Although Long Island Sound is far cleaner than it was half a century ago, the inlets, bays, coves and harbors along the Connecticut shoreline are the new focus of environmental attention and concern.
“The bays are panting instead of taking normal breaths,” said Jamie Vaudrey, a professor of Marine Sciences at UConn who studies nitrogen loading in Long Island Sound. “They cycle between having very high oxygen, beyond what is normal, to very low oxygen, that is very stressful for marine life.”
Although much is known about the interior of Long Island Sound, and the sound as a whole, very little effort has gone into understanding the smaller ecosystems of individual bays, coves and inlets. These areas – collectively known as embayments – can have very different environments and contain pollutants from different sources depending on their watershed. In total, the Sound has 110 different small, watersheds that drain into embayments along the Sound in addition to the four large rivers: Thames, Connecticut, Housatonic and East.
A study by Vaudrey determined that nitrogen in the Sound’s embayments is coming from three main sources: septic systems, atmospheric deposition also known as runoff and fertilizers. The study determined which of these sources is having the largest impact on the water quality in each individual embayment – the places residents and visitors to the Connecticut shoreline most often interact with the Sound.
“Nitrogen and phosphorus are fertilizers for our lawns, but they also fertilize plants and plant like organisms in the ocean,” said Jamie Vaudrey. “If we give them more nutrients, the algae and seaweed grow more and more.”
Overgrowths of algae are known as blooms and can result in rapid consumption of all the oxygen in the water leading to what is known as a dead zone. Dead zones have almost no life because fish, oysters, clams other native sea life can’t live without oxygen. These hypoxic events negatively impact fish, oysters and clams in the Long Island Sound.
“As we feed nitrogen into that coastal system, as we fertilize it, we often fertilize things that we don’t really want like seaweed and phytoplankton. We get a switch in the community,” Vaudrey said. “We are fertilizing the weeds, the things we don’t really want in our coastal oceans.”
Near Fairfield County and New York City — communities mainly served by sewers — fertilizers used by individuals and towns are the biggest contributor of nitrogen to the Sound. Around Middlesex and New London Counties, however, septic, fertilizer and runoff contribute equally to the nitrogen problem.
“Septic systems and lower-end sewer systems are not designed to remove nitrogen. Instead, the system is designed to make sure that what comes out of it does not impact our drinking water not the health of the environment,” Vaudrey said.
In order to have a septic system that truly filters nitrogen, the soil in a leach field must be high in organic matter. On the Eastern sound, the soil is mostly sand.
“Our soil does a really awful job at removing nitrogen,” Vaudrey said.
In Old Saybrook, the soil is especially unsuited to filtering nitrogen. Sixty percent of the nitrogen load in the embayment at the end of the Oyster River is from septic systems.
In Old Lyme, on the other hand, where the soil has more organic material, water at the cove at the end of the Black Hall River shows pollution that is 28% fertilizer and 39% septic.
East Lyme is on the other extreme. The embayment at the end of Bride Brook shows a much higher percentage of nitrogen coming from fertilizer.
In Rhode Island and New York efforts have been made to incentivize individuals and towns to replace older septic systems with versions remove nitrogen.
Connecticut Department of Energy and Environmental Protection just recently began work on a study to determine the state of septic systems in Connecticut and what upgrades could do for the region. This is the first step toward incentive programs like the ones in Rhode Island and New York.
“People overuse fertilizer tremendously,” said Judy Preston, the Long Island Sound Outreach Coordinator for the Connecticut Sea Grant. “Lawns are the biggest issue, we really need more species for soil to be healthier.”
Instead of applying the traditional 4-in-1 fertilizer, Preston recommends getting your soil tested. It’s unlikely that every lawn needs herbicide, pesticides and multiple fertilizers. With a soil test, the nutrients your soil is actually in need of can be identified – saving money while reducing the fertilizer pollution.
“People often blame farmers and orchards for fertilizer pollution, but farmers won’t use any more than they have to because that’s their bottom line,”
With environmental issues it can often be difficult to understand how changes made by an individual can really make a difference – but for those living in coastal regions – even small changes can make a visible impact in as little time as a year.
“I think that if we look back in time to the 1970s before the Clean Water Act, our waterways were in serious trouble. We had massive pollution and huge water quality issues. Since the establishment of the Clean Water Act we’ve been chipping away at pollutions. What we really want is a return to a clean, vibrant healthy system,” Vaudrey said. “We want to see lots of clams, oysters, fish and be able to eat them. That’s the goal.”