On Long Island, towns along the Great South Bay have struggled with flooding caused by erosion. The Cornell Cooperative Extension is looking to help protect the South Shore by planting a type of seagrass that they hope will strengthen the coast.
On a cold, blustery day in December, four divers with the Cornell Cooperative jumped into the Great South Bay with scuba gear to plant eelgrass.
Steve Schott and Kim Manzo were among them.
“When you first get into the water, it stings your face at this temperature, and then it goes numb.”
“You also get used to it, the more you do this. I have been doing this for 17 years. You get used to being cold and miserable…it’s just part of the job.”
Unlike seaweed, eelgrass is a rooted plant, and the Great South Bay used to be one giant underwater meadow.
“When the meadows were still here, [they] would have been covered by acres and acres of eelgrass.”
And that’s what NOAA found when it did its last environmental survey in 2002. But between 2002 and 2012, Schott says pollution and global warming caused it to nearly die off.
“Now it’s basically just a flat sand bottom with very little feature in most cases.”
However, a breach created by Superstorm Sandy four years ago split the Fire Island National Seashore in two, and improved water conditions in the Great South Bay by flushing it out.
Now that the water’s cleaner, the Cooperative wants to restore the underwater meadow.
Partnering with the Town of Brookhaven, the Cornell Cooperative began planting eelgrass this month to try to protect the shoreline and marine life.
“Usually we get about 60, in a tank of air in an hour. So if all four of us get, that’s 240, that’s most of them.”
Schott says eelgrass prevents the tides and storms from washing sand off the beach. The erosion of the beach makes the South Shore more susceptible to flooding.
“You get a storm, that sediment gets kicked up in the water column and suspended. It’ll settle that sand back out and prevent it from being washed offshore.”
And that’s why they are jumping into frigid water. Eelgrass thrives when planted in cold water.
“We’re going to try to establish a foothold and try to bring eelgrass back, give it a starting point to try to spread on its own.”
Manzo pulled out a few more batches of eelgrass from the boat.
“So, these are the rings that we use for planting, we use them almost like a cookie cutter.”
While underwater, Manzo, Schott and two other divers push the rings into the ground and dig out an inch or two of sand. They plant the eelgrass and pat it down inside the ring.
“When we pull it out, it’s nice and level with the surface and gets held down by the sediment so that the roots can get established.”
The Cornell Cooperative will monitor the eelgrass planting fields for the next five years to try to restore the coast.
