Of all the Antarctic mammals surrounding the Western Antarctic Peninsula, seals are the most frequently observed as we travel from dive site to dive site. There are five different species of seals found in this area of Antarctica and each species is unique in appearance and behavior.
The most abundant species of seals are referred to as fur seals. These are the smallest seals weighing an average of 100 kilograms at three to four feet long. These seals are usually seen in packs of two or three playfully wrestling around on the shores of islands or swimming together from island to island, however fur seals are also solitary. They are a dark chocolate color with a puppy-like face and a great disposition. As most seals found in this area, their primary food source is krill, a small crustacean that looks similar to shrimp. Although fur seals are not as curious about the divers as some of the other species, it is not uncommon to come upon a dive site and stay within twenty or thirty feet of a fur seal throughout the entire dive.
Elephant seals are another species that frequents the shores of the islands near Palmer Station. These guys definitely live up to their name with males weighing over 1000 kilograms sometimes over twelve feet long. I hate to say it, but these guys are ugly and they smell terribly.
For a while I thought these were the laziest mammals in Antarctica until Dr. Dan Costa's science lecture. Dr. Costa and his team of sealers study the migration and overall behaviors of elephant seals, and crabeater seals in the waters of Antarctica. According to Dr. Costa theses huge elephant seals travel great distances along the Western Antarctic Peninsula and dive to depths of over 500 ft while feeding on squid and deepwater fish. I, on the other hand, have only seen these guys lying around on their favorite islands bellowing and grunting in a low pitch.
Leopard seals are a species of seal that I would rather not encounter while diving. These are one of the top predators in the area and are magnificent animals. They are amazingly agile and extremely curious and seemingly fearless. These seals will literally come right up to the zodiac and then hover over the divers while they are still in the water. They travel alone most of the time, although we have encountered them in pairs but that is unusual.
Leopard seals are grey and spotted with a large head and wide powerful jaws. The females, which are the larger of this specific species, weigh up to 370 kilograms and have been found at lengths over 12 feet. They are the bully of Antarctic waters feeding on anything they please from krill, to penguins, to the smaller fur seals.
The last two species of seals are crabeater seals and weddell seals. These are not as common in this particular area but have been spotted from time to time. The only weddell seal I have encountered was not the least bit concerned about the divers. We positioned the zodiac ten feet from the weddell. The seal turned its head nonchalantly and then slowly dove beneath the surface. Weddell seals are a grey color, much like leopard seals, with a rounder head and smaller mouth. These seals have a very distinct call that is referred to as the weddell song.
Both crabeater seals and weddell seals feed primarily on krill. Crabeater seals are dark brown with a short snout similar to a bulldog or pitbull. They spend a fair amount of time on ice floats and small pieces of icebergs in colder waters than we have around Palmer Station. Like the elephant seals, Dr. Costa has records of crabeater seals migrating great distances in responses to ice cover and therefore krill abundances.
As an antarctic SCUBA diver, it is not hard to admire these true champions of antarctic diving.