Biological Invasions:
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Program Information

Program Manager:
Andrew N. Cohen, Ph.D.

Program Overview

Biological invasions—the introduction and spread of exotic organisms in regions outside of their native range—has emerged as a major environmental, economic and public health problem tied to the rapid, ongoing expansion in international trade and travel. Recent studies have found that exotic organisms constitute the second greatest threat to biological diversity, ranking below habitat loss and degradation but far above pollution and over harvesting. SFEI's Biological Invasions program conducts scientific and policy research and provides information and analyses on the introduction of exotic organisms into marine and freshwater ecosystems.

Program Objectives

To assess the extent and impacts of invasions.
To identify and characterize the mechanisms that transport and release exotic species.
To investigate and report on the scientific and policy aspects of reducing the transport and release of exotic species.
To understand how species characteristics and environmental factors affect the success of invasions.

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Program History

The Biological Invasions Research program started at SFEI in 1997, building upon several years of prior research by Program Director Andrew Cohen on invasions in the San Francisco Estuary. The research has since expanded to include research at numerous sites in North America, Central America and the Caribbean. Findings from this research have been published in leading scientific journals and in the Congressional Record, have influenced the shape of federal legislation and of state legislation in California, Washington and Oregon, and have frequently been covered or cited by the major national news media in print, radio and television.

Recent Findings

Our study of biological invasions in the San Francisco Estuary found that exotic organisms dominate many important habitats in the ecosystem in terms of species, number of organisms and biomass, leading to the conclusion that it is one of the most invaded aquatic ecosystems and perhaps the most invaded estuary in the world. Our analysis of this data, published in Science in 1998, found that the rate of invasion was accelerating exponentially, with exotic species now arriving and becoming established in the estuary at an average rate of one new species every 14 weeks.
Working in San Francisco Bay in 1993-1997, we pioneered the development of Rapid Assessment Surveys for exotic marine organisms. This approach has since been used in nine surveys on both coasts of North and Central America from Panama to Massachusetts and British Columbia.
We developed the first assessment of exotic marsh plants in the San Francisco Estuary, mapped their known distribution, and prioritized these species for control, arguing that such efforts had to be planned and organized on a regional (i.e. Estuary-wide) basis. This helped to stimulate the interest that lead to the current regional effort to control exotic cord grasses in the Estuary.
We published the initial report and assessment of the establishment of two important exotic crabs on the Pacific Coast. The Green Crab arrived in San Francisco Bay by around 1990 and was subsequently reported from Morro Bay in south-central California to Vancouver Island in British Columbia. We discovered the first Green Crab in the Pacific Northwest in the spring of 1998, where it has been a major worry to the shellfish industry as a potentially important predator of mussels and clams. The Mitten Crab arrived in San Francisco Bay by around 1992 and gradually spread upstream into the Delta and tributary waters (it breeds in brackish water and migrates upstream to grow to maturity in fresh water), where in its peak year it clogged the fish screens at the main federal water project pumps, with approximately 20,000 crabs per day arriving at the screens during the crab's fall migration.
We produced the first assessment and map of the potential distribution of Zebra Mussels in California, based on published data on the mussel's environmental requirements and tolerances. We found a high potential for colonization at 44% of the 160 sites that we analyzed across the state, including most of the coastal watersheds, the west side of the Sacramento Valley, the San Joaquin Valley, and many of the state's largest canals and aqueducts. However, in a subsequent study we found that the information published in the scientific literature probably overstated the mussel's tolerance for low calcium levels, leading to a substantial overestimate of the area vulnerable to invasion in virtually all of the many studies done of the mussel's potential distribution, including our own. In 2003 we will reanalyze the California data based on these new findings on the mussel's calcium requirements.
In 1998 we produced an assessment of the role of ballast water in introducing exotic organisms into San Francisco Bay that included a comprehensive review of ballast water sampling studies and the organisms carried by ballast water, the organisms introduced into the San Francisco Estuary via ballast water, ballast water management approaches, and ballast water laws and regulations. We estimated that from half-a-billion to a billion gallons of foreign ballast water (and 2-4 billion gallons of total ballast water) are discharged into the Estuary each year. In 2000 we followed that study with a comprehensive law review article on the potential for regulating ballast water discharges in California using existing laws. We concluded that the most promising approaches were through laws protecting water quality including the federal Clean Water Act; and secondarily through laws protecting wildlife or the coastal zone, or laws requiring the review and mitigation of environmental impacts, which were most likely to come into play during the permitting process for port expansion or navigation improvement projects. A petition to the U.S. Environmental Protection Agency filed by a group including conservation organizations, a water industry association, Native American tribes and commercial and sport fishing interests, and subsequent litigation filed by these parties, is currently exploring the role that the Clean Water Act may play in regulating ballast discharges.
We organized two surveys of exotic marine organisms in Washington state, and produced the first comprehensive list of exotic organisms known from the waters of Puget Sound. In our second survey, conducted in three bays ranging from a highly urbanized bay that is also a major shipping port to a largely rural bay that is a major aquaculture center, we found that the extent of invasion increased as we moved away from shipping centers and toward aquaculture areas.
In 1998 we drafted a letter from over 100 leading marine and invasions scientists to the Secretary of the Interior requesting an import ban on an exotic marine seaweed that was a popular aquarium species but that had been responsible for devastating thousands of acres in the Mediterranean after it was released there in the 1980s. In response to our letter the ban was instituted in record time, so that in 1999 it became the first marine species and the first alga listed as a prohibited species under the Federal Noxious Weed Act (California state law subsequently extended the ban to the entire genus). We predicted in our 1998 letter that southern California coastal waters would be vulnerable to invasion by this seaweed, and in 2000 it was in fact discovered growing in two southern California lagoons. Because it was listed as a prohibited species under federal law, government agencies were able to react quickly and mounted a $3 million eradication effort, which is still underway.
We recently completed a study of a little-known invasion mechanism, the transport of Atlantic coast marine invertebrates in the seaweed used to pack marine baitworms imported into California from Maine. We found that this mechanism is responsible for the release into San Francisco Bay of an estimated 3 metric tons of seaweed and about 1.2 million invertebrates from the Atlantic Ocean each year; that at least three Atlantic species may have become established in San Francisco Bay by this mechanism; and that the Maine-to-California shipments are just one component in an international trade network that transports at least twelve species of marine baitworms between countries in at least five continents.
We recently published a review and analysis of several generally-accepted theorems of invasion biology regarding the characteristics of successfully invading species and easily invaded habitats. Among other uses these theorems are incorporated into exotic species risk assessments and provide the basic theoretical support for classical biological control. In general we found little to support most of the generally-accepted views. In particular, we found no consistent evidence that more prolific organisms are more likely to become established when released into a new environment; and found no supporting evidence and some significant counter-evidence to the claims that exotic organisms are more likely to become established in disturbed than in undisturbed habitats, and that leaving behind their native parasites helps exotics species to become established.

