The Seahorse Trust is warning that Britain’s native breeds are under threat unless action is urgently taken to preserve their habitats.
To look at Studland Bay is to see the familiar sight of waves washing up hypnotically on a sandy Dorset beach.
The white cliffs of the Old Harry rocks frame the horizon, sheltering the bay from the prevailing south-westerly winds.
Fishing boats and yachts bob up and down with the incoming tide.
But take a glimpse underwater to see an exceptional view as the bay is home to a rather magical creature.
Its Latin name is hippocampus but you are probably more familiar with the term seahorse.
Steve Trewhella, from The Seahorse Trust, has been diving here for as long as he can remember.
In all that time, he’s been searching for the creatures in their natural habitat – among either eel or sea grass.
He said: “Most divers could spend a lifetime looking for seahorses in their natural habitat and never find one.
“This is an exceptional site – a window into the seahorses’ world”.
He remembers when Britain’s native species were captured on film for the first time – in Studland Bay.
That was just four years ago, showing just how rare seahorses are in the wild.
But now a remarkable discovery – a few years on and Steve has seen 40 of them locally this summer alone.
He believes at least half of them were pregnant – an astonishing number.
He believes it makes this site the only one anywhere in Britain where both types of indigenous British seahorses – the Spiny and the Short Snouted – are known to be breeding.
Encouraging news indeed but laced with a warning about how long eelgrass beds will be around.
Mr Trewhella is not optimistic and said: “We could lose this habitat in a single generation.
“We only have a small fraction of this sort of grass we had a hundred years ago.
“The eelgrass is just as important to the seahorse, as the jungle is to the Orangutan.
“And if we lose it, we lose the seahorses that go with it.”
It is this problem the charity is hoping to raise awareness about.
The eelgrass beds tend to be in sheltered, shallow waters.
But that is exactly where many yachts and fishing boats want to moor and are often desirable spots for harbour and marine builders.
The moorings and boat anchors are particularly problematic and damaging.
It is feared the chains scrape the seabed, tearing up the eelgrass with it.
And anchors too can dig up clumps of seagrass every time they are raised.
That is why the Seahorse Trust is calling for a complete ban on anchoring where eelgrass and seahorses are thought to live.
At the nearby Bankes Arms Hotel – just a short walk from the mooring on South Beach, Studland Bay, pub landlord Tim Lightbrown is so proud of the seahorses on his doorstep that he uses them as the logo for his micro-brewery.
He is also adamant, however, that no-one should be banned from anchoring nearby to enjoy a drink.
He said: “Obviously the punter comes first – without the punter you’ve got nothing else, have you?
“People wouldn’t be here – there would be no seahorses to look at and nobody would be bothered about them anyway.
“To be honest, what comes first – a little tiny thing so big or a punter? End of story.”
It will be left to the government to strike a balance between conservation and commercial interests.
The seahorse is already a protected species under the Countryside and Wildlife Act.
But Ian Alexander from Natural England admitted it is difficult to enforce the law.
He said: “To act, we would need to demonstrate any damage was in fact damaging the seahorses.
“Firstly, that is quite difficult to do at the moment.
“Secondly, we would need to demonstrate that the damage was deliberate or reckless.
And it would be very difficult to demonstrate that given the nature of the activities happening out in the bay”.