CRED Map of Percent Hard Coral Cover at Tutuila Island, American Samoa

Title:: CRED Map of Percent Hard Coral Cover at Tutuila Island, American Samoa
Abstract:: This map displays optical validation observation locations and percent coverage of hard coral overlaid on bathymetry.
Supplemental_Information:: Tutuila is the largest of seven islands in American Samoa at 142.3 sq. km. Volcanic in origin, it reaches a height of 653m at Matafao Peak. Tutuila is centered at 14.30S, 169.75W, has 101.3 km of coastline and an estimated 36.2 sq. km of reef area. The port of Pago Pago is a collapsed crater and is one of the largest natural ports in the Pacific. Pago Pago contains a tuna cannery which is a hub of a large purse-seining tuna fishing fleet. The cannery outputs large amounts of nutrients as byproduct into the waters of Pago Pago harbor. The human population of Tutuila in 1990 was 45,043. It is considered a high island and contributes significant nutrient and sediment runoff to coastal waters. Tutuila's waters are protected by the 0.7 sq. km Fagatele Bay National Marine Sanctuary, as well as by the National Park of American Samoa, which covers the north-central part of the island and ~5 sq. km of coastline. Data were collected on the following cruises: Cruises CoRIS Metadata Record Names TC0201 cred_toad_tutuila_tc0201_2002 OES0402 cred_toad_tutuila_oes0402_2004 BV0801 cred_toad_tutuila_bv0801_2008 HI0802 cred_towboard_benthic_tutuila_island_2008.txt Classified data collected by the CRED TOAD camera sled are presented separately on the PIBHMC website (<ftp://ftp.soest.hawaii.edu/pibhmc/website/data/amsamoa/optical/tutuila/TUT_TOAD&TOW.jpg>). This map (TUT_TOAD&TOW.jpg) includes both data collected by the TOAD camera sled in 2002, 2004, and 2008, and data collected by towed-divers during 2008. The TOAD camera sled collected either video or still photographs, depending on the specific equipment set up (see separate cruise metadata for details), but all optical data has been analyzed the same way. Briefly, 5 points per photo, or per 30-second interval on video footage are classified for substrate and living cover, of which one category is 'hard-coral'. For more information on classificiation methods, refer to the PIBHMC website <ftp://ftp.soest.hawaii.edu/pibhmc/website/webdocs/documentation/Optical-Proc_Overview.pdf> For more information on the classification scheme, refer to the PIBHMC website <ftp://ftp.soest.hawaii.edu/pibhmc/website/webdocs/documentation/Benth-Habitat-Class_Codes.htm> TOAD camera sled data were classified using an older version of the current CRED-wide classification scheme that was developed in early 2011. Data was mapped across to the new scheme to allow integration with more recently analyzed data sets. In many cases there was a one to one match between categories in the old scheme versus the new scheme, but in some cases there is a minor mis-match between the old and new classification schemes. In this map 'hard coral' was originally classified as 'scleractinian coral.' 'Hard coral' includes scleractinian coral, plus a small number of non-scleractinian corals with hard skeletons (fire corals, blue coral, stylasterid hydracorals). In the previous classification scheme non-scleractinian hard corals would have been grouped with other non-scleractinian corals (e.g., black corals, soft corals). Examination of the data suggest that this difference in definition would have a negligible impact on the results as non-scleractinian corals were rarely encountered. Towed-divers have collected data around Tutuila biannually. As the surveys intend to cover the same ground, only one year of data are presented here, as the intention is to give an overview of the distribution of hard coral cover around Tutuila, rather than to present temporal variability. Towed-divers record observations of the benthos, as well as take photographs of the sea floor beneath them. Still photographs taken every 15-seconds were analyzed in Coral Point Count with Excel Extensions (CPCe) overlaying 10 stratified-random points and classifying the substrate, living cover and coral morphology (when applicable) beneath the point. The 2011 CRED-wide classification scheme, referred to above, was used. Using this scheme has enabled data from shallow reef areas, as collected by towed-divers, and deeper reef areas, as collected by the CRED TOAD camera sled, to be presented together in a unified map product. Resource Description: Map showing percent cover of hard coral classified from CRED TOAD camera sled video and photos, and towed-diver photos.

Data format:	JPEG
Network links:	<http://www.soest.hawaii.edu/pibhmc/pibhmc_amsamoa_tutuila_optical.htm> <ftp://ftp.soest.hawaii.edu/pibhmc/website/data/amsamoa/optical/tutuila/TUT_TOAD&TOW.jpg>

Data format:

JPEG

Network links:

<http://www.soest.hawaii.edu/pibhmc/pibhmc_amsamoa_tutuila_optical.htm>
<ftp://ftp.soest.hawaii.edu/pibhmc/website/data/amsamoa/optical/tutuila/TUT_TOAD&TOW.jpg>

CRED Map of Percent Hard Coral Cover at Tutuila Island, American Samoa

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