Dataset 120

CRED REA Algal Quadrate Images in the Pacific Ocean 2002-2008 (OBIS-USA)

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Realm: Marine
Climate: Temperate/Tropical
Biome: Tropical coral
Central latitude: 10.778000
Central longitude: -169.454000
Duration: 7 years, from 2002 to 2008

10198 records

260 distinct species

Across the time series Cyanobacteria is the most frequently occurring species


The goal of algal surveys is to quantitatively describe the algal community and prepare a comprehensive species list for each site. Working at depths of 3 to 16 m with teams using other existing rapid assessment methods. a method for algal assessment is needed that will minimize the time in the water yet yield the greatest amount of data possible. A high-resolution digital camera mounted on a 0.18 m? photo quadrat frame (Fig.1) with an Ikelite Substrobe digital slave strobe has been built to quantitatively assess marine algae.In addition to photographs. data from each quadrat are recorded on a waterproof data sheet that includes space for recording the species found in the quadrat. a ?map? area for identifying cryptic species in depressions that may prove difficult in computer analysis. and codes for the most common genera and species of macroalgae. corals. invertebrates. and substrate types to standardize and shorten note taking.Two trained observers move along the transect together with one observer placing the framer and operating the camera and the other taking notes. (Fig.2). Photographs are taken at predetermined random points.After a photograph is taken by the first diver. the second diver identifies algae within the photoquadrat. records the relative abundance of the 5 most abundant algae on a scale of 1 ? 5 (with 1 being most abundant). draws a quadrat map locating species that may be hard to identify in a photograph. and collects representative samples of the algal species in the quadrats for later identification in the laboratory.Once data are recorded. the photoquadrat is moved to the next random point and the procedure repeated. To prevent redundancy. only samples of new algal species found in subsequent quadrats are collected. In the laboratory the photographs taken with the photoquadrat methods are downloaded to a computer. renamed with a unique location code. then cropped and color corrected in Adobe Photoshop using autocorrect.Each photo is analyzed for percent cover using the software PhotoGrid (C. Bird. Dept. of Botany. University of Hawaii). a software program capable of random and stratified random point analysis on digital photography. Once all photos are analyzed. data are imported into Microsoft Excel for further statistical application.Ultimately. field-collected specimens will be critically analyzed in the laboratory to ensure positive species identification. will be cataloged. and will subsequently be placed in research institutions where they can be accessed by researchers interested in a suite of topics ranging from taxonomy to bioprospecting.After identification. provisions are made to ensure appropriate preservation and curation of each specimen. providing a historical record that will be available to future researchers. Unit of abundance = AggregatedPresence, Unit of biomass = NA


"CRED REA Algal Quadrate Images in the Pacific Ocean 2002-2008". (2011) Coral Reef Ecosystem Division (CRED), Pacific Island Fisheries Sciences Center, National Marine Fisheries Service. Available at:, accessed 2012.