Mystery toxin devastates penguins

An unidentified toxin in gravel that attacks the brain, kidney and liver has been blamed for the deaths of 25 fairy penguins at Sea World on the Gold Coast.

Trevor Long, marine sciences director at Sea World, described the deaths of the fairy, or little, penguins at the popular theme park as a "sad day for all".

"There is a toxin involved and it's injured the brain, the kidney and the liver (of the penguins)," Mr Long explained today after receiving a preliminary report from Brisbane laboratory INDEXX.

"We don't know what it is and we don't know how it's got there.

"We're assuming it's come in with some ... gravel that's been changed, but until we get more information it's very hard to say."

Sea World's manager of marine sciences Steve McCourt said he suspected the deaths were caused by a load of contaminated gravel placed in the birds' enclosure as part of three-monthly maintenance.