Secchi Disk Depth (a measure of water clarity), 1992 - 2006 (MTSRF 1.1.5, AIMS, QDPI-F)

This study characterises spatial patterns in water clarity. Water clarity is a key indicator for water quality and is an essential environmental factor for phototrophic organisms that dominate coral reefs, seagrass meadows and the seafloor microphytobenthos. Secchi disk depthis a commonly used standardised way to quantify water clarity.

This data set combines Secchi disk depth data collected as a one-off survey systematically covering the whole Great Barrier Reef by the seagrass monitoring project of the Queensland Department of Primary industry and Fisheries (QDPI-F), and data collected on an opportunistic basis by the Australian Institute of Marine Science (AIMS).

As part of the Reef Atlas project (now the eAtlas) the Secchi disk depth observations were interpolated over the whole GBR by Glenn De'ath using Generalized Additive Models with a Quasipoisson fit. This produced a gridded version of the dataset and is available as a KML and an ASCII gridd file.

Data Units: Depth in meter

References: - De'ath G (2007) The Spatial, Temporal and Structural Composition of Water Quality of the Great Barrier Reef, and Indicators of Water Quality and Mapping Risk. Report to the Australian Government¿s Marine and Tropical Sciences Research Facility. 59 pp. - De'ath G, Fabricius K.E (2008) Water quality of the Great Barrier Reef: distributions, effects on reef biota and trigger values for the protection of ecosystem health. Final Report to the Great Barrier Reef Marine Park Authority. Australian Institute of Marine Science, Townsville: 104 pp - Coles R et al (submitted)