The mapping of the coral reef habitats of the Great Barrier Reef, is going full steam ahead with the recent completion of extensive repeat surveys and mapping for 200 reefs in the area around Cairns and Cooktown.
The mapping combine’s satellite remote sensing imagery, using Landsat 8, with ecological modelling and mapping rules to create maps showing:
- Geomorphic zones, areas with consistent bathymetric form, forcing process, and position on reef (e.g. reef slope, reef crest, lagoon).
- Benthic composition, areas with similar benthic and substrate features (e.g. coral, algae, rock, sand); and
- Coral types (e.g. plate, branching, massive corals).
Development of the mapping and modelling work is a collaboration lead by RSRC SEES with Marine Spatial Ecology lab, and Engineering at UQ, AIMS, JCU, GBRMPA and EOMAP.
The field data collection is now finalised from January and May field trips, and data will be used for mapping and modelling calibration (January) and validation (January, and May) activities. The May field data included 12,000 geo-located photos from 59 transects with a total lenght of 40 km, 57 coral colour surveys using www.coralwatch.org, 59 Crown of Thorn surveys and 51 Reef Health and Impact Surveys.
The May trip took place due to the unique collaboration with the Swiss run Ocean Mapping Expedition from 25th April – 20th May, where two RSRC-UQ team members were on board the sailing vessel MV Fleur De Passion.
Field trips on coral reefs are a unique way to experience the reef, but can be confronting as well, as the field team found out during the May trip. Sadly, many reefs showed signs of past and current bleaching impacts. Luckily we also have seen healthy areas but not as many as during the January field trip. Three reefs visited in January were revisited in May to assess the of the March coral bleaching event using Sentinel 2 satellite imagery in collaboration with European Space Agency.
The field trips helped to create the first draft map of the geomorphic zonation of the 200 reefs, which is currently being refined.
For more information on the GBR habitat mapping contact Dr. Chris Roelfsema (project PI).