PROJECT HIGHLIGHT:
This project will evaluate the potential for commercial cultivation of native Pacific littleneck clams in the Morro Bay Estuary in an effort to help expand shellfish production beyond the non-native Manila littleneck clam. Viability of the species will be determined by directly comparing the native Pacific littleneck with the non-native Manila littleneck clam in both field and laboratory trials.
PROJECT SUMMARY:
California ranks 10th in the U.S. for shellfish production, with most efforts focused on the cultivation of oysters, abalones, mussels and clams. Despite the industry’s substantial economic significance, shellfish hatcheries and farms regularly experience impacts of disease outbreaks and climate change stressors. One promising strategy for increasing the industry’s climate resilience and mitigating current and future disease threats is to integrate native species into shellfish aquaculture cultivation.
In order to expand sustainable shellfish practices in California, many growers are pursuing cultivation of native species. This interest stems from both the environmental and social benefits associated with cultivating native species as many can have both commercial and conservation impacts. The native Pacific littleneck clam (Leukoma staminea) is a species that is highly sought after in recreational fisheries, and is of interest to multiple California commercial growers. While there is commercial potential for this species, there are concerns associated with the survivability and shelf-life of these clams that may limit long-term commercial success.
This project will initiate seed propagation using locally sourced broodstock from Morro Bay. Researchers will then monitor clam growth, survival and mortality rates at three intertidal heights (i.e., low, middle and high) during the grow-out period; and will assess the effect of outplanting intertidal height on physiological resilience and shelf-life of market-sized clams during simulated stress exposure.
This project will directly test whether planting native littleneck clams (L. staminea) at higher tidal elevations can improve post-harvest survival during storage and shipping, easing the economic vulnerability of shellfish farmers to climate change while fostering their participation in the recovery of a species that has experienced decades of decline. Documenting the viability of native littleneck clams can provide farmers with the confidence they need to commit to purchasing commercial-scale quantities of native seed from hatcheries. Expanding shellfish aquaculture to include a local, native species facing population decline will also boost the ‘social license’ growers need to maintain their industry.
Kevin Marquez Johnson