Each winter many Haligonians head south for a little sunshine. However, I overshot the more typical destinations and ended up in the Ross Sea, Antarctica.
I went to join a team under the leadership of Dr. Regina Eisert, of the Top Predator Alliance (with support from Pew, Antarctica NZ, and Boxfish Research, among others), investigating the behaviours of fish-eating killer whales: a major consumer of commercially important Antarctic toothfish. This work is in support of the recently establish marine protected area in the Ross Sea region, which seeks to ensure the fishery doesn’t affect toothfish predators and the local ecosystem.
One way to track killer whales’ movements is through the sounds they make, which is why I got involved: I investigate the effects of ship noise on right whales in my main role as post-doctoral research in the Maritimes with Fisheries and Oceans Canada.
Among other things, we planned to deploy underwater recorders together with surface time-lapse and underwater video to determine when whales are present, using techniques we tested successfully last year. The information will also help us explore the unique dialect of Ross Sea killer whales, allowing us to deploy acoustic recorders in offshore waters in the future to better understand where these specific whales spend their time.
The 24-hour sunlight allowed us to work at night when the whales are most active. The lower sun produces colours not seen in the day and creates shadows in the volcanic back-drop to our study site. (Antarctica is one of the most volcanically active places on Earth.)
Nightshift involved waking around 5 p.m. and having dinner before leaving Scott Base, New Zealand’s main Antarctic base. We’d survey the ice edge by helicopter, photographing any killer whales we saw for identification later and occasionally dodging a suicidal South polar skua (a local seabird related to seagulls).
Once we found a spot to work, we’d land on the sea ice and set everything up. Often the whales would leave, forcing us to move or simply await their return. As an extreme measure, we would break out a warm lunch, an almost guaranteed way to encourage whales to appear. At the end of the night, we’d return home to our dinner, a hot shower, and bed, while the other inhabitants of Scott Base began their day.
But nothing in Antarctica is ever that straightforward. Installing equipment requires a solid section of sea ice so that all your gear does not float away overnight.
Last year we used a channel cut by an icebreaker to allow supplies to reach Scott Base and the U.S.’s nearby McMurdo Station by ship. This year the channel refroze, closing it to both us and the whales.
Instead we collected as much acoustic data as we could from short deployments along the northern ice edge, while sections of the “ground” were frequently breaking off, a process called tiling. We also focused more on other parts of the project: including collecting DNA samples and filming underwater video using a remote operated vehicle (essentially an underwater drone).
This was all hard work. Despite the various recent reports that Canadian temperatures were colder than those in Antarctica, it’s still pretty darn cold down there. And that’s during the summer!
Several warm layers were needed most days in addition to our float suits that are standard safety kit where a dip into the Southern Ocean is a possibility. We’d also be juggling several pairs of gloves in an eight-hour working day, as warmer pairs do not allow for fine motor skills. Occasionally, some tasks required us to abandon gloves entirely, which is never good for the fingers.
A helicopter dropped us at our field sites but we had to carry heavy equipment right up to, and often up to a kilometre along, the ice edge (all depending on how cooperative the whales were that day). Often we had to shovel snow to reach solid sea ice and then drill holes through the ice. Manual labour is dangerous in those conditions, as sweating takes away more body heat as soon as you stand still.
Despite the threats, our field trainer kept us safe on the ice and our pilots kept us safe in the air. The broader staff of Antarctica New Zealand, the group responsible for logistics and science support in New Zealand’s Antarctic research efforts, kept in contact while we worked, kept us fed and made sure we had all the necessary field supplies. This solid support meant we did get some recordings despite the challenges, plus some amazing underwater footage (albeit not of foraging), eleven DNA samples and hundreds of photo-ID images of killer whales to expand our growing catalogue.
With this support, the team will hopefully get more data next year. Meanwhile, I have returned to the comparative warmth of a Maritimes spring.