Mass poisoning is one explanation
Environmentalists in northern Russia have expressed concern at the latest incident of mass deaths among marine fauna on the shores of the White Sea.
Russia TV reported that thousands of dead starfish and crabs have washed ashore near the village of Syuzma in the Archangel region, along a nine-mile stretch of coast.
The marine creatures were deposited on top of each other in layers two to three deep.
"It's scary," schoolgirl Natasha Ludkova told the TV channel.
"There are so many starfish there. You can't even walk around them because the whole shore is full of starfish. We had to tread on them and it wasn't pleasant."
Local children collected several specimens of starfish and crabs and handed them over to Severodvinsk and Archangel ecologists to investigate.
Some 20 dead seals were also found washed ashore on the sandy beach of the island of Yagry in Severodvinsk after a recent storm.
This is not the first time that the White Sea coastline has been hit by the mass death of marine creatures.
In 1990, millions of starfish, as well as a large number of mussels, crabs, dozens of nerpa seals, seals and belugas were killed.
The TV said it was established at the time that the deaths were caused by short exposure to a highly toxic substance, but it said no further details were made known.
A similar incident was reported by the Russian press in 1992. Izvestiya newspaper said at the time that one team of Archangel scientists believed that the deaths were due to the dumping of radioactive debris and chemical weapons in Barents Sea waters.
Vladimir Glushko, spokesman for the Severodvinsk environmental council, said that the latest incident might be a case of mass poisoning.
"That's possible," he said, "but it's just a theory. What we need is a thorough independent investigation."
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