Application of a New Shore-Based Vessel Traffic Monitoring System Within San Francisco Bay

Abstract

Vessel traffic management systems can be employed for environmental management where vessel activity may be of concern. One such location is in San Francisco Bay where a variety of vessel types transit a highly developed urban estuary. We analyzed vessel presence and speed across space and time using vessel data from the Marine Monitor, a vessel tracking system that integrates data from the Automatic Identification System and a marine-radar sensor linked to a high-definition camera. In doing so, we provide data that can inform collision risk to cetaceans who show an increased presence in the Bay and evaluation of the value in incorporating data from multiple sources when observing vessel traffic. We found that ferries traveled the greatest distance of any vessel type. Ferries and other commercial vessels (e.g., cargo and tanker ships and tug boats) traveled consistently in distinct paths while recreational traffic (e.g., motorized recreational craft and sailing vessels) was more dispersed. Large shipping vessels often traveled at speeds greater than 10 kn when transiting the study area, and ferries traveled at speeds greater than 30 kn. We found that distance traveled and speed varied by season for tugs, motorized recreational and sailing vessels. Distance traveled varied across day and night for cargo ships, tugs, and ferries while speed varied between day and night only for ferries. Between weekdays and weekends, distance traveled varied for cargo ships, ferries, and sailing vessels, while speed varied for ferries, motorized recreational craft, and sailing vessels. Radar-detected vessel traffic accounted for 33.9% of the total track distance observed, highlighting the need to include data from multiple vessel tracking systems to fully assess and manage vessel traffic in a densely populated urban estuary.

Tracking the global reduction of marine traffic during the COVID-19 pandemic

“…Fortunately, recent technological advances associated with automatic identification system (AIS), now means that ship-based mobility patterns can be monitored on a global scale [22][23][24] , thereby providing a unique opportunity to monitor the location of large ocean-going ships, passenger liners, and fishing vessels anywhere in the world at high temporal resolution [25][26][27] . Consequently, AIS can provide unparalleled insights into shipping-derived impacts and conservation planning at multiple spatial and temporal scales 4,[27][28][29][30][31] .…”

Coastal radar as a tool for continuous and fine-scale monitoring of vessel activities of interest in the vicinity of marine protected areas

“…The objective of this research was to evaluate the spatial and temporal extent of potential fishing activity in the vicinity of California MPAs using shore-based marine X-band radar, a solution for tracking non-participatory vessels [43,44]. Marine Monitor (M2) systems (https://protectedseas.net/marine-monitor-m2) strategically located onshore near no-take MPAs were used to track vessel activity autonomously and continuously via radar for one year.…”

Assessing anthropogenic risk to sea otters (Enhydra lutris nereis) for reintroduction into San Francisco Bay

“…Despite historic occupancy, sea otters have not continuously inhabited San Francisco Bay since the mid-19th century, after being extirpated during the Maritime Fur Trade (Ogden, 1941). Today San Francisco Bay is host to three major metropolitan cities, bayfront crude oil refineries, fast passenger ferries (median speed > 55 km/h), and five commercial shipping ports-some of the busiest in the world (Grobar, 2008;Jensen et al, 2015;Cope et al, 2020). There is an ever-present risk of large oil spills, historically proven to be devastating events for all kinds of wildlife (Garrott, Eberhardt & Burn, 1993;Peterson et al, 2003).…”

“…An examination of deceased otters from the Exxon Valdez oil spill found that exposure to oil through ingestion or inhalation as a result of grooming to try and rid their fur of oil resulted in pathological lesions in the lungs, liver, and kidneys, and provoked a stress response that lead to shock and consequent mortality (Lipscomb et al, 1994). In addition, the Bay is popular for recreational boating and fishing, making the waterways of San Francisco Bay heavily trafficked by vessels of all types (Cope et al, 2020). There are few limits on the speed of vessels traveling within the Bay, apart from a 15 knots (27.8 km/h) speed limit imposed on large commercial shipping vessels while navigating the shipping channels (Harbor Safety Committee, 2009).…”