Marine Resources Assessment for the Marianas Operating ... - SPREP

AUGUST 2005 FINAL REPORT
fishery in the insular and coastal region with coral reefs (Randall 2001a). They are also valuable in
the aquarium trade. Aquarium species are discussed further as part of a separate management unit
species assemblage (WPRFMC 2001). None of the species found in the study area are listed on the
IUCN Red List of threatened species (IUCN 2004).
Distribution—Surgeonfish are found circumtropically around coral reefs with the majority of the
species occurring in the Pacific and Indian Oceans (Allen and Steene 1987).
Habitat Preferences—Surgeonfish are diurnal herbivores and planktivores seeking shelter on the
reef at night. These fishes are associated with many of the major coral reef habitat types including
mid-water, sand patch, subsurged reef, and seaward or surge zone reef. As juveniles, surgeonfish
are found in reef areas until mature. Adults are found throughout coral reef habitats and are typically
associated with subsurge reef habitats. They are found at depths from 0 to 150 m, but are commonly
found between 0 and 30 m deep (WPRFMC 2001).
Life History—Many species of surgeonfish form large single-species or mixed-species schools
(some numbering in the thousands) which are often associated with spawning or feeding behavior.
Certain species of Acanthurids migrate 500 to 600 m daily for feeding (WPRFMC 2001). Spawning
activities are often associated with the lunar cycle and occur throughout the year with peak activity
during the winter and early spring (Myers 1999). Surgeonfish may also spawn during a new moon or
full moon depending on species and geography (Kuiter and Debelius 2001). Generally, spawning
occurs at dusk involving groups, pairs, or both (Myers 1999). Surgeonfish eggs and larvae have a
wide distribution and are found in pelagic waters (Myers 1999).
EFH Designations—(WPRFMC 2001; Figures D-10, D-14, and D-18; Table 4-5)
Eggs and Larvae―The water column from the shoreline to the outer boundary of the EEZ to
a depth of 100 m.
Adult and Juveniles—All bottom habitat and the adjacent water column from 0 to 100 m.
♦ Blastulae (Triggerfish’s)
Status—Nine species of triggerfish are managed in Micronesia as part of the CHCRT by the
WPRFMC (2001) and occur in CNMI and Guam (Amesbury and Myers 2001; Myers and Donaldson
2003). All have EFH designated within the boundaries of the study area (WPRFMC 2001; NMFS
2004c). Eight additional species of triggerfish are found in the study area and have EFH designated
under the PHCRT (WPRFMC 2001). Currently, no data are available to determine if triggerfish’s of
the CHCRT are approaching an overfished situation (NMFS 2004a). Triggerfish are an important food
fish in western Pacific and some of the more colorful species are popular as aquarium fish (Myers
1999). None of the species found in the study area are listed on the IUCN Red List of threatened
species (IUCN 2004).
Distribution—Triggerfish are predominately tropical reef dwellers found in the Atlantic, Indian, and
Pacific Oceans (Allen and Steene 1987).
Habitat Preferences—Habitat preferences for triggerfish’s includes protected lagoons, high-energy
surge zones, ledges and caves of deep drop-offs, sand bottoms, and rocky coral areas. Adults prefer
steeply sloping areas with high coral cover and a lot of caves and crevices. Depth preferences
depending on species range from shallow sub tidal zones to waters as deeper than 100 m (Myers
1999).
Life History—There is little information on the spawning and migrational patterns of triggerfish in the
western Pacific. Triggerfish are generally solitary, but do form pairs during spawning. Balastid
spawning events show some correlation to lunar cycles and eggs are typically deposited in shallow
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