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Current Projects

Project Title:

Dynamics of an Invasive Non-native Species and its Biological, Physical and Human Impacts: Spartina alterniflora on the Pacific Coast

Total Funding:
$3,799,621

Project Funder:
National Science Foundation

Lead Scientist:
Andrew N. Cohen

Collaborators:
Prime Contractor: U.C. Davis
Co-PIs: Alan Hastings, Donald R. Strong, Susan Ustin, David Layton and Edwin Grosholz, U.C. Davis; Lisa Levin, U.C. San Diego/Scripps Institute of Oceanography
Primary Collaborators: J. Cully Nordby, U.C. Berkeley and SFEI; and Steven R. Beissinger, U.C. Berkeley

Project Description:
The overall project is to investigate and model the dynamics and impacts (including non-market economic impacts) of the invasion and spread of the exotic cordgrass Spartina alterniflora on the Pacific Coast. SFEI's component is to investigate the impacts of the invasion on nesting passerine birds in San Francisco Bay saltmarshes, particularly the impacts on and interactions between saltmarsh song sparrows and marsh wrens. The marsh wrens, which are native freshwater marsh-nesting birds in the south San Francisco Bay area, nest in the exotic Spartina alterniflora in the saltmarshes, and may be affecting saltmarsh song sparrow populations through aggressive territorial interactions or through competition for food.

Work Products:
• NSF Project Summary
• Presentation Abstract: "The impact of invasive Spartina on San Francisco Bay song sparrow populations: direct and indirect influences"
• Presentation Abstract: "Conservation management of exotic cordgrass in Pacific Coast salt marshes: preserving clapper rails vs. preserving the clapper rail?"

