Discovery of dead fish forces loch to be closed

A public exclusion zone was placed around Loch Erisort on the Isle of Lewis yesterday after a shoal of decomposing salmon was discovered.

The Scottish Environment Protection Agency (Sepa) launched an investigation into how the dead fish, hundreds of adult farmed salmon, had polluted the beauty spot in the Outer Hebrides. There were fears they may be toxic.

Sepa took samples of the fish for analysis and found they were killed by Pacific jellyfish, many thousands of which invaded the loch a few weeks earlier, killing salmon worth £3m. A Sepa spokeswoman said: "These fish were probably killed in the same attack but were missed during the clean-up of the loch because the visibility in the water was so poor due to the amount of jellyfish.

"During the operation to recover the salmon killed by the jellyfish two of the nets holding the fish split, causing the release into the loch of a significant number of dead fish and it appears a large number of them drifted further out into the loch than had been anticipated.

"After weeks decomposing in the water several hundreds of them have risen to the surface and it's not a pretty sight."