University of California

Aquatic Invasive Species (coastal)

Quagga and Zebra Mussels (freshwater)

Invasive quagga and zebra mussels have been found in California, according to the California Department of Fish and Wildlife. They pose risks to native, freshwater life and to our water transport system. For links to resources on preventing the spread of quagga and zebra mussels and for other educational materials visit our page Quagga/Zebra Mussel Invasion.


Aquatic invasive species (AIS) attach to all types and sizes of vessels. Measures to prevent and control the hull transport of AIS are necessary as they can have significant ecological and socio-economic impacts.

The Coastal Resources Program of UC Cooperative Extension has created several, research-based publications on preventing transport of aquatic invasive species by boats that are kept in saltwater:


  • The Influence of Boat Hull Coatings on Fouling Growth (2012) This fact sheet discusses the field research we conducted in Santa Barbara Harbor and Shelter Island Yacht Basin of San Diego Bay. The aim of the research was to discover the influence of hull coating type and hull coating age on fouling growth. 4 p.
  • Hull Fouling Species of Concern in Southern California Coastal Marinas (2012)  This fact sheet introduces the reader to hull fouling species of concern found in California's Coastal marinas. The species described were common to abundant, showed invasive characteristics in our field studies and create problems for boat owners.  Photographs, descriptions, scientific names and ecological information are provided for eight Species of Concern! 4 p.
  • Hull Fouling Copper Tolerance Fact Sheet (2011) Fact sheet summarizing recent scientific studies on the ability of hull fouling to tolerate copper antifouling paints on boat hulls and copper pollution in harbor waters. Includes a table of both native and non-native species that the research suggests can tolerate copper. 4 p.

TECHNICAL REPORTS (USER FRIENDLY) on Balancing Management of Aquatic Invasive Species and Water Quality

IPM for Boats: Integrated Pest Management for Hull Fouling in Southern California Coastal Marinas (2012)  This 28-page illustrated technical report introduces Integrated Pest Management (IPM) for fouling control on recreational boats. IPM has been applied successfully for pest control in agriculture and buildings. It seeks to reduce the need for toxic chemicals by using a combination of tactics, such as mechanical, physical, cultural and chemical in a strategy that is tailored to the individual boat or marina and updated over time. The report also presents results of our research on the influence of hull coating types and age and of hull cleaning practices on fouling growth. Finally, it profiles 7 aggressive, copper-tolerant, hull-fouling “species of concern” that include invasive and other species found in our research. Although our report and supporting research are aimed at fouling control for recreational boats in south-central and southern California, the principles of IPM for Boats can be adapted for use in other areas.


  • Crossing Boundaries: Managing Invasive Species and Water Quality Risks for Coastal Boat Hulls in California and Baja California (2012) This 16-page technical report presents the findings of our 2008 survey research of the boating industry on California's coast and 3 major boating areas of the Baja California peninsula. It presents data and analyses of industy capacity and costs to provide fouling control supplies and services that assist boat owners in managing risks of invasive species and impaired water quality. The report also summarizes data on boat travel patterns, analyzes how boater environmental awareness affects choice of hull coatings, and the potential for education to assist in managing water quality and invasive species risks along this 3,000 mile (5,000 kilometer) coast.

This 26-page technical report translates technical information for the general public at a senior high school level. It explains how efforts to control invasive species and reduce antifouling paint pollution might affect each other, ideas for how to balance policies on both issues, has pictures of invasive species that are common in coastal harbors of California and Baja California, tips for avoiding carrying invasive species on recreational boats, a cost analysis for cleaning boat hulls in various situations, and lots of photos and references to scientific and policy documents. The report includes summarized findings and recommendations from the workshop, "white paper" and policy analysis that are described below.

BILINGUAL FACT SHEET on aquatic invasive species - text is in English y Español. It is for owners of boats kept in saltwater in California and Baja California and for staff of marinas, harbors and yacht clubs. It explains problems caused by hull-borne invasive species and how to reduce the risk of transporting them on recreational boat hulls. Colorful photos of invasive species will help boaters identify them and report them to the appropriate agencies. Links below provide downloading instructions in English y Español.


PEER-REVEWED "WHITE PAPER" on Aquatic Invasive Species and Water Quality

  • Managing Hull-Borne Invasive Species and Coastal Water Quality for California and Baja California Boats Kept in Saltwater This confidentially peer-reviewed paper is about 150 pages and includes a review of scientific and other literature  on managing hull transport of AIS and on water quality issues related to antifouling paints for recreational vessels. It also includes recommendations of the 2005 California workshop Managing Hull Transport of Aquatic Invasive Species. Although the focus is California, the paper includes information from other parts of the United States and other countries. Most information is on saltwater species but freshwater zebra mussels are also discussed.

POLICY ANALYSIS on Balancing Management of Aquatic Invasive Species and Water Quality (for California coastal boats)

Considerations for developing policies to balance the management of aquatic invasive species and water quality are analyzed with respect to effects on the environment, the boating industry and boat owners.


WORKSHOP on Aquatic Invasive Species Carried on Hulls of Ships and Boats in Saltwater - held in California in 2005

The University of California Sea Grant Extension Program collaborated with the California State Lands Commission to lay a foundation for solutions by convening a workshop:

to educate participants, learn from them and ask for recommendations. This coordinated approach was chosen because hull transport of Aquatic Invasive Species is a complicated issue affecting commercial and recreational vessels.

The Workshop took place on May 11th, 2005 in San Francisco. To ensure that the recommendations reflect the best available information and consider the concerns of affected parties, 65 representatives from the shipping, boating and coating industries; vessel owners; port, harbor, and marina managers; state and federal agencies; research community and environmental organizations participated in the Workshop.

Workshop Goals:

• Educate stakeholders and facilitate the exchange of perspectives on managing hull-borne invasive species, fouling growth and coastal water quality from the commercial shipping and recreational boating perspectives.

• Develop recommendations on managing the risks associated with the hull transport of invasive species as well as feasible, effective strategies for preventing associated introductions.

• Determine recommendations for action such as research, education, outreach, management measures and policies needed to prevent and control AIS introductions and establishment. For online access to the Workshop Proceedings, please complete this quick survey: Workshop Proceedings Survey

Additional Resources:

"The significant problems we face cannot be solved at the same level of thinking we were at when we created them." - Albert Einstein
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