February 05, 2001

The Townsend Cromwell is nearing the first island that we will visit on this cruise. We expect to be at Baker Island late Tuesday afternoon, where we hope to safely land two US Fish and Wildlife Service (USFWS) scientists. These scientists will spend four days on the island counting birds, mapping vegetation, and searching for contaminants left behind from WWII. We will then head to Howland Island, where we will begin the intensive diver surveys of the coral reef ecosystem there. Let's have a look at the events that led up to the addition of this cruise to the Townsend Cromwell's already rigorous schedule.

The first rapid ecological assessment of these islands was done by the Townsend Cromwell and researchers from the National Marine Fisheries Service's (NMFS) Honolulu Laboratory in partnership with USFWS personnel last year. That cruise was planned as a result of increasing national and international interests and concerns among scientists about deteriorating coral reef ecosystems around the globe. In 1998, President Clinton issued an Executive Order establishing the U.S. Coral Reef Task Force and directing federal agencies to improve their stewardship and conservation of the nation's coral reefs. In early 2000, the Task Force released the country's first National Action Plan to Conserve Coral Reefs. The NMFS is responsible for managing living marine resources and protected species in US waters. The USFWS is tasked with managing the National Wildlife Refuges. The NMFS and USFWS collaborated to share resources and expertise to launch a study to assess the health and condition of the nation's
most remote and least known coral reef ecosystems at Howland and Baker Islands of the Phoenix Islands group and Jarvis Island and Palmyra and Kingman Atolls of the Line Islands group in the central equatorial Pacific Ocean. At the time of last year's cruise, Howland, Baker, and Jarvis were National Wildlife Refuges and Kingman and Palmyra were being considered for protection as Refuges.

Last year's cruise (TC-00-01) was created to rapidly assess the health of the island and fringing reef and atoll environments. We brought NMFS and USFWS scientists and divers to count fish, assess and map the corals and look for marine debris. USFWS biologists came to land on the islands to count birds, map vegetation, and more accurately map the islands themselves. We also conducted a number of CTD casts around the islands from a small boat to determine the salinity and temperature of the water from the surface down to 30 meters. The ship collected ADCP data which uses sound waves to measure current speeds and directions in the waters under the ship.

Three different types of dives were employed to study the reef and fish.  Habitat Survey Tows allowed a lot of area to be covered in a short period of time. In this operation, two divers are towed behind a small boat at slow speeds. The divers hold on to tow-boards that have digital video cameras attached to film the coral reefs and fishes. The divers also made notes on the state of the coral reef and the number and kinds of fishes they saw. Larger ecologically important fish were also assessed by stationary point count or "Bohnsack" dives. At particular spots, divers would go down to about 40 feet and stop and film and count fish for 5 minutes. They would then move on to another spot and do it again. On Rapid Ecological Assessment dives, divers would go down to the bottom and then swim a transect along the reef taking notes on fishes, corals, algae and invertebrates as they went. At each island, a set of permanent markers was put down to mark an area so that when we visit again, we will see how things have changed in that particular area.

As a result of last year's cruise, there is a wealth of knowledge about these five coral reef ecosystems where little was known before. The Baker Island picture shows a good example of what was accomplished at each of the islands.  In general, hundreds of fish and coral species were identified at each island, with many new records and possibly a few new species. The health of the coral was mapped at each island, including areas with dead standing corals that are assumed to have been killed during El Nino warm episodes. The oceanographic conditions around each island were described to better understand the ecology of these ecosystems (see the Baker Oceanography figure). We also determined that there was very little marine debris at these islands. As with science in general, the more you know, the more questions are raised. This year we will be doing all of the things we did last year and much more.

The diving will be the same for the most part. They have added depth and temperature recorders to the tow-boards to collect data as they follow the terrain. This will help map the depth of water along each transect. This depth information will make analyses of satellite images more useful for remote reef assessment. Pairs of lasers were added to the digital video camera mounts so that parallel lines 20 centimeters apart will be seen in the video images. This will help the scientists determine the sizes of objects observed on tapes.

Honolulu Laboratory scientists are collaborating with scientists from NOAA's Pacific Marine Environmental Laboratory and Eastern Caroline University to develop a system to use passive acoustics to remotely monitor the health of coral reefs. During this cruise, we will anchor four sonobuoys around each of the reefs to record the underwater sounds of different reef habitats. Once a library of reef sounds is acquired, the scientists hope to design a system of remote hydrophones which will observe changes in reef conditions and transmit warnings to scientists in Honolulu for distribution on the world wide web.

There have also been additions to the land based science. The USFWS scientists will be taking a ground penetrating radar unit with them to search certain areas of the islands for buried contaminants, such as buried fuel, oil, and chemical drums. One of the ship's officers will be setting up permanent antenna stands for a GPS station that will help pinpoint the location of the islands. Some of these islands are more than a mile away from where the charts say they are. The very accurate position information will also be used to help apply satellite data and the data we collect on this trip.

We have added some oceanography to the cruise as well. In addition to the CTDs done from the small boat, the ship will conduct ADCP transects and CTDs around the island at night. We have added a fluorometer which measures chlorophyll concentration in the water to the small boat CTD and to the shipboard CTD. The fluometery will indicate regions of high and low productivity. The scientists speculate that we will observe increased chlorophyl in the areas of upwelling along the west sides of Howland, Baker and Jarvis, where the Equatorial Undercurrent upwells colder, richer waters from below. The oceanographic data will help the scientists better understand how these complex ecosystems are maintained by the surrounding ocean environment.

We really will have a lot to do during the two days we will spend at each island. We are eager to get going after all the preparations and the long cruise down here. Check with us next Monday to see some new pictures of Howland and Baker Islands above and below the water.

Other Updates from this cruise:

Feb 01  Feb 05 Feb 14 Feb 19 Feb 26

Last Modified 2/6/01

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