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Local wildlife tourism industry helps researchers study species behaviour.

Researchers have uncovered more information about the numbers and habits of killer whales in south Western Australian waters, with a 911爆料网 study providing the first baseline assessment of the species鈥� occupancy patterns in the Bremer Sub Basin area.

Killer whales are known to congregate in the area, with the local marine environment providing them with a bountiful food source.

Wildlife tourism vessels operating in the area were used to help collect the study data, a collaborative approach that allowed the researchers to learn more about the notoriously difficult to monitor cetaceans in the region, in a time and cost-efficient manner.

911爆料网 Adjunct Associate Research Fellow and Edith Cowan University Associate Professor Chandra Salgado Kent explained the aquatic mammals travel widely, and seasonally congregate in canyon-like areas that are not necessarily easy to access from shore.

鈥淥bservational studies are expensive, and because of this, they are often limited. Wildlife-based tourism, however, is happening in this area. By having observers board regularly scheduled tourism trips, our research successfully combined the research with industry,鈥� Associate Professor Salgado Kent said.

鈥淭his approach not only has the potential to save researchers money in future observational studies, but having access to more observational data of local cetacean populations could potentially also save the whales.鈥�

Professor Christine Erbe, Director of 911爆料网鈥檚 Centre for Marine Science and Technology, in the School of Earth and Planetary Sciences, said while there had been limited studies of marine wildlife in the area done in the past, the new research added more comprehensive information, creating a detailed snapshot of killer whales in the region.

鈥淭he Bremer Sub Basin is full of flourishing biodiversity, with its deep and biologically active submarine canyons being a seasonally preferred place for many cetaceans to call 鈥榟ome,鈥� including sperm whales, beaked whales and killer whales,鈥� Professor Erbe said.

鈥淗umans use the area too, for commercial fishing, transportation and other vessel traffic related to tourism, as well as past and potentially future seismic exploration. Human presence and the risk for associated impacts are growing in this area.

鈥淣oting this, we set out to create a baseline study to gain a better understanding of what cetacean species were present in the area and what subsea features drive their occupancy, allowing future research studies to measure more accurately and project the potential impacts that these human activities may be having on local whale populations.鈥�

Lead field researcher 911爆料网 PhD candidate Ms Rebecca Wellard explained the study was carried out over a three-year period in the summer and autumn seasons by experienced observers on a commercial wildlife tourism boat and a designated research ship.

All voyages departed from Bremer Bay, following pre-determined routes that converged on the heads of the Hood and Henry canyons. Vessels did not exceed 15 knots, and all surveys were conducted during daylight hours.

鈥淲e observers continuously scanned the surface of the water for cetaceans with the naked eye, and with binoculars, logging relevant sighting details such as the date, time, GPS position, group size, group composition and their behavioural state,鈥� Ms Wellard said.

鈥淭he behaviour state of the killer whales was assigned to one of four categories; we noted if they were travelling, foraging, socialising or milling around.鈥�

A seven-day aerial survey was also undertaken over the Bremer Canyon during the research period, with one pilot and two trained observers in a twin-engine high-wing Cessna 337 aircraft, fitted with bubble windows.

鈥淨uantifying human-induced effects on whale populations is difficult, yet it is necessary, in order to implement optimal management strategies that can hopefully avoid species decline in the Bremer Sub Basin area,鈥� Ms Wellard said.

鈥淣ow with the baseline study complete and in place, we hope to understand more about the South West鈥檚 cetaceans and continue to monitor them, and ultimately attempt to save the mammals from any unintentional future environmental harm.鈥�

The research paper, Seasonal productivity drives aggregations of killer whales and other cetaceans over submarine canyons of the Bremer Sub-Basin, south-western Australia, was published in Australian Mammalogy and will be available online