Investigating Humpback Whales in Antarctica by Engaging Expedition Cruise Passengers
Covering up to 5,000 miles, or 8,000 km, each way of their migration, humpback whales have one of the longest seasonal migrations of any mammal. Some overwinter and breed in the tropical waters off Colombia’s Pacific Coast before swimming south to their Antarctic feeding grounds in the Antarctic Peninsula to forage on krill. However, despite being able to track their migration over these vast distances, our knowledge about the behaviour and population structure of the whales found in Antarctica is limited.
Meanwhile, just as scientists are striving to understand the status of these magnificent cetaceans, climate change is changing their marine environment around the Western Antarctic Peninsula. This could change the distribution and amount of krill – the whales’ primary food – which could affect their foraging strategies and even their migratory patterns. It’s a race against time to understand their behaviour now, before it’s changed forever.
Identifying cetaceans with the help of Hurtigruten’s passengers
To learn more, scientists from Colombia’s Universidad de los Andes needed a way to get close to these mighty mammals. By joining a Hurtigruten Expedition cruise ship, they were able to travel to the Antarctic feeding grounds and remain there for extended periods of time. What’s more, they could put the many keen eyes of the passengers to work observing and documenting their sightings.
Alongside visual observations and photo identification, the scientists use a special ‘remote biopsy’ rifle that shoots a shallow dart into the skin of humpback whales – as well as other cetaceans such as dolphins. These harmless darts take a tiny sample of skin before falling out and floating to the surface where the scientists can recover them. By then profiling each animal’s DNA, the scientists can build a better picture of which other individuals they are related to and where else they roam.
A perfect fit for Hurtigruten
Scientists also use eDNA samples to track marine mammals. Short for ‘environmental DNA’, eDNA works by gathering water samples where whales have very recently been in order to capture microscopic traces from their bodies, such as skin cells. This is an ideal activity for Hurtigruten’s guests, who can actively participate while watching for whales from a small boat. Later, the scientists can analyse the samples in the Science Center aboard MS Fram to find DNA from the whales and other creatures, sharing their findings and enriching the experience of everyone involved. With multiple techniques, passengers and scientists alike can make useful contributions. The passengers also had “hand on experience” on how to extract DNA from the skin biopsies they helped collecting, just as scientist do in the laboratory. In fact, these DNA extractions, will be then used for the following analyses steps. What’s more, when the weather is unsuitable to conduct small boat surveys and take water samples, observers can still gather data on cetacean distribution, make photo identifications, and record environmental data – all from the safety of the ship’s deck. Hurtigruten Foundation has supported the scientists’ work by providing them with cabins and all the amenities aboard MS Fram, as well as the valuable help of the crew on two expedition cruises, and an additional NOK 75,000 (approx. $8,500) to purchase the necessary equipment and materials.
Findings that will keep on giving
By comparing photographs and DNA profiles of individual humpback whales taken in the Antarctic to photographs taken at the tropical breeding grounds, scientists are increasing our knowledge about the behaviour of these majestic cetaceans by understanding more about the complexity of the connections between the whales found at these places. They have already shown the humpback whales found off the Western Antarctic Peninsula are highly genetically diverse and are now increasing their knowledge about the fine-scale population structure and genetic diversity. This is part of a concerted effort to sample humpback whales around both the Western Antarctic Peninsula and the tropical breeding grounds over the next decade, to help illuminate any patterns linking climate change, oceanographic conditions, and the movements of the whales.
Where can I learn more?
You can read more about how non-scientists can help track whales at Happywhale.If you would like to learn more about Hurtigruten’s expedition cruises to Antarctica, you can find it here. You can follow the scientists experience in their blog.