Wildlife experts fear hundreds more seabirds could be washed up on the coast of Sussex in the coming days.
Hundreds of seabirds have died and hundreds more have been washed up on the coast between West Sussex and Cornwall after being covered in the pollutant.
Conservationists believe fear the situation in Sussex could worsen in the coming days.
Their fears were echoed by the discovery of a waxy substance at Black Rock in Brighton and on Saltdean beach over the weekend.
Grahame Madge, of the RSPB, said: “The number of birds recovered today is very small but we don’t think that reflects the absolute position.
“We really think it is a reflection of the prevailing weather conditions rather than the situation affecting sea birds.
“The winds on Friday were encouraging birds to come into the shore where they could be picked up but the wind since has been pushing birds more out to sea.
“It is quite likely that there has been many, many more birds affected who have no hope of rescue at the moment.”
“I think we are due westerly winds which means the birds could be pushed eastwards and that did seem to be what was happening in the last 48 hours with sightings reported in Hampshire and Sussex.
“It is quite often this way with spills or any pollution incident that we only expect to recover a small proportion of the total number of birds affected.
“It will depend entirely on the weather.” Tests are still being carried out to try to find out what the substance is.
On Friday, tests revealed the mystery substance as a refined mineral oil, but not from an animal or vegetable-based oil. They also ruled out palm oil.
Alex Moore of Eaton Place, Brighton, reported lumps of a waxy substance found on the beach between Brighton Marina and Black Rock to the Environment Agency.
He said: “I found lots of fist to Brick size lumps and larger, made of a white wax.
“Is this pollution connected to the seabirds? Where has this come from and who is responsible?”
June Jarvis said she had also reported a wax balls found on the beach at Saltdean on Friday to the Environment Agency.
See the latest news headlines from The Argus:
- UPDATED: 20 caravans park up on school playing field
- Brighton teenager at Manchester Arena: 'It was one of the most horrific and scariest things I have ever seen'
- Brighton and Hove will stand in 'solidarity and grief' with Manchester
- Sussex Police: 'No current evidence of any specific threat to community safety'
- Exam cancelled as security breach at sixth form college is probed