Marine Mammal Research, Department of Bioscience, Aarhus University, Frederiksborgvej 399, DK-4000, Roskilde, Denmark.
Department of Business Administration and Economics, Bielefeld University, Universitätsstraße 25, 33615, Bielefeld, Germany.
Sci Rep. 2019 Apr 4;9(1):5642. doi: 10.1038/s41598-019-42109-w.
Classifying movement behaviour of marine predators in relation to anthropogenic activity and environmental conditions is important to guide marine conservation. We studied the relationship between grey seal (Halichoerus grypus) behaviour and environmental variability in the southwestern Baltic Sea where seal-fishery conflicts are increasing. We used multiple environmental covariates and proximity to active fishing nets within a multivariate hidden Markov model (HMM) to quantify changes in movement behaviour of grey seals while at sea. Dive depth, dive duration, surface duration, horizontal displacement, and turning angle were used to identify travelling, resting and foraging states. The likelihood of seals foraging increased in deeper, colder, more saline waters, which are sites with increased primary productivity and possibly prey densities. Proximity to active fishing net also had a pronounced effect on state occupancy. The probability of seals foraging was highest <5 km from active fishing nets (51%) and decreased as distance to nets increased. However, seals used sites <5 km from active fishing nets only 3% of their time at sea highlighting an important temporal dimension in seal-fishery interactions. By coupling high-resolution oceanographic, fisheries, and grey seal movement data, our study provides a scientific basis for designing management strategies that satisfy ecological and socioeconomic demands on marine ecosystems.
对海洋捕食者的运动行为进行分类，使其与人为活动和环境条件相关，这对于指导海洋保护非常重要。我们研究了灰海豹（Halichoerus grypus）在波罗的海南部的行为与环境变化之间的关系，因为那里的海豹渔业冲突正在加剧。我们使用了多个环境协变量，并在多元隐马尔可夫模型（HMM）中考虑了与活动渔网的接近程度，以量化海豹在海上的运动行为变化。潜水深度、潜水持续时间、水面持续时间、水平位移和转弯角度用于识别移动、休息和觅食状态。在更深、更冷、盐度更高的水域，觅食的海豹可能性增加，这些水域的初级生产力增加，可能猎物密度也更高。与活动渔网的接近程度对状态占有率也有明显影响。海豹觅食的概率在距离活动渔网<5 公里的地方最高（51%），随着与渔网的距离增加而降低。然而，海豹在海上只有 3%的时间使用距离活动渔网<5 公里的地点，这突出了海豹渔业相互作用中的一个重要时间维度。通过结合高分辨率的海洋学、渔业和灰海豹运动数据，我们的研究为设计管理策略提供了科学依据，以满足海洋生态系统对生态和社会经济的需求。
