TYPE D ORCAS: mysterious stalkers of the Southern Oceans

It’s not often for large animal species to remain a mystery nowadays. One animal which does indeed deserve this title is a virtually unknown ecotype of the orca: Type D. Not many people have seen this unique type of orca with their own eyes. I therefore consider myself lucky that I have met these animals.

Written by Ernst Schrijver

 

Worldwide, orcas are being divided into subspecies, also called ecotypes. These ecotypes differ in morphology, diet, behaviour and genetics. Five such ecotypes have currently been described in the Southern Ocean. The most remarkable of these has to be the Type D. There are currently discussions going on within the scientific community, surrounding this type. Analyses of its mitochondrial DNA have given reasons to declare this type as its very own species.

 

Almost ridiculously small eye patch
In terms of morphology, Type D orcas are very different from other types in the Southern hemisphere. The Type A is the quintessential orca people are familiar with. Then there are the Types B (divided in a large and small form) and C, which subtly differ in the shape of the dorsal fin and more obviously in the positions and shapes of the eye patches, saddle patches and colour. Type D’s, on the other hand, differ substantially in terms of morphology. They lack a snout and the heads are more blunt. The dorsal fins are more pointed and less prominent. Then there’s the almost ridiculously small eye patch, which is a great way to identify this type of orca.

Illustration of a Type D male and female (© Uko Gorter)

Found in the Southern hemisphere, the Type D has first been described in a mass stranding event in New Zealand in 1955. After this, only sparingly has it been observed by science. It is my opinion, that the major cause for this is the wild, vast waters of the Southern Ocean, inhabited by these animals, but infrequently visited by researchers. Additionally, the often rough weather creates very difficult conditions for observation. There are reports from long-line fishermen, who do interact with this subspecies every now and then. I believe some of these fishermen frequently encounter these orcas, but are oblivious with regards to the rarity of this type, or even lack the ability to distinguish between the five different types of orcas which inhabit these southern fishing grounds.


Fishing trip to the end of the world

I have been lucky to have traveled on one of these fishing vessels south of Cape Horn, where I had an encounter with these illustrious marine mammals. Let me take you back to May 2015, when I started my journey in Punta Arenas, which would take me on a fishing trip to one of the most unique habitats on earth.

Tuesday 26 May 2015. At this moment I find myself about 100 kilometres south of Cape Horn. It’s still dark outside and we set out two lines last night in order to catch Chilean Sea Bass at depths ranging between 1000 and 1500 meters. It has taken quite a bit of effort to get here. Six days ago, we departed from Punta Arenas. This is the most southerly city of Chili. From Punta Arenas, many tourists take off towards the Antarctic during the southern summer. The tourist season is long behind us now. The days are shortening and darkening rapidly. During the past few days we passed through the stunning fjords and water ways of Tierra del Fuego to end up where we are now. We anchored in one of the bays to take shelter from one of the many heavy storms this region is famous for. On the way I have been admiring the unique fauna of this area. Large numbers of southern giant petrels, black-browed albatross, Antarctic and Cape petrels have been keeping us company for days. Due to the bad weather, spotting marine mammals has proven to be difficult. I have only seen a large number of Antarctic fur seals near a rookery in the waters of Argentina’s Ushuaia. We left “civilisation” behind us about four days ago, upon passing the most southern inhabited outpost in the world: Puerto Williams. Yesterday we really sailed off the map when we passed the legendary Cape Horn. Under the escort of a group of Peale’s dolphins, the most common dolphin species in the shallower waters of this area. Currently, however, we’re sailing over waters 1200 meters deep and in about an hour dawn will end the darkness of night.

Escort of Peale’s dolphins while passing a bout of snow off Cape Horn (© Ernst Schrijver)

“The house of the whales”
I have come here to observe the interaction between the marine life and this form of fishery. The captain explained to me yesterday in flawed English, that we will be going to “the house of the whales” today. I am very tense. Yesterday one of the crew members showed me a video on their mobile phone. When I mentioned orcas yesterday, he showed me the video. I was flabbergasted to see two Type D orcas, playing in the ship’s wake at full speed. I could not believe what I saw. The crew member assured me we were going to see them. It’s always difficult to gauge if these guys know which type of orca they are talking about, but they often have much more knowledge than us scientists give them credit for.

The radar is quiet. The nearest fishing vessel is about 300 kilometres northwest of us. We are truly alone. The season for Chilean sea bass won’t close for another week, after which the last ships will leave the area. Suddenly the winch is started. We’ve begun taking in the first line. At these depths it will take about an hour before the first hooks appear at the surface. I take my gear and get dressed. It’s dark, inclement and very cold outside. According to the crew, the sea is very calm. The waves are a ‘mere’ 3 metres high today.

“Even though the fishermen appreciate their power and beauty, they curse the black-and-white animals.”

While standing outside, my eyes are beginning to get used to the twilight. I thought I saw distant movement. A blow? Or am I seeing ghosts? It’s all too often under these circumstances that I see ghosts. Then it’s a whole lot of nothing. Suddenly a big blow close by at about 100 metres. The long head of a sperm whale breaches the surface. These whales also benefit from the longline fishery, by scraping their mouths along the lines, ripping fish from the hooks. This behaviour occurs not only here, but also in Alaska. Still, these sperm whales are not the fishermen’s arch nemesis. That title belongs to the orcas. Even though the fishermen appreciate their power and beauty, they curse the black-and-white animals. Once the orcas show up, fishing is over. Each and every fish is torn from the lines, while these are taken in.

