SALMON PENS, GREEN SLIME AND CLAMS
By Jane McCloskey

In the past fifteen years, Cobscook Bay near Eastport has become the home of most of Maine's salmon farms. Of the state's 27 active fish farm leases, 22 are in Cobscook Bay.

Since the arrival of the salmon pens, Cobscook Bay has also become the home of green slime. It is bright green, and grows on about the bottom quarter of the beaches. It is not attractive. It is an annual seaweed made of many small strings that lie flat, creating a solid blanket on the mud. It is also called alga enteromorpha.

Last month, the Department of Marine Resources held a hearing in Perry, Maine, about the applications to site two salmon pen leases in Passamoaquoddy Bay, next door to Cobscook Bay. The fishermen of the two bays took the occasion to say, enough.
One of those fishermen was Julie Hodgkins, fisherman, clam digger, community activist and entrepreneur. According to Julie, the green slime is stopping up the clam holes and smothering the clams. She is seconded in this assertion by Inka Milewski, biologist and President of the Conservation Council of New Brunswick. Enteromorpha creates mats that smother clams.

Green slime, aka enteromorpha, is an increasing problem world wide, as human activities add increasing nutrients to coastal waters. Sewage, agricultural fertilizer, and fish farm feces and waste can all cause blooms of green slime.

It is extremely difficult to prove that one cause rather than another creates a particular enteromorpha overgrowth. However, most people are pretty certain that the slime in Cobscook Bay is caused by salmon pens. Eastport has better human sewage treatment than it ever has, so if human sewage were the problem, the slime should be getting better, In fact, people claim there never used to be slime at all. Since the salmon pens have come, the slime has gotten steadily worse. The blueberry fields near Cobscook do not use much fertilizer compared to other forms of agriculture. Blueberries like barren soil.

In contrast, salmon pens cause an extraordinary amount of fish feces and waste. One salmon site, with 350,000 fish is estimated, from a formula devised by Becky Goldburg of the Environmental Defense Fund, to cause the equivalent of the untreated sewage of 110,000 people. There are 22 sites in Cobscook Bay, each with more or less this number of fish. By conservative estimate, these 22 pens create the nutrient equivalent of the untreated sewage of 2,000,000 people. Salmon pens are almost certainly the cause of the green slime on Cobscook beaches.

This year, for the first time, the enteromorpha did not die out in the winter. According to Milewski, this overwintering is indicative of the increasing load of nutrients in the water. The increasing slime does not bode well for the bay. In places, the enteromorpha grows in patches, mixed with the short "popweed" that kids and grownups love to pop. In other places, the enteromorpha stretches as far out as the flats go, unbroken by any other seaweed. "It looks like a golf course," several people said.

According to Milewski, enteromorpha displaces native seaweeds, including rockweed. Rockweed is the nursery for many fish and other species, sheltering eggs and young from predation. If the enteromorpha displaces the rockweed, , then the nursery for the entire bay and even some of the Gulf of Maine is destroyed. I do not know if the green slime is displacing rockweed, as it seems to be displacing popweed.

The official DMR gauge of the environmental impact of the fish pens is the growth of a bacteria called beggiatoa directly under the pens, and the relative numbers of various worms and other small creatures in the sediment under the pens. The Department of Marine Resources also looks at the nitrogen levels in Cobscook Bay. They are about 10 percent above normal, which John Sowles, Director of Aquaculture at the DMR claims is acceptable.

The salmon industry wants to expand along the coast into Penobscot Bay. Soon, the Penobscot, too, may have green slime on its shores, and clams smothering in the mats of algae.

In fact, the salmon industry may be beginning to clean up Cobscook Bay. The Heritage salmon company has just made an agreement with the National Environmental Law Center to reduce its discharge, including feces and excess feed. The other salmon companies have chosen to pay a fine rather than enter an agreement with NELC. In any case, they will soon have to conform to the Maine Department of Environmental Protection discharge standards, which are in the making. The DEP's discharge standards should decrease the fish pens' nutrient output.

Meanwhile, the green slime on Cobscook beaches is the obvious indicator of salmon nutrient overload. If salmon pens are to coexist with other fisheries, which depend on clean clamflats and abundant rockweed, the enteromorpha slime needs to be cleaned up. Otherwise, clamdiggers will not have any clams to dig. As Julie Hodgkins asks, "If there are no clams, what will the people do for a living?"