Record Details
Report of HURL Cruise KOK0510: Submersible Dives and Multibeam Mapping to Investigate Benthic Habitats of Tutuila, American Samoa
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Report of HURL Cruise KOK0510: Submersible Dives and Multibeam Mapping to Investigate Benthic Habitats of Tutuila, American Samoa |
| Names |
Wright, Dawn
(creator) |
| Date Issued | 2007-03-29T13:07:44Z (iso8601) |
| Internet Media Type | application/pdf |
| Note | Available also from http://dusk.geo.orst.edu/djl/samoa/hurl/KOK0510cruise_report.pdf |
| Abstract | Cruise KOK0510 consisted of three Pisces V dives to the submerged flanks of Tutuila, American Samoa, specifically the coral reef platform of Taema Bank, and the submerged caldera forming Fagatele Bay and Canyon. In addition, a night-time program of Sea Beam 210 bathymetric mapping was conducted along the north side of the island to fill in a data gap from previous multibeam surveys in that region. Night-time deployments of the RCV-150 were also planned, but could not commence due to mechanical difficulties with the ROV. The overall objectives of the cruise were the characterization and groundtruthing of underwater features previously mapped in sonar, and for areas below the reach of SCUBA, the estimation of the amount of live bottom, the species identification of fish and invertebrates, and the assessment, where possible, of benthic change within the coral reefs encountered. These observations were made toward an ultimate goal of groundtruthing previous benthic terrain maps (geo) made in the region, as well as informing the preparation of future benthic habitat maps (biogeo). Research questions guiding the objectives include: (a) What are the significant deep-water coral reef habitats, relative to the territory’s coastal ecology and current initiatives for sanctuary management (i.e., areas of 20% or greater coral cover as mandated for protection)? (b) Where are these critical habitats located, and with what major species are they associated with? (c) Which habitats appear to be “biological hotspots” (e.g., areas of high biodiversity), and what are the implications for coral reef conservation and management? For example, which sites should be deemed of special biologic significance (such as a no take zone within a pilot marine protected area)? All three dives were extremely successful with a cumulative bottom time of 18 hours and identification at both sites of 32 species of invertebrates and 91 species of fish, at least 9 of which are “new records” for American Samoa. The base of extensive live bottom for Taema Bank (coral cover of 20% and greater) was identified at a depth of 36 m. Alternating sections of carbonate reef and basalt were observed at~185-220 m depth along the west walls of Fagatele Canyon, and large, grooved mass-wasting scarps were noted at ~300-400 m depth near the base of the south central wall of Taema Bank. No evidence of eutrophication or slurry from Pago Pago harbor was seen on the south side of Taema Bank. Sea Beam mapping on the north flank of Tutuila revealed 3 new cones that will eventually be added to the Scripps Biogeosciences Seamount Catalog (EarthRef.org). Subsequent benthic habitat maps that may be created with the aid of these data should be of great use for ongoing studies by the American Samoa Government’s Department of Marine and Wildlife Resources (DMWR), the Fagatele Bay National Marine Sanctuary (FBNMS), the American Samoa Coastal Management Program, and the National Park of American Samoa (NPAS); including the selection of sites for habitat class designation and protection (e.g., no-take marine protected areas, a major American Samoa initiative), development of marine park monitoring protocols, and general understanding of species composition and abundance. In addition, we were pleased to have 2 local secondary school teachers join the cruise as observers. These teachers were recently involved in a marine science workshops co-funded by the Fagatele Bay National Marine Sanctuary and the American Samoa Coral Reef Advisory Group, and will be using selected videos, photos from the cruise, and perhaps some of the GIS data sets, directly in their classrooms. Local media coverage of the cruise included a radio interview and an article in Samoa News (facilitated by Nancy Daschbach of FBNMS and Peter Craig of NPAS). |
| Genre | Technical Report |
| Topic | submersible dive |
| Identifier | http://hdl.handle.net/1957/4282 |
