2016 SoE Marine Chapter - State and Trends - Water turbidity, transparency and colour

Brief description

The Marine chapter of the 2016 State of the Environment (SoE) report incorporates multiple expert templates developed from streams of marine data. This metadata record describes the Expert Assessment "The state and trends of physical, biogeochemical and biological processes - water turbidity, transparency and colour". The full Expert Assessment, including figures and tables (where provided), is attached to this record. Where available, the Data Stream(s) used to generate this Expert Assessment are accessible through the "On-line Resources" section of this record. ---------------------------------------- DESCRIPTION OF ECOLOGICAL PROCESS FOR EXPERT ASSESSMENT Australian marine waters are generally low in turbidity, colour and high in transparency. Much of our flora and fauna are highly adapted to these conditions and a deterioration in transparency puts these communities and populations at increased risk. In oceanic and outer continental shelf waters the major determinants of turbidity, transparency and colour is the biomass of phytoplankton (Yentsch 1960). Most of these waters are low in phytoplankton and we have some of the clearest waters on the planet. The light penetrates deeply allowing phytoplankton to grow down to > 100m. On the near shore regions of the continental shelf we have benthic communities dominated by aquatic plants (e.g. seagrasses and macrophytes) that are dependent upon light. DATA STREAM(S) USED IN EXPERT ASSESSMENT In-situ observations collected by the IMOS National Reference Stations and satellite detected ocean colour data. ---------------------------------------- 2016 SOE ASSESSMENT SUMMARY [see attached Expert Assessment for full details] • 2016 • Assessment grade: Good-poor Assessment trend: Deteriorating Confidence grade: Limited evidence or limited consensus Confidence trend: Limited evidence or limited consensus Comparability: Grade and trend are comparable to the 2011 assessment • 2011 • Assessment grade: Very good Assessment trend: Deteriorating Confidence grade: Limited evidence or limited consensus Confidence trend: Limited evidence or limited consensus ---------------------------------------- CHANGES SINCE 2011 SOE ASSESSMENT This assessment uses observations made across a range of spatial and temporal scales that allows a robust assessment of current state and trends to be made. Times series data have been added to since the 2011 assessment.

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Statement: QUALITY OF DATA USED IN THE ASSESSMENT Spatial and temporal coverage of the satellite data is excellent. Point data collected at each reference station oceanographic quality.

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Purpose
To describe the state and trends in water turbidity, transparency and colour for use in the Marine chapter of the 2016 State of the Environment report.