Coral Reef Studies on Moloka'i: a Progress Report
In mid-October, a team of scientists from several institutions revisited
Moloka'i as part of an ongoing investigation into the condition of coral
reefs along the south coast of the island. The investigation is part of
the USGS/CMG effort, led by Mike Field with the assistance of Susan Cochran,
to map Hawaiian coral reefs and to evaluate the impact of sedimentation
and other processes on their condition.
Cheryl Hapke documents her location while monitoring a GPS station.
The tasks for this part of the
project included a complete differential GPS survey of the entire south
coast of the island, groundtruthing of remotely sensed images, evaluation
of potential underwater transect sites via SCUBA diving and snorkeling,
and initiation of across-reef transects to map sediment accumulation.
Cheryl Hapke and Mimi D'Iorio (University of California, Santa Cruz)
designed the GPS survey, and Tom Reiss and Rob Britts provided the technical
expertise and equipment for the extremely accurate delineation of points
on the island. Using a combination of two stationary base stations and
three roving stations, the team gathered nearly 80 points in three days
along paved roads and jeep trails.
Ground surveys by
Curt Storlazzi, Cheryl Hapke, and Mimi D'iorio begin the preliminary
investigation of mangrove progradation along the shoreline.
These positions will be used as ground
control for an aerial photography survey of the island scheduled for November
and December 1999. They will also provide accurate measurements from
historical photographs of shoreline change and mangrove progradation.
Pat Chavez and Stuart Sides were on hand with processed remotely sensed
images, integrating recently flown (April 1999) SHOALS (Scanning Hydrographic
Operational Airborne Lidar Survey) data with aerial photography and USGS
DLGs (Digital Line Graphs). The remotely sensed images were extremely useful, and it is evident from
our groundtruthing of the images that they will significantly advance
our ability to map coral reefs.
Pat Chavez guides
the underwater team to locations for groundtruthing using geo-referenced
images on his laptop.
Paul Jokiel, coral biologist from the University of Hawai'i Institute of
Marine Biology (HIMB), and two graduate students, Will Smith and Ceil
Roberts, worked with the USGS team for four days to examine potential
sites to install permanent transects for monitoring coral condition. The
HIMB team is collaborating with the USGS on several biological aspects of
the coral reef project, as is Jim Maragos (U.S. Fish and Wildlife Service),
who visited the team for several days.
With the assistance of Jim Lugosi and Curt Storlazzi (UC-Santa Cruz), we
continued our efforts to measure sediment thickness along across-reef
transects in an attempt to get a handle on the amount of muddy sediment
being delivered to the coral reef system by erosion and runoff.
Our next trip is scheduled for January 2000. Plans for that trip include
a public outreach lecture at the Moloka'i community center, mapping of
sediment and coral cover on the reef flat, coring in selected areas of
the outer reef, deployment of oceanographic instruments to measure
currents, and installation of permanent underwater transects to
monitor changes in the reef.
For information about our previous work on Moloka'i, please see the
in the May 1999 issue of Sound Waves.
U.S. Army Corps of Engineers
U.S. Geological Survey (USGS)
in this issue:
Myrtle Beach Mapping
Long Island Sound
Moloka'i Coral Reefs
North Carolina Outer Banks
Southern California Benthic Habitat
Cape Cod Community College
Nat'l Environmental Careers Conference
Coral Reef Task Force
Atlantic Offshore Aggregates
DOE Gas Hydrates
Cooper Co-Chief of Antarctic ODP Cruise
Knauss Fellows Tour Reston
Woods Hole Visitors
December Publications List