But comparatively little attention has been paid to the multiplier effect these nutrients have on ocean acidification in those same water bodies. A new report from the state Commission on Ocean Acidification, released Tuesday, said an increasingly acidic ocean threatens the state's $400-million-a-year shellfish industry, and could devastate coastal waters where nutrient loading adds to already elevated ocean acidity. More:Grants offer needed relief for shellfish harvesters“It’s clear we need to establish a broad ocean monitoring system,” said state Sen. Julian Cyr, D-Truro. Ocean acidification occurs when carbon dioxide in the air is absorbed at a rate and quantity that lowers the pH, a measure of how acidic or alkaline a liquid is. The legislation will also amend appropriate existing laws to account for ocean acidification.