Rain, climate change unkind to oysters

OYSTERS, “bump” in oysters’ size in the spring, once waters warm, and again in the fall. But this year, there was no spring bump. “The conditions were there to grow, but the salt wasn’t there,” Petty said. “I’ve just never experienced that in my 20 years.”

Increased rainfall and other issues associated with climate change influence big decisions Maryland must make about how to manage its oyster population. Rising and increasingly acidic oceans also could affect the way the shellfish fare in the long run.

A long-awaited report detailing the state of the oyster fishery is due to state lawmakers this month. It could restart paused discussions about whether watermen should be given periodic access to oyster sanctuaries — relatively robust reefs that have for years been off limits to harvest. Under Gov. Larry Hogan, the state has worked to balance commerce and conservation.

The debate is a contentious one because with oysters, more is at stake than the species itself. The mollusk naturally filters impurities from the water. So the recovery of the oyster population means recovery of the bay.

Allison Colden, Maryland fisheries scientist for the Chesapeake Bay Foundation, said that if heavy rain becomes more routine and harms oyster reproduction, the job of managing oyster harvests would become more difficult.

“The number you can take out continues to get smaller and smaller if you want to sustain the population,” she said.