NARRAGANSETT — Warmer water, sea-level rise, pollution and pressure from increased coastal development are all changing the Narragansett Bay ecosystem, impacting commercial and recreational users as much as the animals that live there.
The 16th annual Ronald C. Baird Sea Grant Science Symposium brought together scientists, fishermen, policy-makers and advocacy groups on Wednesday to share their perceptions of how the bay is changing. The event at the University of Rhode Island’s Graduate School of Oceanography was also an opportunity for the participants to suggest issues for Sea Grant-funded research projects.
“This is an effort to bring together the best scientific minds who have researched, written and published on Narragansett Bay with people that are out there on the bay, every day, using it,” Sea Grant Director Dennis Nixon said. “We have set aside part of next year’s research allocation to address questions that come up today.”
For people who earn their living fishing and shellfishing, the question of why the bay is changing is much more than an intellectual exercise. During the first of a series panel discussions, fishermen said they believed that enhancements to wastewater-treatment facilities to remove more nutrients from sewage effluent had made the bay too clean to support aquatic life, forcing many of them to quit fishing.
“The bay has evolved, it’s changed, but it’s always been productive,” Rhode Island Shellfishermen’s Association President Mike McGiveny said. “We’re now seeing changes, due to the nitrogen reduction, that are adversely affecting Rhode Island. The lack of food in the bay has caused the water to be cleaner, but we’re concerned that there’s not enough for the shellfish to be productive.”
By 2012, the volume of nutrients entering the bay from wastewater-treatment plants had been reduced by half. There is a consensus that nutrient overloads can deplete dissolved oxygen in the water, killing fish and benthic, or bottom-dwelling animals like crabs, but the challenge is determining the nutrient levels that will provide sufficient food for sea life while keeping the bay water clean.
“Is there a certain level of nitrogen that the bay needs?” McGiveny said.
Lanny Dellinger of the Rhode Island Lobstermen’s Association said he and other lobstermen had given up fishing because there weren’t enough lobsters left.
“There’s no way for a person to make a living in my fishery, the crab-lobster fishery,” he said. “It’s pretty much gone in Narragansett Bay.”
Dellinger noted that in addition to lobsters and crabs, kelp, eel grass and rockweed, a once-common seaweed, had all but disappeared around the same time as the bay became cleaner.
“Is a clean bay necessarily a healthy bay?” he asked.
Lobsterman Al Eagles was more blunt.
“Narragansett Bay has turned into a swimming pool,” he said. “You look in a swimming pool that’s treated with chemicals and there’s no life in it. It’s clear. You can see right to the bottom.”
The Narragansett Bay Commission is the agency responsible for the state’s wastewater-treatment facilities. Tom Uva, the commission’s Director of Planning Policy and Regulations, contested the fishermen’s assertion that sea life has declined because there’s nothing left for them to eat.
“It’s not our fault at the Bay Commission that the fish are gone,” he said. “We do have a lot of sea life in the bay and the bay’s been negatively impacted by us for the last 350 years. The water’s cleaner than it’s been in a long time.”
Listening to the exchanges between scientists, officials and fishermen was Rhode Island Department of Environmental Management Director Janet Coit, who said she welcomed the discussion.
“As DEM manages a whole host of programs about improving and restoring water quality in the bay, a lot of questions have arisen, particularly from the fishing community, so I’m not surprised, but I think the level of discourse and the opportunity to have scientists sharing with fishermen and shellfishermen and other stakeholders in the bay is exactly what we should be doing,” she said.
Scientists cautioned that there was no easy fix for dealing with the changes to fish and shellfish populations.
“I certainly understand that climate change can’t be blamed for everything and I agree with that,” Boston University researcher Wally Fulweiler said. “I don’t think that there is a black and white answer for any of this. It is complex and confusing.”
URI professor Candace Oviatt, who has been studying nutrients in the bay for decades, said fluctuations in plankton blooms were having a significant impact on fish and shellfish numbers. Warmer winters have reduced the annual winter-spring phytoplankton bloom, which in turn affects the entire food chain. Phytoplankton are tiny plants that are eaten by bottom-dwelling animals like shellfish, but since the 1990s, microscopic animals, or zooplankton, which thrive in the warmer water, have consumed them before they even reach the bottom. Oviatt said this change meant more fish but fewer clams and crabs on the sea bottom.
“If there is a bloom, they’re getting eaten in the water column by zooplankton,” she said. “The consequence of that is, you have a lower biomass benthos.”
Westerly-based Save the Bay South County Coastkeeper David Prescott said the nutrient issue was different in Little Narragansett Bay, which is still compromised by excess nutrients and does not benefit from wastewater treatment.
“We do know that there’s a nutrient issue and we see that in the amount of macroalgae we see down there, but it begs some bigger questions that I think need to be looked at further in terms of what the right numbers are and what should we really be looking at,” he said.