Shellfish Aquaculture in Washington State Final Report to the Washington State Legislature December 2015 Washington Sea Grant Washington Sea Grant Shellfish Aquaculture in Washington State • 2015 | a Shellfish Aquaculture in Washington State Final Report to the Washington State Legislature • December 2015 This report provides the final results of Washington Sea Grant studies conducted from July 1, 2013 to November 30, 2015 on the effects of evolving shellfish aquaculture techniques and practices on Washington’s marine ecosystems and economy. Funding provided by a proviso in Section 606(1) of the adopted 2013 – 2015 State Operating Budget. Recommended citation Acknowledgments Washington Sea Grant (2015) Shellfish aquaculture in Washington Sea Grant expresses its appreciation to the many Washington State. Final report to the Washington State individuals who provided information and support for this Legislature, 84 p. report. In particular, we gratefully acknowledge funding pro- vided by the Washington State Legislature, National Oceanic and This report is available online at Atmospheric Administration, and the University of Washington. https://wsg.washington.edu/shellfish-aquaculture We also would like to thank the many academic, state, federal, tribal, industry and other experts on shellfish aquaculture who cooperated with investigators to make this research possible. Contact Investigators/staff Washington Sea Grant Jonathan C.P. Reum, Bridget E. Ferriss Research Manager 3716 Brooklyn Avenue N.E. Chris J. Harvey Seattle, WA 98105-6716 Neil S. Banas Teri King Wei Cheng 206.543.6600 Kate Litle Penelope Dalton [email protected] P. Sean McDonald Kevin Decker wsg.washington.edu Robyn Ricks Marcus Duke WSG-TR 15-03 Jennifer Runyan Dara Farrell MaryAnn Wagner Contents Overview ..........................................................................................................................i Patterns in the Economic Contribution of Shellfish Aquaculture ...................1 Evaluating Trophic and Non-Trophic Effects of Shellfish Aquaculture in the Central Puget Sound Food Web ....................... 15 Qualitative Network Models in Support of Ecosystem Approaches to Aquaculture Production: Potential Applications to Management and Climate Change ...................................................................35 An Oceanographic Circulation Model for South Puget Sound .......................59 Geographic Information System Approaches and Spatial Datasets Relevant to Shellfish Aquaculture Siting in Washington State ..................... 71 Overview hellfish aquaculture is both culturally significant and water quality issues) in western South Puget Sound. The Seconomically important to Washington communities, and model also has a wide range of other potential applications in many locations interest exists in expanding production. To and could be an important first step towards better promote and manage shellfish aquaculture in a sustainable prediction of seawater oxygen and acidity levels in South manner, it is essential to understand the potential ecological Puget Sound. and economic effects, both positive and negative, of evolving 5. A framework and data assessment for spatial decision aquaculture practices. At the direction of the Washington State support in aquaculture (p. 71) can further the development legislature in 2013, Washington Sea Grant initiated a research of tools to support decisions such as where to site shellfish program to assess and develop tools and resources that could farms. A decision support study outlines the framework help growers, managers, and other coastal residents address and includes an assessment of publicly available spatial a range of issues. The research program included an economic data in Washington State that will likely be relevant. It analysis, three pilot modeling studies, and an overview of spa- provides a starting point for growers, managers, and tial data approaches: researchers interested in developing spatial tools to weigh 1. An economic trend analysis of Washington shellfish the potential ecological, social, and economic tradeoffs production and value (p. 1) details the economic involved in farm placement. contribution of shellfish aquaculture to different coastal areas in Washington and to the state. The analysis underscores the contribution of aquaculture to generating SHELLFISH AND THE WASHINGTON revenue in the state economy. Results from this work ENVIRONMENT should help guide future development of economic studies and social science on the state aquaculture industry. ommercial shellfish cultivation has taken place in Washing- ton waters since the mid-1800s and has evolved in terms of 2. An ecosystem model of Central Puget Sound (p. 15) was C the species farmed, methods used, product markets, and acre- developed to explore the potential influence of aquaculture age under cultivation. Today Washington State is the nation’s on the environment and, alternatively, how environmental leading producer of farmed clams, oysters, and mussels. The changes affect aquaculture. In this region, sufficient data 2011 Washington Shellfish Initiative estimated that state shell- are available to build a quantitative ecosystem model, fish growers directly and indirectly employ more than 3,200 which can be used to explore different management people and provide an estimated total economic contribution of scenarios. For example, a finding from the model that $270 million. Production includes hatcheries, nurseries, farms, aquaculture gear had stronger ecosystem impacts than and processing, distributing, wholesale, and retail operations. the farmed geoduck themselves points to development of In addition to their commercial importance, shellfish are cen- innovative gear and new culture techniques as a promising tral to tribal cultures and economies and contribute to recre- approach for minimizing impacts. ational opportunities and tourism. 3. Relying on limited data, qualitative food web models of Shellfish are an important component of marine ecosystems, South Puget Sound and Willapa Bay (p. 35) can be used and environmental changes and stressors can affect shellfish to identify whether shellfish populations or other food aquaculture production. For example, the Washington coast web members are likely to increase or decrease given a is especially vulnerable to ocean acidification (OA), a change particular management or environmental scenario. The in ocean chemistry that interferes with shell development in models for Willapa Bay, for instance, indicate that ocean some marine organisms and which may potentially affect both acidification could potentially result in fewer Manila clams cultured species and marine food web dynamics. Harmful algal but more eelgrasses and phytoplankton. The models were blooms and aquatic invasive species also continue to pose seri- relatively simple to build and can be easily refined using ous threats to shellfish resources and seafood product safety. alternative scenarios. Meanwhile, climate change has introduced additional variability 4. An oceanographic study advances development of a in environmental parameters like water temperature, contrib- high-resolution circulation model for South Puget Sound uting to and interacting with other changes. (p. 59). In a preliminary analysis, the model suggests Shifts in Washington’s coastal environment have been coupled that aquaculture may have the capacity to control with growing human populations that affect coastal water phytoplankton concentrations in localized areas. The quality and put additional pressure on regional shellfish results strongly encourage further investigation of both resources. Approximately 65 percent of state residents live in the possible downstream effects on other consumers coastal counties, and the Puget Sound region alone is expected of phytoplankton and a possible role for aquaculture in to grow almost 35 percent, to five million people, by 2040. The mitigating eutrophication (which can be associated with Washington Sea Grant Overview i complex challenges facing shellfish managers and growers have Evergreen State College with participants representing tribes, spurred interest in more comprehensive, ecosystem-based environmental groups, county planners, state and federal agen- research that integrates environmental, social, economic, and cies, scientists, shellfish growers, and legislative staff. The institutional information. workshop provided a forum for the team to present the goals of the research and initial work products, and for participants to provide feedback that informed the development of models and 2013-2015 SHELLFISH AQUACULTURE scenarios. In June 2015, chapter manuscripts were distributed to RESEARCH PROGRAM subject experts for external review, and revised and finalized by November 2015. oused in the UW College of the Environment, Washington Consistent with the direction from the legislature, the research Sea Grant is a federal–university partnership that conducts H team’s products and results are not intended to provide a basis research, education, and outreach to address Washington’s for either increasing the availability of shellfish harvesting per- coastal and marine issues and needs. In 2013, the Washington mits or restricting the extent or intensity of shellfish aquaculture State Legislature directed Washington Sea Grant to conduct a in Washington waters. Several program components involved two-year scientific research program specifically addressing development of modeling