How you can collect scientific data when watching killer whales this winter
Text: Glen Jeffries
In the last few years, as the sun has begun to leave the fjords of Troms for the winter, one of the animal kingdom’s most charismatic animals has been arriving. Orca. Killer whale. På norsk: spekkhogger.
Nearly 500 miles south-west of Tromsø in Andenes, a research project on Norwegian killer whales has been under way since 2013. Norwegian Orca Survey (http://www.norwegianorcasurvey.no/), the non-profit organisation founded by Eve Jourdain and Richard Karoliussen, provides important scientific data about these animals through a census of the population and by monitoring their occurrence patterns and foraging ecology on a year-round basis.
For countless days of the year Eve and Richard’s environment is the coastal waters of Vesterålen or Troms. And it is this year-round commitment to being out on the water that makes their study so dynamic. Collecting observational data of orca behaviour is comparatively easier in the winter: Norwegian orcas mainly follow the migrations of the Atlantic Herring, and in the winter months the herring stock over-winter in coastal waters. It is the arrival of the herring in the Troms fjords that has brought the orca here each year since 2013 (between 1986 – the first year data was collected by whale biologists – and 2006, the herring were over-wintering further south in the Tysfjord and Lofoten region and the orca tailed them there). However, less is known about Norwegian orca feeding habits outside of the winter months. With the herring stocks covering greater distances across pelagic waters in spring and summer – they have been known to go as far south as Bergen and as far north as Svalbard – the orcas, too, are more dispersed. This provides huge challenges for collecting data. Eve says building a picture of their movements and foraging patterns across the entire year «is like completing a puzzle».
Different orca populations across the world have different diets and foraging techniques. For example, in the north-eastern Pacific, two coastal types of killer whales cohabit: one feeds on fish and one feeds on marine mammals. Norway’s orcas have been observed feeding on herring, salmon, mackerel, cod, sei, halibut, and occasionally seals and porpoises. One of Norwegian Orca Survey’s most exciting findings has been that two particular sub-groups of the population are regularly hunting seals. The team was recently able to film one of these two sub-groups hunting and sharing a seal. This activity had never been filmed up-close before. The footage was shown on national television channel TV 2 (it is also available on the team’s Facebook page – https://www.facebook.com/norwegianorcasurvey/?fref=ts). Put simply, this is new scientific data: it is a piece of the puzzle whale biologists did not know existed.
In addition to observing orca behaviour, Eve and Richard are undertaking a census of the orca population. Through photo-identification, Norwegian Orca Survey is maintaining a catalogue of every orca they encounter (available via http://www.norwegianorca-id.no/). Each orca has distinctive natural markings on its dorsal fin and saddle patch. These are the orca equivalent of human fingerprints. Eve reviews each photograph visually – no software is involved – to verify whether it is an animal that has been seen before. If it is a new animal, it will be added to the catalogue. But Eve and Richard are just two people in a small boat in a big sea. Members of the public can assist by sending their own high-quality photographs of the dorsal fin of the orca they see to Norwegian Orca Survey. Send your photographs to: firstname.lastname@example.org (guidelines for photographs available here http://www.norwegianorca-id.no/get-involved). Even after three years of running the project the majority of the photographs being submitted are still revealing new animals.
And why is it important to understand more comprehensively the foraging patterns and populations of Norway’s orcas? Eve is very clear on this point: it is about conservation. The more we know about orca the better we can understand how to properly preserve their habitats and help their survival.
And when will the killer whales arrive in Troms? The simple answer is … when the herring arrive. Last year the first orca sighting was October 23rd. Eve suggests following the Facebook pages of Hvaler I Nord and Norwegian Orca Survey (https://www.facebook.com/norwegianorcasurvey/?fref=ts) for updates on the orcas’ journey north. And then, when you go looking for the animals, ready your cameras in the name of science.