Sailing on the National Oceanic and Atmospheric Administration ship Hi'ialakai, scientists from NOAA, the Hawaii Institute of Marine Biology and Bishop Museum dived at that coral reef at depths not explored there beforeand collected the first specimen of a recently discovered species of butterflyfish.

Divers swam among previously unseen reefs as deep as 250 feet during a monthlong research trip and unexpectedly found nursery grounds for juvenile reef fish like parrotfish and butterflyfish. They also were able to collect specimens that may help them identify new species.

"We were seeing reefs that no human has ever laid eyes on before," Randall Kosaki, the research mission's chief scientist and diver, told Associated Press on Tuesday.
"The coral reef habitat goes four times deeper than where we've been working prior to this," Kosaki said.

At the 200-foot depth, the expedition found 12 to 15 species of fish never seen before in the monument, probably because scientists couldn't get down there to observe, he said. Also, some deep-water algae beds are serving as nurseries for young fish, which is entirely new to the researchers, he said.

"The biodiversity of coral reefs are a lot greater than we had anticipated. So as we continue to explore these deeper waters, I would expect that we'll add significantly to the number of fishes known in the Hawaiian archipelago and the Northwestern Hawaiian Islands," Kosaki said. "It just underscores the need to protect some of this biodiversity and to document it for future generations."

Significance of deep nurseries
Brian Bowen, a research professor at the Hawaii Institute of Marine Biology, said scientists would need to study whether nurseries like these replenish fish populations in shallow reefs. Answering this question will help those managing coral reefs, he said.

"If you're dumping trash at 170 feet of water, you might be dumping it on the nursery grounds that keep your fishery going," Bowen said.