1. Introducción
As global warming leads to the melting of Arctic sea ice, seasonal Arctic sailing becomes possible [
1,
2]. Maritime traffic is a complex, dynamic, and multi-layered system. By analyzing the characteristics of the maritime system and the factors affecting its evolution, we can optimize maritime traffic and reduce the probability of maritime traffic accidents. This helps ensure maritime traffic safety, reduce marine environmental pollution, and improve the overall efficiency of maritime vessels. In 2018, the Chinese government issued the white paper “China’s Arctic Policy”, proposing to rely on the development and utilization of Arctic routes to jointly build the “Polar Silk Road” with all parties. Studying the evolution of Arctic maritime traffic patterns can support the formulation of China’s Arctic shipping plans, reducing dependence on traditional Suez Canal routes.
The Arctic Northeast Passage (NEP) has garnered widespread attention due to its potential to connect the two continents of Eurasia within a shorter route. Global climate change has accelerated the melting of Arctic ice, making this route gradually navigable in summer [
3]. As the route opens up, vessel traffic activity has increased, bringing not only commercial opportunities but also challenges in environmental protection and route management [
4]. Therefore, it is particularly important to use Automatic Identification System (AIS) data to analyze the spatiotemporal evolution of vessel activities on the NEP. The Arctic Northeast Passage is a sea route that traverses the northern seas of Russia, connecting Asia and Europe via the Arctic. Early research concentrated on assessing the economic viability and navigability of the NEP. Smith and Stephenson explored the commercial potential of the NEP by comparing the time cost-effectiveness of traditional routes and the NEP [
3]. Wu et al. ’s research indicates that the NEP offers potential for maritime transport between Europe and Asia due to longer sailing seasons from global warming, but despite lower CO
2 emissions and costs for larger vessels, it remains less economically viable than the Suez Canal Route, especially for year-round operations before 2065 [
5]. Zhang et al. proposed a risk assessment-based method to evaluate the economic benefits of the NEP and emphasized the importance of risk management in route planning [
6]. Petrov and Tulaeva analyzed the potential impact of Arctic route development on local community economies [
7]. Ol’khovik et al. analyzed the shipping development trends of the NEP, noting that while the number of ships remains stable, the seasonal variation in ship navigation has significant impacts on the safety and efficiency of NEP shipping [
8]. Koyama et al. utilized AIS and TOPAZ4 data to propose a non-heuristic optimal route search method, demonstrating the potential of data-driven approaches in Arctic route planning [
9]. Research on the environmental impact of vessel activities on the NEP usually focuses on the disruption of the Arctic ecosystem by shipping activities. Kim and Choi studied the impact of Northern Sea Route (NSR) activities on noise pollution in Arctic waters and proposed strategies to reduce shipping noise [
10]. Silber and Adams quantified the impact of vessels on Arctic waters using AIS data [
11]. However, methodologies and data acquisition for environmental impact assessment still face challenges, especially in extreme and remote areas [
12]. Research on route safety mainly focuses on the operational safety of vessels under extreme climatic conditions. Studies like those by Eguíluz et al. analyzed the risks of the global shipping network using AIS data, but existing research on the safety management of the NEP has yet to fully cover all potential safety risks [
13], such as narrow straits [
14], complex geopolitical [
15] and natural environments, etc. Lee and Kim dynamically simulated the ice conditions of the NEP and assessed the safety risks under different climate change scenarios [
16]. Vanhatalo et al. used Bayesian analysis to assess the probability of ships getting trapped in ice conditions, providing a scientific basis for route safety management [
17]. Yang et al. systematically reviewed the research literature on Arctic navigation safety, summarized the shortcomings of existing studies, and provided future prospects [
18]. In studies on the impact of Arctic international laws and policies on Arctic routes, there is often a lack of in-depth analysis of the differences between the legal systems of different countries and the issues of actual enforcement [
13]. Lynch et al. discussed the application and challenges of international law in managing Arctic routes [
19]. Chen and Huang analyzed the policy differences of various countries regarding the right to use Arctic routes and proposed recommendations for enhancing international cooperation [
20]. International cooperation plays a crucial role in coordinating the interests of Arctic countries and standardizing shipping operations, but it still needs to be strengthened [
21]. Existing studies rarely address the spatiotemporal patterns of vessel traffic on the NEP; this study aims to propose strategies for improving navigation management and route safety by deeply analyzing AIS data, with a particular focus on the safety, economic benefits, and environmental impacts of the route.
