An absorbent boom has been laid across Milford Haven Docks after a fishing boat sank.
Milford Haven Port Authority said the absorbent retaining boom had been set up as a precautionary measure after a "minimal amount" of bilge water was recovered.
The wooden fishing vessel Accordance sank early on January 18th, but as it was not in use, all fuel oil had been removed and weekly inspections were carried out, the Port Authority said.
Harbourmaster Mark Andrews said: "Divers have made an underwater inspection and plans are in hand to identify the best way to remove the vessel, which is well clear of any operational area.
"No other vessels are being affected by this incident," he added.