*Note: this summer, we are fortunate to share live updates on research being conducted by Vancouver Aquarium’s Cetacean Research Lab, whose team is traveling along the coast of British Columbia to gain additional insights that will support its groundbreaking cetacean research.
This fifth installment from the past week was authored by Lance Barrett-Lennard, head of the Aquarium’s Cetacean Research Program, and research assistant Meghan McKillop.
Friday, June 29 – In view of a favourable early morning weather forecast (light winds) and an absence of reports of killer whales anywhere in our vicinity, we decided to run back up the coast to Caamaño Sound, where we knew sport fishermen were having some success catching Chinook salmon – also the favoured prey of resident killer whales. We ran west out of Seaforth Channel, across Milbanke Sound, past the lighthouse at McInnes Island and west into Hecate Strait.
The winds were relatively light as we surveyed along the Hecate Strait side of Aristazabal Island, but the visibility was restricted by drizzle and fog – at times dropping to a mile of visibility or less. We heard nothing on the hydrophone and the only cetaceans we saw were a group of frisky Dall’s porpoises that came speeding over to play in our wake.
After a careful but unsuccessful search for transient killer whales among the harbour seal haulouts in the beautiful Harvey, Moore and Anderson Islands, we finally anchored up at 8:30 p.m. in Borrowman Bay, on the northwest end of Aristazabal Island. Scientists constantly remind themselves that “negative data” – in this case documenting the absence of whales – is a useful finding, but most would admit that obtaining “positive data” is more satisfying. Fingers crossed for tomorrow.
Saturday, June 30 – Woke up to a cool breeze that stiffened considerably as we motored out of our anchorage. Following our usual routine, we stopped as soon as we were clear of land to listen to the hydrophone while making breakfast. As we were eating, we heard a loud, long flute-like note on the hydrophone. It was immediately familiar, but took me a minute or two to recall where I’d heard a similar sound before – and then I remembered. It was in southeast Alaska, in the vicinity of humpback whales using a group feeding technique called bubble netting.
Bubble-netting is a highly-coordinated hunting technique used by groups of three to six or more humpbacks to corral small fish or krill into schools that they can engulf in massive mouthfuls. The whales start by diving below their prey and blowing a ring of bubbles around them. The rising bubbles form a circular curtain that the fish are reluctant to cross – they are, in fact, trapped. The whales then lunge up through the cylindrical curtain in a group, driving the prey ahead of them and gulping them down as they approach the surface. The flute-like call coordinates the behaviour which, as you can imagine, requires that all the whales do the same thing at the same time.
Scanning with binoculars, we quickly spotted four whales simultaneously erupting from the surface a mile from our location. We quickly pulled up the hydrophone and motored over to take identification photos of the whales and to try to determine what they were eating. Both objectives were fulfilled at the same time, as our photos clearly showed herring spilling from their mouths every time the group lunged to the surface. After an hour or so we moved on to search for killer whales, feeling very privileged at being able to witness to what must be one of the most spectacular sights in the natural world.
As we turned in to Caamaño Sound a few miles later, we called our colleagues at Cetacealab, a remote whale research station situated on the south end of Gil Island. They passed on a report of killer whales in Whale Channel, about 15 miles north of us. We immediately headed to the vicinity, spotting the whales close to shore at 2:30 p.m. They turned out to be mammal-eating transient-type killer whales, now commonly referred to as Bigg’s killer whales. Six whales were present in the group, all five of the T60s, including a new calf less than a year old, and an old female called T2B – also known as Pedder.
The whales cruised slowly along the shore of Gil Island, passing right in front of Cetacealab before turning south to move slowly out towards open water. We took ID photos as always, dropped the hydrophone to eavesdrop (as usual with transients, they were silent), and then slowly paralleled their course at a distance of 500 m to watch for signs of hunting or feeding. They seemed sleepy and satiated however, and showed no interest in feeding…although they did pass close enough to a humpback whale to give it a good scare!
We finally left them at 8 p.m. and an anchored for the night in Emily Carr Inlet – a beautiful bay entered through a tiny gap, impassable to boats bigger than the Skana!
Sunday July 1 – When we woke up this morning, the tide was very low and we had to carefully pick our way through the ‘backdoor’ of Emily Carr Inlet – a second gap only slightly wider than the first. The weather forecast for the day wasn’t great so we decided to stop in at Cetacealab to visit with the directors Hermann Meuter and Janie Wray, and their staff and volunteers to exchange photos and recordings taken the day before.
After our visit at Cetacealab, we continued our survey up Whale Channel. We saw a couple groups of Dall’s porpoises rooster-tailing along the surface – a good indication that there were no transient killer whales hunting in the area – and a couple humpback whales. Then we ran up to Hartley Bay to refuel and fill up our water tanks before anchoring for the night in Hawk Bay on nearby Fin Island.
Monday July 2 – The weather forecasts have been inconsistent the last couple of days. Last night the forecast called for strong southerlies but we were pleased in the morning to hear that lighter winds were now called for. If this forecast was accurate, it would mean that we could work our way down the west side of Aristazabal Island, which gave us a better chance of finding killer whales than in the sheltered pass on the other side.
We left our anchorage and travelled through Otter Channel, down Estevan Sound and across Caamaño Sound. The seas were moderate in Estevan Sound, picking up considerably in Caamaño Sound (likely due to a combination of wind on current) and were moderate again off the northwest tip of Aristazabal Island. We heard the wonderful sounds of feeding humpbacks again on the hydrophone and saw a couple surfacing near shore.
As we continued down the west side of Aristazabal Island, we saw a group of Dall’s porpoises zigzagging around and throwing a rooster-tail splash behind them. But as we continued, the wind picked up from the southeast rather than switching southwest and abating, as predicted. We had to run straight into the rapidly building swell, and were forced to turn around and run back up around the north tip of Aristazabal Island, where we could take cover in Laredo Channel.
We listened to the revised weather forecast at 4 p.m. and found it was significantly different from the one in the morning, making us glad we had turned back. We surveyed across Laredo Sound to Meyers Pass, then down Tolmie Channel, into Finlayson Channel. The rain had now changed to showers and Finlayson was sheltered and calm. Drifting on a calm sea under a leaden sky eating our dinner, watching distant humpback whales among the rain showers and listening on the hydrophone was worth the stormy day. The full moon burst through the clouds and stars began to appear just after we anchored in Nowish Cove – a second bonus.