Hope for Long Island’s Bays

Pictured Above: Stony Brook students made short work of planting 80,000 clams into spawner sanctuaries in Shinnecock Bay along with 5,600 oysters in the spring of 2021, as part of an ongoing seeding project in the bay. | Gobler Lab Facebook photo

While the news about warming and acidifying waters and harmful algae blooms in Long Island’s waterways continues to be quite grim, work to restore habitats and find new nitrogen-reducing septic systems has been hopeful, said Dr. Christopher Gobler in his 2023 State of the Bays address.

Dr. Gobler, an Associate Dean of Research at Stony Brook University’s School of Marine and Atmospheric Sciences and Director of Stony Brook’s Center for Clean Water Technology, gave his annual address April 4 at Stony Brook Southampton’s Chancellor’s Hall.

After several years of bleak themes, this year’s lecture, titled “Love Where You Live,” highlighted some major recent successes, including the continuing massive growth in the hard clam population in Shinnecock Bay, and the Center for Clean Water Technology’s Nitrogen Reducing Biofilter (NRB) pilot project, which is expected to be approved for widespread use by the Suffolk County Health Department this spring.

Preliminary data has shown that the NRB “is doing better than and almost as good as any other system approved by the county,” Dr. Gobler told the crowd gathered for his address. “Our systems can also remove very high percentages of emerging contaminants, percentages that are better than sewage treatment plants.”

SoMAS has also been working with the Shinnecock Bay Restoration Program to seed Shinnecock Bay with baby hard clams and to restore eelgrass beds in the western portion of the bay, which has long suffered from low dissolved oxygen levels due to its distance from the tidal flushing at Shinnecock Inlet, in the eastern portion of the bay.

The researchers began seeding the bay with clams in 2012, and over the past two years have seen dramatic growth in the clam population.

“Shinnecock Bay started with the fewest clam landings, and now they’re far greater than all the other estuaries,” said Dr. Gobler. “We did calculations of how quickly they’re filtering the water. In the west it went from a three-week turnover to just a week. We believe this is now enough for the bivalves (shellfish with two shells) to have biological control over the estuary.”

Dr. Gobler said there hasn’t been a brown tide bloom in the bay since 2017 — the longest stretch without a brown tide bloom since it was first recorded there in 1985.

The researchers have also seen a 400,000-acre expansion of eelgrass bed in the bay during their restoration efforts.

Many species of microalgae that cause harmful algae blooms remain a chronic problem in Long Island waters, particularly in Suffolk County, where 70 percent of homes have individual septic systems that are a major source of nitrogen that is feeding the blooms. 

Suffolk County mandated nitrogen-reducing septic systems in all new construction as of 2022, and has an active program to provide grants to homeowners who want to install the systems. Southampton and East Hampton towns also provide rebates for costs above what is paid by the county. 

The IRS also ruled late in 2022 that these grants and rebates are exempt from income taxes, a hurdle that had in the past given homeowners pause about participating in the program. Residents who have already paid income taxes on their grants are also eligible for a refund.

Dr. Gobler said that, with the 2020 adoption of the Suffolk County Subwatersheds Wastewater Plan, the county has gone “from worst to first” in addressing wastewater issues.

“Now it’s not a stretch to say Suffolk County has the most progressive onsite wastewater program of any county in the country,” he said.

The county is also planning to ask voters to approve a ballot proposition this November to create a ⅛ percent sales tax to continue to fund the septic system upgrade grant program. 

But the legacy of Long Island’s dependence on groundwater for drinking while continuing to install on-site septic systems still has consequences.

“Suffolk County’s public water is in the top five percent of nitrate levels in the United States. Most Americans have drinking water with lower levels of nitrate,” said Dr. Gobler, He added that drinking water levels of nitrogen here average 4 milligrams per liter — less than the EPA standard of 10 milligrams per liter, but perhaps not enough to protect human health. He said that new medical research has shown that people who drink water with more than 3 milligrams per liter of nitrogen have increased levels of gastric, colon, bladder, kidney, ovarian and prostate cancers, and it has also been associated with several birth defects in a recent Danish meta study of one million children.

While the effects of nitrates on human health may take time to become clear, the effect on marine ecosystems can be seen far and wide, from 50 fish kill events concentrated across the North Shore in areas with low dissolved oxygen in the summer of 2022 to the annual return of a rainbow of shades of algae blooms in lakes and ponds, in the shallow South Shore bays the Peconic Estuary.

Once algae blooms peak, they begin to decay, and this decay process uses a great deal of oxygen, which can suffocate animal species caught in their midst. Some algae species also contain neurotoxins that can be dangerous to humans and other wildlife.

But the latest algae threat may be the easiest to see. It’s a macroalgae, better known as seaweed — Dasysiphonia japonica, a stringy red plant native to Japan, which colonized Europe in the 20th Century and has been in New York for the past 15 years, where it has been documented before in the Great South Bay.

In 2022, Dr. Gobler said Dasysiphonia has spread into Hempstead Bay, the Long Island Sound, the Peconic Estuary and Quantuck Bay. This seaweed does contain a toxin called caulerpin, and spreads quickly, washing up on shores where it decays and lets off sulphur gas.

“It’s clearly starting to spread across Long Island,” said Dr. Gobler, adding that his lab has been studying the growth of this seaweed and found that it thrives on high levels of nitrate and carbon dioxide. Researchers have also found that between 75 and 100 percent of the nitrate causing the seaweed to grow is from wastewater, most of which is from aging on-site septic systems.

Dr. Gobler’s lab has also been doing research this year on growing beneficial seaweeds like a native species of kelp, which not only use nitrogen in seawater as a food source, but also reduce acidity in surrounding waters. This has proved to be a boon for oyster farmers who have begun growing kelp alongside their oysters.

“Oysters grow faster with a higher pH, or next to kelp, as compared with a control site,” said Dr. Gobler. “I call it a halo effect. We’re protecting aquaculture with seaweed. We’re not going to eradicate harmful algae blooms with seaweed, but we may be able to protect an oyster farm.”

Dr. Gobler said he sees a clear path forward, with upgrading septic systems as the primary strategy to protect the health of the bays in the long run, but using farmed seaweed and shellfish as an “in-the-water solution that can help as well.”

A video of the address is available on SoMAS’s YouTube channel.