Since 2010, vessel activity along the NEP has begun to increase significantly. The main reason is the melting of Arctic ice, which has made the route more navigable for most of the year. The development of icebreaker technology and the growing international interest in Arctic resources have further influenced the increase in maritime activities. Especially since 2015, with Russia’s initiatives to promote the route as a viable commercial shipping pathway, vessel activity through the NEP has significantly increased. The period from 2015 to 2020 serves as an important baseline for understanding long-term trends in Arctic navigation. This timeframe captures the early stages of significant increases in shipping through the NEP, influenced by the melting of Arctic ice and global shipping dynamics. By analyzing this period, researchers can provide a deeper historical context for the changes observed in navigation patterns later on. With the impact of the COVID-19 pandemic in 2020, the pandemic widely disrupted global shipping and trade routes. Studying the period before the COVID-19 pandemic provides insights into the natural progression and growth of vessel activity on the NEP, free from the external disruptions caused by the pandemic, thereby offering a clearer understanding of the potential trends and influencing factors of vessel activity on the NEP. From 2015 to 2020, significant developments occurred in the infrastructure and regulatory policies affecting the NEP. For example, China and Russia deepened their cooperation on Arctic development projects. Analyzing this period helps us understand the policy framework that supported the subsequent increase in shipping activities. During this period, there were advancements in navigation technology and icebreakers, as well as modifications of vessels for ice-bound waters. Research during this period helps understand how technological and operational advancements impacted vessel activities on the NEP, laying a foundation for future studies. Finally, from an economic and strategic perspective, significant geopolitical changes occurred from 2015 to 2020, including the expansion of the Belt and Road Initiative to the Arctic Maritime Silk Road. Studying vessel activities during this period provides insights into the economic strategies of key stakeholders like China and Russia and their long-term impact on global Arctic trade. The outbreak of the Russia-Ukraine war in 2022 significantly affected Russian maritime trade, and the ongoing conflict has introduced non-natural factors influencing Arctic vessel activities. In summary, from the current perspective, the NEP from 2015 to 2020 provides a more stable and undisturbed dataset, allowing for the analysis of growth, challenges, and strategic developments related to the NEP without the abnormal impacts of political changes due to the COVID-19 pandemic and the subsequent Russia-Ukraine war after 2020. This makes the period from 2015 to 2020 a more valuable timeframe for understanding the potential and sustainability of Arctic maritime routes. Against this backdrop, studying the evolution patterns and influencing factors of vessel activities on the NEP from 2015 to 2020 holds significant practical relevance. This paper constructs an Arctic vessel AIS database from 2015 to 2020, utilizing quantitative models and ArcGIS spatial analysis techniques to analyze the temporal and spatial characteristics of Arctic vessel distribution, speed, size, and density, revealing the patterns of Arctic vessel activities and providing support for the planning, safety assurance, and management of Arctic vessel routes.
