Building Mussels: Strengthening Habitat through Shellfish
The quality of nearshore marine environment on Long Island is closely tied to the abundance and diversity of filter feeding shellfish. For this reason, considerable effort has been put into restoring native shellfish populations from Manhattan to Montauk.
To address this, the Cornell Cooperative Extension (CCE) Marine Program has been working with Long Island officials and residents for almost 40 years on all aspects of shellfish restoration. The most recent work for this team involves the ribbed mussel (Guekensia demissa) and the bay scallop (Argopecten irradians). The Moore Charitable Foundation, with its strong focus on restoring coastal habitats and ensuring clean water, is proud to support this important work. Read part one of our two-part series featuring Chris Pickerell, the Marine Program Director of CCE of Suffolk County, and his team:
MCF: Can you tell us a bit about CCE Marine and its focus area and issues? What is its role in driving environmental stewardship?
CCE: The CCE Marine Program is a division of Cornell Cooperative Extension of Suffolk, a not-for-profit organization with a mission to preserve our county’s heritage, protect our natural environment, support families and provide our youth opportunities for community service and research-based education. The Marine Program’s scientists, educators and administrators focus on issues ranging from water quality monitoring and mitigation to habitat restoration and management, and from shellfish aquaculture to the development of conservation gear for the offshore commercial fishing fleet. Everything we do involves some aspect of outreach and education. In keeping with our mission, we also seek to support those that make their living on the water to help preserve the rural maritime heritage of the region.
MCF: What are the issues you are trying to address with ribbed mussels?
CCE: We are looking to develop hatchery protocols that will allow us to produce millions of ribbed mussels (Geukensia demissa) for the purposes of water quality improvement, habitat enhancement and shoreline stabilization. Given that there has never been a commercial market for this species, there was never an incentive to develop such methods unlike blue mussels, clams and oysters which are well-understood. Once such methods are developed, it will allow us to initiate numerous novel programs to help address local water quality and habitat impairments.
MCF: What is special about this species? What is finnicky?
CCE: Since the ribbed mussel is not regularly consumed, there are generally few restrictions on planting into uncertified or polluted waters where its ability to filter the water is most needed. Amazingly, the ribbed mussel is better at filtering water than either a clam or an oyster in that it can actually filter down to a finer-size fraction, allowing it to remove bacteria and even some viruses.
What makes mussels difficult to produce relates to the fact that no one knows how best to raise these in captivity. One significant factor is the fact that they naturally occur on the intertidal shoreline and appear to prefer to be out of the water for half of the day. Normal hatchery operations typically involved holding shellfish in tanks indefinitely with no accommodation for daily draining down. To raise mussels, we may have to include some aspect of exposure to air. Another thing that is different relates to their diet, which may include things — for example, bacteria and organic matter, possibly — beyond the typical algae species produced in hatcheries. Finally, the larvae are incredibly sensitive during culture, and the cues that encourage adults to spawn are still unclear.
MCF: Your research has yielded successful results so far. What have you discovered, and what do you hope to discover or achieve in your project’s next phase?
CCE: We are very excited to say we have made some significant progress in working with the mussel. Over this past year, we have begun to understand the specific spawning cues of the adults as well as the methods most appropriate for rearing the larvae. In addition to this, we have developed novel conditioning protocols for the adults. Over time, we will refine these techniques into protocols that allow us to consistently produce these animals in large numbers.
MCF: If these projects are ultimately successful, what could your research help achieve or be used for? Can you explain the potential environmental impact of the work? Can you elaborate on the everyday impact on communities or fisheries?
CCE: If we are successful in developing and refining our hatchery protocols to the point of producing tens of millions every year — which is commonplace for traditional species such as clams and oysters — it will open up endless opportunities to undertake work that will greatly benefit the local environment. Access to this species will allow us to enhance populations in natural marshes where die-offs or predation have greatly reduced numbers. The same methods can be used as part of habitat restoration projects where marsh creation is a component. These can lead to meaningful improvements in water quality and clarity. Additionally, we plan to initiate a program that will allow local residents to get involved with deploying mussels in and around existing marine structures such as docks and bulkheads. In this way, we can engage the broader community in proactive enhancement of local waters.
MCF: Why is it important to invest in these projects, and what would the restoration of these species mean to the big picture of healthy waters?
CCE: Investment into developing protocols for producing ribbed mussels will enable a paradigm shift in how resource managers approach local water quality and habitat impairments. The future availability of massive numbers of these mussels will enable meaningful improvements in water quality and habitat enhancement that have heretofore been impossible. With this tool, there is no limit to what can be done to improve the local marine environment. As part of this effort, we hope to restore the historic “bottom up” filter-feeding control within coastal ecosystems that will help to improve water quality, enhance habitat value and maintain species diversity.
