The battle against invasive species rages on

Published Jan. 14, 2014

Invasive species management is much like fighting an ongoing war while battling multiple insurgencies. Once an area is cleared, constant, diligent defense against new and known invaders is needed to maintain the ground won. In Jacksonville District, the battle against invasive species rages on.

U.S. Army Corps of Engineers involvement in invasive species management dates all the way back to the introduction of water hyacinth in the 1880s. By 1890, the population had grown to such an extent that it impeded private and commercial river traffic in both Florida and Louisiana. Both states requested assistance from Congress to solve the problem. In the Rivers and Harbors Act of 1899, the Corps was tasked with solving the invasive aquatic plant problem in affected federal navigable waterways. Since then, more than 50,000 exotic species have been introduced to the U.S. Approximately 4,300 of these exotic species are considered invasive and pose a serious threat to navigation, agriculture, public health, flood control, and native plant and animal communities.

Jacksonville District is the only district in the U.S. Army Corps of Engineers with an Invasive Species Management (ISM) Branch. It provides guidance, administration and technical support for the removal and control of aquatic plants and other invasive species, and prepares and manages the annual budgets for these programs.

The ISM Branch also serves as the Aquatic Plant Control Operations Support Center for the nation, providing assistance with invasive species management issues nationwide. It is a big job. The Corps is responsible for the environmental stewardship of 456 water resource development projects located in 43 states and occupying 5.5 million surface acres, 237 navigation locks, 926 harbors, 75 hydropower projects, and 25,000 miles of inland and coastal waterways. Jacksonville District biologists travel around the country to assist in aquatic plant management and other invasive species management issues.

In 2013, the Jacksonville District ISM Branch continued established programs and initiated several new projects.

Due to the mild winter and an early wet season, aquatic plant growth exploded again this year. In fiscal year 2013, ISM treated 24,432 acres of invasive aquatic plants on the St. Johns River and Lake Okeechobee, more than any previous year. “There was a lot of pressure on our crews and on our contractors. They worked hard to try to stay on top of the growth,” said biologist Jessica Spencer.

In April 2013, ISM took on a big new project administering work for the U.S. Department of Agriculture, Natural Resources Conservation Service (NRCS) Wetlands Reserve Program (WRP). The NRCS manages conservation easements on private, county and state-owned land and restores the sites as part of the easement agreements, while the landowner retains the right to hunt, fish, camp and even potentially graze cattle if it will not impact the restoration. “If the land is privately owned, we try to work with homeowners to maintain the use of their land,” said Spencer.

In the brief span of time between April and November, ISM awarded several contracts, resulting in the successful completion of significant amounts of work and the initiation of other projects. The Corps completed exotic removal on four NRCS projects totaling 2,256 acres, and surveys and vegetation assessments were conducted on 59,138 acres of WRP easements. In addition, they were able to obligate $3.45 million to an 8(a) small business firm. The 8(a) Business Development Program helps socially and economically disadvantaged entrepreneurs gain a foothold in government contracting and access to the economic mainstream of American society. The scope of work for the contract award included the requirement to conduct vegetation management activities on 72,560 acres of WRP easements during fiscal years 2014 and 2015.

“We are hoping to receive additional funding from NRCS again this year,” said Spencer. “We have demonstrated that we are very effective at putting together the contracts and obligating the money for these projects. It takes a significant amount of effort, and it’s nice to have another agency recognize our ability to get the job done.”

Many of the sites targeted benefit the greater Everglades ecosystem, including 32,000 acres in the Fisheating Creek basin on the west side of Lake Okeechobee. The work includes control of invasive plants such as Brazilian pepper, old world climbing fern and cogongrass.

Jacksonville District has also been involved as part of the Great Lakes and Mississippi River Interbasin Study (GLMRIS) team, a regional, collaborative effort that includes various Corps offices, as well as centers of expertise and research laboratories, in the effort to conduct the Great Lakes and Mississippi River Interbasin Study (GLMRIS) in Chicago.

The study identifies potential options and controls that could prevent aquatic nuisance species transfer between the Great Lakes and Mississippi River basins. The bighead carp and the silver carp, collectively known as “Asian carp,” are two of the species of concern. They are presently in the Mississippi basin, but have not yet invaded the Great Lakes. Conversely, there are other nuisance species in the Great Lakes that have not yet made it into the Mississippi River basin.

Some of the issues associated with GLMRIS include significant natural resources such as ecosystems and threatened and endangered species; commercial and recreational fisheries; current recreational uses of the lakes and waterways; effects on water users; effects of potential controls on current waterway uses such as flood risk management, commercial and recreational navigation, recreation, water supply, hydropower and conveyance of effluent from wastewater treatment plants and other industries; and statutory and legal responsibilities relative to the lakes and waterways. The complex analysis and report was finalized in mid-December.

In January 2014, the GLMRIS Report will be released to the public and submitted to Congress. The report presents a range of options and technologies to prevent aquatic nuisance species movement between the Great Lakes and Mississippi River basins through aquatic connections. Through an expedited structured study process, the Corps identified aquatic nuisance species of concern established in one basin with the risk for transfer to the other, analyzed and evaluated available controls, and formulated alternatives with the goal of preventing aquatic nuisance species transfer between the two basins, within the Chicago Area Waterway System. The term "prevent" includes the reduction of risk to the maximum extent possible, because it may not be technologically feasible to achieve an absolute solution. As part of this study, the Corps conducted a detailed analysis of various controls, including hydrologic separation.

