Wednesday 7 November 2012

Window Cleaning Poles Aid Against Shark Extinction

Basking shark populations have severely declined meaning that today, the basking shark is considered to be an animal that is under threat from extinction.
The dorsal fin of a basking shark is covered with a black slime which is perfect for DNA sampling.
Basking shark secrets unlocked by DIY kit: A team of experts in the Isle of Man have come up with a DIY kit comprising of a pan scourer and a window cleaning pole to enable them to collect DNA from sharks. The innovative design means they can collect dorsal fin slime with the minimum of disruption to the animal. Basking sharks are classed as "globally vulnerable to extinction" by the International Union for the Conservation of Nature and the key to their survival is finding out as much information as possible about their movements and behaviour. Coordinator of Manx Basking Shark Watch, Jackie Hall said: "This kit is about getting back to basics to help global conservation efforts- we are combining practical solutions with cutting-edge science."

The thick black "diesel-like" slime is collected with a quick swipe of the shark's dorsal fin.
Step two involves a close encounter with a basking shark, something the team have a special licence for.
Step one of the DNA collection involves attaching a sterilised pan scourer to a window cleaning pole.
The kit idea came after government vets warned against the traditional method of DNA collection, thought to be too invasive to use on an endangered species. The old method of DNA collection involves putting a small plug in the shark to get a skin sample. When Mr Hall was told that shark slime was an ideal substance for DNA sampling he set off for his local DIY store for some ideas. He came back with a pan scourer and a window pole. "Having worked with the sharks for several years I thought the best way to collect the slime would be with a brillo pad, well it's not really a brillo pad, it's a green scrubby pad, wrapped round some stainless steel, and attached to the end of a window cleaning pole - it's ideal really because it doesn't harm the shark at all," said Mr Hall.

The sterile scourer is cut up and placed in alcohol to prevent cross-contamination.
Each sample is labelled and sent off for DNA analysis.
The make-shift DNA collector has proved instrumental in attempts to create a series of "shark passports" which will ultimately make it easier to identify each individual fish. Along with the DNA profile each passport includes the shark's gender and a high definition photograph of the dorsal fin. Jackie Hall said: "It takes a great deal of care, skill and some very clever equipment to compile a passport without disturbing the shark, it's essential we don't disturb this protected, endangered species. "We do everything quickly - we take from a moderate distance [the dorsal fin photograph] and then we have to start our first close approach to establish the gender using the pole camera. Then we have a second close approach to take the DNA swab from the dorsal fin - that is just a quick swipe."

The DNA information can be used by scientists to identify individual sharks and map their movements.
Fin soup. And the work is already revealing some fascinating insights. The Hall team have a special licence to conduct shark research "One of the sharks we tagged actually crossed the Atlantic, this is amazing and worrying at the same time," said Mrs Hall. "Sharks are still hunted in some waters as part of the finning industry where, horribly enough, they take the fins for shark fin soup and discard the rest of the body - that is the biggest threat to all sharks worldwide," she said. "If we can provide governments with accurate scientific information about the movements of the sharks informed decisions can then be made about how to manage the marine environment to protect them - it's really important that we find as much information out as quickly as possible because we think there may only be between eight and ten thousand of these amazing creatures left."

The basking shark passport profiling began in the Isle of Man in 2009 and to date, about 100 animals have been identified in the Irish Sea.  In 2013 Jackie and Graham Hall hope to use new technology called Smart Position or Temperature (SPOT) tagging which deploys tags which stay on the sharks for up to five years.

The basking shark is found inhabiting temperate coastal waters around the world, with the exception of the Indian Ocean. The basking shark is one of only three plankton-feeding shark species and is the largest fish in British waters.
  • Basking sharks are the second largest fish in the sea - they can reach up to 7m (23ft) behind the enormous whale shark.
  • Their 1m (3.3ft) wide jaws can filter plankton from 1.5 million litres of sea water every hour.
  • Basking sharks travel large distances in search of food at a pace 3mph (4.8km/h).

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