Project Title:
Southern California Biological Study and Rapid Assessment Survey for Nonindigenous Organisms

Total Funding:
$209,149 .

Project Funder:
State Water Resources Control Board, California Department of Fish and Game, and National Fish and Wildlife Foundation

Lead Scientist:
Andrew N. Cohen

Collaborators:
Leslie H. Harris, Natural History Museum of Los Angeles County; Brian L. Bingham, Western Washington University; James T. Carlton, Williams College-Mystic Seaport Maritime Studies Program; John W. Chapman, Hatfeld Marine Science Center, Oregon State University; Gretchen Lambert and Charles C. Lambert, University of Washington Friday Harbor Laboratories; John C. Ljubenkov, Dancing Coyote Ranch Environmental; Steven N. Murray, California State University-Fullerton; Linda C. Rao, State Water Resources Control Board; Kathleen Reardon, Island Institute; Evangelina Schwindt, Universidad Nacional de Mar del Plata, Argentina

Project Description:
A previous report for the U.S. Fish and Wildlife Service provided comprehensive information on exotic organisms in the San Francisco Bay/Delta Estuary, but no comparable data were available for southern California. This project is to conduct a Rapid Assessment Survey of exotic marine organisms in southern California bays and harbors, based on survey methods developed in San Francisco Bay; and to develop the first comprehensive review of exotic marine organisms in southern California.

Work Products:
• Executive Summary: Project Report for the Southern California Exotics Expedition 2000: A Rapid Assessment Survey of Exotic Species in Sheltered Coastal Waters

Project Title:
Biological Invasions in Tropical Marine Waters

Total Funding:
$150,000

Project Funder:
Fellowship in Marine Conservation from the Pew Charitable Trust

Lead Scientist:
Andrew N. Cohen

Collaborators:
Ernest H. Williams, Jr., University of Puerto Rico; John B.R. Agard, University of the West Indies at St. Augustine, Trinidad; Don Cadien, County Sanitation District of Los Angeles County; Dale Calder, Royal Ontario Museum; Ernesto Campos-González, Universidad Autonoma de Baja California; John W. Chapman, Hatfeld Marine Science Center, Oregon State University; Leslie H. Harris, Natural History Museum of Los Angeles County; Gretchen Lambert and Charles C. Lambert, University of Washington Friday Harbor Laboratories; Fabio B. Pitombo, Universidade Federal Rural do Rio de Janeiro, Brazil; Sergio I. Salazar-Vallejo, El Collegio de la Frontera Sur (ECOSUR), Mexico; Brian S. Wysor, Bigelow Laboratory for Ocean Sciences; and the Smithsonian Tropical Research Institute for hosting the Pacific-Atlantic Expedition

Project Description:
While there have been several regional studies of biological invasions in temperate marine and estuarine waters, little has been published assessing such invasions in tropical marine waters. This study will produce the first comprehensive review of exotic organisms in Caribbean waters; and conduct a Rapid Assessment survey of exotic marine organisms on the Pacific and Atlantic coasts of Panama in the vicinity of the Panama Canal, to assess the role that the Canal has played in transporting marine species between the oceans.

Work Products:
None yet

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2003 PROJECTS

Project Title:
Dynamics of an Invasive Non-native Species and its Biological, Physical and Human Impacts: Spartina alterniflora on the Pacific Coast

Total Funding:
Total Project: $3,799,621; SFEI share: $373, 276

Project Funder:
National Science Foundation

Lead Scientist:
Andrew N. Cohen

Collaborators:
Prime Contractor: U.C. Davis
Co-PIs: Alan Hastings, Donald R. Strong, David Layton and Edwin Grosholz, U.C. Davis; Lisa Levin, U.C. San Diego/Scripps Institute of Oceanography
Primary Collaborators: J. Cully Nordby, U.C. Berkeley and SFEI; and Steven R. Beissinger, U.C. Berkeley

Commitment Status:
(d) Project is underway.

Start & End Dates:
Oct. 15, 2000-Sept. 30, 2005

Project Title:
Southern California Biological Study and Rapid Assessment Survey for Nonindigenous Organisms

Total Funding:
$209,149

Project Funder:
State Water Resources Control Board, California Department of Fish and Game, and National Fish and Wildlife Foundation

Lead Scientist:
Andrew N. Cohen

Project Description:
A previous report for the U.S. Fish and Wildlife Service provided comprehensive information on exotic organisms in the San Francisco Bay/Delta Estuary, but no comparable data were available for southern California. This project is to conduct a Rapid Assessment survey of exotic marine organisms in southern California bays and harbors, based on survey methods developed in San Francisco Bay; and to develop the first comprehensive review of exotic marine organisms in southern California.

