Two years ago, Dr. Leigh Torres documented 50 blue whales in the South Taranaki Bight, some of New Zealand’s busiest and most industrialized waters. Now she’s back, seeking to learn just how many whales are there, how important it is as a feeding area for them, and to what population of whales these rare giants belong.
By Dr. Leigh Torres, Assistant Professor, Oregon State University, Geospatial Ecology of Marine Megafauna Lab
Everyone knows they are long (over 65 feet), they are heavy (more than 100 tons), and they are huge (heart as big as a car). But did you also know that blue whales are fast?
After deployment of our first hydrophone last week to listen in to the calls of the whales in the South Taranaki Bight, we went “on survey”—this is when we have dedicated observers on the flying bridge of the vessel looking for marine mammals. Not too long later, something caught my eye to the right and far off.
I might have let it go but Todd Chandler, a research technician from OSU, said, “I saw that, too.” He had seen me reach for my binoculars. I asked the captain to turn right and we continued looking and looking.
After about two miles of searching I was about ready to move on, but then we saw them: two blue whales bursting out of the ocean at high speed, right next to each other.
They were racing.
It is not completely understood why blue whales race each other, but it has been observed previously in different regions of the world. The most accepted hypothesis is that it is a form of male competition—trying to impress the ladies.
The two blue whales raced each other for about 40 minutes, moving at a constant speed of 15 knots (17 mph), but with bursts of 18 knots (20 mph). The fastest human swimmers max out at about 3.5 knots (4.5 mph).
Truly amazing to witness these animals surging along like this. It takes incredible energy and power to force their massive bodies through the water.
Fortunately, our research vessel (the NIWA R/V Ikatere) is also fast. Our task was to find them, pace them, and let them continue their remarkable behavior without disturbance, while also documenting the behavior and collecting our photos and biopsy samples. Tricky. With a truly team effort, and help from the whales when they slowed down occasionally, we succeeded.
We paced the whales nearby, watching them explode through the water side by side. So close they could have been touching each other.
We managed to capture photos of both the left and right sides of both whales (important data used to identify individuals) and small tissue samples of both individuals (for genetic and stable isotope analysis). Neither of these tasks are easy to accomplish when the vessel is moving at 15-20 knots, bouncing on the ocean, and the whales are moving rapidly.
This remarkable sighting reminded me of the importance and brilliance of field work—it really is never “the same” as we are always learning and observing new, remarkable aspects of our surroundings.
More to come soon as we continue our blue whale research in the South Taranaki Bight of New Zealand.