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Ocean Watch Susan Scott |
Invasive algae
getting boot
at sessionI find seaweed a hard subject to write about. For one thing, it just sits there. Nothing personal, you seaweed researchers and connoisseurs, but plants swaying in the current just doesn't spark my imagination.
Another problem I have with seaweeds is what to call them. Most species have no Hawaiian or English names, and those in the field don't even call seaweed seaweed. They call it algae. It's tough to get people's attention with a story about an algae called Avrainvillea amadelpha.
But thanks to the Hawaii Coral Reef Initiative Research Program, a partnership between DLNR resource managers and UH researchers, seaweeds are getting more writer-friendly. Members of this team, for instance, have given the above plant the common name leather mudweed. The name is easy to remember and paints a vivid picture.
The fact that the picture leans toward the dark side is no accident. Leather mudweed, an introduced species, got a negative name because it is elbowing out Hawaii's only native sea grass.
Other pesky marine plants with common names are hookweed, prickly seaweed, smothering seaweed and gorilla ogo, so called because like a 900-pound gorilla, it goes wherever it wants to go.
You may think you don't know these troublesome seaweeds, and I didn't, either. But when I waded into Moanalua Bay with several interested citizens, a DLNR biologist and two seaweed researchers (called phycologists) last week, I discovered I knew them well. These alien plants are so common, I assumed they were native.
Seaweeds don't usually travel well on their own, but we humans give them a lift, often by ship. A tiny plant growing on a ship's hull or a piece floating in its ballast waters can take hold and start trouble.
Divers and snorkelers also spread alien seaweeds around the islands by getting pieces stuck in their gear and then moving to another site while the plant is still wet.
Drying kills all seaweeds.
Aquaculture projects gone awry are another source of foreign seaweeds, as are saltwater aquarium keepers who tire of their hobby and dump tank contents into the ocean.
Like many of Hawaii's land plants and animals, native seaweeds can't compete with hardy, rapidly growing aliens. Nor can our corals survive with smothering seaweeds soaking up all the sunlight.
The good news is we citizens can help this serious problem by pulling weeds. And we can start tomorrow.
Several private and public agencies have organized a seaweed-pulling session tomorrow morning, 7 to noon, at the Hilton Hawaiian Village.
This group has sponsored previous pulls resulting in the removal of 35 tons of gorilla ogo from the reserve near the Waikiki Aquarium. This time, they plan to entirely eradicate the species from the area off the hotel.
Park in the Hilton garage ($3 with special validation) or free in the Ala Wai Boat Harbor. Bring snorkeling gear if you prefer deep-water work, reef walkers for shallow spots, or help manage bags on the beach.
This is a good opportunity to learn, and teach children, which seaweeds are native and which are not. It's also a hands-on way to help rid Hawaii's reefs and shorelines of the introduced alga Gracilaria salicornia. You know, that foreign seaweed they call gorilla ogo.
See the Columnists section for some past articles.
Marine science writer Susan Scott can be reached at http://www.susanscott.net.