Project description:The aim of the study was to monitor and analyse injured and diseased loggerhead sea turtles (Caretta caretta) plasma proteome profiles during their recovery period in rescue centre within different age and recovery period groups, and determine the potential biomarkers that can be used in diagnostics.
Project description:BackgroundAlthough bycatch of industrial-scale fisheries can cause declines in migratory megafauna including seabirds, marine mammals, and sea turtles, the impacts of small-scale fisheries have been largely overlooked. Small-scale fisheries occur in coastal waters worldwide, employing over 99% of the world's 51 million fishers. New telemetry data reveal that migratory megafauna frequent coastal habitats well within the range of small-scale fisheries, potentially producing high bycatch. These fisheries occur primarily in developing nations, and their documentation and management are limited or non-existent, precluding evaluation of their impacts on non-target megafauna.Principal findings/methodology30 North Pacific loggerhead turtles that we satellite-tracked from 1996-2005 ranged oceanwide, but juveniles spent 70% of their time at a high use area coincident with small-scale fisheries in Baja California Sur, Mexico (BCS). We assessed loggerhead bycatch mortality in this area by partnering with local fishers to 1) observe two small-scale fleets that operated closest to the high use area and 2) through shoreline surveys for discarded carcasses. Minimum annual bycatch mortality in just these two fleets at the high use area exceeded 1000 loggerheads year(-1), rivaling that of oceanwide industrial-scale fisheries, and threatening the persistence of this critically endangered population. As a result of fisher participation in this study and a bycatch awareness campaign, a consortium of local fishers and other citizens are working to eliminate their bycatch and to establish a national loggerhead refuge.Conclusions/significanceBecause of the overlap of ubiquitous small-scale fisheries with newly documented high-use areas in coastal waters worldwide, our case study suggests that small-scale fisheries may be among the greatest current threats to non-target megafauna. Future research is urgently needed to quantify small-scale fisheries bycatch worldwide. Localizing coastal high use areas and mitigating bycatch in partnership with small-scale fishers may provide a crucial solution toward ensuring the persistence of vulnerable megafauna.
Project description:We report the expression profiles of putative genes involved in temperature-dependent sex determination across multiple developmental stages in turtles, and contrast this data with equivalent stages in turtles with sex chromosomes
Project description:Research on the effects of contaminants on fishes is often conducted on well-studied model test species, whose responses may be different than those of species of conservation concern. We used an oligonucleotide microarray to examine the effects of permethrin, a widely used pyrethroid pesticide, on a critically endangered fish species endemic to Northern California, the delta smelt (Hypomesus transpacificus). These results demonstrate the effects of a widely used pesticide on a sensitive fish species at concentrations below those that affect model test species.
Project description:Research on the effects of contaminants on fishes is often conducted on well-studied model test species, whose responses may be different than those of species of conservation concern. We used an oligonucleotide microarray to examine the effects of permethrin, a widely used pyrethroid pesticide, on a critically endangered fish species endemic to Northern California, the delta smelt (Hypomesus transpacificus). These results demonstrate the effects of a widely used pesticide on a sensitive fish species at concentrations below those that affect model test species. Twenty samples were run on twenty arrays, there were four replicates for each of four permethrin exposure concentrations and a control group.
Project description:The homing journeys of nine loggerhead turtles translocated from their nesting beach to offshore release sites, were reconstructed through Argos and GPS telemetry while their water-related orientation was simultaneously recorded at high temporal resolution by multi-sensor data loggers featuring a three-axis magnetic sensor. All turtles managed to return to the nesting beach area, although with indirect routes encompassing an initial straight leg not precisely oriented towards home, and a successive homebound segment carried out along the coast. Logger data revealed that, after an initial period of disorientation, turtles were able to precisely maintain a consistent direction for several hours while moving in the open sea, even during night-time. Their water-related headings were in accordance with the orientation of the resulting route, showing little or no effect of current drift. This study reveals a biphasic homing strategy of displaced turtles involving an initial orientation weakly related to home and a successive shift to coastal navigation, which is in line with the modern conceptual framework of animal migratory navigation as deriving from sequential mechanisms acting at different spatial scales.