Data from: Genetic profiling links changing sea-ice to shifting beluga whale migration patterns

There is increasing concern over how Arctic fauna will adapt to climate related changes in sea-ice. We used long-term sighting and genetic data on beluga whales (Delphinapterus leucas) in conjunction with multi-decadal patterns of sea-ice in the Pacific Arctic to investigate the influence of sea-ice on spring migration and summer residency patterns. Substantial variations in sea-ice conditions were detected across seasons, years and sub-regions, revealing ice–ocean dynamics more complex than Arctic-wide trends suggest. This variation contrasted with a highly consistent pattern of migration and residency by several populations, indicating that belugas can accommodate widely varying sea-ice conditions to perpetuate philopatry to coastal migration destinations. However, a number of anomalous migration and residency events were detected and coincided with anomalous ice years, and in one case with an increase in killer whale (Orcinus orca) sightings and reported predation on beluga whales. The behavioural shifts were likely driven by changing sea-ice and associated changes in resource dispersion and predation risk. Continued reductions in sea-ice may result in increased predation at key aggregation areas and shifts in beluga whale behaviour with implications for population viability, ecosystem structure and the subsistence cultures that rely on them.人们日益关注北极动物群如何适应海冰相关的气候变化。本研究以北极太平洋海域的白鲸（Delphinapterus leucas）为研究对象，结合其长期目击数据与遗传数据，以及该区域海冰的多年代际变化格局，探究海冰对其春季洄游与夏季居留模式的影响。研究团队在不同季节、年份与亚区域中均检测到海冰条件存在显著差异，揭示出海冰-海洋动力过程比北极全域趋势所呈现的更为复杂。此类海冰差异与多个白鲸种群高度一致的洄游与居留模式形成鲜明对比，表明白鲸能够适应广泛变化的海冰条件，以维持其对沿海洄游目的地的归巢习性。不过，研究人员观测到多起异常洄游与居留事件，且这些事件均与海冰异常年份重合；其中一例还伴随虎鲸（Orcinus orca）目击频次增加，以及其捕食白鲸的相关报道。这类行为转变可能由海冰变化、伴随而来的资源分布变动以及捕食风险变化共同驱动。海冰的持续减少可能会导致关键聚集区域的捕食压力上升，改变白鲸的行为模式，并对种群生存力、生态系统结构以及依赖白鲸的生计文化产生影响。