Great Lakes Article:

DULUTH, Minn. - Duluth might be the westernmost point of the Great Lakes, more than 2,300 miles from the Atlantic Ocean, but it's an epicenter of the invasive species plaguing the lakes.

The port of Duluth and Superior, Wis., is home to more than 25 foreign species. At least 12 invasive species have become established in Duluth-Superior harbor since 1980, most of them carried in the ballast water of ships, an expert said.

"There's just no question about it, we're at a high level of risk," Doug Jensen, invasive species coordinator at the University of Minnesota Sea Grant in Duluth, told the Star Tribune of Minneapolis for a series of articles on the effects of foreign species on the Great Lakes.

About 30 percent of all oceangoing ships that move through the Great Lakes each year end up at Duluth, where they take on grain, iron ore, coal and other products. As the vessels load up, they must discharge water from their ballast tanks. Millions of gallons of ballast water are dumped into the harbor, some contaminated with eggs, spores, cysts and live organisms that come from foreign ports.

Duluth-Superior handles far more cargo than any other U.S. Great Lakes port, according to the Duluth Seaway Port Authority. The harbor's annual commercial traffic typically includes about 170 ships from other continents, which can bring foreign invaders, and more than 900 "lakers," ships that travel within the Great Lakes and can spread newly arrived species from port to port.

A recent Canadian study listed Duluth as one of four "invasion hot spots" in the Great Lakes in part because of the heavy foreign traffic and shallow areas of the harbor that seem to make it an incubator. The other three hot spots are narrow, heavily traveled waterways connecting lakes.

Better pollution control, wastewater treatment and fishery management have improved water quality in the harbor and the mouth of the St. Louis River during the past 25 years, allowing foreign species to survive and flourish.

The dominant fish in the harbor is the Eurasian ruffe (rhymes with "tough"), a small, spiny invader from northwestern Europe that made its North American debut in Duluth in 1986, according to the U.S. Geological Survey. It estimates that the ruffe population exploded to 8.2 million in 1998, then declined slightly.

They may not be spreading widely, however. One theory is that Superior, the coldest of the lakes, offers less food for the invaders. Domestic ships also try to limit ballast-water uptake from the infested Duluth harbor, one of several steps to reduce the spread of invasives, said Jim Weakley, president of the Lake Carriers' Association.

Yet the ruffe is not the only invader. Zebra mussels, discovered in the harbor in 1989, now threaten eight native mussel species in the St. Louis River. The question is whether the natives will survive if the zebra mussels move up the river, which flows into the harbor.

"Invasive species went from being one of several problems 14 years ago to the primary threat to the harbor's biodiversity now," said Lynelle Hanson, executive director of the St. Louis River Citizens Action Committee, a Duluth conservation group.

Vast populations of foreign fish, mussels and other creatures have invaded and damaged the Great Lakes in the last few decades, creating a more difficult problem than the industrial contamination that fouled the lakes in the 1960s.

The invasion began in the early 1800s, but accelerated after the St. Lawrence Seaway opened the lakes to oceangoing ships in 1959. More than 40 percent of the 179 alien species have been documented since then, with most arriving by ship from Europe or Asia, according to research data analyzed by the newspaper.

The invasive species come with enormous costs, both in terms of damage to the ecosystems of the Great Lakes in dollars spent managing the pests.

Zebra mussels alone, for example, have cost industries, water companies and power plants nearly $2 billion, according to Chuck O'Neill, a coastal resources specialist with New York Sea Grant, an extension program of Cornell University and the State University of New York.