#Status of Coral Reefs 2002 - International Coral Reef Action Network

Status of Coral Reefs of the World: 2002
MARINE DEBRIS REMOVAL FROM THE NORTHWESTERN HAWAIIAN ISLANDS
The National Marine Fisheries Service (NMFS) recently completed a large marine
debris clean-up in the Northwestern Hawaiian Islands (NWHI). Marine debris, mostly
derelict fishing gear from northern Pacific fisheries, poses a significant threat to coral
reefs, because the gear and entangled pieces of coral scour the reefs as they are
dragged around by waves and currents. Marine debris also entangles animals that use
coral reefs, including the endangered Hawaiian Monk seal. The clean-up effort was led
by the NMFS Honolulu Laboratory and included NOAA's Ocean Service, the NWHI
Coral Reef Ecological Reserve, U.S. Coast Guard, U.S. Navy, Hawaii Sea Grant, the
U.S. Fish and Wildlife Service, State of Hawaii, universities and other local agencies,
businesses and NGO partners. Two vessels were chartered to support rotating teams
of trained NOAA divers for 6 months, who also conducted line transect surveys and
recorded GPS coordinates of debris locations. Divers carefully cut the entangled gear
away from the coral to minimise further damage, and airbags were used to bring balls
of debris to the surface to be totally removed. By September 2002, divers had
removed another 107 metric tonnes of debris, adding to the 100 tonnes collected
since 1996. The divers were also able to disentangle a number of monk seals and green
sea turtles. The NMFS is attempting to determine the primary sources of this derelict
gear and locations in the NWHI where it is most likely to accumulate. From Scot Frew
at NOAA.
ANTHROPOGENIC THREATS TO CORAL REEF BIODIVERSITY
There are far more human pressures on coral reefs of the MHI because they are close to
large urban centres, whereas there are fewer pressures on the NWHI reefs. The major
threats are: urbanisation; tourism and leisure; alien species; destructive fishing practices;
marine debris; military impacts; and ship groundings.
The impacts of the growing resident population and increases in tourist numbers have
resulted in considerable coastline modification and reclamation of reef flats, thereby
destroying nursery wetland areas and fringing reefs. The expanding infrastructure also
results in increased sedimentation and pollution. Tourism is the largest industry in
Hawai’i, with marine tourism the focus. Although it brings in over US$800 million per
year and employs over 7,000 people, there are also negative impacts. Coasts are
continually being developed to cater for the tourists and the increased boating activities
cause direct reef damage and pollution of oil and sewage from the boats. It was found that
in heavily used areas of coral reefs (300,000 visitors annually), the coral cover is
particularly low e.g. 2% cover; whereas in control areas it is much higher e.g. 34%.
Tourist use results in pulverised corals that cannot survive continued exposure to
trampling. However, if the trampling pressures are removed, the coral colonies can
recover, particularly those species from high wave energy environments because they have
much stronger skeletons. Damage to coral from anchors is being continually reduced with
the installation of mooring buoys in collaborative activities of the government and dive
industry. There is virtually no tourism activity in the NWHI, but this is being monitored,
especially sports fishers who are encouraged to fish but adopt a catch-and-release policy.
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