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Summary The Humboldt County Spartina Summit was held in Eureka, CA, on February 13, 2008. Approximately 50 scientists, land managers, environmental professionals, and community members gathered to share information about the status of invasive Spartina and control programs in the region and up and down the West Coast, and to explore regional Spartina management scenarios. The morning and early afternoon consisted of a series of presentations regarding Spartina in Humboldt County, San Francisco Bay, the Oregon Coast, and Willapa Bay in Washington. Many of these presentations are available below. Brief highlights of the presentations are provided below: Andrea Pickart, the Humboldt Bay National Wildlife Refuge ecologist, presented information regarding the natural history and distribution of invasive Spartina, and described the remarkable success of local control efforts, as well as the daunting challenges that lie ahead. She noted that mechanical control of Spartina has been successful at eliminating mature Spartina individuals on a relatively small scale, but has been challenged by the influx of new Spartina seedlings into certain areas. Heinz Falenski, Associate Faculty member at the College of the Redwoods, described his mathematical model relating environmental parameters to the presence of Spartina in Humboldt Bay marshes. Mr. Falenski explained that his model indicates that Spartina is especially likely to occur in sites that are very saturated (i.e. poorly drained), have high available phosphorus levels in the soil, and are at low elevation, and he discussed strategies for preventing Spartina invasion in restoration sites based on this information about its optimal habitat. Dr. Milton Boyd, intertidal ecologist at Humboldt State University, described the mixed non-indigenous and indigenous invertebrate fauna found in Humboldt Bay’s salt marshes. Dr. Boyd raised the important question of whether eradicating Spartina might have negative impacts on the Humboldt Bay ecosystem by replacing a very productive plant that is a major source of carbon with less productive native plant species. Dr. Mark Sytsma, Director of the Center for Lakes and Reservoirs at Portland State University, described Oregon’s efforts to protect its coastal marshes from invasive species. Dr. Sytsma spoke about the threat of seeds from Humboldt Bay Spartina colonizing marshes up the west coast, as demonstrated by a drift card study that showed numerous cards released in Humboldt Bay quickly reaching the Oregon and Washington coasts. Peggy Olofson, Director of the Invasive Spartina Project in San Francisco Bay, described the efforts of her organization to control invasive Spartina. She described the challenges of controlling invasive Spartina in marshes where native Spartina and invasive-native hybrids are found. She also described efforts to control Spartina densiflora in Corte Madera, where herbicide and digging out of Spartina plants have been used. Dr. Kim Patten, of Washington State University’s Cooperative Extension, described efforts to control invasive Spartina in Willapa Bay. These efforts have been underway for about 10 years. Dr. Patten described a variety of techniques that were attempted early on, and initially resulted in very limited success. Recent efforts have focused on herbicide use, and have been very successful. Dr. Patten discussed potential effects from herbicide applications, and potential long term changes to Willapa Bay marshes from the Spartina invasion. Dr. Frank Shaughnessy, Professor of Botany at Humboldt State University, gave the last presentation of the day, focusing on primary productivity in the Humboldt Bay ecosystem and the role of Spartina in contributing to primary productivity. Dr. Shaughnessy stressed the importance of considering all the species that contribute to primary productivity, including algae and diatoms, rather than focusing only on large vascular plants such as Spartina. He also emphasized that it was important to understand the rate at which different species fix carbon in order to calculate net primary productivity, explaining that a large plant may fix high amounts of carbon, but may do so over a long period. Following the presentations, summit participants split into small groups to discuss the following topics:
Joel Gerwein, project manager at the State Coastal Conservancy, concluded the summit by asking participants to remain involved over the coming months as planning for Spartina densiflora control in Humboldt Bay gets underway. A small group ended the day by visiting Vance Marsh to see Spartina and other salt marsh plants in person. For more information contact Andrea Pickart More information on invasive Spartina
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