Satellite tracking
For several decades, scientists have used satellite tracking – also known as satellite telemetry – to better understand the movement patterns and large-scale behaviour of marine mammals. Satellite tags have been developed to track marine mammals for several months at a time, collecting spatial information using orbiting satellite networks. Similar to a GPS, satellite tags send and receive signals to and from satellites several times per day and these are used to calculate the position of the tagged animal. Data is [MS1] sent via satellite and computer to users and offers a remote means for watching animals that otherwise would be nearly impossible to track. Over time, positions from satellite tags can be used to determine the behaviour of the tagged animal (for example, migrating or transiting versus foraging) by using mathematical animal movement models. Because satellite tags can collect data over long periods, they are a useful tool for understanding fundamental aspects of the life history of marine mammals, including when and where they migrate, how much time they spend in migratory corridors and where these corridors may overlap with human activities.
To study whale migration, satellite tags are generally deployed on animals on their breeding or feeding grounds while animals are close to shore and are remaining in more or less the same area. As animals transition to migratory behaviour, satellite tags provide critical information on when migration occurs, the routes that animals take during migration, and when they reach their destination. Continuously tracking migrating animals is nearly impossible to do from a logistical point of view without the aid of satellite transmitters. By using satellite tag technology, scientists can learn, for example, about the routes that marine mammals take, the speed at which they move and whether different portions of the population migrate at different times. Additionally, satellite tag data can be used to show when migrating marine mammals overlap in space and time with human activities such as fishing and shipping, and to determine the amount of time that animals spend in the territorial waters and EEZs of different countries.
Photo-identification
One of the most commonly used methods for tracking the movements of marine mammals is photo-identification. Most animals have markings that are unique to individuals and in the case of baleen whales, specifically humpback whales, the patterns of scarring and pigmentation on the underside of the tail flukes can be used to identify individuals with great precision. Photographing animals is a relatively simple and passive way to collect valuable information on the presence of an animal in a certain place at a certain time. By collecting fluke (or other body part) images regularly in the same place, researchers can learn about occurrence patterns of individuals over long periods of time or within a season. However, some of the most critical information on animal movements comes from when researchers compare photographic images across regions to make matches. In this case, many of the main migratory end points (feeding and breeding grounds) for marine mammal populations have been identified and fidelity to these has been established for many individuals.
Photo-identification is likely the most ubiquitous marine mammal data collected around the world and enables researchers to define migratory destinations for populations and the patterns of occurrence of individuals in these areas over time. As well, photo-identification can help determine the frequency of reproduction in individuals and can provide information on entanglements and other scars/injuries incurred from incidents with human activities.
Indigenous knowledge
Vast knowledge about whales, their movements, behaviour and ecology is held by coastal Indigenous peoples around the world, particularly those who have relied and still rely on whales for their culture, food and livelihoods. Indigenous Knowledge, or Traditional Ecological Knowledge, is accumulated by people who have successfully lived in close connection with nature for generations, often in remote places, and often as the only year-round residents, enabling deep, detailed and experiential observations and knowledge to be gained.
Indigenous Peoples’ knowledge is increasingly recognized by scientists as unique and intrinsic to understanding the nature of biodiversity and ecosystems. Indigenous Knowledge has been used alone and alongside scientific research to understand whale migrations, including pathways, timing, changes and factors influencing its onset (e.g. for beluga and bowhead whales).1,2
