Date: Aug. 31, 2020
Media: Mount Desert Islander
Author: Liz Graves
FREEPORT — Clam landings have declined over the past 40 years, during the same time period when seawater temperatures in the Gulf of Maine have risen substantially. But spreading clam and oyster shells on the mudflats in an effort to counteract the effects of coastal acidification does not increase numbers of juvenile clams and quahogs, according to results from three years of field experiments led by researchers at the Downeast Institute and the University of Maine at Machias.
Studies were conducted at mudflats with relatively acidic mud that had historically been productive clamming areas but with little commercial activity in recent years.
“In none of the experiments did adding shells to buffer acidic sediments result in more clam or quahog recruits, said Brian Beal, a lead researcher on the study. “Instead, we found significantly greater density and size of both bivalve species when the treatment excluded predators, regardless of whether the sediment was buffered.
“Given the findings of this set of research experiments and others, it makes more sense for fisheries managers to focus attention on mitigating effects of predators instead of spreading shell hash to buffer intertidal sediments.”