Originally published in The Weekly Packet, August 7, 2014
Aquaculture on the Bagaduce River
DMR discusses ecology, public wants to also talk policy
From left, Chris Vonderweidt, Deirdre Gilbert, Assistant Commissioner Meredith Mendelson and Aquaculture Environmental Coordinator Jon Lewis of the Maine Department of Marine Resources.
by Anne Berleant
At its second public meeting in four months on Bagaduce River aquaculture, the Department of Marine Resources focused on the science and ecology of oysters and oyster farming. However, many who attended the July 31 meeting were more interested in discussing process and policy.
“We would like to have a holistic approach to the use of our river,” said Castine resident Gunilla Kettis.
The Bagaduce River is a 14-mile waterway that flows between the towns of Brooksville, Sedgwick, Penobscot and Castine, with relatively warm water temperatures well-suited to oyster farming.
Currently, there are 38 Limited-Purpose Aquaculture (LPA) sites on the Bagaduce River, two standard leases, good for up to 100 acres for 10 years, and two experimental leases, for up to four acres and three years.
LPAs are 400-square-foot sites licensed primarily for aquaculturists to test an area’s potential before beginning the arduous process of applying for a standard lease.
“We’ve been trying to address some concerns on LPA [sites] in the river,” Assistant Commissioner Meredith Mendelson said, and the DMR is making a “strong effort” to keep “eyes on them” annually. “We are interested in compliance,” said Mendelson. “That is the number one priority of the marine patrol.”
However, more than one resident in attendance reported oyster bags floating down river, destroying eel grass beds, and many expressed concern over the impact of the sites on seal habitats and use of the river as a natural resource for everyone.
“The ecological tipping point is way higher than the social tipping point,” said Penobscot resident Tom Stewart. “They’re two very different things.”
The science of oysters
Jon Lewis has worked as a field biologist and aquaculture environmental coordinator for the DMR since 1997. In that time he has “been in, on, under or around” every aquaculture lease site in Maine, he said.
Oysters “basically just sit and filter water,” up to 50 gallons per day per oyster. For these reason, states along the Atlantic seaboard have started oyster restoration programs, both as a “clean-up tool,” in the polluted waters like the Bronx River, and for commercial purposes.
Oyster farming doesn’t require hormones, antibiotics or chemicals. “It doesn’t happen,” Lewis said. “All oysters need is clean water and algae to filter feed.”
In oyster farming, oysters are often placed in mesh bags to protect them from predators. The bags contain HDPE, or high-density polyethylene, “the same as [in] public drinking pipes,” Lewis said. “I’m not too concerned about plastics coming into the water.”
Another source of contaminants is oyster feces. “We have heard testimony that oysters poop, and they do,” Lewis said. However, oyster do not generate their own heat, so do not produce warm-blooded coliforms.
The presence of MSX (multinucleated sphere unknown) diseases, which recently infected 96 percent of oysters in the Damariscotta River, does not “kill off [other] ecological life,” Lewis said. “They kill only oysters.” The source of MSX is unknown, but after “pretty heavy die-offs,” the oyster mortality rate in the Damariscotta and St. John rivers “seems to have stabilized” at 25 percent, “which is not unusual in oyster culture.”
Oysters feed on zooplankton, a “food source other species rely on.” What happens when zooplankton is taken out of the food chain [as a result of oyster farming]? Penobscot resident Tom Stewart asked.
“Theoretically, it could happen,” Lewis said, but tides provide “regeneration of clean ocean water.”
Another question was monitoring water quality and temperature of the river, given the DMR’s limited resources. “Is temperature rise in the Bagaduce…more important to monitor than water quality in [the] Damariscotta [River]?” Lewis asked. He continued: “In my lifetime, I’ve seen pretty significant changes [in the environment]. Monitoring will have to change accordingly.”
Seals and oyster farming
The effect of oyster leases on seal haul-out sites has been repeatedly raised at public aquaculture meetings held by the DMR.
Seals fall under the federal Marine Mammal Protection Act, and the law says you cannot disturb seals, said seal expert John Gilbert, retired from the Department of Wildlife Ecology at the University of Maine in Orono. He was one of three “seal experts” who attended the meeting.
Seals haul out onto rocks and ledges; these sites “are required [for seals] to pup, molt, thermo-regulate and rest,” according to a report Gilbert co-wrote in 1998 for the National Marine Fisheries Service.
“We’re not disturbing seals as much as we think we are,” Gilbert said. “They’re not getting hauled out all the time.”
The guideline under NOAA Fisheries Service is to keep 150 feet away from seals, said Mendy Garron, Marine Mammal Stranding Coordinator with NOAA. “There’s a little bit of gray area,” because seal behavior can be changed from over 150 feet away, and seals are protected by law from acts that result in a change in behavior.
An LPA that was 40 to 50 feet from a major seal haul-out has expired, said Mendelson, and a new application has it sited in a different area. “People have listened,” she said. “I think we’ve seen a lot of responsiveness from aquaculturists in this community.
“What are the limits?”
At the start of the meeting, Mendelson told those in attendance, “The first step to finding solutions is to know our neighbors.” By its end, she concluded, “The state will not make legislation based on the needs of one community….This community needs to organize itself to make those changes.”
After the meeting, Penobscot resident Barbara Joy Hare said that while she felt the DMR had prepared well, “I felt there was almost a veil.”
Hare can see markers on the Bagaduce River for a potential standard lease site that was the subject of a pre-application meeting with the DMR two years ago. “[The DMR] is attempting to educate [the public],” she said. “But what are the limits?”
“I understand why people have lingering policy questions,” Mendelson said when questioned after the meeting. “Some deserve more attention….Policy questions deserve a larger, statewide conversation.”