Although maritime traffic and maritime transport both involve vessel activities on water, they have essential differences, mainly in terms of purpose, scope, and management: (1) Purpose and Scope: Maritime traffic is defined as the movement and flow of vessels in the ocean or other waters, similar to traffic systems on land. This includes all types of vessel movements on water, regardless of their purpose. Maritime transport is a subset of maritime traffic, specifically referring to the activities of transporting goods or people by ships on the ocean. It is one of the most important modes of transport in international trade, crucial to the global economy. (2) Management and Regulations: Maritime traffic mainly focuses on the safety and efficiency of vessel navigation, involving a wide range of rules, such as those by the International Maritime Organization (IMO), Vessel Traffic Services (VTS), and the Automatic Identification System (AIS). Maritime transport, on the other hand, emphasizes the management of commercial logistics and transport services, including cargo handling, route planning, vessel maintenance, and economic efficiency. The NEP is still in its early development stages; studying maritime traffic is more practical than studying maritime transport. This is mainly because it is crucial to comprehensively understand and assess the potential impacts, safety, feasibility, and environmental factors of the route. Research on maritime traffic can provide comprehensive information on route safety, risk factors, route selection, and management. This is crucial for ensuring the safe operation of routes, especially in extreme and sensitive environments like the Arctic. Research on maritime traffic can also lay a solid foundation for understanding the impact of Arctic vessels on the fragile Arctic ecosystem, providing data support for the formulation of sustainable development policies. Maritime traffic also involves route operational efficiency, identifying optimal routes and potential bottlenecks through traffic flow analysis. For an emerging route, the formulation of regulations and policies is also crucial; research on maritime traffic helps understand and construct the legal and policy framework in this area, ensuring the legal and efficient operation of the route. In summary, this paper focuses on studying the evolutionary characteristics of maritime traffic on the NEP, identifying four types of vessels as the research subjects through preliminary data analysis: cargo ships, tankers, fishing vessels, and passenger ships. Other vessel types are currently relatively few in number; as the route develops, they will become targets for future research. For an emerging route like the NEP, comprehensive research on maritime traffic will provide a solid foundation, offering critical support for the development and operation of the route. As the route matures and commercializes, specific research on maritime transport will become more important to optimize operational efficiency and enhance commercial benefits.
3. Results
3.1. Spatiotemporal Distribution Characteristics of Vessel Numbers
3.1.1. Monthly Change in Number of Vessels
The monthly distribution of traffic flow density for four typical types of vessels—fishing vessels, cargo ships, passenger ships, and tankers—on the NEP is shown in
Figure 3. Traffic flow density reflects the number of vessels on the NEP to a certain extent. It can be observed that the number of these four types of vessels on the NEP has been increasing annually, with their numbers in the summer far exceeding those in other seasons, especially for fishing vessels and cargo ships. Among the Arctic maritime vessel numbers, fishing vessels outnumber the combined total of cargo ships, passenger ships, and tankers (as shown in
Table 1). Further analysis reveals that all four types of vessels exhibit strong temporal variation patterns. The monthly variation patterns of the four types of Arctic maritime vessels are generally consistent. In 2015, the numbers of all four types of vessels were relatively low, but after 2018, their numbers increased significantly. January to June is the low peak period for the numbers of the four types of vessels, reaching the annual lowest point in June. From July, the numbers of the four types of vessels increase significantly, reaching the annual peak in September. From October to December, the numbers slowly decrease but remain much higher than in January to June.
3.1.2. Quarterly Change in the Number of Vessels
Table 1 presents the seasonal variation statistics for the number of different types of vessels on the Arctic Northeast Passage. “Unique vessel” indicates each vessel (MMSI number) counted only once, while “voyage” indicates a single trip counted as one voyage. From the table, it can be seen that the number of unique cargo ships nearly doubled from the first stage in 2015 to the second stage in 2018. However, the number of voyages did not increase as much as the number of unique vessels. Some cargo ships joined the Arctic Northeast Passage due to climate and policy reasons but did not have many voyages. From 2018 to the third stage in 2020, the number of unique cargo ships remained relatively stable, but the number of voyages decreased, likely due to the global economic downturn caused by the pandemic in 2020. The trends for tankers and passenger ships across the three stages are generally similar to those of cargo ships, except that the number of voyages from the first to the second stage increased almost as much as the number of unique vessels. Unlike the other three types of vessels, the number of unique fishing vessels showed a continuous doubling trend from the first stage in 2015 to the third stage in 2020. A large number of fishing vessels have entered the Arctic Northeast Passage, closely related to the warming climate and melting sea ice, with the pandemic having very little impact on seafood. From a seasonal perspective, except for passenger ships, which are most numerous in summer, the other three types of vessels reach their highest numbers in autumn. September is the peak month for vessel activities on the Arctic Northeast Passage, leading to a significantly higher number of vessels in autumn compared to other seasons. The high demand for summer tourism makes the higher number of passenger ships in this season reasonable. In
Table 1, the overall trend from the first stage to the second stage shows significant growth, but this trend halted from the second stage to the third stage, indicating that the pandemic’s impact on the global economy also affected the Arctic Northeast Passage region.
