This article is from the Coastguard Facebook page -
We are asking members of the public to keep a close eye on their dogs and to keep them on leads if they see an unusual substance on beaches around the UK. We’ve had reports that some beaches have had a waxy substance wash up on their shores like in these photos.
We are currently investigating the origins of this material.
Past incidents have shown it is likely to be residues from a vessel that has cleaned its tanks after discharging its cargo.
This type of substance could be harmful to dogs, so we recommend that people keep their dogs within sight, preferably on leads, whilst enjoying the coast. If you do see a whitish sponge like substance in appearance that looks out of place on the beach then please report it to the UK Coastguard.
The local Coastguard number is 01305 760439
We are not aware of any on the beaches of Swanage at this time although there has previously been palm oil washed up by Sheps Hollow which this substance could be.