satellite tracking of male loggerhead sea turtles (Caretta caretta) in the eastern Atlantic. Satellite linked transmitters were attached to five adult males, captured in the near shore waters off Boavista, Republic of Cape Verde. This archipelago hosts the single most important breeding site of loggerhead turtles in the eastern Atlantic. Animals were tracked for periods ranging between 48 and 537. days, including a probable annual remigration to the vicinity of the nesting ground for one turtle. Males showed a variety of movement patterns both during and after the breeding season. Of three males that transmitted for 85, 329 and 537. days, two (the smallest) migrated east and remained in oceanic waters for the tracking period and another (larger turtle) migrated 810. km northeast, to neritic waters off the coast of Mauritania, Western Africa. Results suggest males may show the same size-linked dichotomy in migratory strategies, as has been shown for females from this population. © 2013 Elsevier B.V.
Marco A.,CSIC - Doñana Biological Station |
Abella E.,CSIC - Doñana Biological Station |
Liria-Loza A.,Instituto Canario Of Ciencias Marinas |
Martins S.,Cabo Verde Natura 2000 |
And 8 more authors.
Animal Conservation | Year: 2012
The main nesting area for loggerhead turtles in the eastern Atlantic is in the Cape Verde Islands, largely restricted to the island of Boa Vista. Extensive monitoring demonstrated a globally significant population for the species despite a sustained high level of anthropogenic take of nesting females for local consumption. Through an extensive stratified monitoring program across the island in the seasons 2007-2009, we estimated a total of 13955, 12028 and 19950 clutches in the 3 years, respectively. These values indicate that the mean number of nesting females averaged 3700. Considering that a female breed, on average, every 2.4 years, we estimate that the overall number of adult females in the population during these three seasons was 8900. These levels are much higher than those suggested in previous studies which were more constrained in spatial coverage. Our findings indicate that Cape Verde hosts the third largest nesting aggregation for this species in the world after the south-eastern US and Oman, with some sites having a particularly high density of nests, facilitating targeted monitoring and conservation. Consumption of sea turtle meat is a traditional practice in Cape Verde that continues despite national sea turtle protection laws. We estimated that 36, 18 and 5% of nesting females were harvested in the 3 years of the study, respectively. Increasing beach protection and monitoring, ongoing educational programs and cooperative projects with local communities are urgently needed to further safeguard the only major loggerhead nesting aggregation in the eastern Atlantic. © 2012 The Zoological Society of London.
Camacho M.,University of Las Palmas de Gran Canaria |
Luzardo O.P.,University of Las Palmas de Gran Canaria |
Boada L.D.,University of Las Palmas de Gran Canaria |
Lopez Jurado L.F.,Cabo Verde Natura 2000 |
And 3 more authors.
Science of the Total Environment | Year: 2013
The Cape Verde nesting population of loggerhead sea turtles (Caretta caretta) is the third largest population of this species in the world. For conservation purposes, it is essential to determine how these reptiles respond to different types of anthropogenic contaminants. We evaluated the presence of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) in the plasma of adult nesting loggerheads from Boa Vista Island, Cape Verde, and studied the effects of the contaminants on the health status of the turtles using hematological and biochemical parameters.All turtles had detectable levels of non-dioxin like PCBs, whereas dioxin-like congeners (DL-PCBs) were detected in only 30% of the turtles. Packed cell volume decreased with higher concentrations of PCBs, which suggests that PCB exposure could result in anemia in sea turtles. In addition, a negative association between some OCPs and white blood cells (WBC) and thrombocyte estimate was noted.The DDT-metabolite, p,p'-DDE was negatively correlated with the Na/K ratio and, additionally, a number of correlations between certain PAHs and electrolyte balances were found, which suggest that exposure to these environmental contaminants could affect the kidneys and salt glands in sea turtles.Additionally, several correlations were observed between these environmental pollutants (OCPs and PAHs) and enzyme activity (GGT, ALT, ALP and amylase) and serum protein levels, pointing to the possibility that these contaminants could induce adverse metabolic effects in sea turtles.Our results indicate that anthropogenic pollutants are present in the Cape Verde loggerhead turtle nesting population and could exert negative effects on several health parameters. Because of the importance of this loggerhead nesting population, protective regulations at national and international levels as well as international action are necessary for assuring the conservation of this population. © 2013 Elsevier B.V.