EELGRASS HABITATS ON THE U.S. WEST COAST: STATE OF THE KNOWLEDGE OF EELGRASS ECOSYSTEM SERVICES AND EELGRASS EXTENT Kate Sherman1 and Lisa A. DeBruyckere2 1 Pacifc States Marine Fisheries Commission. 205 Spokane St. SE, Portland, Oregon 97202. 2 Creative Resource Strategies, LLC. 6159 Rosemeadow Lane NE, Salem, Oregon 97317. Reference: Sherman, K., and L.A. DeBruyckere. 2018. Eelgrass habitats on the U.S. West Coast. State of the Knowledge of Eelgrass Ecosystem Services and Eelgrass Extent. A publication prepared by the Pacifc Marine and Estuarine Fish Habitat Partnership for The Nature Conservancy. 67pp. photo © Brent Hughes ACKNOWLEDGEMENTS We would like to thank the many experts and Dave Fox (Oregon Department of Fish and Wildlife), stakeholders who provided data and information, Sarah Beesley (Yurok Tribal Fisheries Program), Jennifer EELGRASS HABITATS ON THE U.S. WEST COAST: participated in webinars and surveys, or reviewed a Gilden (Pacifc Fishery Management Council), Adriana draft of this report. Their contributions ensure that this Morales (U.S. Forest Service), John Netto (U.S. Fish and STATE OF THE KNOWLEDGE OF EELGRASS ECOSYSTEM summary of the present state of scientifc knowledge Wildlife Service), and Lisa Phipps (Tillamook Estuaries of ecosystem services and extent of eelgrass habitats Partnership). SERVICES AND EELGRASS EXTENT in Washington, Oregon, and California will be an The Nature Conservancy staf essential tool for use in estuarine restoration and conservation projects to sustain healthy fsh and Gway Kirchner, Jena Carter, and Bryan DeAngelis invertebrate populations. NOAA Fisheries West Coast Region staf Reviewers included: Bryant Chesney and Eric Chavez. PMEP’s Science and Data Committee We additionally thank the following people for Bill Pinnix (U.S. Fish and Wildlife Service), Correigh providing datasets that are included in this inventory Greene (NOAA Fisheries), Dayv Lowry (Washington of eelgrass data: Lisa Ferrier (Washington Department Department of Fish and Wildlife), Eric Grossman (U.S. of Natural Resources), Suzanne Schull (Padilla Bay Geological Survey), Laura Brophy (Estuary Technical National Estuarine Research Reserve), Pat Clinton Group – Institute for Applied Ecology), Scott Heppell (Environmental Protection Agency), Tony D’Andrea (Oregon State University), Steve Rumrill (Oregon (Oregon Department of Fish and Wildlife), Andrew Department of Fish and Wildlife), Van Hare (Pacifc Weltz and Paulo Serpa (California Department of Fish States Marine Fisheries Commission), Walter Heady and Wildlife), Jenni Schmitt (South Slough National (The Nature Conservancy), Beth Sanderson (NOAA Estuarine Research Reserve), Ann Kitajima (Morro Bay Fisheries), Kevin O’Connor (Central Coast Wetlands National Estuary Program), and Charlie Endris (Elkhorn Group), and Brett Holycross (Pacifc States Marine Slough National Estuarine Research Reserve), Bryant Fisheries Commission). Chesney (NOAA Fisheries), and Eric Grossman (U.S. Geological Survey). Andy Lanier and Tanya Haddad PMEP’s Steering Committee (Oregon Department of Land Conservation and Doris Small (Washington Department of Fish and Development), and Allison Bailey (Sound GIS), provided Wildlife), Andy Lanier (Oregon Department of Land additional review of the data processing methods. Conservation and Development), John Stadler (NOAA We would also like to thank Bryan Pestone (NOAA Fisheries), Fran Recht (Pacifc States Marine Fisheries Fisheries) for assisting with data processing and to Commission), Korie Schaefer (NOAA Fisheries), John Adrienne Harris and Katie O’Grady (Adrienne Harris Bragg (South Slough National Estuarine Research Consulting) for additional contributions to the content Reserve), Bradley Bales (Pacifc Birds Joint Venture), of this report. Stan Allen (Pacifc States Marine Fisheries Commission), EELGRASS HABITATS ON THE U.S. WEST COAST: EELGRASS ECOSYSTEM SERVICES AND EELGRASS EXTENT ii EELGRASS HABITATS ON THE U.S. WEST COAST: STATE OF THE KNOWLEDGE OF EELGRASS ECOSYSTEM SERVICES AND EELGRASS EXTENT Kate Sherman1 and Lisa A. DeBruyckere2 1 Pacifc States Marine Fisheries Commission. 205 Spokane St. SE, Portland, Oregon 97202. 