[Updated: March 12, 2020]
Here’s our report on Humpback Whale numbers in our study area in 2019 and yes, our updated catalogue is ready to go too. 🙂
But first, for clarity, please know that we are not reporting on the entire number of Humpback Whales estimated to feed in British Columbia marine waters.
The estimate for that dates back to research by Ford et al which concluded: in 2006, the abundance for Humpback Whales in British Columbia waters was 2,145 whales. This estimate did not include 1st year calves.
In is anticipated that soon there will be an updated estimate for the number of Humpbacks in BC waters as a result of the 2018 Pacific Region International Survey of Marine Megafauna (PRISMM). It is important to note that the results of the PRISMM line-transect survey will be for a much larger area than that which led to the 2006 estimate.
How many Humpbacks did there used to be off our coast? As you can imagine, there is poor data for this as no one was studying whales as individuals prior to the early 1970s. The estimate is that a minimum of 4,000 Humpback Whales existed just off the west coast of Vancouver Island in 1905. Legal whaling for Humpbacks ended by international agreement in 1966 and it is estimated that, by the 1970s, there were only ~1,400 Humpbacks in the WHOLE North Pacific Ocean i.e. not just off our coast.
Now that that’s all been emphasized, the area for which we are reporting is from the upper Strait of Georgia to northern Vancouver Island and around to northwest Vancouver Island. We identified 161 individuals who were in that area at some time in 2019. There are now over 380 whales in the MERS catalogue for the area.
The sub-area for which we have the longest dataset is northeastern Vancouver Island (upper Johnstone Strait, Queen Charlotte Strait and the inlets of the Broughton Archipelago). The graph below shows how sudden the increase in Humpbacks has been. Numbers have increased from just 7 individuals documented in this area in all of 2003, to identifying 93 in 2019 Note too how many of the whales are returnees to the area each year (compare the blue bar in the graph to the red bar). This indicates how strong the site fidelity of Humpbacks is. They generally return to the same area(s) to feed year upon year.
For the Campbell River / Comox / Hornby Island area, we catalogued 88 individuals that were there at some point in 2019. Of this number, 35 were also sighted around northeastern Vancouver Island.
Note that the size of this increase in Humpbacks off the coast of BC cannot be population growth alone (post whaling). There must also be a shift from somewhere else. That mystery is something we and our colleague researchers, have not solved, nor what the shift may indicate about changing ocean conditions.
We emphasize how this work would not be possible were it not for the contribution of photos from naturalists, boaters and others who care. The photos, together with the location of sightings, not only aid our Humpback Whale population studies but also help in understanding how the whales use the area.
With the number of Humpbacks so predictably being around central to northern Vancouver Island, it is essential that boaters are aware of how to avoid collision and what to do (and not to do) if entanglement is witnessed. Humpback Whales are much more unpredictable than the Orca many boaters are accustomed too. Please see www.SeeABlowGoSlow.org.
We also have a national teaching resource on boaters and marine mammals at www.BoatBlue.ca. This was developed in collaboration with the Canadian Power and Sail Squadron.
For further highlights of our work in 2019, please see this link.
Note that our research, conducted in collaboration with Fisheries and Oceans Canada, shows that approximately 50% of the Humpbacks in BC waters have scarring from an entanglement. This indicates how widespread a risk entanglement is but does of course not allow us to know how many whales become entangled and die since dead whales usually sink to the bottom of the ocean.
It is even more difficult therefore to know how often whales die from injuries related to boat collision. It is now thankfully the law that collisions and entanglements must be reported.
Click here for examples of the severity of human injuries and material damage resulting from collisions with Humpback Whales.
Ford J.K.B., Rambeau A.L., Abernethy R.M., Boogaards M.D., Nichol L.M., and Spaven L.D. 2009. An Assessment of the Potential for Recovery of Humpback Whales off the Pacific Coast of Canada. DFO Can. Sci. Advis. Sec. Res. Doc. 2009/015. iv + 33 p.