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.
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.