After leaving Paulet Island we set off on the forty mile trip to Brown Buff, which is a beach on the Antarctic mainland. I had a quick lunch before heading back up to the port bridge wing to look for Cetaceans and Emperor Penguins. There were plenty of ice floes with Adelie Penguins sitting on them, but not unexpectedly, no Emperor Penguins.
I noticed the Expedition Leader Ali was inside the bridge. I popped my head inside to check if she had seen the Fin Whale. She was watching some more distant Fin Whales, about a mile or two further away, along with a pod of Orca. She asked the bridge crew to turn to port and to slowly approach the Orca, while she put out a message on the Tannoy about the Orca. Despite only being relatively close, it took a good fifteen to twenty minutes to reach the Orca, as the Plancius slowed down for a very gentle approach. One of the great things about the Plancius is she is an ex-Dutch Navy submarine hunter and research ship. As a result, she is a very quiet ship in the water and the bridge crew are very capable of approaching Cetaceans slowly without spooking or disturbing them.
One of the Fin Whale resurfaced which allowed its identification to be confirmed.
As we got closer I checked my photos and improved the exposure settings so they weren't over-exposed.
After we departed, I asked Ali if the Orca could have been following the Fin Whales because there was a calf there: not that I had seen a calf surface. Ali said there weren't interested in the Fin Whales and introduced me to the complexity of Orca taxonomy. At the time, there was thought to be one species of Orca. However, there are a number of very distinct and in some cases, well studied populations of Orca. These were Type B (Small) Orca which are also called Gerlache Orca. They are believed to feed on fish, squid and the occasional Penguin. The likelihood was there were lots of Fish in the area, which had attracted the Orca and Fin Whales.
The excellent Marine Mammals of the World Ed 2 states "the taxonomy of this genus is clearly in need of revision, and it is very likely that the Orca species will be split into several species and/or subspecies over the next few years. Provisionally, the Marine Mammalogy recognises Resident and Transient (Bigg's) Orcas as unnamed subspecies". It describes some of the more distinct populations as:
Antarctic Forms
- Type A Orca - They are a large black-and-white Orca with a medium-sized eyepatch orientated parallel to the body axis and normally without a cape. They are a circumpolar Type and occur in ice-free Antarctic waters areas, where they mainly prey on Antarctic Minke Whales. They migrates to lower latitudes and appears to spent more time there than Types B and C
- Type B Large (Pack Ice) Orca - They are a large two tone grey-and-white Orca with a dark grey dorsal cape and pale grey sides. Individuals acquire a coat of diatoms (algae) in Antarctic waters giving them a dull yellowish wash. The eyepatch is very large and orientated parallel to the body axis. They appear to have a circumpolar distribution in Antarctic waters. They feed mainly on Seals that are often found around dense pack ice. The BBC have filmed this Type in the Antarctic Peninsula spy-hopping to search ice floes for resting Seals, then working together to create waves which knock the Seals off the ice floes. They undertakes rapid round trips to the Tropics, but appears to spend most of its time in Antarctic waters
- Type B Small (Gerlache) Orca - This Type are about one metre smaller than the Pack Ice Orca and perhaps weigh only half the weight. They are a two tone grey-and-white Orca with a dark grey dorsal cape and have a large eyepatch which is orientated parallel to the body axis. Individuals in Antarctic waters can acquire a coat of diatoms (algae) giving them a dull yellowish wash. They are a deep diver and are most often seen foraging in relatively ice-free waters where it appears to feed on fish, squid and the occasional Penguin. They undertakes rapid round trips to the Tropics, but appears to spend most of its time in Antarctic waters
- Type C (Ross Sea) Orca - This is a dwarf Type of Orca about one to three metres smaller than the large Types of Orca. They are a two tone grey-and-white Orca with a distinct cape and a narrow slanting eyepatch which is orientated about 45 degrees to the body axis. Individuals in Antarctic waters can acquire a coat of diatoms (algae) giving them a dull yellowish wash. They are currently only known from Eastern Antarctica, where they hunt fish along the fast ice edge and deep into the leads. They undertakes rapid round trips to the Tropics, but appears to spend most of their time in Antarctic waters
- Type D Orca - This newly recognised Type is a black-and-white Orca with a tiny eyepatch which is orientated parallel to the body axis. The melon appears more bulbous than in other Types and the dorsal fin may be more falcate and pointed. They have a circumpolar distribution in Antarctic waters, but are perhaps restricted to Subantarctic waters.
North Atlantic Forms
- Type 1 Orca - They are a small black-and-white Type of Orca, with a parallel eyepatch which feeds on schooling fish (Herring & Mackerel)
- Type 2 Orca - They are a large black-and-white Type of Orca, with an eyepatch which slants downwards in the rear and which may feed mainly on Cetaceans.
North Pacific Forms
- Resident Orca - They are a medium-sized Orca which often inhabit inland waterways where they feed on Fish (mainly Salmon). They are often found in very small pods of one to twelve Orca, but some pods can be as many as fifty. An important feature is a dark saddle within the otherwise larger pale grey saddle
- Bigg's (Transient) Orca - They are slightly larger than the Resident Orca, with a more pointed dorsal fin. They do not have the a dark saddle within the otherwise larger pale grey saddle. They are often found in very small pods of one to five Orca. They are Mammal-eaters, taking mainly Common Seals, but also Minke Whales, Dolphins, Porpoises, Sea Lions etc
- Offshore Orca - They are the smallest of the North West Orca with a relatively small and more rounded dorsal fin. They are often found in very large pods of fifty to one hundred Orca around the continental shelf edge and thought to regularly feed on Sharks.
After the best part of an hour we had to move on, if we were to get a second landing in at Brown Bluff that afternoon. While it wasn't dark till around ten or eleven that evening, many of the passengers would have wanted their dinner on time and secondly the kitchen staff would already be starting to prepare for dinner.