Belugas and narwhals make up a vital part of Inuit culture and the Arctic ecosystem. Keeping track of their population size and understanding migration patterns are important in making sure their populations stay healthy. We can monitor them in the following ways. Each of these methods, on their own, might not provide a clear idea of population size and range, but together they give researchers a much more complete picture. Some scientists find that they save time and make fewer mistakes if they work with local communities when they design their studies.
Aerial surveys: Taking photographs of beluga or narwhal populations from a plane is time-efficient and covers large areas, but doesn’t show underwater animals and only provide a snapshot in time. Scientists would also need to know the range of a population to get full coverage.
Satellite tagging: Satellite tagging is expensive and difficult to accomplish in large numbers, but provides information on population range and individual migrations by locating animals every time they surface. Satellite tags also provide oceanographic information like water temperature and salinity.
Traditional knowledge and local observations: This method includes generations of history and knowledge that covers long time spans over years and across seasons. However, this knowledge is usually not recorded, mainly limited to areas where people are living and is descriptive rather than quantitative.
An example: Dr. Hammill tracks belugas with satellite tags to gather information on their habitats and migration routes. He’s found that in eastern Hudson Bay, the belugas go back and forth between the coast and offshore waters in the summer, and they leave Hudson Bay in the winter. But local Inuit hunters told him they often see belugas close to the coast in the summer. They also said the belugas stay in the area in the winter.
The information from these two sources may seem contradictory at first, but putting them into context provides a better understanding of the big picture. Hunters tend to stay near the coast, so it's likely they don't have much of a chance to see belugas in offshore waters. They spend a lot of time hunting, however, so their observations take place over a longer time span. Satellite tags, on the other hand, aren't constrained by location, but they only give information on a few tagged belugas over a short period of time. This information doesn't necessarily reflect the location and movement of the entire population.
Like pieces of a puzzle, these two sources of information provide a better idea of the big picture.