Don't kill sharks with kindness

FOR MANY divers the dream of diving with sharks is becoming reality, as operators market the best sites to experience the ultimate in wildlife-watching.
In the Red Sea and Baja California, reef sharks and hammerheads naturally occur in large groups and can be observed by divers with little intrusion. Such experiences can be beneficial to both parties; the diver has the experience of a lifetime, while a monetary value is given to sharks as a living resource. Changing the old adage "the only good shark is a dead shark" is an important step in their conservation, especially as they are currently worth far more dead than alive to many fishermen. But if shark tourism is to grow it must be developed responsibly, with the well-being of the shark, minimal impact on the ecosystem and diver safety put before getting as many sharks and divers as possible in one place at a time.
Shark-feeding and baiting is increasingly used to guarantee divers a close-up view. Yet creating the potential for sharks to associate divers with food could lead them to approach divers unwilling or unprepared to come face to face with a shark. Feeding frenzies have already resulted in divers being bitten, so far with no reports of serious consequences, but how long before a diver panics, or a shark bites too hard?
Also, the effects of regular site-specific feeding on sharks' social and feeding behaviour are unknown. Feeding bears in US National Parks was banned when bears started to attack, with fatal consequences, campers while searching through tents for food.
The MCS urges divers to be cautious. Enjoy observing sharks in their element, but do not support shark-feeding. Diving in with a bag full of fish puts others at risk and, if attacks become more frequent, could set back seriously the protection of sharks.

Role model of Oz

Stopping the rot

Volunteer power

Conservation diving has grown beyond the realm of a couple of divers noticing that they have caught fewer lobsters than last year, to become an important part of the UK and indeed world diving scene. More diving hours are spent on underwater surveying than ever before.
But how useful are the observations of volunteers who usually have little or no scientific training? "Very useful," says marine biologist Rob Irving, recently returned from an annual expedition to the Isles of Scilly.
The IoS possesses nationally important populations of eel-grass, which over the past century have periodically been infected by a wasting disease. "We would not have known about the patterns of infection if volunteers had not been surveying the beds for the past five years," says Rob.
Well-organised surveys do not require the diver to have intricate knowledge of marine life but are designed to get an overall picture of the nature and health of marine habitats. English Nature and the IoS Environmental Trust are so impressed with the data collected by diving volunteers that they are now setting out a five-year strategy to survey more of the islands.
On another island, this time in the Irish Sea, sponsorship has just been secured for a third year of underwater surveys. Marine biologists stationed on the Isle of Man believe that with the help of volunteer divers they will have surveyed the whole of the island's coast by next year.
Survey organiser Mike Bates says there is a "lack of baseline knowledge of underwater habitats around the island. Because of oil and gas exploration off the coast we need to identify the important areas."
So it looks as if with the enthusiasm and experience of British divers a lot of interesting and useful data is being produced. In any case, if divers can learn a little about the complexity and sometimes vulnerability of marine habitats by carrying out these surveys, this can only be good news.

• You can contact the IoS Expedition at CCC-SAC, 154 Clapham Park Road, London, SW4 7DE, and Mike Bates at the Port Erin Marine Laboratory, Port Erin, Isle of Man IM9 6JA.

Invisible legacy

Clean campaign

Do you see as many drink cans lodged among the boulders of your favourite site as you used to see shore crabs? Have you ever been caught by a fishing hook lurking among the seaweed? Or been horrified to identify a 'new species of marine life' as a floating remnant of sanitary waste on closer inspection?

Our seas are being used as a communal dumping ground for anything and everything from plastic bottles to plastic sandals; from fishing nets to traffic cones and condoms to cotton bud sticks. The Marine Conservation Society has been fighting this tide of litter for four years through an annual national clean-up and survey of the litter found on beaches and beneath the waves.

In Beachwatch '95 over half of the 300,000 items of rubbish recorded were made of plastic, which takes decades to break down and accumulates in the seas and on our beaches. Sources of this litter include sewage outfalls, rubbish dumped overboard at sea, fishing vessels, rivers and day-trippers.

Under water, the most common item found is fishing line, which can entangle both diving equipment and marine wildlife. World-wide, an estimated 100,000 marine mammals and sea turtles die every year from entanglement in, or ingestion of, plastics. On Grassholm, off Pembrokeshire, over 90 per cent of the gannet nests contain plastic, which often entangles the young chicks. The Orkney Seal Rescue Service is recovering increasing numbers of seals found entangled in netting. All seven species of sea turtle are threatened with extinction - many that are found dead on beaches have plastic bags, which they mistake for jellyfish, blocking their guts.

But it's not only wildlife which faces a deadly obstacle course of marine debris left in the wake of humans. Divers also suffer from the increasing amounts of rubbish both above and below the low water mark. Dive sites are being polluted with sewage debris, fishing debris and consumer waste. Get involved with our Adopt-a-Dive Site scheme to collect and record the litter at your dive sites.

Call 01989-566017 for details.