2023 California Invasive Species Action Week Lunchtime Talks
Act Today to Protect Tomorrow
Invasive species are arriving in California with increasing frequency. The best time to stop them is before they arrive, and federal, state and local agencies are keeping their eyes out for new arrivals and threats on the horizon. When they do arrive, Early Detection and Rapid Response is critical to their management. Many detections are made by individuals not associated with any agency or university, and through community/participatory science programs, almost anyone can help to spot the next invasive.
The 2023Invasive Species Lunchtime Talks all took place via Zoom Webinar from noon to 1:00 p.m. from Monday, June 5 through Friday, June 9. See below for more details and to view the recordings.
Monday, June 5
Rapid Response and Eradication of Caulerpa in California: Lessons learned
Presented by Rachel Woodfield
This presentation provided an overview of infestations of marine algae in the genus Caulerpa, with a focus on introductions discovered in California. The highly invasive strain of Caulerpa taxifolia was discovered in two lagoons in Southern California in 2000. Based on its aggressive nature and the displacement of native marine resources observed upon its discovery, it was recognized that the infestations potentially posed a major threat to coastal ecosystems, and recreational and commercial uses dependent upon coastal resources. A rapid response plan was quickly developed, funding promptly secured, and C. taxifolia was successfully eradicated at a cost of over $7 million and 7 years. In 2021, Caulerpa prolifera was confirmed growing near the mouth of Newport Bay. Attempts to mount a similarly prompt and comprehensive response have been hampered by limited funding, as well as less government and public engagement. The presentation will discuss lessons learned and the importance of an immediate and sustained response when invasive species are detected early on.
Tuesday, June 6
Participatory Science as a Tool to Monitor Invasive Tree Pests
Presented by Dr. Beatriz Nobua-Behrmann and Hannah Vasilis
Invasive shothole borers (ISHB) are tiny invasive beetles that are responsible for the decline and death of thousands of trees in Southern California. Detecting infestations early is key for successful management of this pest and to prevent the spread to new areas, and participatory science could be a useful tool to identify infestation focuses and help monitor high-risk areas. However, we know that accurately identifying the presence of ISHB and other tree pests is challenging, even for professionals. Together with the California Naturalist program, we developed a participatory science project to evaluate how accurate volunteer observations are and to find out ways to improve it so we can use participatory science as a tool to monitor for this pest. Come learn about our journey, what we learned on the way, and how you can participate in this project and contribute to the local and state-wide efforts to monitor the presence of this invasive tree pest.
Wednesday, June 7
Proactive Biological Control of Invasive Pests
Presented by Dr. Ricky Lara
Invasive insect pests pose an ongoing threat to California’s agriculture and natural resources. The best time to stop them is before they arrive. The California Department of Food & Agriculture (CDFA), US Department of Agriculture (USDA), and other organizations are on high alert to prevent the arrival of insects that have devastated other regions of the United States such as Emerald Ash Borer and Spotted Lanternfly. Emerald Ash Borer, which was recently detected in Oregon, has killed tens of millions of ash trees in the Midwest and East and has cost municipalities, property owners, nursery operators, and forest product industries many millions of dollars. Quarantine efforts for this pest proved ineffective and ended in 2021, and available resources are now focused on finding biocontrol agents such as parasitoid wasps that naturally prey on the insect. Spotted Lanternfly, another invasive pest that currently is plaguing the East Coast, would be a serious danger to California’s grape industry and other agricultural products. Human activity, such as movement of firewood, help these and other invasive pests to spread over long distances.
Thursday, June 8
Early Detection and Rapid Response for Invasive Plants in California
Presented by Dr. Chris McDonald
Early Detection and Rapid Response is critical to management of invasive plants, but it can be a high risk, high reward approach. For example, Desert Knapweed (Volutaria) is a case study of missed detections and slow responses, coupled with a naturally fast spreading weed. Desert Knapweed is a highly invasive, noxious weed and A-rated pest by the California Department of Food and Agriculture. There are three known populations in North America, two of which are Borrego Springs and Chula Vista. While the Chula Vista site is small and well-controlled, Volutaria continues to spread in Borrego Springs. A single Volutaria plant can produce hundreds of flowers and thousands of seeds. As this plant spreads it threatens to reduce wildflowers and wildlife, and could become a pest for growers. Chris McDonald will share the Desert Knapweed experience as well as other examples where Early Detection and Rapid Response has proven more successful.
Friday, June 9
Rapid Spread of Invasive Aquatic Plants in the Changing San Francisco Bay-Delta Estuary
Presented by Dr. Brenda Grewell
Biological invasions by alien plant species are a global change factor linked to declines in native species diversity and ecosystem functions. On-going detections of new invasive alien plant species in waterways and wetlands of the San Francisco Bay-Delta Estuary continue to challenge ecological restoration goals. Rapid response actions to curtail these invasions are difficult given the swift dispersal and spread of buoyant, reproductive parts of aquatic plants with water currents. With global climate change, plant species in tidal marshes are being exposed to increasing salinity and longer inundation periods related to sea level rise and alteration of local watershed runoff and precipitation amounts and patterns. Despite extensive tidal wetland restoration plans for fish recovery, actions to prevent spread of invasive plant species in tidal sloughs and tidal wetlands of Suisun Marsh are largely overlooked. The distribution of some alien plant invaders in upper estuaries and tributaries were considered limited to freshwater, yet range expansions into Suisun Marsh and areas with higher salinity suggest a need to broaden our view of rapid response to include range-expanding populations. Climate-driven environmental variation can influence the fitness, establishment and invasive spread of alien plants, yet adaptive evolution may support their invasiveness. A broad vision of ecosystem recovery encompassing system-wide integrated weed and restoration management could advance efforts to achieve current and future conservation goals.