Travelling south with a marine biologist
By Jim Zakreski
As a marine biologist from Canada, I never gave Antarctica much thought. Wasn’t it that big hunk of ice and snow somewhere “down there”? Heck, if I wanted ice and snow all I had to do was to step outside my house. Perhaps it was my natural curiosity for all things wild that led me to investigate Antarctica further. Besides, wasn’t there an ocean “down there” as well?
The journey south begins on the Beagle Channel. This channel is a great habitat for a variety of seals, dolphins, and whales. It is not uncommon to catch a glimpse of South American sea lions posturing on the many islets or foraging for food in the kelp beds. Peale’s, dusky, and hourglass dolphins often roar up to the ship escorting the vessel while entertaining those aboard with stunning aerobatic displays.
As the Beagle Channel widens and nears the open ocean sei, fin, and humpback whales can be seen hunting the shallows. They’re in search of krill and small fish forced to the surface by upwelling and prevailing oceanic currents – a testament to the richness of this area and a harbinger of things to come.
Where the Beagle Channel ends, the Drake Passage begins. The Drake Passage is part of the vast Southern Ocean spanning the gap between the Antarctic Peninsula and the southernmost point of South America. This ocean surrounds the continent of Antarctica and is an extension of the Southern Atlantic, Pacific and Indian Oceans. There are many ways to define the boundaries of the Southern Ocean. Most biologists would likely define this boundary as all waters south of the Antarctic convergence.
The Antarctic convergence, or polar front, is simply the area where the warm, temperate northern waters meet the cold, nutrient-rich Antarctic waters. It is here that the wind blows west to east uninterrupted creating the Antarctic Circumpolar Current. The resulting boundary formed by the combination of these phenomena is as formidable as any terrestrial mountain range – the result being organisms unique to each side of the polar front in quantities that truly boggle the mind.
Euphausia superba is a species of krill unique to the Southern Ocean. It is known as a keystone species – a staple in the diet of most birds, seals, and whales living in the Southern Ocean.
When crossing the Drake Passage, one enters the realm of some of the largest animals to ever live on our planet. Blue, fin, sei, humpback, sperm and minke whales can be encountered as well as some of the least seen and understood species known, the beaked whales. These whales exploit the many trenches, troughs, pinnacles, and banks that characterise the Drake Passage.
As one approaches the Antarctic Peninsula the ocean shallows and the seas calm as the result of the protection gained from the continent, mountains, and islands. The wildlife abounds as the sea ice has melted releasing nutrients into the cold, oxygen-rich, sun-drenched waters. Plankton blooms quickly follow, providing Antarctic krill a seemingly endless food source. It is the resulting concentrations of krill that make the Antarctic Peninsula a destination for migrating whales. It can be said that if the animal you are watching does not directly eat krill then the animal it eats, eats krill.
Encounters with humpbacks and minkes are the norm in the Peninsula, but these beauties are the by-products of my passion as a marine biologist: the search for, and study of, orcas.
Currently, there are at least four orcas ecotypes that ply these waters. Killer whales are apex predators that rule the oceans of the world. To encounter them on their terms in such a pristine and unique setting can only be described as spiritual.
Thanks to expedition travellers and staff actively contributing to citizen science projects, the cataloguing of wildlife in this remote part of the world has begun. The information gained is changing the way we see our planet.
Jim is a Marine Biologist and received his BSc in biology from the University of Victoria. For the last 21 years, Jim has been a captain and a marine biologist in the whale-watching industry of southern Vancouver Island, where he hones his wildlife-spotting skills primarily in the search for orcas, his passion.
Image by David Merron