Identifying New Culture Candidates Among Maine’s Shellfish Species: Targeting Arctic Surf Clams

Project Description

Arctic surf clams are a commercial species only in Atlantic Canada, although their distribution ranges from Rhode Island to Labrador. Researchers have been culturing this species, Mactromeris polynyma, at UMaine–Machias’ Marine Science Field Station at the Downeast Institute since 2012, thanks to an NSF grant (PFI-BIC: Award # 1317268). While project personnel have previously examined the hatchery and nursery phases of this species, they are examining the grow-out phases with SEANET support. Students conducted field and laboratory experiments during Summer 2016 to examine the effect of local predators on growth and survival of cultured M. polynyma juveniles in several lower intertidal soft-bottom areas in eastern Maine.

The impact of the project will be to diversify the shellfish culture candidates produced in Maine and the Northeast U.S. This will increase the quality and quantity of cultured shellfish available to the public.

Results and Accomplishments

Experiments were established in September/October 2017 to advance field work with cultured Arctic surfclam, Mactromeris polynyma, juveniles. Animals were seeded in 10 different field treatments to examine the efficacy of different types of predator-exclusion and predator-deterrent netting. The comparative experiment was established at five lower intertidal locations in eastern Maine from Trenton to Lubec. These experiments will be removed from each location during April/May 2018, and the data analyzed to determine which predator-deterrent treatment(s) performed the best. In addition to the small-scale experiments (Fall 2017-Spring 2018), a series of larger-scale trials will be deployed at each of the five sites during April, May, and June 2018. In those trials, the interactive effects of stocking density and predator exclusion will be examined in terms of survival and growth parameters.

Summary of Data Being Collected

Data	Type	Quantity	Location
Growth	Seasonal	Treatments are replicated using a generalized completely randomized block experiment (GRCBD). Longitudinal study to be replicated for several years.	The towns of Cutler, Machiasport, and Beals
Survival	Seasonal	Treatments are replicated using a generalized completely randomized block experiment (GRCBD). Longitudinal study to be replicated for several years.	The towns of Cutler, Machiasport, and Beals
Predator behavior	Quantitative	Both field and labroatory trials to determine the effectiveness of deterring predators with different types of exclusion netting. Longitudinal study to be replicated for several years.	Laboratory = Marine Science Field Station at the Downeast Institute (Beals, ME); Field = Mud Hole Cove (Beals, ME)