Cape Cod Times
By Doug Fraser
Posted May 4, 2019 at 8:30 PM
Updated May 5, 2019 at 6:46 AM
Cape scientists, inmates explore life in the dead zones
EAST FALMOUTH — If you were looking out the window from one of the homes along the Eel River last Sunday, you saw a very different crew at work on the water.
A dozen or so fishermen-types were crowded onto two rafts. The larger float was anchored, but the smaller one, powered by a tiny outboard, was working its way methodically along a line of buoys, pausing at intervals determined by a laptop GPS flipped open on the decking while two crewmen plunged what looked like a hybrid post hole digger/bull rake into the water. The device brought up black mud from the pond bottom that was then dumped into individual crates, and shuttled via skiff to the larger raft.
Barnstable County Correctional Facility inmates Richy Lapointe and Robert LaBoissiere were pouring buckets of water into the crates carefully washing away the muck, like panning for gold, but picking out mostly broken shells, sometimes an occasional live razor clam or quahog. Lapointe and LaBoissiere had become desensitized to the rotten-egg smell emanating from the mix of sand, clay and organic matter pulled from the river bottom, the product, Falmouth town fisheries biologist Christine Lovely said, of specialized bacteria that could decompose organic material even in low or no-oxygen zones and produced hydrogen sulfide.
The smell was a sign that portions of the river had been slowly dying over the past 10 to 20 years. Nitrogen in septic system effluent acts like lawn fertilizer, fueling explosive growth in algae that that can be both unsightly and smelly. A few cloudy days and photosynthesis grinds to a halt. The bloom dies and the algal mats sink to the bottom and get swept by currents into low-lying portions of the river. Their decomposition sucks all the oxygen out of the water, forming anoxic dead zones that kill other plants and wildlife such as fish and shellfish.
Coring down into these dead zones was being done in part to address the concerns of shellfishermen in town who worried there might still be living quahog beds there.
Sunday’s work, with 144 corings, yielded just 11 stout razor clams, a species that seemed to be able to live in the low-oxygen zones, and a few quahogs. The razor clams were sent to Roger Williams University for study and spawning.
Lovely and Barnstable County Deputy Jeff Wiseman measured every mud core sample like it was a striped bass. LaBoissiere and Lapointe then washed out the muck and picked out the few survivors of what was essentially a blighted benthic ecosystem, pausing over each living thing, from lowly clam worm to fist-sized quahog, like it was a precious nugget.
“These are sweet,” said R. Charles “Chuck” Martinsen as he lifted the mustard-colored inhabitant of a slipper shell to his lips. Falmouth’s deputy director of marine and environmental services and the town’s shellfish constable, Martinsen was overseeing survey work for a pilot project to test the filtering power of oysters and other shellfish and whether these natural filtration organisms will make a quantifiable and substantial impact on nitrogen contamination in town estuaries.
The hope was that oysters, a sweeter and more universally accepted fare, could be coming out of the waters of these areas within a few years as a direct result of the work done Sunday, and that shellfishermen eventually would be bidding to set up aquaculture farms in the three Eel River survey zones.
But to get there, the shellfish projects intended for wastewater cleanup have to prove themselves. The Falmouth ponds and rivers that reach deep into the mainland from Nantucket Sound are so contaminated with nutrients that they chronically suffer from algae blooms. Scientific research has determined that between 72% and 100% of the nitrogen must be prevented from entering the water for those water bodies to recover to the point that they are suitable for bottom plants like eelgrass, and for swimming and fishing.
Typically that level of nitrogen removal could only be done through expensive sewering. But state and federal officials recognized that the public, faced with unprecedented costs in the hundreds of millions of dollars per town to clean up wastewater contamination of bays and ponds, was demanding cheaper alternatives should at least be tried. When the Cape Cod Commission updated the regional wastewater management plan in 2014, it evaluated more than 40 alternative nitrogen-removal technologies, including the use of shellfish, and the DEP and EPA signed off on their use, as long as monitoring showed they were effective.
The town already has installed pilot projects in Little Pond, Bournes Pond and Waquoit Bay, growing around 6.5 million scallops, clams, but mostly oysters. Each oyster can filter as much as 50 gallons of water per day, using the nitrogen to build their shell. A recent Woods Hole Oceanographic Institution/Sea Grant study was able to calibrate an average of the grams of nitrogen contained in oyster shells allowing for a more precise estimate of the efficacy of aquaculture projects in a wastewater plan. Other studies in Falmouth and Orleans looked at determining the amount of nitrogen in the tissue of these animals. A third line of inquiry looks at how feces and other indigestible particles excreted by shellfish that drifto the bottom may create an environment favorable to bacteria that also can remove nitrogen from the water.
The survey of three Eel River sites is scheduled to be completed this month, followed by hearings before the Conservation Commission and selectmen with permit applications for the sites sent to the state Division of Marine Fisheries in June. At the same time, the town will solicit applications from private aquaculturists with licenses awarded sometime in June or July.
Falmouth’s comprehensive wastewater management plan approved by the state includes the use of aquaculture to remove approximately 7.2% of the nitrogen from seven ponds, bays and harbors. The plan estimates that aquaculture will remove nearly 7,800 pounds of nitrogen a year from these water bodies, eliminating the need for 550 sewer connections. The remaining 92.8% of nitrogen will be handled through a combination of sewering and alternative technologies such as composting toilets, permeable underground barriers and low-tech solutions such as inlets, lawn fertilizer bans and improved stormwater management.
The goal is to be able to accurately quantify the amount of nitrogen being removed by the shellfish so the town is able to meet the nitrogen-removal goals laid out in the plan.
“People wanted to know how is it working, what is the amount that that is being removed, and we’re able to get a little bit closer to that answer,” Martinsen said.
Karplus said generally, the tissue contains about 40% of the total nitrogen, and the shell around 60%, but that can vary depending on the site and the growing technique, he said. That’s why the state Department of Environmental Protection requires each wastewater aquaculture project to submit tissue and shell samples to a lab to quantify the nitrogen content.
Last week, inmates Arthur Ashley and Al Randell worked on the smaller float with Karplus. The two inmates did the heavy work of shoving the coring device down into the muck, compressing the core sample as water squirted from the top of the device, then lifting that compact, heavy sample back onto the rack for loading into the individual crates.
Inmate Jason Battles worked in the skiff transporting the crates to the big float for processing.
The inmates selected for the project have to be nonviolent offenders near the end of their term. Lapointe, who lives in Harwich and is an electrician by trade, and LaBoissiere, a carpenter from Wakefield, both worked steadily as if they were on a job site.
“Who wouldn’t want to work?” said Lapointe, who will be released in October. LaBoissiere will be released next month.
If they were not on the work detail, Lapointe said they’d be inside the whole day with the exception of a few hours of recreation. Here, they work outdoors for most of the day, something that helps ease the transition to the real world.
“We’ve been working with the Barnstable County inmates and staff for approximately six years,” Martinsen said. The work crew built a propagation center for Falmouth that has grown tens of millions of shellfish, including oysters that will be used on the pilot project and in similar ones in Bourne and Orleans, Martinsen said.
“They’ve been wonderful to work with and they come here and learn a new skill,” he said. Some have gone on to find jobs in aquaculture.
Martinsen tells inmates that after their release they are welcome to come back, bring their families and children.
“They can show them what they did when they were here, that it’s something to be proud of and very fitting that they are making a contribution to the environment and fisheries of Cape Cod,” he said.
— Follow Doug Fraser on Twitter: @dougfrasercct.