Vessel traffic trends in the Arctic and overlap with important marine mammal areas. Report for Transport Canada
William D. Halliday
As the Arctic becomes more ice-free, ship traffic and its associated underwater noise have been increasing. Arctic marine mammals appear to be sensitive to underwater noise, therefore an assessment of underwater noise in the Arctic and how it overlaps with marine mammal areas is needed. Here, we present the first step in this process by assessing trends in vessel traffic in the Arctic. We analyzed PAME’s Arctic Ship Traffic Database (ASTD) to calculate distance traveled by different classes of ships within the Arctic, and then calculated the total distance traveled and area-corrected total distance traveled within different marine mammal areas in the month of September over three years, from 2016 to 2018.
Vessel traffic was highest around Iceland, along the Norwegian coast, and between the Norwegian coast and Svalbard, with vessels in many areas around Iceland and the Norwegian coast travelling more than 100,000 km within the 100 km2 grid cells during the month of September. By comparison, shipping in the rest of the Arctic was sparse, but obvious routes were visible along the Northern Sea Route and the Northwest Passage, as well as between eastern Canada and west Greenland. After controlling for the total area within the different seas of the Arctic, the most traffic in September was in the Norwegian Sea, followed by the Bering Sea and North Atlantic around Iceland, then the Barents Sea and Baffin Bay-Davis Strait.
Based on the area-corrected total distance traveled, 50% of the top ten marine mammal areas with the most vessel traffic are in the Russian Arctic. These top ten areas are equally split between cetaceans and pinnipeds, but most notably, the top three areas are all for beluga whales and are all in the Russian Arctic in the Gulf of Anadyr, East Siberian Sea, and White Sea. The most common vessel classes in marine mammal areas were fishing vessels and bulk carriers, and bulk carriers specifically have a relatively high source level, suggesting that these areas may receive relatively high amounts of underwater noise.
The marine mammal data used in this analysis were from Hauser et al. (2018). In that study, Hauser et al. assessed risks associated with vessel traffic to marine mammal populations, and came up with a list of marine mammal populations that were most at risk. An underlying component of that analysis was the amount of vessel traffic that each population was exposed to, and this metric was based on the overlap between each marine mammal area and either the Northern Sea Route or the Northwest Passage. In this report, we go a step beyond what was done in Hauser et al. (2018) by quantifying levels of traffic within each marine mammal area rather than just assessing overlap. Comparing the exposure values from Hauser et al. (2018) to the levels of vessel traffic in this report show large differences. For example, the population with the greatest level of vessel traffic in our study was assigned the lowest possible exposure value in Hauser et al.’s study. This demonstrates the importance of quantifying vessel traffic when assessing the exposure of marine mammals to vessel traffic.
The underlying marine mammal data provided a good representation of the distribution of each population in the month of September, and also included a metric of uncertainty related to each population. Notably, pinniped populations generally had more uncertainty than cetacean populations, and some geographic regions, such as the North American Arctic, had more certainty than other regions. This marine mammal dataset is rare for the Arctic, and only represents a single month of the year. Further work is required to assess the distribution of all marine mammal populations in other months of the year, and this analysis is required before overlap with vessel traffic can be assessed in these other months.
The analysis presented in this report creates a good foundation for PAME’s future work on underwater noise in the Arctic by quantifying vessel traffic in different Arctic seas and in different marine mammal areas in the month of September. PAME can use these results to frame their underwater noise modeling and to select certain marine mammal areas or regions of the Arctic to focus their efforts.
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Halliday, W.D. (2020). Vessel traffic trends in the Arctic and overlap with important marine mammal areas. Report for Transport Canada. Toronto, Canada: Wildlife Conservation Society, Canada, 1-45.