Sperm whale raises its flukes prior to a deep dive (© Ernst Schrijver)

Thus far no orca in sight. Now that dawn is advancing, I can see more blows and sperm whales in the distance. More and more keep showing up. At the height of it all, I’m counting seven in a straight line on our starboard side. Not coincidentally, that’s the side where the lines are being hauled in. It suddenly dawns on me, that there must be a bunch more underwater, munching away. It’s crazy to realise we arrived in this area less than ten hours ago and already we are being surrounded by so many animals. Though it’s still too dark to take pictures.

All of a sudden, the first hook surfaces. At almost exactly that moment, I hear a blow very close by, but I can’t see anything. Then when I walk to port, it immediately becomes clear that wasn’t a sperm whale. A big black sword cuts through the water. “Shit, they’re here!”, I hear myself say. I have already seem orcas quite often in Iceland, but this is quite something else. When the adult female orca resurfaces right next to the boat, it’s abundantly clear: it’s a Type D! The rest of the pod are still quite some distance removed, but are approaching at high speed. It’s a group of about eight animals, with two large males and one juvenile. More empty hooks surface, indicating predation. Every now and then the orcas venture off, followed by a swarm of albatross and petrels, feasting on 60 kilo Chilean sea bass. While the birds fight for scraps, the orcas come back for more. Sometimes close to the boat, when I’m able to film them, other times at roughly 300 metres away.

One of the orcas close to the boat  (© Ernst Schrijver)

Too much to photograph
The sperm whales are still here. There’s a huge one among them, reminding me of a southern right whale, sidewise. As if that weren’t enough, a fin whale shows up too. The animal seems very interested and swims under the boat a couple of times, leaving large fluke prints. The chaos is complete with the plethora of albatross and rare petrels flying around our ship. While the sun briefly shines through the clouds, I find myself in heaven among all these animals. It’s all a bit too much to photograph.

As the icing on a cake, all of a sudden a dozen super fast, stiff looking black-and-white dolphins zip by underneath us. It all happened so fast, I couldn’t take a picture. In Punta Arenas I often observed Peale’s dolphins. But judging by the completely different attitude, speed, rigidity and sharply contrasting colours, I know this was a group of hourglass dolphins. Incredible! From the wheelhouse someone shouts at me more dolphins are headed our way. Watching from the stern, I can see a lot of commotion headed our way. A vast group of dolphins is hurrying towards us. Their large size, large numbers and blunt, long dorsal fins of the males gives away their identity. This is a group of 200 to 250 long-finned pilot whales.

Long-finned pilot whales chasing away the orcas (© Ernst Schrijver)

Males, females, juveniles and calves are circling us clockwise in a wide berth. Remarkably, the orcas immediately leave the site. The fishermen say the pilot whales don’t feed off the lines, but their presence always coincides with the departure of the orcas. And it’s certainly true. The pilot whales stick around for about half an hour and the orcas are nowhere to be seen. Only when the pilot whales disappear from view do the orcas return and the hooks come up empty once again. Except perhaps a few odd fish heads. When the last hook has been taken in, the orcas leave again. We need about an hour to haul up the line’s anchor before we head towards the location of the second line. The fishery master has already decided to explore other grounds after this line.

“Only when the pilot whales disappear from view do the orcas return and the hooks come up empty once again.”

Refined game
When the orcas are near, there is really only one way to get rid of them: haul in the lines and go. It’s at least a twelve hour sail before we start again. But not yet. We still have to take in that last line. Its location is about 30 kilometres away from us. Half way through, I see fins on the horizon. Considering the grouping, I decide it’s the same pod. In line abreast they swim calmly side by side in the direction of our next line. They swim slowly and we can easily pass them at about ten knots. I now get the feeling that the orcas are playing a highly refined game. They know exactly where we need to be and how to best exploit us without wasting a single calorie. The orcas disappear out of sight behind us and we reach the buoy indicating the next line almost an hour later. The winch is running full speed to outrun the orcas, but it’s to no avail. At nearly the exact moment the first hook reaches the ship, so do the orcas. They even make a break for it and sprint the last 500 odd metres in no time. They routinely get back to work, Not a single fish makes it aboard and after about an hour the orcas seem to become satiated.

The birds are having a great day as well. Remarkably, though, no sperm whales present this time. We are visited by a pod of long-finned pilot whales again. It appears to be the same group from this morning. Again the orcas are driven away. This time the orcas linger at about 400 metres. Sometimes the pilots whales approach the orcas to 200 metres, but there’s no clear confrontation. And just like the first time, the pilot whales stick around for an hour or so before leaving again. Twilight is upon us and with the fading light my opportunity to observe these animals also fades.

 

Albatross and petrels share in the feast (© Ernst Schrijver)

In the darkness I have mixed emotions. The line predation is relentless until the very last hook. We decided to pack up and head towards better fishing grounds. Of course, I’m very happy to have seen these rare animals with my own eyes. It strikes me, however, that these poor fishermen have to struggle for a day just to fill a couple of orca stomachs and they didn’t stand a chance. Though primarily I’m amazed by the knowledge these animals have built up of the fishing methods and to benefit from it. And not only that, but also their ability to time their actions to our activities. It has become abundantly clear who reigns supreme in these mysterious waters.

About the author

Early on in life, Ernst Schrijver has been interested in cetaceans. As a child, the adventures of Jacques Cousteau provided the perfect foundation for his fascination. He studied Animal Management and specialised in research of marine megafauna and ecosystems. Through internships and work, both in The Netherlands and abroad, he gained a lot of experience with marine mammals. In 2010 his graduation project involved research into the behaviour of Harbour Porpoises in Wales. After that, he became involved with Stichting Rugvin, where he became a board member in 2015.

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