Like something out of a science fiction movie, thick green mats of microscopic cells are working their way toward Del Norte County.

The monster is toxic algae blooms, which spiked a few days ago in two reservoirs behind dams on the Klamath River. The Environmental Protection Agency, state agencies and local Indian tribes have issued warnings for people, pets and livestock to stay away from the blooms. After all, in people, the blooms can cause rashes, vomiting and flu-like symptoms. Yurok and Karuk data about the toxic algae suggests it may reach our county next month.

While algae in water is normal, widespread blooms of the slimy blue-green variety that produces toxins is a rather new phenomenon. No one knows exactly what causes the blooms, but they do occur in one kind of environment: waterways with low flow rates. Hence their peak during summer on the what amounts to man-made lakes along the Klamath.

Though little is known about the algae blooms, they are atypical for the Klamath River. They were first noted in 2001. Based on deadly blooms that have occurred elsewhere in the country, one shouldn't expect that they'll have a positive effect on the river's fragile ecosystems. Fortunately, salmon do not appear to carry any of the toxins, so no fish consumption advisories have been issued. Still, change the ecosystem and salmon numbers themselves will be affected. Low salmon populations already have hurt the coast's commercial fishing industry, limited the area's sportfishing-tourism businesses and threatened the Yurok's long-standing traditions and way of life.

While removing the dams may seem to be the best immediate solution, until water and energy issues for upriver farmers and communities are worked out, that isn't likely to happen. In any case, low flow rate probably isn't the sole cause of the toxic blooms; while it creates the right conditions for those blooms, too little is known about what role other factors, such as chemical runoff into the water, may play.

Ultimately, the dams must be removed to return the Klamath to a pristine condition. The toxic algae blooms demonstrate how imperative working out the river controversies are so the dams can be dismantled sooner rather than later.