Feasibility of Atlantic Surfclam Culture in New Jersey

Photo: Shucking a dead clam for sampling.

Shucking a dead clam for sampling

Photo: Cleaning a tray of adult clams.

Cleaning a tray of adult clams

Photo: Examining a flesh biopsy under the microscrope.

Examining a flesh biopsy under the microscrope

Background

As shellfish farming efforts expand in New Jersey, it will be critical for farmers to have options that contribute to seafood sustainability. Crop diversification allows farmers to build resiliency into their business models and bolsters regional food security. Currently, shellfish aquaculture in New Jersey and other Northeast states focuses almost solely on two species: the Eastern oyster (Crassostrea virginica) and the hard clam (Mercenaria mercenaria). The Atlantic surfclam (Spisula solidissima) is an ideal candidate species for crop diversification in the Northeast region because it is native, grows rapidly and tastes delicious. Farmed surfclams would not directly compete with the wild surfclam fishery, which catches very large clams that are processed and packaged as frozen clam strips or canned-clam products. Instead, farmed surfclams would be harvested and sold around the same size as a littleneck clam, supporting live and value-added markets.

Faculty, staff and graduate students at the AIC and the Haskin Shellfish Research Laboratory are partnering with industry to test the feasibility of surfclam aquaculture in New Jersey. Specifically, they will test various strategies for nursery and grow-out culture conditions, such as ideal rearing temperatures and farming gear. They will also identify timelines for planting and harvesting farmed surfclams. Identification of optimal culture strategies and production timelines are important first steps in determining surfclam farming feasibility.

Methods

Michael Acquafredda, PhD Candidate in the Ecology and Evolution Program at Rutgers University, under the direction of Dr. Daphne Munroe of the Haskin Shellfish Research Laboratory and extension specialist Lisa Calvo, is building on existing research to find the optimal techniques for rearing surfclams in the region. His work focuses on techniques for the husbandry of surfclams during the nursery and grow-out phases.

During the nursery phase, the clams are grown at the AIC. The nursery phase follows the hatchery phase, which consists of spawning and larviculture. The nursery phase lasts from metamorphosis to the time the clams are ready to be put out onto farms, when they reach a shell length of 10-13mm. The grow-out phase occurs on subtidal clam farms across the backbays of New Jersey, and generally lasts from several months to a year.

Research Questions

  • How is the surfclam’s growth and survival influenced by nursery temperature, location, and gear type?
  • How does the surfclam’s growth, health, and survival differ across three New Jersey clam farms through grow-out phase trials?
  • Can surfclams be selectively bred for greater thermal tolerance?
  • How does the surfclam’s shelf-life compare to that of hard clams?
  • How can we best market surfclams (including taste tests with local chefs)?

Results and Next Steps

Experiments have identified optimal nursery techniques and farm production trials are underway. The goal of the grow-out trials is to identify production timelines and to determine which gear-types and environmental conditions lead to the fastest surfclam growth and the greatest surfclam survival. Farm trials are being conducted in collaboration with three shellfish farmers. Ultimately, the lessons learned will be shared widely through publication of peer-reviewed articles and a "Surfclam Grower’s Guide" that will be distributed to interested farmers.

Funding

Funding is provided by the New Jersey Sea Grant Consortium, NOAA Sea Grant Extension and Northeast Sustainable Agriculture Research and Education (NESARE).


Aquaculture Innovation Center