Footage of a reef near the beached cargo ship MSC Napoli appears to show it has not caused any damage to rare corals and pink sea fans in Lyme Bay.
The pink sea fan is listed as a species of conservation concern
Devon Wildlife Trust has welcomed the news, but said it was still concerned about damage closer to the wreck, which is currently out of bounds to divers.
The 62,000-tonne vessel was grounded off Branscombe on 20 January after its hull was damaged in a storm.
More than 1,600 birds were contaminated by fuel oil which leaked from the ship.
The exclusive underwater pictures for BBC News were taken by Dr Jason Hall-Spencer, a marine biologist and diver, who went down to record the seabed at Tennants reef - just outside the 500m exclusion zone.
His footage shows red deadman's fingers, starfish, coral cups, cliona sponges and the rare pink sea fans.
The South West is the stronghold of the pink sea fan in the UK, with dense populations known to occur in waters to the east of the Lizard, the east of Lundy Island, around Plymouth Sound and in Lyme Bay.
It has partial protection under section Five of the Wildlife and Countryside Act 1981 and is listed as a species of conservation concern.
"It's a big relief because there's been talk in the news about chemicals coming off the wreck and oil damage," Dr Hall-Spencer said.
"But to be honest, the reefs I saw looked pristine and well worth protecting for the future.
Sian Rees from Devon Wildlife Trust said the footage was encouraging.
She told BBC News: "These pink sea fans are of national importance.
"We've been campaigning within the wildlife trust to limit damaging activity such as dredging."
However the trust said it remained worried about any possible damage within the exclusion zone caused by litter and oil pollution.
Ms Rees said: "Species such as the pink sea fans are very sensitive and they grow very slowly, so when one is knocked down, it takes decades to grow back again."