3.1.3. Spatial Distribution of Vessels
As shown in
Figure 4, over time, the distribution range of various types of vessels on the NEP has gradually expanded. Initially, tankers operated in small numbers in the Norwegian Sea and Barents Sea, but later, their activity extended widely throughout the entire NEP, reaching as far east as the East Siberian Sea. Influenced by ocean currents, most fishing vessels operate in the Norwegian Sea and Barents Sea. Due to the development of tourism, most passenger ships operate between the Svalbard archipelago and Norway. The activity range of cargo ships has gradually moved to the Laptev Sea and East Siberian Sea, thanks to Russia’s construction and policy support for its eastern ports.
3.1.4. Spatial Distribution of Traffic Flow Density
As shown in
Figure 5, the spatial distribution of traffic flow density can show the areas where ships tend to gather on the Arctic Northeast Passage, which plays a vital role in analyzing navigation safety. Regarding vessel density in the Arctic, the entire NEP had a similar overall density in 2015 due to the low number of vessels. By 2018, vessel density increased significantly in the Norwegian, Finnish, and Swedish waters, with denser areas gradually approaching the Arctic center. Some areas in the Kara Sea also reached a density of over five vessels per hour, and the high-density area gradually extends eastward. In 2020, the area with a density greater than five vessels per hour further expanded, showing a significant change compared to 2015.
3.2. Spatiotemporal Distribution Characteristics of Vessel Speed
3.2.1. Temporal Distribution Characteristics of Vessel Speed
A statistical analysis of vessel speeds in the Arctic region was conducted using ArcGIS 10.7 spatial analysis tools. As shown in
Table 2, the results indicate that fishing vessels primarily operate at medium to low speeds, with the proportion of low-speed fishing vessels gradually increasing over time. Cargo ships primarily operate at medium to high speeds; however, the proportion of low-speed cargo ships is increasing year by year. Tankers primarily operate at medium to high speeds, and the proportion of high-speed tankers has increased annually. Before 2020, passenger ships mainly operated at high speeds; nevertheless, the proportion of low-speed fishing vessels has increased significantly in 2020.
3.2.2. Spatial Distribution Characteristics of Vessel Speed
As shown in
Figure 6, The NEP spans many sea areas, and vessel speeds vary significantly across these regions. In the Norwegian Sea, vessel speeds are mostly between 8–12 knots, while in the Barents Sea, they are mostly below 8 knots. In the Kara Sea, Laptev Sea, East Siberian Sea, and Chukchi Sea, vessel speeds near the coast are slower, likely due to the extensive distribution of coastal ice and numerous shoals, and they predominantly have medium speeds, with a few high-speed vessels. The central sea areas have many straits and complex navigation environments, which may be why vessel speeds cannot be too fast. In the northern sea areas, there are more high-speed vessels. During the ice-free period in summer, the navigation environment is better, and vessel speeds are relatively faster.
