They are among the largest and most exotic marine mammals in the world -and fortunate is the scientist who gets to study them. One such man is Dr. John Ford, a marine mammal research scientist with the Pacific Biological Station in Nanaimo, British Columbia. He heads the Department of Fisheries and Oceans Pacific Region cetacean research program which is mandated to undertake research and provide science advice on whales that are listed as endangered or threatened under the Species At Risk Act (SARA). On Canada’s West Coast that includes the mighty blue whale, the largest mammal in the world, as well the fin, sei, humpback, killer and North Pacific Right whales.
Dr. Ford came to DFO from the Vancouver Aquarium in 2001 thanks to funding support via the SARA program. That funding allowed researchers to form a group to do surveys off the coast – to better understand population abundance. "We have had a long tradition of studying killer whales at the DFO Pacific Biological Station," according to Dr. Ford "but no other large whales. Under SARA, we now also assess the status and develop recovery strategies for listed species."
Researchers use a number of tools to assess population, genetics and other relevant studies.
Just as it has been done with killer whales for years, a fundamental counting tool is through photographic identification. In the case of humpback whales, for example, researchers focus on tail flukes. As the animal dives, they photograph the underside of its tail that can show individually unique pigment patterns or nicks and scars. Today, researchers have a catalog of about 2000 individual humpbacks photographed in British Columbia waters.
Dr. Ford: "These photographs not only give us an idea of the overall number of animals we have in any one season – we can use the individual identification as a kind of overall population abundance estimate. As we photograph them each year we see how many are back again and how many are different over a two-year period. From that we use statistical techniques to estimate the population as a whole."
There are also submersible autonomous acoustic recording units deployed in strategic places along the coast, out on the continental shelf. The devices sit on the bottom and record underwater sounds for about a year on a cycle typically about five minutes out of every 15 minutes. Retrieved after a year, the hard drives are pulled and the data analyzed.
Dr. Ford: "Our equipment is capable of recording all these large whales some of which make really low-frequency sounds – lower than our hearing ability – down to around 20 Hz in the case of the fin whale. We can differentiate between species and in the case of the killer whales, we can even narrow identification down to specific pods and identify whether they are transients or residents."
To get a better sense of the seasonal distribution and density of these large whales, researchers also conduct aerial surveys off the West Coast of Vancouver Island in partnership with Transport Canada using their Marine Aerial Reconnaissance Team aircraft. They have been able to spot rare blue whales and fin whales this way.
Tools to Study Population Genetics
Researchers also work on population genetics by doing biopsies taken from a bit of skin and blubber obtained by using an ultra-light dart that simply bounces off the whale. Not only can they study genetics, they can pick up contaminant levels that may be present.
Another research strategy is to use satellite tagging. Scientists can tag fin whales with ultra-light tags with small titanium barbs that are projected from an air gun and embedded in the dorsal fin of the fin whales. There is a small antenna sticking out of the tags and these can transmit for months. The attachment eventually fails and the tag falls off before the battery is exhausted.
Dr. Ford: "This sort of tagging tells us a lot about the movements of fin whales. Recently, we discovered some fin whales in the protected waters of Caamaño Sound, which is unusual since they are normally an offshore species. So we are tagging animals there to try to get a sense of how they are using the area."
Researchers also engage in distant sampling surveys. From their reconnaissance surveys, they identify an area and draw a big box over it and design a systematic survey that can be done in a couple of days from a ship. This involves using giant binoculars called "big eyes". They follow a zigzag pattern through the survey area and count up all the whales they see and how far they are from the ship and in what direction. Then using statistical techniques, they can come up with a population abundance estimate for that study area.
Tagging Tool to Monitor Behaviour
One of their more interesting projects with killer whales is looking at their behaviour using data logging tags. Typically these are stuck on the animal with suction cups and stay attached for a period of less than a day. The tags record the movements of the whale by using accelerometers that allow them to recreate - in three dimensions - the movement of the animal as it forages underwater. It is very data-intensive as these tags collect huge amounts of information.
Dr. Ford: "We are trying to profile the behaviours the whales use to find Chinook salmon and how they catch them, what their catch per unit of effort is, and so on, to better understand the prey availability that might be needed for them to prosper."
The data the scientists collect can give them clues on the effect of human impact and possibilities of when and how to mitigate those impacts. In the case of resident killer whales it is clear that humans can affect their survival in ways that might never have been predicted years ago. In the early days, biologists did not know that these ecologically specialized populations survived primarily on Chinook salmon, which is also a highly valuable species from a human fisheries perspective. Nor did they know that these animals had been accumulating high levels of human pollutants such as PCBs in their systems. Dr. Ford: "Without these early studies we would never have any idea that we were creating conditions that could compromise their survival. So the more we understand the more we can mitigate these kinds of unforeseen impacts we were having on these animals so that they can recover."
Similarly, we have been able to take mitigation strategies on other fronts; for example, altering the movement of ships to minimize whale strikes. Likewise, seismic surveys have been found to be very disruptive in some cases - to the point of causing strandings in some species of whales. The way that seismic surveys are done offshore can be modified to reduce those kinds of impacts. In the same way, military sonar can be incredibly intense for all species of whales so DFO is working with the Department of National Defence to determine how best to make sure those impacts are reduced. To that end they have developed an observer program and protocol for making sure that there is no by-catch in the form of disturbed whales.
Dr. Ford: "In the final analysis if we don't get out there and do this work we just won't have any sense of how those populations are doing: how well they are recovering, or if they are recovering; and if there are human impacts that may be limiting that recovery. And mitigation is certainly possible in many cases."
For which future generations of whales – and humans – will be eternally grateful.
Postscript: In June of 2013 Dr. Ford and his DFO colleagues James Pilkington and Graeme Ellis had what they called a "thrill of a lifetime" when they got to see an extremely rare North Pacific right whale. It was first spotted by Pilkington on June 9 off Haida Gwaii and the scientists observed it eating zooplankton over the course of three days. Almost hunted to extinction, the recovery of these whales has been seen as very problematic. This was the first such sighting of the right whale in BC waters since 1951. Dr. Ford is hopeful that more evidence of right whales may be picked up via the acoustic recording devices placed around Haida Gwaii.
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