As the annual humpback whale migration begins from the Antarctic to the Kimberley coast, one WAMSI project, working to model their spatial distribution, is looking to combine satellite imagery and bathymetric LiDAR (Laser or Light Detection and Ranging) for the first time as an efficient and safe means to monitor these giants of the sea.
The number of humpback whales travelling the coast of Australia from their feeding grounds in the Antarctic to their breeding grounds in the Kimberley has increased from around 300 in 1963 to some 30,000 today since hunting was outlawed.
The challenge now for lead researcher on the WAMSI project Michele Thums, from the Australian Institute of Marine Science, is to map habitats that are important to them when they are on their breeding grounds in the Kimberley which, in turn, could help to manage marine park boundaries and the potential to overlap with human activities such as boating and industry.
“We already understand quite a lot – timing of the migration, spatial extent of the calving area, and general distribution of migrating whales but there has been very little attempt to bring this data together and synthesise it to get a quantitative understanding of their habitat requirements and the specific habitats that breeding humpbacks rely on,” Dr Thums said.
The project is analysing data from some of the extensive aerial and vessel line transect surveys gathered over the last 25 years mostly on behalf of industry. This study is predominantly relying on data released by WAMSI research collaborator Curt Jenner, Inpex and Woodside.
“It’s very expensive to do these surveys,” Dr Thums said. “Collecting data from aerial and boat surveys is especially prohibitive in the Kimberley because it is so remote. So we’re fortunate to get access to this rich source of data collected by industry as part of their legislative requirements to operate.”
In September the project team is going to take an opportunity to head out into the field and test the reliability of monitoring whales using a scanning laser fixed to an aircraft that is capable of generating precise 3-dimensional information about the characteristics on the earth’s surface (bathymetric LiDAR system), in this case whales.
“We’re still developing this project but, if successful, it doesn’t require observers on the flight, so it’s safer and it could still allow us to analyse the data later to count the whales,” Dr Thums said. “We’re also hoping to get satellites tasked to capture high resolution images so we can compare the satellite data with LiDAR and, if it’s a good match, we might be able to rely on monitoring the Kimberley humpback whales with satellite in the future.”
The findings for the WAMSI Humpback project are expected to be released by early next year.
The $30 million Kimberley Marine Research Program is funded through major investment supported by $12 million from the Western Australian government co-invested by the WAMSI partners and supported by the Traditional Owners of the Kimberley.