Clamming is not glamorous or highly lucrative, but with limited equipment and an easily obtainable license, it still offers a viable income. Red tide, green crabs and areas closed by pollution, however, have negatively impacted dependable flats and harvesting conditions. More recently, a new name has been added to this list. “Dead mud” is how St. Joseph College professor Mark Green refers to those flats that are suffering from acidification. Whether due to an increase in atmospheric C02 or other factors, scientists agree that the world’s oceans have become more acidic. (See “Fathoming: An acid test for fisheries” Dec/Jan, 2010).
Part of Green’s notable research on the impacts of lower pH levels on clam survival includes the use of crushed clam shells on mud flats to buffer acidic conditions.
Since his data have become public, people are asking, “Why can’t we use the same restorative measures in our own back yard?”
Dick Forrester, shellfish committee member in Wiscasset, listened as Green delivered his research results at a March 2009 forum. Later that spring, he procured clam shells from a licensed dealer and began broadcasting them from his boat at high tide over several acres of tidal flats. Forrester later obtained the necessary permit through Department of Environmental Protection (DEP). “It was pretty straight forward; I checked off ‘improving water quality.'” Now at the end of the two-year period where he spread 1600 tons over about 25 acres, he has seen a dramatic increase in clam-setting in one area in particular. “Is it due to spreading shells? We cannot be sure,” Forrester said. “We did not treat it like science,” he said about the methodology, but believes that it was worth the effort. “It could help create some jobs.”
This use of clamshells might be beneficial for those looking to dispose of byproducts from seafood processing facilities.
A.C. Inc.’s Albert Carver has been buying and selling seafood for over 35 years in a business begun by his grandfather. His company’s shucking facility produces an average of 3,000 pounds of clam shells a week. Historically, the shells were used on road surfaces, in gardens and “wherever people wanted them.” In recent years, Carver has been paying to ship most shells to Sunrise Seafood Compost in Addision. But eighteen months ago when he dumped some on a road near his facility, the Department of Environmental Protection (DEP) informed him that they were solid waste, “I had to scrape them up and properly dispose of them.” explains Carver.
Working with Mark Whiting of the DEP, Carver obtained a permit to build and utilize what he refers to as the “clam castle,” a prepared surface with walled-in bins used to store clam shells until they are “cured.” Now, as an alternative to paying for their disposal in Addison, he plans to produce a product of value. “Once I have spent all this money, I plan to market,” says Carver, suggesting a list of possible uses including spreading in salmon rivers.
Dennis-Marc Nault is a biologist with the Department of Marine Resources one of only two employees tasked to manage bivalve shellfish for the entire state of Maine. Most of his work is focused on helping to manage the clam ordinances in 78 Maine communities. Many of these towns have committees made up of local diggers who work with Nault to try various enhancement projects, including transporting clams to better grow-out locations, applying nets over seeded areas and using conservation methods such as flat rotation. He notes that there are still many productive areas. The “dead mud” conditions are localized and their occurrences are not fully understood.
Commenting about the spreading of shells in coastal mud flats, he says, “We need to build some common sense into these type of projects. I am planning to work with DEP to streamline the process,” but adds that additional permits will be needed for coastal spreading in the downeast region (as opposed to western waters) due to their proximity to the Atlantic salmon rivers.
Ironically, there is already a permit in place to add clam shells in one of these rivers. According to Dwayne Shaw, executive director of the Downeast Salmon Federation (DEF) “clam shells are being used in an experiment within the Machias River watershed in partnership with DEP, Project SHARE (Salmon Habitat and River Enhancement) and others.” Shaw said that early data returns show an increase in insect diversity, which bodes well for young fin fish.