When you go on or begin planning any sort of wildlife tour, the first thing you should consider is that wildlife is well, wild, and unpredictable at that. Nothing is guaranteed, but you always have the things that you hope to see. Of course as a guide we can't call the wildlife to action, but it is important for us to know what your wishlist is so we can modify our tours to try to maximize the chances you'll see those things. This summer, regardless of the week, the Top 3 list always included bubblenet feeding whales. It's something you always hear about, especially as we learn more and new, sexy, articles and videos come out about the subject.
But what is bubblenetting, and why is it so exciting and enticing? Whales usually feed alone or in pairs, finding a school of small fish and engaging in a behavior called lunge-feeding. They are not pack animals like orca, and prefer to keep to themselves. After a very short dive, the whale(s) open their lower jaw completely, flex their tail and lunge forward on the surface or right below the water. They capture tons (literally) of water and, hopefully, bunches of fish as well. As baleen whales can't swallow salt water, they then close their lower jaw which forces the water out of their mouth and their baleen trap fish, kelp, krill, and anything else inside. This kind of feeding is quite common and seen almost every week last summer.
Bubblenetting, on the other hand requires a set of very specific circumstances before whales even think about setting up together. First and foremost, there has to be lots and lots of food. Enough food for 8-12 whales to continually feed for at least an entire day, which is...a lot. The food has to be there for an extended period of time so the group can make it energy efficient to travel there and then to partake in the actual action of bubblenetting. But if all these criteria are met, and the whales are around, sometimes a bubblenet will occur and the fun begins.
Once they've grouped up and talked about it, roles are assigned. Groupers circle around the fish, blowing bubbles as they swim. It took me a while to understand why the bubbles would matter to a small fish, but the chemist in my finally made my brain understand. Each bubble creates surface tension and a large number of these bubbles, especially quick moving ones, create an impassable barrier to small fish. While all this is happening at various water depths, one whale stands almost vertically about 20 feet below the commotion. This is the shot-caller and their job is to signal the others when to tighten their net, and then to all dive together and lunge upwards, engulfing the trapped fish.
This extremely intricate process is beautiful to watch and even to just think about. Keep in mind that these are 20-ton, 45-foot long whales. And that there's 8-12 of them in a small space. All in all, it's a feat of nature to pull all this off but whales are insanely good at it. And if you're lucky enough to get to see this happen in person it can truly be life changing.
Throughout our summer, we got better and better at finding these sets of whales, or just got luckier. But the fact of the matter is it got to almost be predictable in where we might find them. Simultaneously we were learning the conditions in which they preferred, and finding areas more and more often. Anyways, there's only one more enhancement to my knowledge and personal experience with the activity, which I've already mentioned in my blog post here: Talking To The Whales in which I put a hydrophone in the water and we cut the engines in order to hear the shot-caller talk to the others.
If you want more detail click on that link, but after multiple hours of listening to these whales speak, hearing the switches in shot-callers and learning the timing of it all, I feel like now I can understand whale. Being able to narrate this kind of activity with confidence is such a privilege I never thought I'd have. I hope I've been able to portray all this with enough accuracy and experience that through these two articles you too feel as if you understand these beautiful creatures.
I'll be publishing a whole bunch of whale bubblenetting, breaching, and lunge feeding sequence shots soon, so make sure to keep an eye out for those if you enjoyed learning about whales!