La cinquième étude de Clear Seas sous l’initiative des couloirs de navigation maritime a été publiée le 2 mars dernier. Cette recherche met en lumière et décrit le trafic maritime dans la région canadienne du Pacifique.
Le 2 mars dernier, Clear Seas a tenu le webinaire Le trafic maritime dans la région canadienne du Pacifique : tendances, trajectoires et densité au cours duquel le Centre a présenté les faits saillants en matière de mouvements de navires et d’hydrocarbures sur la côte du Pacifique, basés sur les résultats de la plus récente analyse du trafic maritime commercial dans cette région à ce jour.
Présentation des résultats
Assistez à la discussion au cours de laquelle notre équipe de recherche présente le rapport et ses principales conclusions (vidéo en anglais seulement):
Réponses aux questions qui n’ont pas été répondues lors du webinaire (en anglais seulement):
What do the oil density figures represent?
The oil density figures represent the relative amount of oil carried by ships as cargo or fuel at points along the coast. The oil density is found by taking each grid cell on the map and calculating the sum of the oil carried as cargo and as fuel by all the ships passing through that cell in 2016, and scaling it by the length of time those ships spent in the cell.
Was a sensitivity analysis performed on the accuracy of the classification of AIS vessel types recorded in the AIS data used in the analysis?
The raw AIS data was augmented and corrected by Nuka Research using the company’s internal database and with additional data on vessels’ classification from IHS Markit.
What is considered port calls assessment? Do the figures represent both entries and exits to ports, or just entries? Does the traffic analysis include bulk cargo ships making multiple visits to the same port (i.e. does the analysis consider the role of anchorages outside of port).? If yes, I would be interested in their emissions impact.
The port calls analysis uses passage lines at port entrances to count the number of vessels that enter into each port – the methods account for the fact that vessels cross the passage line on both entry and exit and considers that as one port visit. Movements within the port were not counted as additional port calls, meaning that if a vessel makes multiple stops at different berths within the port it is counted as a single visit. A specific analysis on anchorage visits including length of time spent and emissions released while at anchorage was not considered in the current analysis.
Victoria is not included in the ports analysis. Does this mean that the cruise ship maps do not include vessel traffic transiting Ogden Point?
Although a passage line was not put in place at the entrance to Victoria harbour, the AIS data for cruise ships entering and leaving Victoria was included in the vessel traffic density plots and on the oil density plots.
Did you see a decrease in cruise ship traffic since the beginning of the COVID-19 pandemic and was oil contamination reduced as a result?
The oil density plots are a map of the oil carried in ship fuel tanks and cargo holds, not environmental contamination. The period of analysis did not include the COVID-19 pandemic timeframe, however the analysis can be used as a benchmark for comparison.
How has the volume of persistent oil changed with the global sulphur cap from January 2020? I assume quantities of persistent oil has declined substantially and will continue to.
Very Low Sulphur Fuel Oil (VLSFO) that is manufactured to be compliant with the January 2020 IMO 0.5% Sulphur cap is also considered to be a persistent oil and so the introduction of the 2020 sulphur cap is unlikely to reduce the persistent oil density in the study region.
Do you consider Marine Gas Oil similar to Marine Diesel Oil and, if similar, are they separated from your description of persistent oils? Why is such a strong distinction made in risk analysis for HFO if MFO is also persistent?
The oil volumes in this analysis are calculated based on bunker capacities of the various vessels in the study. Fuel oil used for main propulsion was assumed to be persistent oil. This may include various grades of marine fuel oil that contain some fraction of residual heavy oil including intermediate and medium fuel oils. Marine Gasoil (MGO) is made exclusively from distillates so would be classified as a non-persistent oil. Marine Diesel Oil (MDO) is generally made from a blend of distillates (non-persistent) and residual oil (persistent) and is therefore usually classified as persistent.
Were you able to distinguish tug traffic by cargo, particularly oil cargo? Does the study consider articulated tug barges (ATBs) which carry oil product loads?
The analysis accounts for estimates of the amounts of oil associated with each tug and barge track. Because barges are not required to have AIS transmitters and do not transmit information on cargo over AIS, it was necessary to identify tugs that tow or push an oil barge and determine the capacity of the barge; this information was obtained through interviews with personnel from Canadian and U.S. companies operating tugs transporting oil barges and other data sources. This information was recorded on an individual track level to estimate the amount and movement of oil carried by tug/barges in the study area during year.
ATBs are an important part of how oil is transported in the Pacific region. While not mentioned specifically in the webinar, ATBs are included as a vessel sub-type with under the tug ship-type category and are considered in the analysis.
What do you see as the solution for shipping voyage plan changes (i.e., burn less low sulphur fuel while burning much more fuel in total)?
By highlighting the fact that ship operators take different approaches to complying with sulphur emissions regulations with different consequences for air pollution and greenhouse gas emissions, it is not Clear Seas’ intention to recommend any single approach as a solution. We hope that by drawing attention to the consequences of environmental policy regulation, industry and policy makers will be able to move forward with the facts to establish a regulatory environment that prioritises safe and sustainable practices while preserving the economic benefits of marine shipping.
Does the group plan to expand this analysis to other regions in Canada (e.g. the Great Lakes and Arctic Regions)?
Yes, we are looking to apply the methods developed in the vessel traffic analysis and the other phases of the Marine Transportation Corridor work to other regions in Canada in our future research projects. This work would take into account the unique ship traffic characteristics, geographical and environmental attributes, and associated risks to and from shipping in each region.
Questions were posed on analyses that were outside of the scope of this report, which will be taken into consideration for future work. These include:
• Correlation between oil density and world oil prices
• Containers lost at sea, include data on the type of cargo
• Future vessel traffic in Douglas Channel
• Changes in vessel traffic due to IMO 2020 sulfur limits
• Effects of pilotage on safety
• Emissions impact from ships at anchorage
The point is made in the webinar and report on how regulated large vessels are. I would like to suggest a webinar on the topic of international, domestic and industry led regulations that ships need to comply with.
This topic is the focus of the multi-part Demystifying Maritime Governance project to complete an analysis of the frameworks and emerging issues for the governance of shipping in Canada. Co-led by Dr. Aldo Chircop, Dalhousie University, and Dr. Desai Shan, Memorial University, this work will help to explain the global and domestic structures, frameworks, actors, interconnections, and processes relating to maritime governance in the simplest terms possible.
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Date de publication : 18 février 2021
Date de modification : 24 mars 2021