Rarely seen beaked whales spotted off Kangaroo Island, Australia
Together with colleagues from Marine Conservation Research (who operate IFAW’s unique whale research vessel Song of the Whale) and a bunch of experienced Australian whale researchers, I set sail last month on a study of whales off the west coast of Kangaroo Island.
The waters off Kangaroo Island are considered to be a whale hotspot--numerous government documents and previous research point to this area as important for a range of whale and dolphin species. Despite this broad understanding, detailed scientific data are severely lacking for this area, particularly during the months of April and May.
This is also the location and time of year that Bight Petroleum, an oil and gas company, intends to conduct seismic testing to try and locate oil and gas under the sea bed. IFAW is very concerned that such an intrusive, noisy activity could be allowed to commence in a place where a thorough assessment of its importance to whales has yet to be carried out.
So we set sail on the SV Pelican to conduct a visual and acoustic survey. Throughout the survey, observers looked for whales during daylight hours in suitable conditions and acoustic monitoring was conducted 24 hours a day, using underwater microphones called hydrophones. As whales and dolphins spend very little time at the surface and use sound to communicate, navigate, and find prey underwater, acoustic monitoring is one of the most effective methods to detect these animals.
We spent long days surveying the area of interest, listening to the world beneath the waves and collected large quantities of acoustic data. Then, on the last day in our survey area, the weather and sea conditions improved considerably and the mood of the team became increasingly enthusiastic, as we all agreed that conditions were ideal for spotting whales.
Luckily enough for us, we didn’t have to wait long! During a morning shift change, field assistant Bec Wellard suddenly shouted “blow!” and after double checking through her binoculars, confirmed there was a group of whales on the horizon.
As we tracked the whales, we soon realized that they were in fact, beaked whales. Sightings of beaked whales are usually very brief as these whales are not normally curious around boats, so we were very surprised when the three animals began to approach our research vessel. This gave us great views of their body size, well-defined rostrums (beaks), unique head shapes and distinctive body coloring, which enabled us to positively identify the animals as Shepherd’s beaked whales, one of the world's most rarely seen whales!
These very mysterious marine mammals have only ever been seen a handful of times worldwide. They are one of the larger species of beaked whale, measuring about seven meters long, which is around half the length of a humpback whale. Little information exists about the diet and diving behavior of Shepherd’s beaked whales, but other beaked whales dive to depths of up to 1,000 meters for prolonged periods, searching for squid and fish in deep underwater canyons.
Worryingly, beaked whales are the group of whales thought to be the most susceptible to the negative impacts of man-made noise. Strandings and deaths of beaked whales have been linked with the use of military sonar and it is thought that other noise sources, such as shipping and seismic testing, are likely to affect this acoustically sensitive group of whales.
You can read about our encounter here on the piece ABC ran about it recently. While we’re still analyzing all of the acoustic recordings we made during the survey, it is our hope that this unique sighting will contribute to the limited knowledge of these elusive whales and this remote and pristine whale hotspot.