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Studies: Invasive species traveling in ballast water

Posted: Tuesday, October 28, 2003

Recent studies in Kachemak Bay have found potentially dangerous species of sea critters foreign to the local ecology, likely brought here in the ballast water of ships arriving from abroad or perhaps even from domestic ports in the Lower 48.

Homer Harbor, in particular, now is home to at least 13 foreign species, according to a field study done in the summer of 2000. Four species were reported but not yet confirmed to be lurking in Kachemak Bay. Four other species known to exist in Kachemak Bay are being called "cryptogenic" because taxonomic experts don't yet know where they came from.

Scientists who have been studying invasive species in Alaska are expressing concerns about how they arrived and whether they could spread. How dangerous they might be to the local ecological balance and what a rapid explosion of their numbers would do to valuable commercial harvest species are among the looming unknowns.

Similar concerns attend ports in warmer U.S. waters, where conditions may prove even more favorable to invading species. Indeed, in some parts of the country damages caused by foreign species are being measured in the hundreds of millions of dollars annually.

In response, Congress is considering stiffer regulations and the U.S. Coast Guard currently is taking public comment on amendments to federal laws passed in the 1990s that were aimed at controlling the transport of invasive species in ballast water.

Today, those laws have only limited geographic range, applying mandatory ballast record keeping, reporting and management requirements only on vessels entering U.S. waters from beyond the 200-mile Exclusive Economic Zone and only if they are heading to the Great Lakes or the Hudson River north of the George Washington Bridge.

For all other ports of call, the federal laws made reporting merely voluntary, and compliance has been poor, according to federal records.

Proposed amendments would require mandatory ballast-water management programs on all ships equipped with ballast water tanks entering any U.S. waters, and make record keeping and reporting mandatory as well, including for ships moving between domestic ports.

Scientists say the potential threat to Alaska is real and growing and stiffer federal law is a must.

"It is essential, not just for Alaska, but for the nation, that the ballast water regulations be tightened," said Phyllis N. Windle, senior scientist with the Union of Concerned Scientists' Global Environmental Program. "Ballast water and the sediments in ballast tanks are the leading means by which aquatic organisms are unintentionally moved around the world. Alaska's ports receive some of the nation's largest amounts of these materials and will benefit directly from better regulation."

The Union of Concerned Scien-tists is preparing a report on invasive species in Alaska as part of its "Invasion Portfolio," a series of reports from key states. Windle said that report would be made public by mid-November.

A recent study of marine invasive species and biodiversity in South-central Alaska done by the Smithsonian Environmental Re-search Center showed the overall number of invasive species in Alaska is low compared with tested sites in the Lower 48.

However, the study noted, "Homer Boat Harbor appeared to have a greater number of nuisance invasive species than other sites in the region. This finding elevated concern about risk of invasive species, because of the history of recently increased shipping activity for wood products at Homer and tankers at Nikiski, as well as the long history of fishing vessels at Homer and Seldovia."

Successful invasion could spread to other areas of Cook Inlet and the general region, the study said.

In August 2000, a team of 20 taxonomic and ecological experts conducted intensive field surveys in Kachemak Bay. The survey found 13 nuisance invasive species, including vascular plants, hydroids, bryozoans and bivalve mollusks.

Four others species were reported to be present in Kachemak Bay but not confirmed by taxonomic experts. They included a salt marsh grass, a boring sponge, a polychaete worm and a clam. Four "cryptogenic species" of unknown but suspicious origin also were found in the bay, including a new species of ascidean, a seastar, and two species of hydroid.

Researcher Anson Hines, with the Smithsonian, said studies of invasive species and biodiversity in Prince William Sound have been ongoing for several years, focusing intently on tanker traffic, but also on other vessels.

"Prince William Sound is at particular risk because it receives the third largest amount of ballast water in the country," Hines said.

That work recently has been expanded to cover other areas in the North Pacific arc from Sitka and Ketchikan to Dutch Harbor, including sites in Kachemak Bay and Cook Inlet. The 2000 study in Kachemak Bay was part of that expanded survey program.

Little was known about Alaska waters, or indeed about northern latitude waters anywhere, prior to the recent studies. Hines said Alaska surveys showed the state has generally fewer invasive species than other ports, but they are diverse in their nature, meaning Alaska is unlikely to possess any particular immunity. The rate of invasion is simply slower, perhaps due to the long, dark winter months when food supplies dwindle, he said.

While surveys in Kachemak Bay and parts of Cook Inlet have demonstrated the presence of invasive species, there may be little risk from oil tankers on this side of the Kenai Peninsula. Tankers coming to Cook Inlet are typically not empty, but filled with product to be unloaded at facilities here, explained Susan Saupe, with the Cook Inlet Regional Citizens Advisory Council, which is in the process of drafting comments on the proposed regulatory changes. If anything, those ships pick up Cook Inlet ballast water and take it elsewhere, she said.

The situation is different in Prince William Sound, which sees hundreds of tankers each year loaded with ballast water. Currently, however, federal law exempts oil tankers engaging in "coastwise trade" between U.S. ports from ballast-water regulations.

There still is a concern, however, over other vessels plying Cook Inlet and Kachemak Bay waters, Saupe said. Those picking up natural gas, urea and, in Homer, logs and wood chips, do unload ballast before filling their holds with local products. The bay and inlet also see their share of barge and cruise ship traffic, vessels fully capable of transporting invasive species in their ballast.

While species known to have invaded Alaska oceanic waters have yet to demonstrate real detrimental harm, either to the ecology or the economy, the potential is there.

An example of that potential can be seen in the presence of northern pike in Kenai Peninsula fresh water lakes, where the fish has wiped out native populations of trout and salmon. Biologists fear the northern pike, apparently transported from the Interior and introduced purposely in the 1960s, could find its way into the Kenai River, threatening the commercially valuable salmon runs there.

How bad can it get? Federal estimates suggest the zebra mussel's tendency to foul water intake mechanisms in the Great Lakes caused an accumulated $1 billion in damage between 1989 and 2000. Other studies show similar, highly costly impacts from other species in other areas.

In Alaska, there is concern over the green crab, an invasive species known to be migrating northward from California. Scientists have set traps along the Alaska coast in the hopes of detecting its presence. The species could compete for food -- and win -- against juvenile Dungeness crab and shorebirds if it takes hold in Alaska, according to Hines.

Also of concern are numbers of Atlantic salmon escaping from British Columbia fish farm pens and heading to the open sea, where they compete directly with Alaska wild salmon species.

So far, perhaps Alaska has been lucky. But it would take only one seriously aggressive species to do real economic damage to Alaska fragile fisheries industry, Hines said.



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