American Aquafarms plans to acquire the Main Fair Trade Lobster plant in Gouldsboro and to invest between $50 million and $100 million to redevelop the site for salmon processing, but the sale is contingent upon getting state approval to grow salmon at 30 pens in Frenchman Bay. The company projects harvesting 66 million pounds of salmon grown in the bay each year. Credit: Courtesy of Maine Fair Trade Lobster

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Renata Moise of Hancock is a member of the board of Friends of Frenchman Bay. She wrote this commentary on behalf of the board.

It doesn’t take a marine biologist to see the potential for harm to Frenchman Bay from a plan to produce thousands of tons a year of salmon in Frenchman Bay. Industrial-scale fish farming could damage a fragile marine ecosystem, with implications for the traditional shellfish harvesting, lobstering and baitfish trawling that depend on those waters — not to mention how it could affect the lure of the bay for summer visitors.

At issue is a proposal by American Aquafarms, which is Norwegian-owned, to build a hatchery-to-fish-processing operation centered on 30 floating pens constructed in Gouldsboro. The goal is to raise 66 million pounds of fish annually, three times Maine’s current annual output. The company’s pitch is that it will be an “eco-friendly” neighbor employing a “proven and robust” closed-pen technology — large bags anchored over the deeper waters of Frenchman Bay that will enable solid waste to be disposed of on land. The company is seeking Department of Marine Resources approval of its proposal.

There are many problems with American Aquaculture’s approach. For starters, the closed-pen technology has not been demonstrated to be either commercially viable, based on the length and scale of existing deployments, or environmentally sustainable.

What are the dangers? While the company says the solid waste will be removed, dissolved waste — potentially including antibiotics and chemicals — will remain in the water. A huge amount of water will be entering and leaving the pens: The company plans to pump cold water from the depths of the bay into the densely packed salmon pens and then drain back into the bay. In public statements, the company has only committed to solids removal from sediment traps located in each pen and not to treating the entire wastewater stream associated with its operations.

This would be worrisome even under the best of oceanographic conditions, where the action of tides and currents can dilute waste and move it out to sea. Frenchman Bay has no large rivers flowing into it, so its ability to flush out effluents is quite limited. Many of us out on the bay have seen this firsthand as various floating objects will hang around for weeks at a time.

Temperatures in the Gulf of Maine — including Frenchman Bay — already are rising faster than 99 percent of the oceans on the planet. A buildup of nitrogen and phosphorus that can be caused by aquaculture, combined with rising temperatures, increases the chance of the toxic algae blooms that Maine has experienced with increasing frequency in recent years.

Many local lobstermen, fishermen and small-scale scallop, mussel, oyster and kelp farmers working the bay say they are deeply worried about the damage the fish farms could do to their livelihoods by potentially degrading water quality. This is not an idle concern. In May 2019, a massive and persistent algal bloom in Norway suffocated 8 million farmed salmon. Experts note that such blooms are most prevalent when waters warm and currents slow, causing algae populations to explode, as we have seen in Frenchman Bay.

Some lobstermen and fishermen also are concerned because the fish farm will block access to an area where lobsters and scallops are taken at various times during the year. There is also the potential threat of fish escapes, spills of diesel fuel used in pumps and electrical generators, and spills of fish feed. The best-laid plans always go awry in the face of the forces of nature, and in a worst-case scenario escaped salmon could potentially introduce disease and unwanted genetic stock into the area.

Taken together, the proposed fish farm presents a set of risks that could have any number of unintended consequences for Frenchman Bay, even with the most eco-conscious of businesses. One cannot overstate the cumulative impact of large-scale fish farms on a bay that already faced the presence of nearly 200 cruise ships a season before the COVID pandemic, heavy recreational use, and increasing toxic algae blooms.