The Observer, September 2003

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Guest Opinion: Alaska not totally free of invasive species, those pests who come to dine

By U.S. Senator Lisa Murkowski

Most Alaskans consider themselves fortunate to live here. We are blessed to be a part of the largest, wildest, most beautiful and most exciting state in the Union.

And among our many blessings has been freedom from the worst kinds of exotic invasive species, such as the zebra mussels that plague other regions of the country. We can thank distance, climate and foresight.

Unfortunately, we cannot be completely free of invaders that can threaten our own indigenous plants and creatures, nor are we free of the responsibility to prevent dangerous organisms from gaining a foothold. Among the most dangerous are aquatic invasive species, because their colonies may go unnoticed until they are well-established and harder to eradicate.

Alaska has strong laws to prevent exotic species from becoming permanent residents. It’s too bad such laws only work to deter people from deliberately introducing exotic species.

Even then, some species may find humans willing to help them out. The Northern pike now infesting Southcentral Alaska drainages come to mind, along with the yellow perch that someone dropped into a lake on the Kenai. Luckily, the latter was discovered and eradicated -– we think. Both species are capable of decimating native fish, including salmon.

Plants can be threats, too. Aquatic species such as Japanese knotweed, Reed Canarygrass and Foxtail barley are colonizing in some parts of Alaska. Where they thrive, they can overwhelm Alaskan species. They don’t care that they were supposed to be ornamental additions to someone’s garden; in the wild, they are on their own.

But the worst threat may be from species that can’t read the laws and are adept at hitchhiking to new places.

A number of aquatic invasive species and at least one non-aquatic species of significant concern have found their way to Alaska already. Others are near our border, and still more appear to be headed our way.

Atlantic salmon –- escapees from salmon farms in British Columbia or Washington state -- are another threat. They have been found in streams from Southeast Alaska to Prince William Sound, and in ocean waters as far north as the Bering Sea. Natural reproduction of escaped Atlantic salmon has been observed in British Columbia streams, and it is possible this species could find a foothold in Alaska that would be disastrous for Pacific salmon using the same streams.

Several other species have not yet been observed in Alaska, but are considered imminent threats, and Prince William Sound may be where they show up first.

The European green crab is an example; it became established in California and has moved as far north as Vancouver Island. It is highly aggressive, and preys on juveniles of other crab species, as well as on clams, mussels, urchins, other fish and plants. In Alaska, all the major crab species – king, Dungeness and Tanner – could be at risk if it becomes established here.

Another is the Chinese mitten crab, which is now at home in the San Francisco area and may be moving northward. One specimen has been found near the mouth of the Columbia River. Because this creature comes into fresh water to spawn, potentially moving hundreds of miles up rivers, it is a serious threat.

Larvae of both crab species could travel in ballast water entering Alaska from Outside. Valdez harbor is especially vulnerable, as it receives the third-largest volume of ballast water of any U.S. port, due to the regular arrival of tankers filling up on Alaska North Slope crude. Many of these arrive from ports already infested with invasive species. This is a significant and continuing threat, although to date only a small number of problems have been detected.

I strongly support efforts to develop technologies and practices to meet this challenge. Among the promising ideas is a new method of introducing ozone into ballast water when it is pumped aboard and when it is discharged; so far, it has shown excellent results in removing small biological hitchhikers. This research has been funded by BP. The oil industry’s willingness to step forward on this issue should be recognized and applauded.

Another technology under development involves reducing air pressure in the ballast water tank and introducing inert gas via bubbler pipes near the bottom. This creates an oxygen-poor environment that may kill a variety of unwanted species, including some too large and hardy for ozone treatment.

These technologies, and others under development, have a long way to go. But the fact that they are being developed is positive. The problem of aquatic invasive species is not being ignored, and the government’s obligation to address it will not be overlooked.