Harmful pollutants in the ocean can disrupt the reproductive capacity of many species. That the future of sharks hangs in the chemical balance is a devastating thought – and it’s a scenario that Franco is trying to understand so that we have a better chance of mitigating it. He believes that the impact of marine pollutants is probably greater than we already recognise, but a lack of research mutes its real importance to us. By using the American elephant fish as a case study and assessing its reproductive health in polluted waters, this project hopes to set a baseline for future monitoring of ocean health.
Since childhood I have felt passionate about the oceans and marine life. This passion persisted through my formative years as a biologist, when I discovered the world of sharks, rays and chimaeras and I was totally smitten by this amazing group of fish. When I finished my degree I got involved in many shark conservation projects worldwide, such as the first tagging programme in Patagonia (Argentina), monitoring whale sharks in Cebu (Philippines) and a white shark conservation programme at Guadalupe Island (Mexico). After a long journey and different experiences, I now find myself pursuing a PhD in another subject I...
To understand the impacts of marine pollution on the reproductive health and future reproductive success of sharks, rays and chimaeras.
It is crucial to conduct long-term monitoring of marine pollution in order to predict how populations that are fundamental to the conservation of biodiversity will fare in the future. By studying how pollution impacts the reproductive health of chondrichthyans, we will be able to foresee to what extent chondrichthyan reproduction is likely to be successful. Only if the species have the capacity to produce offspring can we be sure that they will be conserved over time.
Pollution from chemicals derived from human activities is increasing quickly and causing ocean conditions to deteriorate at an unprecedented rate. Marine animals are highly susceptible to pollution as they are in very close contact with the surrounding environment. One of the most distressing effects of marine pollution is the disruption of reproductive processes that are essential to the survival of a species over time. Unfortunately, many pollutants are capable of this disruption. For example, up to 12.7 million tons of plastic enter the ocean every year, leaching chemicals that are harmful to reproductive systems. The negative impacts of pollution on reproductive health have been reported for marine mammals, seabirds and fish, but very little is known about such impacts on sharks, rays and chimaeras (chondrichthyans), in which high concentrations of pollutants can accumulate. More than 30% of chondrichthyans are at risk of extinction and although overfishing is the primary threat, others such as pollution are recognised.
We believe that the threat of marine pollution is even greater than already identified, but is masked by the lack of research. We will study how pollutants can alter reproductive success by using the American elephant fish as a model. Understanding the impacts of pollution on the reproductive health of chondrichthyans will alert us to how the species will adapt – or not – to contamination of the oceans. Marine pollution is already happening and once the water has been contaminated it cannot be cleaned; the damage has been done. Our research will provide information about the impacts of marine pollution on chondrichthyans to decision-makers charged with keeping the oceans healthy.
To evaluate the impacts of marine pollution on the reproductive health of chondrichthyan species by:
Outside the USA, The Bahamas is the only place where Critically Endangered smalltooth sawfish can reliably be found. Tristan wants to ensure that protection measures in The Bahamas are understood and enforced as far as sawfish are concerned to close the current gap between policy and the people. He’ll be using aerial surveys, sonar and BRUVs, combined with interviews that draw on local knowledge, to identify essential sawfish habitats that need protection. Engaging with the community through workshops and by training students and meeting with government, Tristan intends to advocate for smalltooth sawfish protection throughout The Bahamas’ territorial waters.
Steven and Kevin are using genetic techniques to understand how Caribbean reef shark populations are connected across the extent of their range. Populations of this Endangered shark are in decline generally, but where they are managed and there is effective protection, their numbers are stable. With the integration of the correct information, Steven and Kevin are convinced that we can give Caribbean reef sharks a better shot at recovery and population stabilisation. They will also explore any barriers to connectivity, looking to the future recruitment and recovery of these sharks.
With very little information available about Endangered sicklefin devil rays, their seasonal aggregations at sea mounts in the Azores give Sophie an opportunity to learn more about their lives. She will be collecting satellite-tracking data that show how they move in the Azores’ exclusive economic zone. The information she collects will be used to develop maps of how the rays are using the zone and to identify essential areas that multiple species use. With this information at hand, Sophie hopes her work can contribute to a network of marine protected areas.