Story highlights Officials are testing the water for pesticides and oxygen levels

The cause of the mass deaths remains unclear

(CNN) The carcasses of thousands of sea creatures have mysteriously washed up on the western coast of Nova Scotia.

As many as 20,000 fish, lobsters, starfish, scallops, crabs and other animals have turned up dead at Savory Park, Canadian authorities said. And they have no idea why.

CNN Map

Canada's Fisheries and Oceans department tweeted images of the massive cross-species graveyard.

Herring found by DFO C&P Officers in Southwest Nova Scotia yesterday was not fresh (4-5 days old) pic.twitter.com/CyQzxwxQrH — DFO Maritimes (@DFO_MAR) December 29, 2016

Environmental officials are testing the water for pesticides and oxygen levels for possible clues. As a precaution, they're warning consumers to only buy seafood from authorized vendors.

"Dead fish found on shore should not be collected by general public," the Fisheries and Oceans department tweeted. "Consumers should only purchase from licensed harvesters/sellers."

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