No abstract

With increased warming and open water due to climate change, the frequency and intensity of storm surges is expected to increase. Although studies have shown that strong storms can negatively impact Arctic ecosystems, the impact of storms on Arctic marine mammals is relatively unknown. In July 2016, an unusually large storm occurred in the Mackenzie Delta while instrumented seabed moorings equipped with hydrophones and oceanographic sensors were in place to study environmental drivers of beluga habitat use during their summer aggregation. The storm lasted up to 88 h, with maximum wind speeds reaching 60 km/h; historical wind data from Tuktoyaktuk revealed a storm of similar duration has not occurred in July in at least the past 28 years. This provided a unique opportunity to study the impacts of large storms on oceanographic conditions, beluga habitat use, and the traditional subsistence hunt that occurs annually in the delta. The storm resulted in increased water levels and localized flooding as well as a significant drop in water temperature (∼10 °C) and caused belugas to leave the area for 5 days. Although belugas returned after the storm ended, the subsistence hunt was halted resulting in the lowest beluga harvest between 1978 and 2017.

Vessel traffic negatively affects marine mammals by causing behavioural disturbance, acoustic masking, contamination (i.e., oil spills), and ship strikes. Few studies have examined the effects of vessels on marine mammals in the Arctic, but beluga whales appear to be especially sensitive to vessel traffic. We examine how the vocalizations of belugas are impacted by vessel traffic in the Tarium Niryutait Marine Protected Area in the Mackenzie River estuary of the western Canadian Arctic. Between one and four acoustic recorders were deployed between June and August each year between 2015 and 2018 near the only shipping channel at this site. We examined beluga vocalizations from acoustic recordings over four summers and assessed how the distance to the nearest vessel passing the acoustic recorder affected the number of vocalizations. Beluga vocalizations within the range of the acoustic recorder decreased significantly when vessels were within 5 km of the acoustic recorder. This result suggests either that belugas are avoiding the vessel or that they reduce their vocalization in response to vessel traffic. Future work is needed to assess exactly how belugas are reacting to vessel traffic in this area and what the long-term consequences of these reactions are. Management measures for reducing these impacts must be carefully considered, especially since these vessels are very restricted in where they can travel, and many of the vessels are necessary for the livelihoods of local communities.

No abstract

Inuit are at the forefront of ecosystem change in the Arctic, yet their observations and interpretations are rarely reported in the literature. Climate change impacts are rapidly unfolding in the Arctic and there is a need for monitoring and reporting unique observations. In this short communication, we draw upon observations and experiential knowledge from western Canadian Inuit (Inuvialuit) harvesters combined with a scientific assessment to describe and interpret an unusual account of gelatinous organisms at high densities during summer 2019 in eastern Amundsen Gulf, near Ulukhaktok, Northwest Territories. The gelatinous organisms were identified as primarily Appendicularian Larvaceans (Oikopleura spp., pelagic tunicates) and their gelatinous ‘houses’. The organisms were observed within 3-5 kilometres of the marine coast, from ~1-2 metres below the surface and to depths of ~30 metres with an underwater camera. Pelagic tunicates have rarely been documented in the eastern Amundsen Gulf and to our knowledge, this was the first time these organisms had been noted by the people of Ulukhaktok. The pelagic tunicates clogged subsistence fishing nets and Inuvialuit harvesters were concerned of negative impacts to marine mammals and fishes, which they depend on for food security. These interpretations highlight major knowledge gaps for Appendicularians in the Arctic.