Great Lakes invaders wreak $200 million damage-study

By Michael Conlon, Reuters

CHICAGO, July 16 (Reuters) - Invasive species that have hitched rides into the Great Lakes since they were connected to the sea nearly 50 years ago are causing $200 million a year in damages, according to a study published on Wednesday.

The figure is conservative and does not include damage done to the Canadian economy or other parts of the United States where some of the invaders have traveled by water, said the report from the Center for Aquatic Conservation at the University of Notre Dame in Indiana.

Since the St. Lawrence Seaway opened in 1959, 57 species have been carried in via oceangoing vessels, usually in ballast water, the report said.

But if the parade of organisms, which includes the zebra mussel and round goby, stopped tomorrow, the costs "would unfortunately continue" because the damage estimates are based on what has already happened, said David Lodge, an ecologist who directs the Notre Dame center.

The report said that as of 2006 the losses to sport and commercial fishing and tourism and impacts on water treatment and supplies was at least $200 million per year. Lodge said the study did not go beyond 2006 but it could be assumed the costs were continuing.

"Considering that new invasive species are being discovered every year, and species already present are spreading, it is likely that the losses experienced in 2006 will increase in following years," the study said.

Zebra mussels, which can clog water intake pipes and rob the water of small plankton on which other species live, have spread across North America as far west as Nevada and California, the report said.

Species such as the Eurasian ruffe compete for survival with native yellow perch and walleye while the round goby preys on smallmouth bass nests.

Of the estimated losses the biggest -- $123.6 million - were in the recreational fishing sector, in which total annual spending amounts to $1.5 billion. People enjoying Great Lakes wildlife spend $9.3 billion annually, with the loss in that sector put at $47.7 million. Water use facilities, including 13 nuclear power plants, suffered $27 million in losses, the study found.

Great Lakes United, a conservation group, said the invasive species problem is a "growing national crisis."

"Before the U.S. Congress adjourns for the elections, the Senate must agree to legislation already passed by the House of Representatives that puts in place protections against invasive species," said the group's Jennifer Nalbone.

She said the legislation would require ocean vessels coming to any U.S. port to install treatment technology by as early as next year to clean their ballast water. (Reporting by Michael Conlon; Editing by Andrew Stern)