Rare, Threatened, and Endangered Species
Maritimes & Northeast Pipeline, L.L.C. Siting Rare Freshwater Mussel Surveys
Maritimes and Northeast Pipeline, L.L.C. (Maritimes & Northeast) constructed a natural gas pipeline to connect natural gas customers in New England with the Sable Offshore Energy Project off the coast of Nova Scotia, Canada. Phase II of this project involved 209 miles of mainline and 119 miles of lateral and spur lines stemming from the mainland route. En route, the pipeline crosses approximately 320 perennial water bodies. Freshwater mussels inhabiting these water bodies were potentially impacted by construction of the pipeline. Eleven species of freshwater mussels are present in Maine, and five of these are state-listed species.
Review potential impacts to rare freshwater mussel species from construction and operation of the pipeline facilities. This review included consultations with state and federal wildlife agencies, development of survey methodology, selection of potential mussel habitat and field survey sites, conducting field surveys, preparation of study reports, and development of mitigation strategies.
Devine Tarbell & Associates, Inc.’s (DTA) biologists met with state and federal wildlife agency biologists to determine their concerns and to develop mutually suitable mussel survey techniques. Three of the five state-listed species, the rarest in the state, were designated as target species for mitigation purposes. Over 60 water bodies were selected for survey, with additional sites the next year based on intervening route changes. Survey methods included use of glass-bottom buckets and view tubes for very shallow stream and shoreline areas, snorkeling in deeper water, and scuba diving in the deepest areas. Stream banks were searched for relic mussels and muskrat middens. Four levels of survey intensity were employed, based on the expected degree of impact. DTA’s staff investigated mitigation possibilities and developed and conducted mitigation measures in consultation with state agency biologists. Pre-construction mussel relocation surveys were conducted.