The southeastern Tasmania marine habitat project 1:25000 depicts marine habitats from Marion Bay [147 57, -42 44] to Second Lookout Point [146 52, -43 40] from the coastline to the 40metre depth contour. The habitat types depicted in the dataset include High profile reef, Medium profile reef, Low profile Reef, Patchy Reef, Sand, Hard Sand, Silty Sand, Silt, Seagrass, Patchy Seagrass, Sparse Seagrass and Caulerpa. The data was collected through intensive field sampling from June to December 2000 by marine researchers at the Tasmanian Aquaculture and Fisheries Institute. The use of underwater camera equipment, echo sounder data and a Differential GPS unit allowed for the extensive area to be surveyed. The dataset is intended to be used to fulfil coastal management objectives according to The Living Marine Resources Act 1995.

Depth and positional point data was captured using a Garmin 135 GPS unit coupled with a RACAL differential correction unit. A FURUNO 600L colour sounder was used to discriminate habitat type. Employing a specially designed program, Seabed Mapping Tool Version 1.3, point data was attributed with one of eleven habitat classifications. The point dataset was checked for extraneous data, cleaned and converted to a point coverage using ESRI ARCVIEW Version 3.2. The point data was used to interpret boundaries and formed the basis of a polygon coverage that was generated from the data. Selected aerial photographs were scanned at 600dpi and stored as 24bit colour TIFF images. Each was georeferenced using ESRI ARCINFO Version 7.2.1 to the Tasmanian Coastline coverage in AGD66. The point data was overlayed on the aerial photographs to check for continuity especially in generating the reef habitat polygons. The generated polygon coverage was edge matched to the 1:25000 coastline shape. The 1:25000 coastline was supplied by the Land Information Services Division of the Department of Primary Industry, Water and Environment Tasmania. Equipment employed to record and measure the data included [Furuno 600L colour sounder, Garmin 135 GPS map unit with a RACAL differential correction unit, Benthos Model 4208 8x zoom colour camera unit] Habitats identified: [High profile reef, Medium profile reef, Low profile Reef, Patchy Reef, Sand, Hard Sand, Silty Sand, Silt, Seagrass, Patchy Seagrass, Sparse Seagrass and Caulerpa]. Areas were sampled following transects in from the 40metre contour line to the coastline. The sampling method resembled a zigzag pattern at 200m intervals. The GPS recorded depth and position regularly at 5second intervals to generate a point dataset of 200 000 points. Sampling effort was increased in areas that demonstrated complex habitat composition.

Position Accuracy: The accuracy of the GPS was assessed by recording at fixed points over extended time periods. It was found to vary by no more than 12meters over a three-hour period. Aerial photographs were rectified using a minimum of 15 ground control points for each image. The average root mean square error for the photographs was X8.157 and Y10.246. Attribute Accuracy: The attributes assigned to the 1:25000 Habitat Mapping Series were based on the interpretation of the readings given from the FURUNO colour scanner. These attributes were cross-referenced with underwater video information used to ground truth the sounder interpretations. Hotlink images have been made available for 894 of the sites to allow for user clarification on attribution. Logical Consistency: All data has been checked for duplicate features, extraneous points, unclipped polygons and unattributed polygons by both visual and automated means. Completeness: The 1:25000 Habitat Mapping Series has been completed for the south eastern section of Tasmanian waters from the coastline to the 40metre depth contour. Additional: Tasmanian Habitat Mapping Contour Series