Hundreds of sharks accidentally caught in a trawler’s nets have been examined by a team of scientists at the University of Portsmouth.
Scientists from the University’s Institute of Marine Sciences and many student volunteers from the MSc and BSc Marine Biology courses helped dissect hundreds of the spurdog sharks.
They were joined at the University’s Eastney laboratories by marine scientists from the government’s Centre for Environment, Fisheries and Aquaculture Science (Cefas); the University of Southampton; the University of Aberdeen, Nord University in Norway, and the UK’s Shark Trust, a charity which promotes safeguarding sharks, skates and rays.
The sharks arrived in Portsmouth a frozen cube.
Our team worked hard to capture as much information as we could in a short period. Although these sharks were caught unintentionally, we will make sure the data collected contributes to better understanding their biology.
The team of marine scientists worked on the carcasses for two days to try to capture as much information as possible, including their age, general health and whether any had been contaminated by pollutants, including plastics.
The data collected will be analysed and later reported in the hope scientists can better understand the species. Chemical analyses can help reveal shark breeding grounds and their movements, while diet analyses help to establish their role in the marine ecosystem.
Dr Trevor Willis, marine scientist at the Institute of Marine Science, said: “Our team worked hard to capture as much information as we could in a short period. Although these sharks were caught unintentionally, we will make sure the data collected contributes to better understanding their biology.”
This has been a great multi-institutional effort that included some brilliant effort from student volunteers. The information we have gained will help with the conservation of sharks in UK waters.
According to British Sea Fishing, spurdog sharks are one of the few venomous fish in UK waters, along with the stingray and weaver fish, with the spines behind the two dorsal fins secreting a venom which can cause swelling and discomfort in humans.
Spurdogs grow up to 4ft long and can weigh up to 20lbs and they are common in British waters. They are classed as vulnerable by the International Union for the Conservation of Nature, and have been subject to a fishing ban for several years.
Cefas lead scientist Victoria Bendall said: “This has been a great multi-institutional effort that included some brilliant effort from student volunteers. The information we have gained will help with the conservation of sharks in UK waters.”