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You are here: Home / Manager's Tool Kit / Early Detection and Rapid Response / The Early Detectives / Orange County Coastkeeper: Killer Algae
Manager's Tool Kit
Early Detection and Rapid Response

The Early Detectives: How to Use Volunteers Against Invasive Species, Case Studies of Volunteer Early Detection Programs in the U.S.

Orange County Coastkeeper: Killer Algae

Contacts: Gary Brown, Orange County Coastkeeper
Address: 3151 Airway Avenue, Suite F-110, Costa Mesa, CA 92626
E-mail: Garry@coastkeeper.org
Phone: (714) 850-1965


The Orange County Coastkeeper is a volunteer and membership based-non-profit environmental activist organization in Orange County. It is dedicated to the principal that "protecting the waters of Orange County is the job of everyone." With this as their mission the Orange County Coastkeeper has developed an early detection program by default. When "killer algae" (Caulerpa taxifolia) presented itself as a potential threat to Orange County's coastal waters, Coastkeeper stepped in to see if the highly invasive algae had started to colonize in the Newport Bay. Early detection efforts utilized over thirty volunteer divers to inspect the waters of Newport Bay. With ten thousand dollars in initial funding, divers searched the entire bay in three weeks during July and August 2001, but did not find any "killer algae."

Program Track Record

"Killer algae" was discovered in a coastal lagoon near Carlsbad, California, in June, 2000. The same species was first reported in the Mediterranean in 1984. That year, the algae covered a square yard. Now the incredible invasive has blanketed more than 10,000 acres of Mediterranean seafloor. It will take purchase on any substrate and has been found from the shoreline to depths of up to 250 feet. These statistics, and a second Californian discovery in an artificial pond close to Orange County's Huntington Harbor, were enough to alarm the Coastkeeper organization and spur its volunteers into action.

To perform the survey of the Newport Bay, Coastkeeper had small groups of volunteer divers survey the bottom whenever the tides were right and divers were available. After three weeks, the divers had covered every accessible corner of the Bay. During the search for "killer algae," Coastkeeper wisely had divers search for native eelgrass, to see how it was doing in the Bay.

By the time the survey was completed, no Caulerpa taxifolia had been found. After the survey was completed, Coastkeeper created a new plan to defend against "killer algae" on all fronts. Coastkeeper has sent its volunteers out into the community, to spread knowledge at schools, to citizens and especially to fish-tank merchants. The Caulerpa taxifolia invasion has been well publicized and Coastkeeper volunteers are using this publicity to tell people not to dump their aquarium water in the gutter or runoff channels. Apart from this type of prevention, Coastkeeper will continue to monitor Orange County waters to ensure that "killer algae" will not find a new home in the waters off Southern California.

Coastkeeper Volunteers

The Coastkeeper early detection program for Caulerpa taxifolia was much different from most invasive species early detection programs. Prior knowledge of the invasive in the Mediterranean made it easier to take action. The survey volunteers were people with a love for the coast and its resources, and most were already devoted Coastkeeper volunteers and members. They had personal motivation for giving up their time for the early detection efforts.

The killer algae threat is very clear and its impacts are frightening. This is not the case for many invasives, for which environmental and economic impacts are not as clear. "Killer algae" will suffocate everything in its path and it can utterly destroy an ecosystem.

While the volunteers for the Newport Bay survey were already Coastkeeper members, the organization is now reaching its tentacles out into the community to make people aware of the invader and to get those who frequent Orange County waters to keep a look out. This is the type of volunteering which is currently appropriate for the Caulerpa problem. Coastkeeper does not need constant volunteering yet. Instead, the organization wants to spread its mission, that protecting the waters of Orange County is everyone's responsibility and all Orange County residents should voluntarily keep a lookout for Caulerpa and not act in a manner which may promote its introduction to coastal waters.

Survey Methodology

Using maps of the bay teams of divers searched every possible square meter of Newport Bay's floor. Coastkeeper did not survey beyond the Newport Harbor Jetties or in the upper reaches of the bay where there is a tidal estuary. GPS units were used to record exact survey locations and results. This data was integrated into a GIS to create a survey map. Divers marked survey areas with steel rods that had orange flags attached. Had they found Caulerpa taxifolia, these flagged rods would have remained as semi-permanent "killer algae" markers. Volunteers with experience trained the Coastkeeper volunteer divers to do the surveying and mapping. To accomplish this, Coastkeeper worked closely with the Orange County Water Quality Control Board and experienced consultants from San Diego. A volunteer marine biologist led what was called the Coastkeeper Dive Task Force.
The survey utilized 35 divers that worked in teams of 4-5 and made dives when the water was clear, usually during ebb tides. Some parts of Newport Bay were simply too murky to be surveyed. The murky waters normally do not harbor many species, so the probability of Caulerpa being in those places was statistically very low.

Quick Facts

Staffing: Survey Volunteers: Approximately 40

Operating Budget: Initially $10,000, Currently $0

Species Targeted: Killer algae (Caulerpa taxifolia)

Habitats Patrolled: Seafloor anywhere, sand, rock or coral

Location: USA, Newport Beach, California

Threatened Species: Spiny lobster, California Halibut, Native Sand Basses

Report prepared by: Lucas Nagy

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Last Modified: Sep 09, 2017
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