Another area where Jacksonville District manages invasive species is in the Corps’ dredged material management areas (DMMAs). When the Corps dredges for navigation projects, the spoil may be used for restoration projects, or may be stored on spoil easements on upland areas or “spoil” islands created from dredged material. It is said that “nature abhors a vacuum,” and whenever a bare new soil surface appears, pioneer plant species are not far behind. Monitoring, follow-up and treatment of invasive species are important missions in these areas. While monitoring one site in St. Johns County, Spencer identified old world climbing fern (Lygodium microphyllum), an aggressively invasive plant with a northern extent that had previously been restricted to the I-4 corridor near Orlando and a few sites such as the Tomoka area in Flagler County. “This represented a significant jump north and has a lot of people concerned that this population could contribute to an even greater expansion of this plant’s range. Old world climbing fern spreads via miniscule spores, and is dispersed quickly by both wind and water.”

Jacksonville District is part of the First Coast Invasive Working Group, a five county task force working to prevent and control invasive species in Baker, Clay, Duval, Nassau and St. Johns counties. Volunteers in the working group responded quickly to get the fern under control with herbicides, before it could be established and spread further. “We had to get on top of it immediately,” said Spencer.

Spencer has also been battling salt cedar (Tamarix canariensis) on some of the DMMAs. “Salt cedar seedlings colonize the mud flats as the water draws down in a spoil disposal cell. These conditions create the perfect habitat for the seeds to germinate. The seeds are wind dispersed, so if we don't control the plants on our spoil islands, they have the capability of spreading seeds for miles,” she said.

Another important achievement in 2013 was the implementation of CERP Guidance Memorandum 062.00 (CGM-62) (Invasive and Native Nuisance Species Management) into the Central Everglades Planning Project (CEPP), a component of the Comprehensive Everglades Restoration Plan (CERP). The CGM provides guidance to CERP projects on how to assess and incorporate invasive and native nuisance species management throughout a project’s lifecycle. The CGM requires each project to develop and implement an Invasive and Nuisance Species Management Plan (INSMP), which is intended to be a living document, updated throughout the life of a project.

CEPP will be the first CERP project to address invasive species issues and impacts during every phase of the project:  planning, design, construction and operations, maintenance, repair, replacement and rehabilitation. It is also the first CERP project to address both invasive plant and animal species. The CEPP Project Implementation Report (PIR) and INSMP thoroughly addressed each proposed project feature and the potential new pathways that could result and contribute to the spread and establishment of invasive species. The PIR/INSMP also evaluated the potential adverse impacts to intended ecological restoration benefits. The INSMP thoroughly addresses potential spread and establishment of invasive species due to project implementation, impacts to anticipated project benefits and methods for preventing and managing invasive species. The creation and inclusion of the first in-depth INSMP in a PIR required significant effort and provides a model for future projects.

This year, there was another first. An in-depth invasive species assessment was completed in 2013 for inclusion within RECOVER’s System Status Report (SSR). This will be the first time that the SSR includes an invasive species section. The 2014 SSR will be the fifth in a series of systemwide reports that provide an accounting of the CERP Monitoring and Assessment Plan program. The invasive species section discusses trends in invasive species spread and establishment within the CERP system and associated impacts that could affect the success of Everglades restoration. The invasive species section also assesses invasive species issues/impacts associated with CERP project features that have been constructed and are operating, and projects that are currently under construction. 

Construction of an addition to the existing U. S. Department of Agriculture (USDA) Agricultural Research Service (ARS) biological control laboratory building was completed in 2013. Located in Davie, Fla., the new annex houses a mass-rearing facility for large-scale rearing, dispersion and monitoring of permitted biocontrol agents to combat established invasive species such as melaleuca (Melaleuca quinquenervia), Brazilian pepper (Schinus terebinthifolius), Australian pine (Casuarina equisetifolia), and old world climbing fern (Lygodium microphyllum), and to facilitate a rapid response to new non-native introductions. The construction was done as part of the Melaleuca Eradication and Other Exotic Plants Project, a component of  CERP.

Alligatorweed (Alternanthera philoxeroides) invades aquatic areas and adjoining uplands throughout the southern United States. The thick mats often displace native vegetation and wildlife habitat, clog waterways, restrict water oxygen levels, increase sedimentation, interfere with irrigation and prevent drainage. One of the successful biological controls for alligatorweed is the flea beetle. Every year, Jacksonville District biologists collect alligatorweed flea beetles from local waters for shipment to locations where alligatorweed is becoming a problem. In May, the Aquatic Plant Control Operation Support Center collected and sent 49,799 alligatorweed flea beetles to six different states. These hungry creatures are such effective biocontrol agents that three years after the release of the alligatorweed flea beetle in Florida, the Corps was able to suspend herbicide spraying of alligatorweed.

ISM also maintains ongoing treatment and surveillance at projects such as the Picayune Strand Restoration Project near Naples in southwest Florida, Water Conservation Area 3 (WCA-3), Decompartmentalization (Decomp) and Sheetflow Enhancement Physical Model (DPM) in the heart of the Everglades.

“In 2013, the Invasive Species Management Branch successfully executed several big new challenges in addition to our ongoing efforts,” said Jon Lane, ISM chief.  “We will continue to pursue every key strategy for invasive species management, including control, prevention, coordination, early detection, rapid response and public outreach.”