Our last look at I46

It is not often that a dead killer whale is found and even more rare when it is fresh enough to be recognizable. A number of people congregated last saturday to help in the necropsy of an adult male northern resident killer whale known since birth by researchers with Fisheries and Oceans Canada as I46. He was 28 years old and is survived by his 3 sisters and their offspring. (see pages 62-63 of the latest northern resident killer whale population catalogue for details on I46’s family relations.)

I46's body awaiting necropsy.

I46’s body awaiting necropsy.

The northern resident killer whale community is a population listed under the Species at Risk Act as Threatened due to its low numbers (261 in 2010) and vulnerability to several threats including limited prey availability. While it is not known exactly how I46 died it is hoped that the analysis of several samples acquired during the necropsy will shed some light on why he did not live into his 50s like some males in the population. At less than 300 individuals, this population needs all the diversity it can get, so it is somewhat disturbing to see an animal that should be in its prime turn up dead.

The area in which we at MERS carry out the majority of our studies off northeastern Vancouver Island  is known as “critical habitat” for the northern resident killer whale population. Thanks to the work of both orcalab and DFO it is known that I46 was one whale in particular who utilized this habitat regularly in both the summer and winter. We have seen him here foraging for salmon with his closest sister I68 on many occasions. Unfortunately, we will never see his bent over dorsal fin plying these waters again.

I46 in July 2012.

I46 in July 2012.

Like many things in the cetacean research community in British Columbia, the study of I46’s body would not have been possible without so many people. Rod Palm with the Strawberry Isle Marine Research Society organized the retrieval of the body of this whale while most other plans were carried out by the Marine Mammal Response Network at DFO and Mike De Roos, master cetacean skeleton articulator. Today, with the necropsy and associated smell still fresh on all of our senses we are reminded of how mysterious the lives and deaths of individuals in one the most heavily studied and well understood cetacean populations in the world remain.

~MERS

About MERS

We are a non-profit organization dedication to promoting conservation and understanding of marine ecosystems through scientific research and environmental education.
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8 Responses to Our last look at I46

  1. MarcieCallewaert says:

    In the ID catalogue, I46’s fin flops to the right. Because it is hardened cartilage, one would expect it to be permanently on one side as other collapsed fins are. I have never heard of an orca with a fin that changes sides – is I46 an exception?

  2. MERS says:

    You raise a really interesting point Marcie. I46s dorsal fin was upright and rigid for most of his life. He had 2 small nicks and a distinct saddle patch (which is how he was identified). When he was seen in summer of 2010 his dorsal fin had sustained an injury of some kind since the previous winter and appeared how you see it in the catalogue (bent to the right). When photographed in 2011 his dorsal fin had curled over to the left side and stayed that way until his death. In his injury the tissue was affected near the leading edge of the dorsal fin and the fin remained upright to that point. I can not explain exactly why the top portion lay to one side in one year and the other side in years thereafter but there are likely several natural responsible forces. I have witnessed the same thing on an outer coast Bigg’s (transient) killer whale who has lost most of his dorsal fin due to an injury of some kind. The remaining tissue has flopped to one side in some years and to the other in other years…

    ~Jared

  3. Michele says:

    Thank you for this nice article and information.. Also, thank you for your comment regarding his dorsal fin. Lots of good info.

  4. I am so glad that we at Jamie’s Whaling Station too were involved with this amazing find. It was I who spotted this animal off Long Beach, Tofino. We were busy looking for live whales for our guests aboard our whale watch vessel, but the bobbing mass on the horizon was too odd to ignore. I knew it looked too round and concave to be a tree or branch, so I asked the captain to go see. After initial communication with Rod Palm, who then organized the tow in, an amazing chain of events and people took charge.
    Many thanks to all involved, may I46’s investigation reveal many facts for science, and may his skeleton once rebuilt delight all those who look upon it

  5. “The northern resident killer whale community is a population listed under the Species at Risk Act as Threatened…” Hmmm, I thought they were listed as endangered?

    • MERS says:

      Thanks for the comment… the southern resident killer whale community is listed as endangered, while the northern resident community is listed as threatened.

  6. Pingback: It’s a Tough World | Birds and Baking

  7. Uko Gorter says:

    Responding to Marcie’s comment: Dorsal fins are not made up of cartilage. They’re made up of connective tissue with a ligamentous sheath near the skin.

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