RESEARCH AT SEA
Knowledge about species’ biology, ecology, life history and threats is of tremendous importance to wildlife conservation. Scientific data and literature is indeed necessary to inform full assessments of conservation status and to further design management and conservation strategies.
Norwegian Orca Survey aims at better understanding killer whale population(s) that inhabit the Norwegian Sea. Data is being collected throughout the year in Andenes, Northern Norway. Location for winter fieldwork varies and is adapted to seasonal distribution of herring and killer whales aggregations.
We are working on various research projects, mainly focusing on population dynamics (size and trends), home range (site fidelity and long-range movements), feeding ecology (diet and group specific dietary habits), contamination patterns (chemical pollution), social organisation and genetics.
To complete research projects, we rely on diverse data types. First and foremost, we collect high resolution photographs on each killer whale encounter. Using pigmentation patterns and scars naturally occurring on the dorsal fin and saddle patch, individuals can be identified and catalogued. Logging re-sightings of individuals (accounting for date, location and companionship) overtime in a database enables building the raw baseline material necessary to further studying social structure, demographics, population dynamics and life-history.
Because hunting and feeding occur underwater and out of sight, identifying with certitude targeted prey species can be challenging. To assess the diet of encountered groups, we collect prey remains after feeding events. Prey identification can then be conducted visually or through analysis of DNA contents.
Using a lightweight dart, we collect skin and blubber samples of individual killer whales. Fatty acid composition of the blubber layer, as well as stable isotope ratios in the epidermis are useful to assess dietary preferences and foraging areas. Contaminant loads measured in the blubber layer further inform about killer whales' health status and assist in identifying potential threats. Molecular genetic analyses performed on skin samples is relevant to studying relatedness among groups and individuals, and population structure. Biopsy sampling only induces short-term behavioral reactions with no long lasting injury or disturbance, and is conducted under permit.
We have deployed data loggers with inbuilt cameras on killer whales using suction cups. These devices can be used to get insights into underwater behaviors and feeding techniques. Remaining for a few hours and up to a few days on the back of the whale, this minimally invasive method enables high-resolution data logging of depth, time, temperature, sound production, pitch and acceleration of the tagged animal. Collected data and footage have been very beneficial to study dive characteristics, assess energy budgets, interactions with conspecifics and prey and habitat use.
Killer whale groups use different types of calls in order to communicate. Killer whales also produce sounds at various rates depending on activities (feeding, travelling, socialising or resting) they involve in. In the field, we collect underwater acoustic recordings to better understand the relationship between surface activity and acoustic behaviour.
Flying drones above whales enable us to remotely collect observations of sub-surface behaviors and other data whilst minimising boat disturbance. Aerial still photographs are also useful to assess killer whales' body condition indicative of general health status.
Dead cetaceans can sometimes be found stranded onshore. We collect basic data such as measurements, photographs and tissue samples that constitute valuable material impossible to get from live animals. While measurements can provide us with basic information about anatomy, tissues can be analysed for genetics, diet, hormones and pollutants. These results can assist in resolving potential causes of death, and in assessing important threats faced by wild populations. An ongoing project in collaboration with the University of Oslo aims at sampling dead stranded cetaceans in Norway in order to conduct a first broad screening of emerging pollutants in these top marine predators.
We recognise the greater value of focusing conservation efforts on populations rather than individuals. Nevertheless, we believe that animal welfare should be promoted whenever possible. Challenging situations involving single or small groups of cetaceans in distress may infrequently arise in coastal waters. These include by-catch or entanglement in fishing gears, live standings, natural entrapments in shallow bays, or sick or lost single individuals. Often, there are no protocols in place to manage these risky situations and outcomes appear rather uncertain. This often leads to important controversy and lack of action taken. To assist local communities and further promote animal welfare, we put great efforts into travelling onsite and conducting situation assessments whenever possible. Our strategy typically consists in advising on possible solutions if any. We always establish contact and solicit approvals from the Norwegian authorities prior initiating interventions.
A group of five killer whales were entrapped in the bay of Trælvikosen, Brønnøysund, Northern Norway in May 2017. Possibly, the long narrow and shallow inlet may have deterred the whales from returning to the open water. Norwegian Orca Survey travelled to Brønnøysund and conducted a situation assessment. Because no fish schools could be detected in the bay and because the whales displayed signs of stress and malnutrition, a rescue operation involving the local community was conducted to free the whales. It took 25 boats and four hours to successfully drive the whales out. These whales were all re-observed in Andenes in September 2017.