Commitment Status:
(d) Project is underway.

Start & End Dates:
Oct. 1, 1999-Sept. 30, 2003

Project Title:
Assessment of On-shore Ballast Water Treatment

Total Funding:
$79,212

Project Funder:
U.S. Fish and Wildlife Service

Lead Scientist:
Andrew N. Cohen

Collaborators:
Contra Costa Water District, San Francisco Bay Regional Water Quality Control Board, State Water Resources Control Board, Port Of Oakland, Contra Costa Sanitary District

Project Description:
The project is to assess the technical and economic feasibility of on-shore treatment of ballast water, and identify and investigate the most promising approaches, using the ports and marine terminals in the San Francisco Bay/Delta Estuary as a case study. The project will also develop a scope of work for bench-level or field-level investigations into the most promising approaches identified through this assessment

Commitment Status:
(d) Project is underway.

Start & End Dates:
July 14, 1999-Dec. 31, 2003

Project Title:
Harmful Algae, Bacteria, and Fauna Transported by Department of Defense Vessels

Total Funding:
$486,620 (on prime contract). Expected funding to SFEI is to pay for two months of consulting by Cohen at federal billing rate.

Project Funder:
U.S. Department of Defense, Strategic Environmental Research and Development Program (SERDP)

Lead Scientist:
Andrew N. Cohen

Collaborators:
Prime Contractor: North Carolina State University, Center for Applied Aquatic Ecology (CAAE)
Co-PIs: JoAnn M. Burkholder and Howard B. Glasgow, CAAE; David W. Oldach, Institute of Human Virology and University of Maryland School of Medicine; and Gustaaf M. Hallegraeff, University of Tasmania, Department of Plant Science

Project Description:
This project will sample the ballast water from a selection of Department of Defense vessels on the Atlantic and Pacific coasts, and identify and quantify the species of harmful algae, bacteria and fauna.

Commitment Status:
(c) Prime contract has been signed, subcontract language is being negotiated. Cohen is a co-PI on the proposal, and we have a written commitment from the prime contractor.

Start & End Dates:
2002-2004. Our participation will be in 2003 and 2004.

Project Title:
Zebra Mussel Early Detection Monitoring and Public Outreach

Total Funding:
$4,999 on SFEI subcontract (plus up to $5,000 in in-kind publication costs)

Project Funder:
CALFED project # 99-B18

Lead Scientist:
Andrew N. Cohen

Collaborators:
Prime Contractor: California Department of Water Resources (DWR)
Project Manager: Cindy Messer, DWR

Project Description:
SFEI's role is to develop information relevant to a risk assessment of zebra mussels invading California, especially in regard to the mussel's calcium requirement and its effect on potential distribution in California.

Commitment Status:
(c) Prime contract has been signed, subcontract with SFEI to be completed. SFEI is written into the proposal, and we have a written commitment from the prime contractor.

Start & End Dates:
2003?

Project Title:
Aquatic Nuisance Species Monitoring Approach

Total Funding:
$40,000

Project Funder:
U.S. Environmental Protection Agency

Lead Scientist:
Andrew N. Cohen

Collaborators:
Lower Columbia River, Tillamook Bay and Puget Sound National Estuary Programs
Prime Contractor and Project Manager: Kevin Anderson, Puget Sound National Estuary Program

Project Description:
The goal is to develop a consistent approach for monitoring aquatic nuisance species in the Lower Columbia River, Tillamook Bay and Puget Sound National Estuary Programs. The intent is to transfer expertise and knowledge from the San Francisco Bay area to Washington and Oregon estuary programs by developing generalized monitoring plans through a collaborative effort between the NEPs, SFEI and prominent regional scientists and resource managers.

Commitment Status:
(c) Prime contract has been signed, subcontract language is being negotiated. Cohen assisted with the development of the proposal, and we have a statement of intent from the prime contractor to subcontract the project to SFEI.

Start & End Dates:
The schedule in the proposal is summer 2002 to fall 2003, but the project will likely start sometime in 2003 due to delays in the awarding of the grant and prime contract.

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