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:
Anna is collecting genetic information from white shark fin clips to assess this species’ population size in South Africa. Using close-kin mark-recapture analysis instead of traditional methods, she hopes to provide an accurate account of South Africa’s white shark population size. She also aims to develop a monitoring protocol that can use genetic samples collected during shark net and drumline patrols by the KwaZulu-Natal Sharks Board. This information is needed in South Africa, where the conservation of a protected species is balanced against concerns about bather safety, and where sharks are caught in bather protection gear.
Faqih is filling the gaps in the scant knowledge of giant guitarfish in Java’s Karimunjawa National Park marine protected area (MPA). Karimunjawa is located near Northern Java’s main fishing grounds, but evidence of giant guitarfish caught in some of the use-zones of the MPA hints that the park may be a sanctuary for the species. Managing giant guitarfish in Karimunjawa requires species-specific information.
Faqih’s project is a socio-ecological one to help inform management and draws on new information about relative abundance and distribution, historical occurrence and fishing pressures to paint a contemporary picture of the species in the park.
Cindy wants to know if bonnethead sharks in the Eastern Pacific constitute a third, cryptic species. The Bonnethead complex need clarification in all its distribution range, and Panama is a key country to solve this question since we have the Caribbean sea and the Pacific Ocean. By collecting fin clip samples to compare species at the genetic level and collecting specimens to compare how they look (morphology), Cindy hopes to resolve the taxonomy of Sphyrna tiburo vespertina – that is, whether it’s a cryptic third species for bonnetheads in the region. Her information can help update the IUCN Red List for bonnetheads and improve fisheries policies in Latin America where bonnethead sharks are commonly caught.