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

Status of Coral Reefs in the Hawaiian Archipelago
Another area where management is needed is in the trade of ornamental fish and
invertebrates which are exported to the mainland USA. Evidence of this trade is seen in
markedly reduced populations of the better aquarium species. There are 5 species of sea
turtles and 24 marine mammal species on the coral reefs off the MHI. These include the
threatened ‘Hawaiian’ green sea turtle (Chelonia mydas) that feeds in shallow waters of
the MHI, as well as the Hawaiian hawksbill sea turtle (Eretmochelys imbricata). Turtle
tumours (fibropapillomatosis) were rare prior to 1985, but are now common on turtles on
Maui, Kaua’i, and O’ahu; with up to 60% of the turtles in Kane’ohe Bay infected. The
endangered Hawaiian monk seal (Monachus schauinslandi) occasionally visits waters of
the MHI.
The average total fish biomass in the NWHI is 260% higher than in the MHI with a far greater
proportion of top predator (‘target’) species, whereas on the MHI, the predator species are a smaller
proportion of a much smaller biomass, thereby showing indications of serious over-fishing.
NWHI
A total of 266 species of fishes are listed from Midway Atoll of which 258 are reef and shore
fishes. Cooler water temperatures, lack of some high-island habitat types, and lower
sampling effort may all contribute to the lower number of species compared to the main
Hawaiian Islands. However, average fish biomass in the NWHI is nearly 3 times greater
than in the MHI, with more than 54% of the total fish biomass consisting of top predators
(there were fewer than 3% of these in the total fish biomass in the MHI). Jacks, sharks and
groupers are the dominant species, while they are either rare or absent in the MHI and the
target species that were present, regardless of trophic level, were nearly always larger in
the NWHI. Mean weight of apex predators in the NWHI was 570% greater than in the
MHI, and herbivores were 97% heavier in the NWHI. These differences represent both
near-elimination of apex predators and heavy exploitation of lower trophic levels in the
MHI compared to the largely un-fished NWHI. The only substantial fishing pressure
comes from commercial vessels larger than 20m. The National Marine Fisheries Service,
through the Western Pacific Regional Fisheries Management Council, is now managing
the fishing industry, and the lobster fishery is closed.
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