WHAT DOES IT MEAN TO BE A WHALE?
Scientists attempting to determine how changing environment affects cetaceans
Humpback whales are the size of school buses. Minkes, by comparison, are small ... for whales that is.
All of which is to say that Ari Friedlaender’s work seems almost ridiculously dangerous. To get the data he needs, Friedlaender must be close enough to touch humpback and minke whales.
Depending on the day, he and his team will attach one of two kinds of transmitters to the backs of whales to monitor their movements and feeding patterns, or they will be taking small skin and blubber samples.
The biopsy samples are used to determine how many are pregnant, how frequently they are reproducing, and how a population trajectory is changing over time.
Friedlaender’s team also use drones flown from zodiacs to get an estimate of the length of an animal as well as the width, which gives an idea of the whales’ body condition.
“Basically, we are trying to get a grip on what it means to be a whale in the Antarctic and what the threats are to their existence now, and how the animals are coping,” he said in a Skype interview from his office at the University of California in Santa Cruz before he returned to the Antarctic for his 20th season in late January.
The suction-cupped transmitters are only meant to stay on for a day or so. They track the whales’ underwater movements, the depths they dive to, how many times they feed and what depths they are feeding at. That data is used to determine the “energetic cost” of feeding.
Satellite tags last anywhere from weeks to months, sending back information several times a day about where the animals are. This gives Friedlaender data to infer more about seasonal, behavioural changes — are the whales migrating north during the Antarctic winter? Is that migratory pattern consistent or does it vary?
Because krill — tiny shrimplike crustaceans — are the primary food source for baleen whales such as humpbacks and minkes as well as most of the species in the Southern Ocean, how much food the whales are eating can, in turn, be an indication of the health of krill stocks. So far, climate change — warmer sea and air temperatures — has been good for humpbacks, which are making a comeback after an estimated 250,000 of them were hunted in the last century and their survival was in danger.
“The humpback whales are taking advantage of the fact
that there is less and less sea ice around the Antarctic Peninsula,” says Friedlaender. “The inverse to that ... is that while it’s a great place to be a humpback whale now, it’s a very bad place to be a minke whale.”
Because of their size, minkes weren’t heavily hunted and are believed to be the most abundant of the baleen whales. But minkes have evolved to use sea ice both to find their prey as well as stay away from predators. And with climate change, there is less sea ice.
Some research suggests that the minke population dropped 60 per cent between 1978 and 2004. If that decline is accurate, the International Union for Conservation of Nature says the species would qualify as endangered.
But the IUCN also says that so little is known about minkes that the data is insufficient. That is why Friedlaender’s focus this season has shifted more to minkes.
His hope is that his research — supported by One Ocean Expeditions, which provides Friedlaender berths on its ships, as well as with zodiacs and drivers — may help determine the need for a proposed conservation area in the Weddell Sea.
The sea borders the Antarctic Peninsula, which was one of the most popular whaling areas and remains a popular fishing ground. Last October, the European Union, along with several other countries, proposed to the Antarctic Ocean Commission that it be designated as an ocean sanctuary. That proposal was defeated.
But in January, Greenpeace launched a global effort to garner support for the plan, which will once again be before the commission this October.
“Understanding trends in these animals is a very longterm process because these are long-lived animals just like us,” says Friedlaender. “So, if they have a calf every two or so years and it takes them seven or eight years to mature, the time between when you’re going to see a change in the population might take a decade or two.”
Still, with one flick of a fin, any one of the whales could flip a zodiac and send the scientists flying into the frigid waters below the Antarctic Circle.
So, I can’t help smiling when, for what seems like the 100th time, our expedition leader Danny Johnston reminds us to be careful getting in and out of the boats as we head out to look for whales and other wildlife.
Because only a week ago, it was Johnston — a Texas-raised, former special education teacher and philosophy major — who was driving Friedlaender.