Toxic Pfiesteria inhabit foreign waters

The notorious Pfiesteria microbes, implicated in gory fish kills and human illness along the mid-Atlantic U.S. coast, have turned up in Norway.

Pfiesteria from Norway: Characteristic pattern of plates (identified by numbers) on piscicida (left), and the toxic stage of shumwayae (right). Proc. of the Royal Soc. of London B

No one reported a fish kill at the estuary of the Sandvikselva River, but it does contain the two known Pfiesteria species, according to Kjetill S. Jakobsen of the University of Oslo and his colleagues. In lab tests, both species killed fish, the team says in the Jan. 22 Proceedings of the Royal Society of London B. This appears to be the first scientific paper identifying toxic Pfiesteria outside the United States, say its authors.

Research teams have found Pfiesteria in far-flung places, such as Tasmania, but have not yet formally published their results, says study coauthor JoAnn M. Burkholder of North Carolina State University in Raleigh.

The Norwegian find “confirms what many people in the field of harmful algal blooms would expect,” says Don Anderson of the Woods Hole (Mass.) Oceanographic Institution. Typically, a disaster reveals a new menace, and then testing finds it to be widespread.

Biologists discovered the one-celled alga in 1991 while investigating fish kills in North Carolina estuaries. The Norwegian water and sediment samples came from a river mouth colder than Pfiesteria‘s U.S. habitats.

The team found the Norwegian organisms by using DNA tests and microscopy. Norwegian Pfiesteria piscicida differs slightly from U.S. samples, says study coauthor David W. Oldach of the University of Maryland in Baltimore. “It’s different enough to say it’s a different strain,” he reports.

Identical strains in the two countries would support fears that ships’ ballast water has distributed these algae around the globe. However, more genetic analysis will be required to learn just when and how Pfiesteria spread, says coauthor Dag Klaveness of the University of Oslo. “We need to keep our estuarine waters clean–that’s the important thing,” he says.

Susan Milius is the life sciences writer, covering organismal biology and evolution, and has a special passion for plants, fungi and invertebrates. She studied biology and English literature.

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