Nearly five years after the invasive seaweed Caulerpa taxifolia was found in a lagoon in San Diego County, officials are still debating which species of the marine algae to list as a noxious weed.

California in 2001 banned the sale, possession and transport only of C. taxifolia and some look-alike species, while San Diego enacted its own ordinance to ban the entire genus of Caulerpa. The importation of the Mediterranean strain into the United States as well as interstate trade are federal offenses under the Federal Noxious Weed Act of 1999 and the Plant Protection Act of 2000.

The renewed focus on the controversial algae comes after the U.S. Department of Agriculture published a notice in the Oct. 26, 2004, Federal Register seeking comments about the marine algae’s inclusion on the Federal Noxious Weeds list.

Proponents of a broad ban believe the entire genus should be included because of similarities in DNA and appearance among species, and because it is easier to ban an entire genus.

Listing the entire genus would prohibit the importation and interstate movement of the algae without a USDA permit, according to the Pet Industry Joint Advisory Council (Washington). Depending on how the USDA rules, various mediums for transporting Caulerpa species, such as ornamental fish shipments and live rock, could be severely restricted or shut down, the trade organization said.

At press time, PIJAC was preparing comments for the Dec. 27, 2004, deadline. [January 2005 PET AGE]