I know it doesn’t do much good around my house. Vacuum one day, and the next the floors look like the bottom of a chicken coop.
Photo: only_point_five, Creative Commons, Flickr
However, researchers have discovered it can do wonders for coral reefs overgrown by “alien” algae.
Coral reefs have a symbiotic relationship with specific types of algae, called zooxanthellae. These algae grow inside the individual polyps of coral and provide oxygen. Some corals support only one sub-type of zooxanthellae, while others are more democratic and harbor two or three varieties. As climate warms, and oceans acidify, some corals are learning to accept new varieties of algae, and this ability to integrate what were once “foreigners” ups their likelihood of survival – a tactic humans don’t seem to adopt as readily.
There are algae, and then there are algae. The types that grow over the top of coral, or spread wildly in oceans as a result of eutrophication (too many nutrients), are coral killers. These are the types of algal bloom the Chinese recently cleared out of a harbor to facilitate Olympic sailing contests. In China, the problem was reportedly largely due to sewage releases. Elsewhere, as in the Gulf of Mexico, the problem results from fertilizer runoff from the Mississippi.
In Hawaii, where invasive species of algae from 1970’s experiments by Maxwell Doty have overtaken reefs, researchers are simply vacuuming. And, no, they’re not using Hoovers, but a reverse of the technology that allows divers to disperse sand from the ocean floor to find treasure. These barge-mounted, underwater mechanical devices, developed in 2006, are Super Suckers, and reef rescuers are using them to vacuum up offending algae and deposit it on the deck of a barge, where it is then sorted – marine animals back to the ocean, algae to one side for eventual use as fertilizer.
Of course, as with any dirty floor, the team originally conducting the experiment couldn’t get it all in one pass. Project leader Eric Conklin, a marine science advisor for the Nature Conservancy in Honolulu, Hawaii, says his team did achieve about 90 percent success. Conklin, who apparently considers this result less than impressive, has clearly never run a conventional vacuum on shag carpeting.
Then Conklin and his group waited, expecting the two plots (separated by a control plot) to get “dirty” again. Instead, to their surprise, the vacuumed reefs have remained algae free for two years.
Conklin, who admits he was “flat-out amazed”, suspects his team removed enough of the mess so that algae-grazing fish were able to keep up with the chore. These fish are apparently the equivalent of the iRobot (NasdaqGM: IRBT – $12.33) floor cleaner, but a lot less technologically daunting.
The Super Sucker is still in use at other locations around Hawaii, operated by a small group of Sucker-trained crew under the joint auspices of The Nature Conservancy, the University of Hawai’i (UH), and the State Department of Land and Natural Resources (DLNR).
The recovered algae, besides being used in fertilizer, may be the focus of a pilot project to convert algae to biofuel. The project faces significant hurdles however, uppermost being the fact that algae – which naturally sequester carbon dioxide – may become carbon-negative when processed. The process is also expensive, which led the Department of Energy’s National Renewable Energy Laboratory (NREL) to abandon the idea back in 1996. At that time, oil was $20 a barrel.
A better solution may be to use algae-filled tubes in power plants to soak up the carbon dioxide generated as a result of fossil-fuel burning. This concept, already tested by the Massachusetts Institute of Technology (MIT), showed that 50-85 percent of carbon dioxide was sequestered in the algae, along with 85 percent of nitrogen oxide, another greenhouse gas that negatively impacts lung function.
I, for one, am delighted to discover someone has made the vacuum useful. On land (and especially on my carpet), it’s the equivalent of telling teenagers to drive slower; a lot of effort for short-lived reward.
Disclosure: I don’t own IRBT stock.