3.3. Spatiotemporal Distribution Characteristics of Vessel Size
3.3.1. Temporal Distribution Characteristics of Vessel Size
The classification of various vessel types in the NEP region was conducted based on the “International Ship Classification”. From
Table 3, before 2020, fishing vessels were mainly medium to large-sized ships with lengths between 20–80 m, accounting for about 75%. Over time, the proportion of small vessels under 20 m gradually increased, reaching 54.4% by 2020, while the number of mega fishing vessels remained low, consistently in the single digits. It can be seen that fishing vessels show a trend of decreasing in size, while cargo ships and tankers show a trend of increasing in size. The size of passenger ships remains relatively stable, with most being medium to large-sized.
3.3.2. Spatial Distribution Characteristics of Vessel Size
As shown in
Figure 7, initially, in 2015, small fishing vessels were mostly distributed in the coastal waters of Norway, Sweden, and Finland, regardless of the season, but the scope of activities is limited. In 2018 and 2020, the activity locations of small fishing vessels remained relatively stable, and their activity range gradually moved away from the coast. Most medium-sized fishing vessels were distributed in the waters between Norway, Sweden, Finland, and the Svalbard archipelago. In the winter of 2020, a small portion of medium-sized fishing vessels appeared in the coastal waters of the Kara Sea. Large fishing vessels were mainly distributed in the offshore waters around the Svalbard archipelago and Franz Josef Land archipelago. In summer and autumn, large fishing vessels appeared in the Kara Sea and Laptev Sea. Mega fishing vessels were sparsely distributed in the central offshore areas, with almost none in the winter of 2015 and small numbers present throughout the year in 2018 and 2020.
As shown in
Figure 8, in 2015, small tankers were mainly primarily distributed in the coastal waters of Norway, Sweden, and Finland. In summer and autumn, medium to large tankers with a deadweight tonnage of 50,000 to 100,000 tons were spread across the entire NEP. Mega tankers were only active in the Norwegian Sea and Barents Sea. In the spring and winter of 2018, small tankers were mainly concentrated in the coastal waters of Norway, Sweden, and Finland, while medium to mega tankers were mainly in the Norwegian Sea, Barents Sea, and Kara Sea. In summer and autumn, small tankers appeared not only in their spring and winter locations but also in the coastal areas along the entire NEP. Medium to mega tankers were spread across the entire NEP. Nevertheless, the distribution of small to large tankers narrowed in 2020, while mega tankers further expanded their range of activities.
Overall, the size of fishing vessels has gradually decreased over time, and by 2020, small fishing vessels had become the most prevalent type in the NEP region. Cargo ships show a slow increasing trend in size. While they have mainly been less than 50,000 tons, the number of cargo ships in the 50,000 to 200,000 tons range significantly increased in 2018 and 2020. The size of tankers has significantly increased, and over time, the number of mega tankers over 100,000 tons has noticeably grown throughout the Arctic region. The size of passenger ships has remained relatively stable, with medium-sized passenger ships (50–100 m) being the most common. Only in 2020 did the number of small passenger ships significantly increase, primarily concentrated in the coastal waters of Norway, Sweden, and Finland.
3.4. Spatiotemporal Distribution Characteristics of Vessel Trajectories
From
Figure 9, it can be seen that in 2015, vessel trajectories on the NEP were mainly concentrated in the Barents Sea and Norwegian Sea during spring and winter, primarily involving passenger ships and fishing vessels. In the summer and autumn of 2015, vessel trajectories extended to the Kara Sea, Laptev Sea, and East Siberian Sea, with denser trajectories in autumn compared to summer. In 2018, vessel trajectories increased significantly compared to 2015, with a broader sea area coverage. In spring, vessel trajectories appeared only in the Norwegian Sea, Barents Sea, and Kara Sea. In summer, autumn, and winter, vessel trajectories were present across the East Siberian Sea, Laptev Sea, Kara Sea, and Barents Sea along the entire NEP. Summer and autumn trajectories approached the center of the Arctic Ocean, while winter trajectories were relatively sparse compared to summer and autumn. In 2020, the global COVID-19 pandemic affected vessel numbers and activities to some extent. However, the track density in the Norwegian Sea, Barents Sea, and Kara Sea increased.
