Research links clam behaviour to climate change
Could be cause of increasingly low soft-shell clam populations on the Bay of Fundy
New research is linking clam behaviour to climate change. That shift in behaviour could be contributing to increasingly low soft-shell clam populations on the Bay of Fundy.
Researcher Jeff Clements at the University of New Brunswick in Saint John says clams tend to refuse to burrow into ocean sediment that has high acidity.
"One of the things that climate change does is change the chemistry of the oceans," explains Clements. "So what we've been seeing is with increasing CO2 concentrations, we see more acidic conditions in the ocean and this is altering the way clams behave and make decisions."
Under ideal conditions, clams burrow into mud and silt at the bottom of the Bay of Fundy. But Clements’ research indicates that environments with high acidity lead to different clam behaviour.
"When we make muds more acidic, what they do is stay on top of the sediment and let the water current take them to another area."
Clams rolling around on top of the sediment are easy prey for hungry predators, so they have to burrow as quickly as possible. But Clements says if they burrow into sediment where the pH is too low, shells will start to dissolve; so they have to make a decision.
Clements says that if the environment changes quickly, many species simply keep up. "What we're seeing with climate change and ocean acidification is an abnormally rapid shift to conditions that these animals are not adapted too," he said.
Clements says the clam population is important to the Bay of Fundy ecosystem for a number of reasons.
"They are a big source of food and nutrition for fish and crustaceans. They can also act as ecosystem engineers," he said.
In addition to being a link in the food web for the bay, clams also bring oxygen into the sediment that they burrow into. This oxygenation of their habitat makes the area much more habitable for other animal species living within the sediment.
"Not quite what we would call "dead zones," but we could see more areas of less oxygenated sediments," said Clements.
"This could lead to less hospitable environments for other animals living there."