2 Creative Resource Strategies, LLC. 6159 Rosemeadow Lane NE, Salem, Oregon 97317. photo © Dayv Lowry EXECUTIVE SUMMARY Eelgrass, a type of marine fowering plant, can serve consulted with U.S. West Coast eelgrass experts (see as a biological indicator of ecosystem health and is acknowledgements). To avoid duplicating prior eforts, threatened by numerous human activities. Eelgrass we relied on summary or synthesis documents when populations along the U.S. West Coast are genetically available, and then expanded on them, using more unique; therefore, conservation and restoration of focused references that were associated with the goals these habitats should be guided by information gained of this report. from these populations. This report was commissioned A companion geodatabase of eelgrass data was also by The Nature Conservancy to provide a synthesis of the compiled illustrating presence/absence and, where state of scientifc knowledge of U.S. West Coast estuary able, current and historic extent of eelgrass in 444 eelgrass habitats and the ecosystem services they estuaries along the U.S. West Coast. This information provide. The Pacifc Marine and Estuarine Fish Habitat was organized into four ecoregions: (1) Salish Sea, (2) Partnership (PMEP) synthesized the literature relevant Washington, Oregon, Northern California Coast, (3) for the U.S. West Coast and standardized existing Central California, and (4) Southern California Bight. geospatial data on the current and historic extent of These regions and designations align with boundaries eelgrass for Zostera spp. We investigated the role of used by PMEP and the Pacifc Fisheries Management 444 U.S. West Coast estuaries in providing eelgrass Council as well as The Nature Conservancy’s Marine habitat and compiled our fndings in a geodatabase. Ecoregions of the World. Data collection relied on a This report synthesizes information on: 1) Presence data call; no new feld studies were conducted for and extent of eelgrass along the U.S. West Coast, 2) this project. To view the data online visit http://www. Ecosystem services provided by eelgrass habitats, 3) pacifcfshhabitat.org/data/. Important and emerging threats to eelgrass habitats in Overall, we found that eelgrass occurs in 162 (36 U.S. West Coast estuaries, 4) Knowledge and data gaps, percent) of 444 U.S. West Coast estuaries. A total and 5) Management strategies to conserve and restore of 24 percent of the 444 estuaries either did not eelgrass habitats and their ecosystem functions along have eelgrass or were not suitable for eelgrass. The the U.S. West Coast. remaining 40 percent of the estuaries had no eelgrass To compile information on extent of eelgrass (Zostera data. We documented current or historic presence of spp.) and services provided by eelgrass, we reviewed eelgrass in the following ecoregions: nearly 550 peer-reviewed articles and reports and Salish Sea ecoregion—98 of 166 estuaries. EELGRASS HABITATS ON THE U.S. WEST COAST: EELGRASS ECOSYSTEM SERVICES AND EELGRASS EXTENT v Washington/Oregon/Northern California Coastal extent of eelgrass (using a consistent methodology) ecoregion—24 of 110 estuaries. makes it difcult to quantitatively measure eelgrass habitat loss. As a result, identifying and monitoring Central California coast ecoregion—18 of 107 specifc threats to eelgrass habitat is challenging on a estuaries as well as areas of the nearshore from coastwide scale. Monterey Bay southward. Numerous reports document existing and emerging Southern California Bight—22 of 61 estuaries threats to eelgrass. We identifed 19 threats specifc and throughout the mainland nearshore and the to the U.S. West Coast. Four were identifed in all Channel Islands. four ecoregions: increased sedimentation, coastal development, sea level rise, and sea temperature Summary information on presence by ecoregion is changes. Previous reviews of ecosystem service provided in the table below. values of eelgrass beds have focused on a particular Although this report builds on past efforts to estuary or a specifc service. This report details the summarize coastwide extent of eelgrass, we remain information provided in the literature based on limited in the ways we can accurately use this four ecosystem service categories — supporting, information for regional analysis. Data collection regulating, provisioning, and cultural and amenity dates, methods for data collection, and data post- services. For all ecosystem services reviewed, a key processing methods vary across estuaries and challenge remains that few studies capture the value datasets, making it challenging to compare data of these services quantitatively. across the U.S. West Coast. Although we can more Based on our fndings, we recommend the following easily determine presence/absence of eelgrass from management strategies to conserve and restore existing data, determining adequate eelgrass extent eelgrass habitats and their ecosystem functions: is limited by lack of data. Limited monitoring on the Washington, Oregon, Southern California Ecoregion Salish Sea Central California Northern California Bight Estuaries with eelgrass 59% 21% 17% 36% present (%) Estuaries with eelgrass 6% 17% 39% 49% absent/unsuitable habitat (%) Estuaries with no data (%) 35% 50% 44% 15% Nearshore eelgrass? Present NA Present Present Zostera marina, Zostera pacifca Zostera marina, Zostera marina,