The Real Tourists – 18/4/22

Happy Easter Monday! No ordinary day out in the canyon with SPECIAL visitors. These are the real tourists this Easter. and the first potential record in Western Australia.

At first glance we thought ‘super pod’. The orca burst out of the water straight at our 12 o’clock heading towards us. This initial reaction felt taken a back. The intensity of the whales bursting out of our nearing on three metre swell took my breath away.

The first thing we noticed was the colour. They were a yellow and brown tinge… This colouration is distinctive of a COLD WATER diatom which grows on the outer layer of the orcas skin. In POLAR water it flourishes as the skin has a low cell turn-over and this moss-like growth stays put. Once the whales are in warmer water, the skin cell production increases and the diatom growth, plus skin underneath, sloughs off. Leaving a ‘clean’ appearance. These orca are not our familiar pods. They are tourists!

Next we noticed the size. They were much smaller. The largest male was only as big as our typical females (approximately 5 metres) although still exhibiting the tall erect dorsal fin.

The eye-patch was the final distinguishing feature. Small and slanted, these eyes matched to the narrow, wispy, 45 degree skewed eye patch of the Type “C”, Ross Sea Killer Whale. These morphological features meant a perfect match for the ecotype.

So what in the ocean are Type “C” Killer Whales?

APPEARANCE: They are two-toned grey and white, the smallest of all orca populations. They have a dark grey dorsal cape, demarcated by a narrow white border from the saddle patch to the eye patch.

DISTRIBUTION: They are found in the Ross Sea in Antarctica living in dense pack ice but there are at least some migrations to tropical waters such as New Zealand and south-east Australia during winter. Five encounters have been documented in Australia, with NONE here in Western Australia.

FEEDING: Only observed to eat fish; such as Antarctic Toothfish and also smaller species of icefish.

GROUP SIZE: 10 to 200.

Our three hour interaction with them let us gather a large amount of data! Such as potential ID photos, group composition, group size and behaviour.

They were trailing a handful of pelagic birds. Eight species to be exact. Black-browed, Shy and Indian Yellow-Nose Albatross. A Soft-Plummaged Petrel, Great-Winged Petrel and Flesh Footed Shearwaters. Plus Wilson’s and Black-Bellied Storm Petrels.

At one point we were able to get a good group size estimate. Counting each whale as it surfaced in a small area then applying that abundance to the adjacent areas. A section of 20 whales would surface, their formation was so tight, similar to that of a Pilot Whale. 20, 40, 60… The pod ahead was the same. I will easily underestimate there to be more than 120 individuals here!!! At a higher vantage point, the eye could observe more orca over two mile away.

An unexpected but most-welcomed interaction. Our crew are absolutely buzzing! There are so many possibilities and questions we can ask from this interaction and what this means.

Do these orca come here each year during winter?

Why do they come here? What are they doing here?

Where are they going?

Has anyone spotted these orca before?

How do our local Bremer orca react to their presence?

The three other cetacean species we encountered should definitely not be overlooked but serve as a reminder of the distinguished diversity we have here. Firstly Common Dolphins within a mile of the marina. Second, a small pod of Long-finned Pilot Whales. Third, the Ross Sea, Type “C” Killer Whales. And lastly, a lone male sperm whale, who logged at the surface for over forty minutes.

For right now we will enjoy going back through our photos and reminiscing on the once again incredible day in Bremer Bay.

Blog post by onboard marine biologist, Pia and images by our onboard photographer Nathan Piesse.

Naturaliste Charters

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