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May 2006 Mission Overview and
Objectives

2006 NWHI Expedition: exploring ecosystem connectivity and coral health investigations
By Malia Rivera

On May 18th, 2006 scientists from the Hawai‘i Institute of Marine Biology (HIMB) and the Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve (NWHICRER), with support from US Geological Survey and the State of Hawai‘i Division of Aquatic Resources, embarked on a 25-day scientific expedition to study ecosystems connectivity and coral health in the Northwestern Hawaiian Islands. As part of a one year old partnership between HIMB and NWHICRER, this is the third research cruise aboard the NOAA Ship Hi‘ialakai, the partnership was established to provide science based information to help support ecosystem management in the Northwestern Hawaiian Islands. This year, 18 HIMB research faculty, post-docs, graduate students and research staff are onboard focusing on three main topic areas.

The team: 20 scientists from HIMB, NWHICRER, USGS and DAR assembled in the ships dry lab, discussing the upcoming research expedition.

Migration studies of apex predators including several species of sharks, jacks and the grey snapper Uku will continue during this cruise. Dr. Carl Meyer is leading a team whose objectives are to capture and surgically implant radio tags into these migratory species and deploy complementary “listening” devices that can detect where these large predators are moving once they are surgically tagged. Last year, Carl set out several of these acoustic receivers across the archipelago and on this current voyage, he will collect nearly a years worth of migration data that is stockpiled in those receivers.

A similar question to the predator migration, but using a very different type of technology, are several genetic research programs looking at historical connections between populations of reef fish, coral reefs and invertebrates using DNA technology. Led onboard by Dr. Brian Bowen, Dr. Iliana Baums and Dr. Steve Karl, researchers are collecting specimens to bring back to HIMB to continue work in the laboratory. Each individual coral, invertebrate and fish sample will be isolated for DNA and “fingerprinted” using technologies such as microsatellite DNA markers and DNA sequence information. By comparing individuals’ DNA profiles, indications of population connectivity both across the archipelago and within a coral reef can be inferred.

The third aspect of the 2006 Expedition examines coral reef health. Led onboard by Dr. Greta Aeby, monitoring of reef diseases and possible causes will be investigated both in the field and back in the laboratory. Dr. Michael Stat will look at these same samples of healthy and diseased corals in the laboratory to investigate whether certain types of the zooxanthellae, a algal single celled symbiont living in the tissues of corals may be correlated with bleaching or disease resistance or susceptibility. Finally, Jennifer Salerno is studying the types of bacterial communities that are associated with both normal and compromised coral tissues. Both Michael and Jennifer’s work involves the use of DNA technology as well, in order to identify the genetic characteristics of the algal symbionts and bacterial communities.

This year, Hi‘ialakai will travel to Nihoa, French Frigate Shoals and Gardner Pinnacles, which is about midway up the Hawaiian Archipelago. New in the 2006 NWHI Expedition will be a trip down to Johnston Atoll, several hundred miles southwest of the island chain. The importance of this site results from several sources of scientific and anecdotal evidence that Johnston Atoll may be the “source” population, or the stepping-stone for colonization of new species to the Hawaiian Islands. Samples collected from Johnston and studied with DNA, disease and migration studies as compared to the NWHI will provide insight into this important hypothesis. Maintaining the biological and migratory connections across the Pacific and within the Hawaiian archipelago, including that of the populated main Hawaiian Islands, will be fundamental to the development of an ecosystem-based management plan.

Click here to see a map of the area covered by the voyage

Click here for other maps of the region