Our thanks go to Shark Trust’s Mark Packer for travelling up from Plymouth to give an excellent shark presentation last Monday evening (15th December). It was both beautifully presented, very informative, and sobering in its outlook for this vital member of our ocean ecosystem.

Worldwide there are over 1000 species of shark and their close cousins, skates, rays and chimaeras. Species found in UK waters including basking, blue, short fin mako and thresher sharks. Greenland sharks, found in the North Atlantic and Arctic oceans, are the longest lived vertebrate at 400 years and reach sexual maturity at 150!

Mark also gave us a little shark biology, in particular their teeth which are generally arranged in up to 10 rows behind the front. If they lose a tooth, the one in the row behind moves forward to replace it. Sharks can go through up to 35,000 teeth in a lifetime! They also have sensors on their snouts called ampullae which detect electrical fields and help them hunt prey.

Sharks are key to a healthy ecosystem, one example being that sea grass (which holds massive amounts of carbon) is sometimes stripped bare by grazing turtles and dugongs.  However the presence of a tiger shark, which will predate these species, keeps them moving on and therefore helps the sea grass recover.

Sadly Shark Trust research has found that one third of sharks are threatened with extinction due to overfishing.  It was shocking to learn that blue shark is overfished by the EU and US which is sold as ‘white fish’ and if you choose rock salmon in a fish and chip shop you are in fact eating shark, usually spiny dogfish. The Shark Trust is working hard to reduce quotas to make them more sustainable and make transparent labelling on consumer products a legal requirement. The Shark Trust work with partners around the world to work towards protecting these amazing creatures.

Citizen science is vital to help the Trust get data so you can do your bit by reporting any egg cases found – a photo and location can be sent via the Trust website www.sharktrust.org or use their app.

We look forward to seeing you in the new year for our next talk on January 19th from Brian Clews on Wildlife of the Jubilee River.

Regards

Heather King