Diver Julie Hatcher tells us more about Studland Bay's seahorse residents, the 'almost mythical creatures' that this year were deemed a legally protected species

Studland Bay has long been known to be an important and wildlife-rich area, home to one of the nation's rarest marine habitats, seagrass meadows. Several years ago it was found to be the only known breeding site in Britain for the spiny seahorse. It is also adjacent to one of the busiest tourist beaches in Dorset and a popular anchorage for boats. This year, protecting the wildlife of Studland Bay received new impetus when seahorses were added to a list of species protected by law.

Seagrass is not a seaweed but one of only a handful of flowering plants that live in the sea. Its leaves look like tall grass with seeds that are dispersed by the tides and currents. An extensive root system binds the soft sand of the seabed together, stabilising it and thus playing an important role in protecting the coast from erosion. The dense meadows create sanctuary for a wide assortment of juvenile fish, including commercially important species. In short, seagrass transforms an otherwise fairly bare and mobile sandy seabed into a stable, rich and economically important environment.

At Studland, the seagrass meadows in the sunlit shallows extend out into the bay and create an extraordinarily rich habitat for a multitude of species. Predatory cuttlefish and shoals of bass patrol above the metre-high blades, while fifteen-spined sticklebacks, gobies, wrasse, pipefish and all kinds of juvenile fish seek shelter down below. Spiny spider crabs, masked crabs, swimming crabs, brown shrimps and many other crustaceans burrow in the sand or forage in the shade of the swaying grass stems, while sea snails, snakelocks, anemones and hydroids live in the light-drenched 'canopy'. The meadows are home to all six species of British pipefish, including the rare Nilsson's pipefish. This year it has been proven to be the only known site in Britain with breeding populations of not only the spiny seahorse but also the short-snouted seahorse - our two native species.

As a diver I feel privileged to have seen these mesmerising underwater treasures at first-hand. No matter how many times you see seahorses, the awe at their presence never diminishes. It is an almost mythical creature, a fish that looks like nothing if not a horse. It relies so totally on its camouflage that it remains fixed to the spot, its prehensile tail wrapped as tightly around its blade of seagrass as a baby's finger does around its mother's. As it sways gently with the swell, blending in with its surroundings, it gracefully turns its head away and down to the seabed to hide its tell-tale eye from the potential predator, trying not to give away the fact that it is in fact a fish and not a piece of drifting alga.

Unfortunately, divers at Studland take their life in their hands as boats skim above their heads and small tenders whizz about transporting their occupants to and from the beach, oblivious to the divers' surface marker buoys indicating people just below. It's like crawling around a field looking for butterflies while the field is being used as a festival car park. In fact, Studland Bay can look like a car park on busy days in the summer when upwards of 300 boats can be anchored there. The problem for the wildlife comes when each of those 300 boats pulls up its anchor, dripping with seagrass ripped up by the roots and leaving a bare crater of sand on the seabed.

Despite the dangers, divers this year have recorded more than 40 sightings of seahorses at Studland, generating unprecedented media interest in the site. Among the divers keen to spot seahorses in British waters were wildlife presenters Nick Baker and Kate Humble, and Blue Planet underwater cameraman Doug Anderson. None of them was disappointed, with up to eight seahorses being spotted on each dive. All have been elated by the encounter but shocked by the lack of protection for such a unique marine site.

In April 2008 seahorses and their habitat were added to a list of British wildlife given legal protection under the Wildlife & Countryside Act 1981. However, in reality the site still faces a very uncertain future. When seahorses were added to a list of other species already protected, no thought was given as to how this could be enforced, or indeed what they were being protected from. Only 'intentional or reckless damage' is regarded as an offence and because things living in the sea are always out of sight and out of mind, any harmful activity is automatically regarded as accidental.

The future of this remarkable habitat and the wildlife it supports is therefore dependent on the goodwill of the boating fraternity and the local community and all of us who are proud to have such rare treasures here on our doorstep in Dorset. Are we willing to make the slightest sacrifice and voluntarily close a small area of Studland Bay to anchoring? Here, more than anywhere, we must find the balance between keeping this special place special and enjoying our stunning coastline. Or will our reluctance to make the most trivial changes to our habits mean allowing what we have today to decline and disappear, depriving future generations of the chance to see it first-hand?

Great British Life: Spiny SeahorseSpiny Seahorse (Image: CC BY-NC 2.0)

Seahorse Facts

• The two British species of seahorse are the spiny seahorse (Hippocampus guttulatus) and the short-snouted seahorse (Hippocampus hippocampus). The spiny seahorse prefers to live in seagrass while the short-snouted seahorse is found in a wide range of seabed habitats, including seagrass.

• In the spring and summer, seahorses tend to move into shallower water to breed. Females produce eggs, which are deposited in the male's breeding pouch where they develop. After approximately 28 days around 300 baby seahorses are born and the male can become pregnant again almost immediately.

• Seahorses pair for life and during the breeding season undergo an elaborate courtship display each morning.

• The juvenile seahorses fend for themselves from the moment they are born and are prey to many animals - very few will survive to adulthood.

• In the winter months seahorses tend to move offshore into deeper water to avoid storms and wave action.

• More information on British seahorses can be found on the Seahorse Trust website at www.theseahorsetrust.co.uk.

• Any seahorse sightings should be reported to the British Seahorse Survey run by the Seahorse Trust, www.britishseahorsesurvey.org.

• Do not touch, disturb or follow a seahorse when you find one. Observe it in situ and allow it to accept your presence before photographing it.

• If it moves away, do not chase it.

• It is illegal to take a seahorse.

Great British Life: Short-Snouted SeahorseShort-Snouted Seahorse (Image: CC BY 2.0)

Quotes

"Few creatures are as weird and wonderful as the charming and enigmatic seahorse. But like all too many species, they are fragile and require our care and conservation to survive. That a small population has retained a tenuous tail-hold in the UK is amazing - a new treasure for us to cherish and protect and I hope that all endeavours will be made to effect a secure future for these little beauties." Chris Packham, TV wildlife presenter

"I spent two days diving Studland Bay in August and found it to be one of the most magical dive sites I have experienced in the British Isles. It is the detail that makes it special. If you spend time to get your 'eye in', a fragile world appears beneath the canopy and protection of the seagrass that is as complex and beautiful as any gaudy reef." Doug Anderson, Blue Planet underwater cameraman