Scientists from Curtin University and CSIRO have been investigating how data collected from satellites can help to provide the information needed to monitor the extensive waters of the Kimberley Marine Park.
The Kimberley region is vast and remote, making it difficult and expensive to access and monitor, but satellite remote sensing technologies are providing a cost effective method to gather historical and baseline data with broad spatial coverage and high repeat frequency at metre to kilometre scales of resolution.
A Western Australian Marine Science Institution project has focused on measurements of the turbidity of marine waters using NASA’s MODIS sensor on its Aqua satellite.
“The murkiness or turbidity of waters directly impacts the amount of light reaching the seabed, so plays an important role in determining what organisms can exist and grow in these environments,” CSIRO’s Dr Nick Hardman-Mountford said.
To confidently monitor turbidity through time and quantify how it changes seasonally and between years, it is necessary to know the precision of the satellite-derived measurements. However, as with any derived data, there are uncertainties about how accurate a picture remotely sensing can provide and at what scale. These have not been determined previously for Kimberley waters.
To help remedy this, a key component of the research has been to analyse these uncertainties for remotely sensed turbidity ‘products’ by making comparisons with archived “in water” measurements, and by looking at what resolutions work best.
In situ data was obtained from a number of recent expeditions that occurred along the Kimberley and Pilbara coastline including sites in King Sound, Collier Bay, in the vicinity of King George River, and near Onslow on the Northwest Shelf. Data being used by the team includes specialised optical measurements, as well as measures of turbidity and vertical light attenuation.
The project is due to be completed in December 2016.
|Landsat image pan-sharpened to 15 m resolution. The town of Derby is clearly visible, as well as extensive mudflats exposed at low tide.|
The $30 million Kimberley Marine Research Program is funded through major investment supported by $12 million from the Western Australian government’s Kimberley Science and Conservation Strategy co-invested by the WAMSI partners and supported by the Traditional Owners of the Kimberley.