3.5. Analysis and Summary
Based on the AIS data of vessels on the NEP from 2015, 2018, and 2020, and using ArcGIS 10.7 spatial analysis tools, the spatiotemporal distribution characteristics of fishing vessels, cargo ships, tankers, and passenger ships were explored, and the factors affecting their evolution were analyzed. The results show the following:
In 2015, the number of various types of vessels was relatively low. As the climate warmed and navigable time increased, along with the introduction of national policies, the number of all types of vessels has been steadily rising. Overall, various types of vessels are greatly influenced by seasonal and climate changes. Every year, after the ice starts to melt in June, the number of vessels begins to rise, peaking in August and September. After October, as some areas start to freeze, the number of vessels gradually decreases. Cargo ships, tankers, and passenger ships experienced a significant acceleration in growth starting in the second stage (2018) against the backdrop of deepening Arctic cooperation between China and Russia. Due to the global pandemic, the international economy weakened with the exception of seafood, and the number and activity frequency of other vessel types declined compared to the second stage. Especially the number of tankers, which was lower than in the first stage (2015 to 2017). One reason was the decreased demand for crude oil due to the COVID-19 pandemic, and another was the oil price collapse caused by disputes between Russia and Saudi Arabia over production cuts, which reduced global oil supply and significantly impacted crude oil transportation. Additionally, the International Maritime Organization (IMO) implemented stricter ship emission regulations in 2020 (IMO decided to enforce a global 0.5% sulfur cap starting in 2020). These factors combined led to a reverse growth in the number of cargo ships, tankers, and passenger ships in 2020.
Fishing vessels on the NEP are mainly medium to small-sized, primarily distributed in the Norwegian Sea and Barents Sea. The proportion of small fishing vessels is increasing yearly, with most operating near Norway, Sweden, Finland, and Murmansk ports and at relatively slow speeds. Medium to large fishing vessels mostly operate in the waters around the Svalbard archipelago at relatively higher speeds. Most cargo ships are medium to small-sized vessels under 20,000 tons. The proportion of medium-sized cargo ships (5000–20,000 tons) is increasing yearly, mostly operating in nearshore channels and usually traveling at speeds of 8–12 knots. The size of tankers is gradually increasing, with the proportion of small tankers decreasing and that of large and mega tankers increasing. Tankers typically travel at speeds of 8–12 knots, but when navigating the East Siberian Sea, speeds can reach 12–23 knots. The East Siberian Sea offers more open waters and a reduced sea ice threat compared to other seas like the Chukchi Sea, where icebergs and narrower channels restrict vessel speed. Most passenger ships are medium to large vessels (50–150 m), primarily operating in the Norwegian Sea and around the Svalbard archipelago. Passenger ships in the Norwegian Sea travel at relatively slower speeds, while those around the Svalbard archipelago travel faster. The peak season for Arctic tourism is in summer, resulting in higher numbers of passenger ships during this season compared to others, with tourism interest continuously growing.
From the spatiotemporal trajectories of vessels on the NEP, it is observed that vessel trajectories in the Norwegian Sea and Barents Sea are dense year-round. This is due to the influx of the Atlantic Current and North Cape Current, providing rich fishery resources in these sea areas. The Barents Sea also has abundant oil and gas resources. Additionally, Norway’s Arctic tourism is well-developed, with ice-free areas suitable for navigation throughout the year. Consequently, these areas see a high year-round activity of fishing vessels, tankers, and passenger ships. The Kara Sea, Laptev Sea, and East Siberian Sea primarily see activity from large tankers and cargo ships. Seasonally, the activity periods for tankers and cargo ships are increasing yearly, extending the navigation season. From the trajectory positions, it is evident that the paths of cargo ships and tankers are gradually approaching the Arctic center over time. All these observations indicate that under the influence of Arctic policies from various countries and global warming, year-round navigation in the Arctic is within reach.