Fenella is studying Scotland’s spurdogs, a small shark found across the British Isles and in temperate regions around the world. While commercial targeting of spurdogs has been banned after major population declines, whole aggregations can be caught as bycatch. Fenella’s team is asking how related a population might be, if it’s caught in a single aggregation event off the Isles of Scilly. Her project’s work can look at relatedness of spurdogs across the British Isles, and also provide insights into the diet and movement of spurdogs within aggregations.
For as long as I can remember, I have felt an affinity with water. As a youngster, I spent every summer along the South Wales coast, exploring rock pools and swimming as much as I could. For the rest of the year, I would fill up on nature documentaries, longing to get back into the water the following summer. I was determined to turn my summer experience into my every day, instead of once a year. To do that, I moved to South Wales and started my BSc (Hons) in zoology at Cardiff University. Despite living relatively...
To investigate the family relationships between individuals within a single spurdog aggregation and estimate their genetic connectivity with the wider north-eastern Atlantic population.
The spurdog is an aggregating species, which makes it particularly vulnerable to being taken as by-catch in large quantities by commercial fisheries. There has been limited research into this aggregating behaviour and the impact by-catch may have on the population. This project has the rare opportunity to assess genetic relatedness within a single aggregation and thus to reveal the impact that removing these aggregations may have on the gene pool in the north-eastern Atlantic.
The spurdog, also known as spiny dogfish, is a wide-ranging and highly mobile small shark that can be found in temperate seas around the globe. Like most elasmobranchs, it exhibits slow life-history traits, including a long generation time of 25–35 years and a gestation period lasting 18–24 months. Once a commercially important species, it is now categorised as Endangered in the north-eastern Atlantic by the IUCN Red List of Threatened Species due to a 77% decline in biomass between 1955 and 2010. The aggregating nature of the species means that when individuals are caught by commercial fisheries, they are caught in large numbers. Not only is this an issue in that the population size is reduced, but there could be unknown effects on genetic diversity. Previous research suggests these aggregations may contain a high proportion of closely related individuals (perhaps as siblings) and losing these family groups can decrease genetic diversity, reducing the species’ ability to adapt to environmental change. Understanding the genetic composition of spurdog aggregations is crucial to assessing the potential impact of by-catch on population sustainability in the north-eastern Atlantic. This is the first time family relations will have been assessed for an elasmobranch aggregation on such a scale. However, previous work using relatedness information has proven key in understanding the ecology and life history of elasmobranchs.
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.