Fisheries Biology and Stock Assessment Division (FBSAD) Recruit and Predator Reef Fish Belt Transect and Habitat Quadrat Surveys at Hawaii Island (Big Island), Main Hawaiian Islands, 2008; and Midway Atoll, Northwestern Hawaiian Islands (NWHI), 2008 (NODC
Vydavatel National Oceanic and Atmospheric Administration, Department of Commerce
Datum vydání před více než 9 roky
Shrnutí
Popis
Shore-based belt transects were conducted and habitat quadrats were surveyed using transects at 1 to ~ 5 m depths at a total four (4) sites: at (1-2) 2 longshore sites on the leeward coast (South Kohala district) of the Big Island (Hawaii Island) in the MHI during spring-summer 2008; and (3-4) at 2 longshore sites on the back reef of Midway Atoll in the NWHI during summer 2008. For recruit reef fish survey, from 18-20 randomly positioned transects were surveyed at each site or site-group in 2008. Each transect was 50-m long x 2-m wide (100 m**2 area). Raw survey data consist of species-specific and size-specific (total length, TL, in cm) numerical counts of recruit (≤ 5 cm total length, TL) reef fishes encountered within transect boundaries. For predator reef fish survey, from 18-20 randomly positioned transects were surveyed at each site or site-group in 2008. Each transect was 50-m long x 4-m wide (200 m**2 area). Raw survey data consist of species-specific and size-specific (total length, TL, in cm) numerical counts of large juvenile and adult (≥ 6 cm total length, TL) stages of PREDATOR reef fishes encountered within transect boundaries. Inclusion as a predator fish in the transect tally was based on either known or likely (based on functional morphology) inclusion of small fishes in the species' diet. For habitat quadrat survey, substratum cover and rugosity were characterized within multiple quadrats at each site. Two types of quadrats were surveyed: "Reference" ('REF') quadrats (whose positions were randomly selected) and "Target" ('TAR') quadrats (positions centered on sightings of recruit fishes); each quadrat was square and 1-m**2 area. In each quadrat, the benthic cover of each of fourteen (14) main substratum types were estimated, as was a "Rugosity Index" based on the ratio of conforming-to-straight line distances along both major axes of the quadrat.