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	The SeaBED autonomous underwater vehicle (above) provided high-resolution images of the groundfish habitats (below) off Oregon and Washington, to help assess areas proposed for protection.
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In 1996, Congress passed the Sustainable Fisheries Act, calling for direct action to stop or reverse the continued loss of habitats that fish need to spawn, breed, feed, or grow to maturity. To protect essential fish habitats, you first need to identify them. Therein lies the challenge: how to see through the oceans to find out what’s down there?

To assess the abundance and habitats of groundfish such as rockfish, haike, cod, flatfish, and petrali, the NOAA National Marine Fisheries Service (NMFS) has relied on bottom trawling. That method isn’t precise and has obvious disadvantages, especially in the rocky seafloor habitats preferred by groundfish. Sonar doesn’t work well because it can’t easily distinguish fish that bury themselves among rocks.

So NMFS tested an alternative. In 2005, it brought SeaBED, the underwater autonomous vehicle (AUV) developed at WHOI by Hanu Singh and colleagues, to survey seafloor areas proposed for protection off the coasts of Oregon and California.

SeaBED provided high-quality photomosiacs of groundfish habitats (below), giving scientists the ability not only to identify particular species but also to assess their relationships with invertebrates in the ecosystem, said Elizabeth Clarke, director of the NMFS Fishery Resource Analysis and Monitoring Division. Maintaining a constant altitude above the seafloor, SeaBED works well in near-bottom missions and maintains a consistent field of view, which is important for quantitative estimates of fish abundances, she said. The AUV is also cost-effective, because it can cover a 5-to-10-kilometer (3-to-6-mile) transect on a typical six-hour dive, and once SeaBED is deployed from a research vessel, the ship can go off and do simultaneous work to assess habitats.

“We think autonomous underwater vehicles have a lot of potential,” Clarke said. So SeaBED will be back for another test in May 2006, this time equipped with a forward-looking (rather than a sideview) camera to improve fish identifications.

—Lonny Lippsett

Photomosiacs of groundfish habitats.

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