FIRST it was dead dolphins and porpoises, washing up along the coast of Dorset and even the Isle of Wight.

Then, over the Easter weekend, reports started to come in of rare sea-horses, all dead, having been found over the past month or so at Kimmeridge and as far along as Chesil near Portland.

Now a wildlife watcher has claimed that Studland Beach - one of the UK's premiere coastal locations for wildlife and beauty - was 'full of dead crabs'.

So, what's going on with our local marine wildlife?

And should we be concerned?

Admittedly a pod of dolphins looking happy and healthy was filmed over the weekend by delighted jet-skiers off Purbeck.

But this sight does not erase the other sights witnessed on our coast in recent months and all of them, it's claimed, coming after permission was given for the test-drilling rig, which struck oil and gas off Bournemouth last month.

In March Dorset Wildlife Trust raised concerns after what they claimed was an 'unusual number' of marine mammals were washed up.

The creatures included a dead seal and a dead porpoise at Southbourne.

Bournemouth Echo:

A dead porpoise washed up on the beach at Southbourne. Picture: Andy Earley

Meanwhile a dead common dolphin was also reported to the charity after being found washed up at Seatown, near Bridport.

Although the cause of the animals’ deaths was unknown, the charity said it was not ruling out a possible link with the oil well drilling taking place in Poole Bay.

At the time it voiced strong concerns over the drilling being carried out by Corallian Energy. Further fears for local wildlife were raised following the announcement drilling operations could be extended until the end of March – a “critical” period for fish spawning and bird migration, the trust said.

Emma Rance, marine conservation officer for DWT, said at the time it was “unusual to get this many strandings in a two-week period”.

She added: “In the last 15 years that I’ve worked for the Dorset Wildlife Trust, I can only remember one or two washing up at this time of year.

“We’re all on high alert and concerned about the oil rig. Poole Bay has a very productive environment, with spawning and nursery grounds for commercially important species such as cod, as well as both species of seahorse."

Now DWT have said a number of seahorses were washed up within a couple of weeks of each other and had been reported by members of the public on social media.

The first sighting came at Studland on March 29, when Rene Smith picked up a small, dried spiny seahorse on the beach. This was followed by others at Worbarrow Bay, near Kimmeridge, Greenhill beach in Weymouth and Chesil Beach at Portland. The finds include examples of both spiny and short-snouted seahorses, the UK's two native species.

DWT’s marine awareness officer, Julie Hatcher, said: "To have so many seahorses washing up in Dorset in such a short time is unheard of and we are very grateful to the people who found them for publicising their finds.

"While there is no obvious reason for the deaths it certainly indicates that Dorset has a good population of seahorses along the coast."

The crab deaths were noted by Simon Britton, who posted his comments on Twitter.

Much of the concern voiced around the test drilling came from the announcement that the operation would be allowed to dump 6.7k tonnes of chemicals in Poole Bay.

Government regulator OPRED previously stated the environmental risk assessment carried out “confirmed that proposed chemical use and discharge would not pose a significant environmental risk”.It also stated operations “are unlikely to result in any significant disturbance or any other adverse impacts on marine mammals”.

However, a spokesman for Dorset Wildlife Trust said it could not attribute the seahorse deaths to anything in particular, at the moment.

Spokeswoman Sally Welbourn said: "We have no evidence at all to suggest the seahorse deaths are anything to do with the oil rig. If people are saying this, it's pure speculation."

She said the apparent crab deaths might be down to their moult, where they outgrow and then discard their old shells. "It can look like deaths at first." she admitted.