Seagrass coverage in Cockburn Sound, Western Australia (1999)

Cockburn Sound is a sheltered marine embayment 16 km long 9 km wide, and consists of a deep central basin (17-22 m deep) surrounded by shallow platforms. The shallow platforms vary in width from 50 m to 3 km and are where seagrass meadows are found (see thumbnail). The seagrass mapping area was delineated as shallow platforms to a depth of 10 m and covered an area of approximately 3667 ha. In 1999, flights to acquire aerial photographs were purpose-flown in late-February to early-March when conditions were optimal. These conditions included maximum seagrass leaf cover; maximum water clarity; minimum haze from the adjacent industrial zone; minimum turbidity from dredging, river outflow or industrial activities; minimum cloud cover; weak prevailing winds; and incident sun angle at 20-30. Colour photography with a yellow lens filter was obtained at two altitudes. High altitude imagery was collected at 10,000 m (scale, 1:55,000) for accurate ortho-rectification. The resulting imagery was used as a rectification base for the low-altitude imagery that was obtained at an altitude of 3,800 m. This dataset is hosted by the Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, on behalf of a consortium of industries and Western Australian Government Departments for the purposes of the Seamap Australia collaborative project (testing a national marine benthic habitat classification scheme). Data and metadata is from https://metadata.imas.utas.edu.au/geonetwork/srv/eng/metadata.show?uuid=81edfca0-9d59-11dc-a0ca-00188b4c0af8