Sept. 25, 2007 — Alien algae are infesting and killing some of Hawaii's coral reefs at an unprecedented rate. But a new underwater vacuum cleaner is helping curb the growth.
Dubbed the Super Sucker, the machine can hoover up to 800 pounds of the thicket-like algae in an hour, which should give reefs a fighting chance of recovery.
"Now that we have cleared the algae, we are starting to see new coral recruits come in. It's going to be a process of recovery that takes years," said Eric Conklin, marine science advisor at the Nature Conservancy in Honolulu.
Recuperation wouldn't even be necessary had humans not introduced the
aliens to Oahu's Kaneohe Bay in the first place. Back in the 1970s, researchers decided to grow two kinds of non-native algae — Gracilaria salicornia, also known as gorilla ogo, and Eucheuma denticulatum — as part of an experiment in aquaculture.
These underwater plants, which are harvested commercially in other parts of the world, contain compounds that can be extracted and used as thickening agents in everything from toothpaste and shaving cream to whipping cream and nonfat ice cream.
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But in Hawaii, the alien algae have few natural predators. When the aquaculture scheme was eventually abandoned, the algae grew to uncontrollable proportions.
"Not only does it kill the coral, but it denudes all of the three-dimension space," said Jennifer Smith, a post-doctoral researcher at the University of California, Santa Barbara, and an expert in coral reef ecology.
"It reduces species diversity and leaves a really homogenous, barren,
single-species-dominated environment in its wake," said Smith.
Efforts to remove the algae began in 2002 with a program to recruit community-based volunteers. The volunteers snorkeled or dove along reefs close to shore, removing the mats of algae by hand. But it was clear that a more aggressive plan was needed.
