Volunteers and local federal agencies eradicate non-native algae

0 Comments | Oakland Tribune, Jul 7, 2008 | by Paul David Lampe

It's brittle, slimy, green and invading Alameda's Bay Farm Island shoreline. It's not "Swamp Thing," but it's not supposed to be in Bay's water. It's the non-native alga known as Ascophyllum nodosum.

"It's just nasty," said Betsy Wells, a UC Davis graduate student studying Predation Dynamics of Invasive Invertebrates in the San Francisco Bay.

Monday morning, Wells along with 10 volunteers -- federal, state and university employees -- helped gather the alien alga on the Bay Farm Island next to the Bay Farm Island Bridge.

"Nobody had ever documented it as a large patch," said Natalie Cosentino-Manning, marine habitat resource specialist with National Oceanic and Atmospheric Administration.

Cosentino-Manning led the effort Monday morning to help eradicate the alga. NOAA, along with staff from Save the Bay, Fish and Wildlife Service, and Bay Area universities, removed 228 pounds of the alga over 400 meters.

In 2002, Cosentino-Manning and other NOAA and Smithsonian officials helped lead the eradication of the same non-native alga in the backwater slough on the western shore of San Francisco Bay at the Port of Redwood City. Smithsonian researchers stumbled upon it while investigating another non-native species -- a small snail Littorina saxatilis. The Smithsonian Environmental Research Center found the new patch of the alga while out researching the same non- native snail back in May. During the eradication in 2002, NOAA helped remove 50 pounds of algae over 40 meters.

Paul Silva, a research botanist emeritus at UC Berkeley, said the alga has not been noted as a harmful or invasive species, but an introduced species. The difference is that a harmful or invasive species would grow quickly and take up resources necessary for other species and an introduced species would simply be a non-native species.

"I think there is just a general feeling that we need to preserve what we have," Silva said.

But Christopher Kitting, a professor of biological sciences at California State University, East Bay, said he would be careful of saying the algae is not harmful.

"It's not a known invasive algae, but the fact that it has spread this quickly in the last year makes me cautious," Kitting said.

Steve Lonhart of the Monterey Bay National Marine Sanctuary said that the non-native species has the potential to displace native species and could potentially alter community structure and function. Structure is how an ecological community is built. It's not known if the non-native species has the same functional role as the native species.

"Where do native species that rely on the habitat go?" Lonhart said.

The alga usually floats in the water, using photosynthesis for growth and survival, but it could attach to rocks taking up wetlands for other algae that would be food for native herbivores. Herbivores in the area potentially may not eat this alga as they probably would not recognize it as edible or may not be able to digest it, Cosentino-Manning said.

"This particular seaweed is interesting because it is free living, it doesn't attach to rock, however, if its salinity changes the algae could attach to rock displacing our native seaweed," Cosentino-Manning said. "We moved forward with a really quick eradication."

In addition to potentially taking over wetlands that natural grasses and other native algae use, there is a worry that the alga, often found in bait packaging from the East Coast, could be harboring other small, non-native crustaceans.

"It allows the worms to live while they are coming form the East Coast to the West Coast," Cosentino-Manning said.

Although algae in the bait packages helps the worms live, Cosentino-Manning said it carries everything from the East Coast such as small snails and crustaceans, including amphipods and isopods, and copopods.

"They could be even harboring things we can't see like small cyst," Cosentino-Manning said.

"We are doing two other things in addition to the eradication," said Andrew Chang, a UC Davis graduate student studying marine ecology and an intern at NOAA. "We are drawing up a map to figure our which areas in the Bay are the highest risk for invasions from this algae and we are putting up signs for fishers to throw bait packaging in the garbage instead of the water in these high risk areas."

NOAA will be leading another cleanup at 7 a.m. Aug. 4 at the Bay Farm Island Bridge to see if there are any Ascophyllum nodosum surrounding the shore line. Individuals interested in helping can contact Natalie Cosentino-Manning at natalie.c-manning@noaa.gov or call her at 707-575-6081.

Reach Paul David Lampe at plampe@bayareanewsgroup.com or 510-208- 6406.