Bare et al. 2010

scientific article | Coral Reefs

Mesophotic communities of the insular shelf at Tutuila, American Samoa

Bare AY, Grimshaw KL, Rooney JJ, Sabater MG, Fenner D, Carroll B


An investigation into the insular shelf and submerged banks surrounding Tutuila, American Samoa, was conducted using a towed camera system. Surveys confirmed the presence of zooxanthellate scleractinian coral communities at mesophotic depths (30–110 m). Quantification of video data, separated into 10-m-depth intervals, yielded a vertical, landward-to-seaward and horizontal distribution of benthic assemblages. Hard substrata composed a majority of bottom cover in shallow water, whereas unconsolidated sediments dominated the deep insular shelf and outer reef slopes. Scleractinian coral cover was highest atop mid-shelf patch reefs and on the submerged bank tops in depths of 30–50 m. Macroalgal cover was highest near shore and on reef slopes approaching the bank tops at 50–60 m. Percent cover of scleractinian coral colony morphology revealed a number of trends. Encrusting corals belonging to the genus Montipora were most abundant at shallow depths with cover gradually decreasing as depth increased. Massive corals, such as Porites spp., displayed a similar trend. Percent cover values of plate-like corals formed a normal distribution, with the highest cover observed in the 60–70 m depth range. Shallow plate-like corals belonged mostly to the genus Acropora and appeared to be significantly prevalent on the northeastern and eastern banks. Deeper plate-like corals on the reef slopes were dominated by Leptoseris, Pachyseris, or Montipora genera. Branching coral cover was high in the 80–110 m depth range. Columnar and free-living corals were also occasionally observed from 40–70 m.

Research sites
Depth range
12- 105 m

Mesophotic “mentions”
28 x (total of 5334 words)

* Presents original data
* Focused on 'mesophotic' depth range
* Focused on 'mesophotic coral ecosystem'

Community structure

Scleractinia (Hard Corals)
Overall benthic (groups)

American Samoa

Drop / Towed Video

Author profiles