$125 billion: Estimated annual cost of invasive aquatic species, nationally

11: Number of non-native aquatic plant species found in Maine

2.4: Percentage of boats on which inspectors found fragments of invasive plant species in 2004

400: Number of new volunteer boat inspectors trained in 2004

Cost of invasive species just too great’

By John Plestina

Special to the Sun Journal

LEWISTON – Economic impact could spur efforts to eradicate invasive species from Maine lakes, keynote speaker Evan Richert told about 200 people at the Maine Milfoil Summit at Lewiston-Auburn College Friday.

Richert is an associate research professor at the University of Southern Maine’s Muskie School of Public Service and a former director of the Maine State Planning Office.

He referred to his service as chairman of the Great Ponds Task Force in 1997, a time when variable-leaf milfoil and 10 other invasive species had not yet been recognized as a serious threat in Maine. Since that time, the impact on the food supply, the economy and recreation have been significant, he said.

“How much are we willing to invest? How much are we willing to regulate?” he asked.

Potential economic impacts of the invasives include reduced values of shorefront properties, dampened tourism affecting business owners and job loses, and direct and indirect impacts resulting from the use of herbicides to control invasive species, Richert said.

The estimated annual cost of invasive aquatic species nationally is $125 billion, he said. The impact in Maine “is just too great to ignore,” he said, not offering a specific cost.

But, what if the economic impact didn’t exist?

“Would we care about invasives if it weren’t for the impact on property values and livelihoods?” Richert asked.

There are 11 non-native aquatic plant species known in Maine but the most common offender is variable-leaf milfoil, an aggressive plant that forms dense mats in shallow water. The plants congest waterways and crowd native plants, creating threats to habitats. Infestations have been documented in Lake Auburn, Thompson Lake and about a dozen others in Maine.

Roberta Hill, of the Maine Center for Invasive Aquatic Plants, offered the Maine Volunteer Lake Monitoring Program as a partial solution.

The program is a statewide nonprofit organization based at the Woodbury Brackett Environmental Center in Auburn. It is dedicated to protecting Maine’s lakes and ponds through the acquisition of scientific data and enhancing public awareness of the ecological, aesthetic and economic value of Maine lakes. It serves about 6,000 lakes.

Hill said that 400 new volunteer boat inspectors were trained in 2004. That training included the ability to recognize all 11 non-native species known to exist in Maine waters.

This year will be the third that inspectors have been on duty at Lake Auburn checking boats and educating boat owners. Invasive species are transmitted from one lake to another by plant fragments on the bottoms of boats.

Statewide in 2004, inspectors found that 2.4 percent of boats they inspected had fragments of invasive plant species on their hulls. That figure was down from 2.6 percent in 2003.