Eelgrass on decline in
Rhode Island waters
Michael
Bradley calls eelgrass “the canary in the coal mine for estuarine health.” The
flowering plant that grows beneath the surface of coastal waters and salt ponds
provides nursery habitat for shellfish and finfish while also dampening wave
energy, stabilizing sediments and serving as an indicator of clean water.
But
according to a recently issued report by the University of Rhode Island’s
Environmental Data Center, eelgrass in Rhode Island is declining in
Narragansett Bay and in most of the state’s coastal salt ponds.
The
report found 1,144 acres of eelgrass and other submerged vegetation in state
waters, an 18 percent decrease from 2012. The largest declines occurred in Quonochontaug Pond (52 percent),
Point Judith Pond (48 percent) and Little Narragansett Bay (25 percent).
More
than half of the state’s eelgrass occurs around Jamestown, which experienced a
19 percent decrease in eelgrass acreage. Ninigret Pond was the only coastal
pond not to have a decrease, and the Narrow River was the only site that
experienced a significant increase (45 percent) since 2012.
“It’s difficult to know exactly what’s going on,” said Bradley, a URI research associate and lead author of the report.
“The reasons can be varied. An
increase in water temperature could have something to do with it. Pollution in
the water or soil could have something to do with it. And severe storms like
Hurricane Sandy could certainly affect it. We need more surveys, more data and
more analyses to get a better handle on what is determining eelgrass changes.”
Eelgrass
beds can also be degraded by algal blooms or disease or be physically damaged
by human activities like shallow-water boating, dredging, and construction of
docks and other structures.
Data
for the report was collected by aerial surveys funded by the Rhode Island
Coastal Resources Management Council.
Bradley
said that the decline in eelgrass is worrisome.
“If you care about shellfish,
if you like to have scallops, if you care about commercial or recreational fishing,
then you should care about eelgrass,” he said.
“The bottom line is that’s where
the little critters go to hide to become big critters that can become
commercially or recreationally available.”