Members of an intertidal monitoring expedition to Papahanaumokuakea Marine National Monument returned Tuesday from the fourth consecutive year of conducting research in the rocky intertidal zones of the Northwestern Hawaiian Islands.

This year, the team focused on learning more about 'opihi spawning activity.

"We have preliminary evidence that female 'opihi live higher on the rocky shore than male 'opihi," says Dr. Chris Bird, a scientist from Texas A&M University, noting an interesting highlight from the research.  "This is a groundbreaking discovery that will contribute toward better understanding of 'opihi reproduction, which will help marine managers when considering restoration of 'opihi habitat in populated areas like Oahu."

The team spent 12 days on the rocky shorelines of Nihoa Island, Mokumanamana Island, and French Frigate Shoals, part of the Hawaiian Islands National Wildlife Refuge within Papahanaumokuakea Marine National Monument, conducting various activities within the little-explored intertidal zone, which is the area that is above water at low tide and under water at high tide.

This mission is part of a five-year partnership among scientists, cultural researchers and community members to study the rocky intertidal zones in the main Hawaiian Islands as well as the Northwestern Hawaiian Islands.

"The importance of this work is to gain new information on this iconic food species to better manage fisheries across the archipelago," says Hoku Johnson, The National Oceanic and Atmospheric Administration's coordinator of the expedition.  "The research in the Monument is connected to similar research begin done in partnership in the main Hawaiian islands, which we hope will lead to better management of 'opihi statewide."

The monitoring team consisted of participants from NOAA, Texas A&M University, the Scripps Institute of Oceanography, The Nature Conservancy, Na Maka o Papahanaumokuakea, Conservation International-Hawaii Fish Trust, Kaho'olawe Island Reserve Commission, Kalapana Fishing Council, Na Mamo o Muole'a and Kipahulu 'Ohana.

For more on the expedition, click here.