Marine Biologist from the Environmental Protection Agency (EPA) Phil Colarusso is no stranger to eelgrass restoration. It’s a noble look into how rising temperatures and water clarity issues affect the eelgrass, as he tries to find clues as to what this might mean in relation to climate change.
His latest mission has brought him into Nahant to study the effects the Wharf has on eelgrass within the area.
Eelgrass is a flowering plant that lives underwater, which produces pollen and seeds as tiny as grains of rice. Its scientific designation is “Zostera marina,” and it is also the dominant seagrass species throughout the northeastern United States. It forms underwater meadows in shallow bays at depths that can range from 15-25 feet.
Colarusso dove deep into his background, explaining how his love for the beach and the water influenced his career path.
“I grew up in Winthrop, and my mother would take me to the beach every day from 1-4 p.m. once school was out. Whether it rained or shined, I was on the beach every single day, and I think that really led to my career path,” Colarusso explained.
When he started at the EPA, his job originally was mostly reviewing reports. Then, he went to his boss and asked, “Is there a way for me to get in the field?”
“As much as I was interested in reading about things, I was more interested in reading them,” he said. “My boss said, ‘We have no money, but if you pitch me a project and convince me that it serves the agency, I’ll support it’” he recalled.
After doing some research, Colarussio quickly realized the importance eelgrass plays in the environment.
“You can do a lot of science work around eelgrass without much money needed,” he said. “I pitched a proposal, she agreed, and from there I kept doing research.
“I’ve been working on eelgrass since 1989-1990, and I’ve been diving at the meadow in Nahant since the early ’90s,” he added. “That was probably one of the first meadows that I dove in and started studying. The shallow end of the meadow, the ends nearest the beach, have been lost.”
This year, he and his team have been out to the Wharf several times, he added. “There are seedlings growing on the shore of the existing meadow, so we’re hopeful that area will eventually recolonize and recover,” he explained.
He said it was unusual because usually when meadows begin to decline, it starts from the deep-end first.
“Primarily, they decline due to lack of light, and with the deeper end, there’s more light that’s needed to reach the eelgrass, so that end is light-limited, and any chance in water clarity will cause that deep end to decline and move into shallower waters.”
Now, they’re noticing in some locations losses in the shallow end of meadows, which Colarusso thinks may be related to climate change.
“The shallow end of the meadow, there’s less volume there, so the water heats up faster, and that end is exposed to much higher temperatures than other parts of the water,” he said.
Colarusso and his team of marine biologists look at the various stages of flower development for eelgrass, as well as the number of seeds the plants produce. Once they collect samples from the meadow, then they take a handful of plants that the team harvested before analyzing the flowering stage of what they’ve gathered.
“Meadows that are south of us go through these seed development processes in a very discreet, short period of time. South of Cape Cod, the process starts in May and ends in June… But these meadows start a little bit later and produce flowers all the way into September, it’s a much more elongated process,” he said.
He said that from an ecological standpoint, some populations put out all of their seeds within a very short time-frame, citing a million seeds produced at one time. “That’s one strategy to possibly evade predation of these seeds, flooding the ecosystem with seeds, which is a strategy that a lot of fish follow
“They put out a lot of reproductive effort, knowing a lot of them won’t survive, but that a few will make it. .. But if it occurs over an elongated period of time, and the seeds spread over a two-month period rather than two weeks, it’s not so much looking at evading predators, it’s: ‘Will these seeds find an optimal temp and climate condition?” he said.
He explained that if the seeds are spread at one time during a shorter duration, the chance of finding those optimal conditions is greater than if the process had been elongated.
“Whenever you do field work, there’s constant challenges and setbacks. Salt-water and equipment don’t always mix, and we’ve lost gear, had gear malfunction, or where something goes wrong with the boat,” Colarusso said. “One of the biggest challenges is putting equipment out there and finding it again.
“Even with differential G.P.S., which will give you plus or minus a couple feet, if you’re working in a system where visibility may be a foot or two — if you’re off by 10 feet — you may not find what you’re looking for.”
He continued, saying that eelgrass restoration is not a project with typically high success rates. “We can’t control mother nature … We need a little luck when doing this, but it’s important that we keep trying, and not give in, because the resource is not doing well, and it certainly needs help.”
