Integrated oyster and littleneck clam aquaculture to increase seafarm yield

View the project final report

Commodities

• Animals: shellfish

Practices

• Animal Production: aquaculture
• Crop Production: double cropping, intercropping, multiple cropping

This project aims to test crop diversification on subtidal oysters farms by introducing littleneck clams (Mercenaria mercenaria) as a secondary crop species. Adding clam culture to an existing oyster farm would utilize different (and otherwise wasted) vertical space within the footprint of an aquaculture lease- potentially increasing total farm yield. Subtidal culture of littlenecks would bypass the inherent drawbacks of traditional inter-tidal clam culture (disturbance of wildlife, conflict with wild-harvest fisheries, aesthetic complaints, and co-option of what has traditionally been a commons) and would offer the farmer the benefit of crops with different maturation times
and increased resilience to disease and pests. A polyculture of oysters and littlenecks would present farmers with two-high value crop species that can be sold on the halfshell market.

Outreach for this project will focus on a website and digital pamphlet targeted towards farmers and aspiring farmers and promoted through wildly read region-wide aquaculture industry list-serves. A digital focus on outreach would allow information to persist beyond in-person presentations and would allow the target audience of small farmers to see project outcomes without necessitating costly travel to a conference.

This project will test the viability of growing clams in contained-culture in the sediments below a suspended-culture oyster farm
1) Measure the growth rates of clams under three different stocking densities
2) Note degree of mortality under different treatments
3) Record fouling and pest presence
4) Determine the market value of clean, cultured littlenecks through interviews with area shellfish buyers
5) Estimate projected value of crop (if best stocking densities were applied across the entire farm)
6) Perform a cost/benefit analysis to determine if this method could supply a viable supplemental farm income given equipment costs and labor
7) Determine actual value of crop (if market size within the study period)