Are shellfish canaries?

Oreti Beach - Takitimu mountains in background

It is a worry when this happens.

"The unexplained deaths of endangered shellfish on a Southland beach late last week was an "ecological catastrophe", a University of Otago scientist says.
Several hundred toheroa on Orepuki beach were lost in a mass die-back, the first of its type since the early 1990s."

"An estimated 58,000 toheroa lived on the beach and it was a concern some of the mature shellfish, which can live up to 20 years, appeared to have died.

Toheroa were located at Oreti, Orepuki and Bluecliffs in Southland."

We know so little about the sea, yet we dump crap into it as if everything will magically work itself out. These shellfish are the canaries of the sea. Yes they grow and decline in natural cycles... but that doesn't mean we shouldn't be concerned.