Sperm whales off Western Australia

by Chris Johnson

"Crowdsourcing Moby Dick! Modern and historical data identify sperm whale (Physeter macrocephalus) habitat offshore of SW Australia" is a research project years in the making and was my Master of Science thesis at Murdoch University (2011-2013).

As part of the Voyage of the Odyssey expedition from 2000-2005, we published a wide variety of research related to the primary mission of the project - sourcing tissue biopsies from sperm whales to build a baseline dataset of global pollant levels. Studies included a number of toxicology reports sperm whales on levels of chromium, cadmium, arsenic, lead,  silver, mercury and selenium found.  In addition, we produced papers on acoustics and sightings of cetaceans in areas with historical low research effort, such as the Maldives and Sri Lanka as well as encounters of rare animals such as the Longman's beaked whale.

The aim of the project was to explore Odyssey's database to see if it could be used to model sperm whale distribution off the coast of Western Australia. Historically, an area of commerical whaling until 1978, research was primarily conducted via aerial surveys due to poor weather.

I went back over records in the Odyssey database, spoke with a number of modellers, and the consensus was we could not produce a model solely with these data. This was because Odyssey always searched for sperm whales travelling along the -1000m to -2000m depth contours, the areas of submarine canyons, listening for animals through our acoustic array. This gave us the best chance of quickly locating sperm whales to take a biopsy. As we were not conducting a survey such as a line-transect which modellers primarily like to estimate abundance and distribution, I had to take another tack.

The trackline of the RV Odyssey (2001-2002) off the coast of Western Australia. The orange areas are where we heard sperm whale echolocation 'clicks'.

The trackline of the RV Odyssey (2001-2002) off the coast of Western Australia. The orange areas are where we heard sperm whale echolocation 'clicks'.

 

Crowdsourcing is a term used in a variety of industries as more information is becoming available online. By gathering various information from various sources, this approach can help inform the decision-making processes. However, data is in a variety of formats which makes answering a question, sometimes very challenging to answer. The following is the abstract from my project and we are currently submitting it for publication.

Any questions, please feel free to contact me.

Project AbstRact

The distribution and use of pelagic habitat by sperm whales (Physeter macrocephalus) is poorly understood in the south-eastern Indian Ocean off Western Australia.  However, a variety of data are available via online portals where records of historical expeditions, commercial whaling operations, and modern scientific research voyages can now be accessed. Crowd sourcing these online data allows collation of presence-only information of animals and provides a valuable tool to help augment areas of low research effort. Four data sources were examined, the primary one being the Voyage of the Odyssey expedition, a five-year global study of sperm whales and ocean pollution. From December 2001- May 2002, acoustic surveys were conducted along 5,200 nautical miles of transects off Western Australia including the Perth Canyon and historical whaling grounds off Albany; 57 tissue biopsy samples were also collected.  To augment areas not surveyed by the RV Odyssey, historical Yankee whaling data (1712-1920), commercial whaling data (1904-1999), and citizen science reports of sperm whale sightings (1990-2003) were used. Using Maxent, a species distribution modeling tool, we found that the submarine canyons off Albany and Perth provide important habitat for sperm whales. 

Current technology along with current understanding of sperm whale bioacoustics and habitat preferences provides strong motivation for undertaking long-term passive acoustic studies that can monitor the sperm whale population within Australia’s EEZ waters (Perth and Albany canyons) as a way of informing future marine management and policy decisions