A team of marine scientists has launched a 23-day expedition into the Northwestern Hawaiian Islands to catalog the forms of life that don't get much respect.

Other researchers have done surveys of the turtles, seals, corals, fish and the dominant seaweeds, but this cruise, which left Sunday aboard the NOAA vessel Oscar Elton Sette, will be looking at worms, slugs, miniature crabs and microbes, as well as algae.

It's part of the international Census of Marine Life, but the research is also critical to the understanding and oversight of the reefs to the northwest of the main Hawaiian Islands, said Don Polhemus, administrator of the state Division of Aquatic Resources.

"We cannot properly manage what we don't know we have," he said in a press release.

The species being tallied are ones nearer the bottom of the food chain than the ones people normally think of on coral reefs, like sharks, big ulua and cruising sea turtles, and they can be important in understanding what's going on in a reef.

Changes in their numbers and in how they are distributed can be an early warning of larger-scale environmental change on the reef, said Russell "Rusty" Brainard, NOAA's chief scientist on the mission, which is sponsored by NOAA, the U.S. Fish and Wildlife Service and the state of Hawai'i.

"We plan to provide for the state of Hawai'i a baseline record of the diversity of a relatively pristine area in order to have some basic working knowledge of what lives in the Northwestern Hawaiian Islands chain. There will never be any way to measure impact on the environment without first knowing what is there," said Joel Martin, chief of the Division of Invertebrate Sudis and Curator of Crustacea at the Los Angeles Natural History Museum, in a press release.

Participating scientists hail from Bishop Museum, Florida Museum of Natural History, the Los Angeles County Natural History Museum, University of Hawai'i Institute of Marine Biology, Census of Marine Life International Census of Marine Microbes, National Park Service, NOAA, Fish and Wildlife Service, and universities in Brazil, Puerto Rico and Hawai'i.

The cruise progress can be tracked at www.hawaiianatolls.org and http://sanctuaries.noaa.gov. The results will be posted at www.creefs.org.

Reach Jan TenBruggencate at jant@honoluluadvertiser.com.