The long-term analysis of blue whale and fin whale vocalisations in the eastern Fram Strait offers valuable insights into seasonal and annual patterns regarding these species’ occurrence in the region. For example, blue whales can primarily be heard in the summer and autumn, whereas the acoustic data on fin whales indicates that their occurrence is much longer and more variable. The unprecedented long-term dataset also confirms the sporadic occurrence of blue whales – the largest fauna on the planet – during the winter months. The team of researchers, led by the Alfred Wegner Institute, has just released its findings in the journal PLOS ONE.