Scientists talk about source of nitrogen, water acidification at commission meeting
This story originally was published in the Warwick Beacon, a publication partner of Ocean State Stories.
PROVIDENCE — “How many digital quahogs do I have to dig a day to make a day’s pay?” asked Mark Johnson, concluding the fifth meeting of the Special Legislative Commission to Study and Provide Recommendations on the Issues Relating to the Reduced Catch of Quahogs in Narragansett Bay Jan. 24. A commission member, Johnson’s reference to “digital quahogs” was to data included in studies and not the bivalves he’s harvested since he was a boy.
Created with passage of legislation last June introduced by Sen. Mark McKenney and Reps. Joseph Solomon and David Bennett, the commission aims to find out why, after its peak in the 1980s, the bay quahog catch has dramatically dropped by more than 50% of its previous level, severely impacting the industry. Shellfishermen have been offered some relief with periodic openings of the highly productive Providence River beds that have been closed for more than 70 years.
The commission heard testimony from Chris Kincaid of the University of Rhode Island’s Graduate School of Oceanography and Dr. Jason Grear of the Environmental Protection Agency about possible sources of nitrogen to the bay and the effects of ocean acidification on quahogs, respectively. The scientists’ testimony introduced new considerations to the debate on the cause of the reduced quahog catch. A popular theory held by many shellfishermen is that a reduction in nitrogen has cut into the plankton that the shellfish fed on.
Blame has been placed on the Department of Environmental Management’s efforts to clean up wastewater outflow to the bay. Nitrogen is a vital food source for the plankton that clams feed on, so fishermen like Mark Johnson believe a lack of nitrogen in the bay has indirectly led to a lack of food for clams. On the other hand, the DEM and environmentalists say algae blooms arise when the nitrogen load is high. These blooms cause hypoxia, or lack of oxygen, when the large population of algae die and decompose, which can lead to the death of fish, crabs, and other animals. Avoidance of hypoxic events is a major motivation for nitrogen’s removal from wastewater.
Kincaid, though, presented findings that nitrogen intrusion from the bottom of Rhode Island Sound seems to be a larger source of nutrients than from runoff and wastewater treatment facilities. This has possible implications for quahogs and the algae blooms.
Commission member and shellfisherman Jim Boyd called the finding “surprising” and “higher than I was thinking.”
Kincaid cautioned that his models are imperfect and more research must be done before any definitive conclusions can be drawn as to how nitrogen flows into the bay and how it affects quahogs and hypoxic conditions.
Grear of the EPA presented research on how ocean acidification may negatively impact quahogs in the bay. Grear started by noting that in coastal areas like the Bay, respiration of organisms like algae and bacteria that decompose them can raise carbon dioxide levels, and with them water acidity. He presented laboratory experiments that sought to replicate the acidity conditions of the bay. These found that acidification similar to that of the bay “very clearly” negatively affects the early life stage survival of quahogs. This occurs through a weakening of the clams’ shell density or “integrity.”
Grear said that acidity level has fluctuated less over time since 2005, which is “consistent with the possibility that the reduced nutrient load to the bay is dampening the seasonal fluctuation of CO2 and pH.” Grear concluded by saying that he “can’t really say he has an answer” for whether ocean acidification is affecting abundance of quahogs in the bay, but reiterated that in a laboratory setting acidification clearly negatively impacts the quahogs.
Grear was careful, though, to acknowledge that the conditions in the lab do not perfectly replicate those in the bay, advising that different results may have been found if the clams had been fed different quality plankton in the lab.
Mark Johnson was less than satisfied. Johnson has been a quahogger for 50 years, starting when his father “made the mistake of letting me have a boat.” At the age of ten, he began shellfishing making about $20 a day.
“When you’re ten years old, you couldn’t get a job anyway!” he said.
By its peak in the 1980s, Johnson said, there were more than 2,000 shellfishermen working on the bay, harvesting millions of pounds of quahog each year. But for reasons being investigated by the commission, the harvest dropped to 900,000 pounds in 2012, and has plummeted to less than 400,000 pounds in 2022, according to EcoRINews.
Today there are “only thirty or forty full-time guys left,” Johnson said. Johnson ended the meeting with an impassioned speech on behalf of shellfishermen, asserting that “they (DEM) always say that they listen to the fishermen, but that doesn’t happen.”
Johnson claimed state government is not performing its duty to protect and maintain natural and cultural resources such as fisheries. He also alleged that DEM “has a history of making promises and not following through,” such as a unfulfilled 2017 commitment to invest in shellfish seed production infrastructure, and never creating a shellfish hatchery, despite this being recommended in the 2014 RI Shellfish Management Plan, which the DEM was involved in creating. In general, he claimed, DEM has not adequately balanced the productivity of the fishing industry and its ecological priorities. Johnson made a plea for the commission to listen to fishermen, not just scientists.
“We’ve heard a lot about your modeling and digital stuff. How many digital quahogs do I have to dig a day to make a day’s pay?” Johnson said the day-in, day-out knowledge of shellfishermen is too often ignored in favor of scientists that are not as intimately familiar with the quahogs and the bay and thus “don’t ask the right questions” in their research.
The commission is scheduled to meet again on February 27th.
Editor’s note: Recent Brown University graduates, Benjamin Balint-Kurki is exploring a possible career in journalism and Steinfeld is focused on photo journalism