Agua Hedionda Lagoon Foundation Fighting Another Ecological Threat

CARLSBAD, Calif. - July 13, 2018 - PRLog -- First, it was an infestation of the invasive Caulerpa taxifolia (a non-native, aquarium strain of a highly invasive tropical algae) eradicated successfully in 2006 at a cost of $6 million.  Now, another non-native, invasive weed known as Algerian Sea Lavender or Limonium ramosissimum (ASL) is threatening the ecosystem around the Agua Hedionda Lagoon.

The Agua Hedionda Lagoon Foundation and other state agencies are collaborating to protect the Agua Hedionda Lagoon Ecological Reserve (AHLER) from plant invasions.  In 2015, the San Diego Department of Agriculture, Weights and Measures (AWM) prepared an Invasive Plant Species Annual Work Plan for the San Diego Association of Governments (SANDAG)  in which it identified 12 acres at the Agua Hedionda Lagoon as the county's oldest, most invaded ASL site encountered.

ASL can be seen in low marsh areas in the tidal zone.   It threatens native vegetation and bird and fish species by forming dense mounds of leaves up to 30 centimeters wide and tall.  The mounds can grow edge to edge thereby snuffing out native vegetation needed to support nesting habits of endangered species of birds and the reproduction of endangered fish species.  Native vegetation such as the Salt Marsh Bird's Beak, a state and federally endangered plant species, and other species are also threatened.

ASL has invaded wetlands along the entire coast of California.  The method of treatment depends on the site, and studies are continuing to determine the best way to achieve total eradication.

"We are concerned about using herbicides, the usual method of controlling infestations, around Agua Hedionda Lagoon," stated Lisa Rodman, CEO of the Agua Hedionda Lagoon Foundation.  "Agua Hedionda is one of the few lagoons that supports recreation, aqua farming, education, agriculture and residential activities.  We want to do everything we can to prevent the use of potentially environmentally harmful substances."

The plan to control the invasion of ASL at the lagoon involves a collaboration of the U.S. Fish and Wildlife Service, the Agua Hedionda Lagoon Foundation, the University of California Santa Barbara Marine Science Institute (UCSB), the Carlsbad Strawberry Company, Inc.  and the California Department of Fish and Wildlife (CDFW), which is the legal owner of the reserve.

UCSB and the U.S. Fish and Wildlife Service collaborated on scientific eradication experiments in the Carpinteria Salt Marsh, part of the University of California Reserve System 20 miles east of the UCSB campus.  The experimental results indicated that solarization (tarping with black plastic) from 3 to 6 months or longer eliminated ASL above-ground plants and prevented regrowth and the recolonization from seeds while having significantly less of an effect on native plants.  However, the experiments did not include a comparison between the effects of solarization and herbicides (such as Telar®) which CDFW commonly uses to control infestations.

New and ongoing scientific experimentation being conducted at AHLER involves using blocks of land where solarization is used on one section, herbicide treatment is used on another and a block is untreated control.

Rodman, as CEO of the Foundation, has been designated as head of the cooperator agency (Foundation) and administers all contracts, coordinates all project participants, and maintains all books and records.

Kyle Lunneberg, project coordinator for the Agua Hedionda Lagoon Foundation, manages the day-to-day eradication efforts, carefully documents progress made, coordinates interns, and ensures that care is taken to minimize the impact to sensitive plants, fish, birds and animals as eradication is ongoing.

"We got involved because we believe solarization is more effective than traditional means," Lunneberg said.  "Telar herbicide is quick and easy to apply but leaves biological matter which prevents re-establishment of native plants.  It also leaves the ASL seed bank intact. These problems make herbicide treatment ineffective in the long-term.  ASL is, by far, the most threatening and widespread invasive species at the Agua Hedionda Lagoon. This project has proved solarization is a cheaper, more effective, and more long-term solution to the ASL infestation."

An important objective outlined in the work plan is to create both a public awareness concerning how detrimental ASL is to the native habitats and a mechanism by which citizens can report occurrences to the foundation and to the CDFW.

Public awareness is being accomplished through presentations, press releases to the media and training of volunteer work parties.  In addition, the Agua Hedionda Lagoon Foundation staff, in conjunction with environmental scientists, biologists and teachers and students at Cal State University San Marcos, created a unique Bio-Survey App that allows public participation in scientific study.  The app is easily accessed from any smart device with an Internet connection and creates citizen-scientists who can assist in identifying areas where ASL has invaded and spread.  The app provides a less costly way of environmental analysis of invasive species.

"The eradication of ASL is an ongoing process at AHLER for the foreseeable future," states Rodman.  "We are excited to solicit the help of the community while raising awareness of the damage an invasive species can inflict on an ecosystem.  Increased community engagement encompasses all age groups and creates a stimulating, real world scientific application.  The whole community becomes more knowledgeable of the work that is necessary to protect our natural wetlands."

https://www.aguahedionda.org