Assessing reef fish assemblage structure: how do different stereo-video techniques compare?

Quantitative sampling of benthic communities is central to a wide range of ecological research, from understanding spatial distribution and ecology to impact studies. With the need to sample deep as well as shallow regions, limited sampling capabilities of diver-based methods and the expanding footp...

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Bibliographic Details
Main Authors: Watson, D., Harvey, Euan, Fitzpatrick, B., Langlois, T., Shedrawi, G.
Format: Journal Article
Published: Springer-Verlag 2010
Subjects:
Online Access:http://hdl.handle.net/20.500.11937/3374
Description
Summary:Quantitative sampling of benthic communities is central to a wide range of ecological research, from understanding spatial distribution and ecology to impact studies. With the need to sample deep as well as shallow regions, limited sampling capabilities of diver-based methods and the expanding footprint of human activity, there is a need for an effective system capable of classifying benthic assemblages and able to monitor potential anthropogenic impacts. Here we describe a remote system capable of collecting benthic photo-quadratsto depths of 100 m. A procedure for the classification of these images into 64 abiotic and biotic categories is also described. During a64-daysamplingprogramthatincludedsamplingatseven locations along 1,200 km of coastline that resulted in the collection of over 9,000 images, only one day of sampling was lost due to equipment malfunction, with 99.5% of points able to be classified to the taxonomic resolution required, demonstrating the reliability and accuracy of this system. Furthermore, the incorporation of differential GPS and ultra-short baseline positioning system allowed collected images to be geo-referenced to within 0.5 m. Such precision allows the system to be used in conjunction with hydroacoustic habitat mapping techniques and potentially for repeated monitoring of areas with a small spatial extent. Development of this system provides a cost-effective means of quantifying benthic assemblages over broad scales.