Eye Witnesses

Bubble-Net Fishing By Humpback Whales

by Lucas Barrow-Townsend

While on a cruise to Alaska, we took an excursion to go Whale Watching on Auke Bay close to the state capital Juneau. This is the summer destination of humpback whales which have journeyed from Baja California to feed during the summer. Our boat sailed into the bay and a few minutes later our lady captain announced that they had spotted a pod of whales and were immediately steering towards them.

A few minutes later with great excitement she informed us that there were about sixteen whales in the pod and furthermore they appeared to be ‘Bubble-net Fishing’. She went on to say that she herself had only seen this once before. We of course didn’t understand what she was talking about but she explained that the pod of whales had evidently found a shoal of fish and had devised an ingenious means of catching them.

This involved the lead female whale, often over 35 feet long and weighing some 45 tons and assisted by other whales, to swim in a circle below the fish exhaling air bubbles which rise to the surface and confuse the fish which tend to stay within the circle (net) of bubbles. The lead female then gives an audible hoot under water, which we could actually hear on the ship’s hydrophone. This evidently was an order to the other whales to lunge upwards with their jaws fully opened to catch the fish trapped in the bubble net. As the ship got closer we saw several re-enactments of this performance and the sight of so many whales simultaneously hurling up out of the water in a such a tight formation was truly exciting and awesome. The excitement was amplified by the behaviour of hundreds of sea birds who dived and screeched over the area as they themselves attempted to catch the fish thrown into the air.

Seeing and hearing all this was a truly remarkable and memorable experience which we of course tried to photograph. That however, was quite difficult as we didn’t know exactly where the pod would plunge upwards out of the water so, by the time we focussed the cameras we were often taking photographs of massive whale tails disappearing into the water. Since then we have learnt that Bubble-net fishing occurs only very occasionally. Apparently not all humpback whales and whale pods can actually perform in this mode of fishing and scientists now believe that those that do so have had to learn and be taught the techniques as individual whales and as a pod working together.

Such is the wonder of nature!

Roger and Margaret Townsend