Marine
experts are calling on the public to report sightings of basking sharks in UK
waters this summer. The sharks are drawn to warm, plankton-rich surface waters off
the west coast of Great Britain and Ireland. These huge sharks are harmless,
but experts are also asking people to "keep a respectful distance and
enjoy the spectacle". Basking sharks are protected under European and UK
law, so it is illegal to disturb or harass them. "They're here for most of
the summer," said Dr David Gibson, managing director of theNational Marine
Aquarium in Plymouth. "We're asking people to let us know
whenever they see one of these fantastic animals. Basking sharks are the
ocean's second biggest fish, measuring up to seven metres in length. A large
adult male can have a dorsal fin up to 1.5m high, which protrudes from the
water when the fish are feeding at the surface. "We'd also like people to
take photographs if they can," said Dr Gibson. "These animals live
for between 30 and 40 years, so [with photos] we might be able to identify
individuals that are returning to UK waters." Researchers at the aquarium
also use photographs to spot any signs of damage to sharks' fins that could
indicate where the fish might be "coming into conflict" with
fisheries.
The shark code
The sharks visit
British and Irish shores as the warming sea surface creates "a healthy
soup of nutrient-rich seawater around our coastline". Miniature plants
that bloom in the sun-warmed water attract tiny marine animals, or zooplankton.
This, in turn, attracts the basking sharks. It is difficult to predict exactly
when and where these plankton banquets will occur, but experts say that
hot-spots for shark sightings are the south-west of England, the Isle of Man,
south and west Ireland and the Firth of Clyde on the west coast of Scotland. To
allow people to observe the sharks without disturbing them, the Shark Trust has
published a code of conduct to be followed in any basking shark encounter.
There are separate checklists for
swimmers, boat-users and kayakers, but the key points to note
are:
Keep your distance:
keep at least four metres between you and the shark so as not to startle it.
If
you are swimming with other people, stay in a group, but don't invite others
over to take a look.
If you're in a boat,
turn off your engine (boat propellers are a major cause of serious injury to
basking sharks feeding near the surface).
If you have a camera
handy, take lots of photos of the dorsal fin and any distinguishable features
on the shark, as this may help the researchers identify the individual.
Move away gently and
quietly and report your sighting to the Shark Trust
Ali Hood, director of conservation at the Shark Trust, told BBC
Nature: "Basking shark are not aggressive, but a fish of that size (mature
basking sharks can weigh well over four tonnes) could cause serious injury. "Basking
sharks are extremely strong and surprisingly able to breach clear of the water.
"If people get too close and the shark makes a rapid movement, it could
cause harm to both the shark and the person. "The code of conduct is there
to allow people to comply with the law and enjoy seeing these magnificent
animals." But Dr Gibson says he hopes people will take pleasure in witnessing
the ocean's second largest fish and says the data gathered from reported
sightings is invaluable for marine conservation work. "Understanding when
they first appear and when they leave shows us year on year trends of the
plankton blooms. "This has already given us evidence that habitats are
shifting in response to climate change, and that basking sharks are moving
north." People can report basking shark sightings to the Shark
Trust via its website.
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