HomeCollege of Arts and SciencesStudents' Research Aims to Shore Up State's Eroding Beaches

Students’ Research Aims to Shore Up State’s Eroding Beaches

Summer is finally here, and that means heading to Connecticut’s coast to splash in the waves and sunbathe on the beach. But you may want to go right now. According to analysis conducted by Brooke Mercaldi and Lauren Brideau, juniors at Southern and paid researchers for Southern’s Werth Center for Coastal and Marine Studies (WCCMS), those miles of beach are quickly shrinking, and unless the state changes the way it handles coastline management, they won’t be back any time soon.

It’s a long-held belief that there is a seasonal rhythm to beaches in Connecticut: they erode during winter storms and are rebuilt during calmer summer months, thanks to fair-weather wave fields. However, Mercaldi and Brideau’s research on wave energy asymmetry is proving otherwise — that the state’s beaches don’t work this way and that our neighbor, Long Island, is the reason why.

Using laser surveying technology, Mercaldi has been studying the dynamics of Connecticut’s coasts since 2015. “We take three profiles at five beaches across the Connecticut coast: Sherwood Island State Park in Westport, Bayview Beach in Milford, Hammonasset Beach State Park in Madison, Rocky Neck State Park in Niantic, and Ocean Beach in New London,” she says.

Mercaldi’s research has shown that Long Island actually intercepts the fair-weather waves, the waves that originate in the Atlantic and have sufficient energy to rebuild our beaches after a storm. Mercaldi has found that Connecticut’s locally generated fair-weather wave field lacks the requisite energy to move the sand from the bars back onto the beach.

“Brooke has discovered some things about how Connecticut beaches work that go against the textbook train of thought,” says James Tait, professor of marine and environmental sciences and co-coordinator of WCCMS. “Along Connecticut shorelines, swell waves from distant storms, they run into the South shore of Long Island before they reach Connecticut,” he says. “So, the shoreline of Connecticut erodes and nothing happens. If we could get rid of Long Island, we’d be all set.”

Since moving Long Island isn’t an option, alternatives that combat erosion are needed, and that’s where fellow researcher Brideau is lending her expertise. She has focused exclusively on Hammonasset, which draws more than one million annual visitors and has had beach and dune erosion problems along its western half. As part of her beach sand transport and deposition study, Brideau is evaluating the fate of a 2017 U.S. Army Corps of Engineers project that involved transporting about 300,000 cubic yards of sand dredged from the Housatonic River on barges to Hammonasset — for an estimated $9 million.

“If you showed up at Hammonasset you wouldn’t notice right away, but pictures show what’s happened,” says Mark Sulik, Environmental Protection, Parks and Recreation supervisor at Hammonasset. “We know we lose sand, and you’ll see after a storm that the drop-off is really noticeable. Then two weeks later it’ll be back, but we have noticed that over the past 30, 40, 50 years consistently, most of it disappears for good.”

Brideau, who has become the “go to” beach scientist for the park, has set up a network of approximately 30 beach profiles that she measures every three months using a total station and reflector. She has been working with park management and with the State Department of Energy and Environmental Protection as well as supplying additional data to the Corps such as depth of closure measurements and measurements of the dunes.

“Right now I’m still monitoring sediment and taking beach profiles,” says Brideau. “I survey the beach, the beach volume and width, and see where sediment is moving from and where it’s accumulating. We graph everything and compare all of the graphs on top of each other. It’s a visual way to see where sediment is going.”

The next phase, according to Brideau, is moving into designing sediment management — that’s where her expertise and Mercaldi’s have saved, and can continue to save, the state a significant amount of money.

“The towns don’t have the money to hire independent researchers to do this kind of investigation,” says Tait. “We’re doing it for free. It would probably cost them $100,000 to do this study if they hired a private company. We are saving the state millions in the long run, hundreds of thousands in the short term.”

What’s more, says Tait, importing sediment at the cost of $9 million per trip isn’t practical or sustainable. The idea, essentially, is to use Brideau and Mercaldi’s research to change the state’s mindset about coastal sustainability.

“What Lauren is doing — and Brooke as well — is to help them understand what’s happening to their eroded beach materials, and they use our data to move forward,” says Tait. “Nature isn’t going to put the sand back. We have to do the work that nature does. We always run into the erosion issues. We’re trying to push this idea that we do it once, then try to keep track of where it’s eroding and accumulating. So the idea is to reclaim and not re-nourish. It makes a huge amount of economic sense.”

Brideau hopes that by bringing her findings to General Assembly, the research will help spur better coastal management and policy.

“Connecticut’s Department of Energy and Environmental Protection is aware of these projects and has been helpful in guiding our initiatives,” Brideau says. “But a better approach is to bring it to the legislature to implement policy change. Connecticut state beaches need to be manually replenished. People don’t know this or recognize it, and there’s no money for it. The next step is to bring it to the legislature and find someone who understands the urgency of it.”

Sulik, of Hammonasset, understands. “In the long-term, we don’t really have a plan to protect the beach,” he says. “Any information we get is beneficial. For future generations we need to look at better management plans.”

WTNH did a story recently on the students’ research at Hammonasset. Watch the video to learn more about Brideau’s and Mercaldi’s research, along with fellow student David Bakies.

 

RELATED ARTICLES

Most Popular