Foreign invaders cost U.S. billions; Congress urged to draw the line
Bio-invaders are costing billions of dollars in damage to local marine ecosystems, and in some cases, eliminating native marine and plant species if they take hold. The unwanted invaders are, for the most part, tiny hitchhikers that are dumped along with the ballast waters of ships that traverse the world’s oceans.
Cornell University scientists reported two years ago that more than 30,000 non-native species cost the United States roughly $123 billion a year in economic loss. This includes $35.5 billion for alien weeds, $23.5 billion for crop diseases, $20 billion for insects, $19 billion for rats, $6.5 billion for human disease-causing microbes, and $3 billion for zebra mussels alone.
In recent years, exotic species have come under increasing attack from the U.S. government. Before leaving office, President Clinton directed federal efforts to prevent and control invasive species. Nearly $30 million was appropriated, and an Invasive Species Council was formed to develop ways to manage the problem. Recently, the Pew Oceans Commission released a report urging the government to quickly develop mandatory programs to attack the problem, and to spend much more money to achieve that goal.
"Introduced species are a growing and imminent threat to living marine resources in the United States. Hundreds of species arrive in U.S. waters from overseas each day, playing a game of ecological roulette with ecosystem and economic stability," the report said.
It added: "At least 7,000 different species of marine life are likely transported each day around the world. Ballast water carrying this wide array of non-native life arrives in the U.S. at the rate of 2 million gallons per hour."
Studies around the world reveal a remarkable array of invaders, representing all of the major and most of the smaller groups of life. Many species are in their larval stages, and include anemones, worms, barnacles, snails, clams, seaweeds, jellyfish and many others. Certain viruses and the bacteria that cause cholera have been detected in ballast water.
Alaska’s waters are not exempt from the foreign invaders.
"Up to a dozen species from Asia have been identified in the waters of Valdez and Prince William Sound from all the oil tankers over the years," said Bob Pierkowski, former head of Alaska Department of Fish and Game’s mariculture division. He added that state biologists are on the lookout for green crab, which since 1990 have migrated from California to Washington.
The tiny crab have wiped out all other crab they’ve encountered, including much larger species like Dungeness.
"We expect to see them in Southeast Alaska. It’s not a matter of if, it’s a matter of when," Pierkowski said. Interestingly, the Pew report considers the thousands of Atlantic salmon escaping from fish farms in the Pacific Northwest among the bio- invaders.
There are some regulations already on the books to prevent introduction of exotic species into U.S. waters, but they are largely voluntary and mostly ignored. The Invasive Species Act of 1996 provided ships entering American ports with a three year window to undertake a voluntary program whereby coastal derived ballast water would be exchanged on the high seas, followed by re-ballasting with midocean water.
The program went into effect in July 1999; however, during the first year only 12,170 of the 58,000 vessels arriving in U.S. ports had filed a mandatory reporting form. While several states have passed or are considering ballast water control legislation, there are no legal or regulatory frameworks yet in place to eradicate or reduce marine introductions, or to prevent the spread of bio-invaders.
Chemical control is one option that is readily available and in use, although it’s come under considerable scrutiny. For example, an Asian fouling mussel was discovered two years ago in large densities, nearly 30,000 mussels per square yard, in three marinas in northern Australia.
Researchers treated the marinas with liquid chlorine and copper sulfate, which appears to have successfully killed the mussels, along with a considerable amount of other marine life. Researchers have not yet attempted to use biocontrol, the release of one species to control another in the ocean.
The Pew Oceans Commission, which is heralded as "an independent group of American leaders conducting a dialogue on the policies needed to restore and protect living marine resources in U.S. waters," will make formal recommendations to Congress next year. The group will recommend that the National Invasive Species Act include strengthened federal measures for research, prevention and response.
They suggest that an improved program for compulsory ballast management should provide expanded funding for the Coast Guard for enforcement and advanced research.
Kodiak-based free-lance writer Laine Welch can be reached via e-mail at ([email protected]).