scholarly journals Changes in Underwater Noise and Vessel Traffic in the Approaches to Halifax Harbor, Nova Scotia, Canada

2021 ◽  
Vol 8 ◽  
Author(s):  
Heather Breeze ◽  
Shihan Li ◽  
Emmaline C. Marotte ◽  
James A. Theriault ◽  
Jessica Wingfield ◽  
...  
Keyword(s):  
Nova Scotia ◽  
Frequency Band ◽  
Coast Guard ◽  
Automatic Identification ◽  
Identification System ◽  
Underwater Noise ◽  
Acoustic Data ◽  
Sound Levels ◽  
Study Sites ◽  
Passive Acoustic

Over the past two years, researchers at Fisheries and Oceans Canada have been running an acoustic monitoring project at multiple study sites throughout Nova Scotia, Canada to investigate baleen whale presence and levels of underwater noise. At the onset of the COVID-19 pandemic, a passive acoustic monitor (PAM) was in place in the study site located in the approaches to Halifax Harbor, a major Canadian port. This provided a unique opportunity to determine if changes in vessel noise levels occurred after pandemic restrictions were put in place. To investigate this, we analyzed and compared acoustic data collected from March 28 to April 28 and August 6 to October 22 in both 2019 and 2020. We also investigated possible changes in vessel traffic from February 1 through April 28 and July 1 through July 28 in 2019 and 2020 using terrestrial-based automatic identification system (AIS) data provided by the Canadian Coast Guard and cargo information provided by the Port of Halifax. The acoustic data were analyzed in 1/3 octave frequency bands. For the 89.1–112 Hz frequency band, we found an 8.4 dB increase in the daily minimum sound pressure level (SPL) in April 2020 compared to April 2019 due the presence of a large crane vessel stationed near the mooring site. For the period of August to October, we found an approximately 1.7 dB reduction in the same metric from 2019 to 2020. The most noticeable change in vessel composition was the dramatic decrease in the number and occurrence of pleasure craft in July 2020 compared to the same period in 2019. While this analysis looked at only a single PAM and a limited amount of data, we observed changes in sound levels in the frequency band known to be associated with shipping as well as changes in vessel traffic; we conclude that these observed changes may be related to pandemic restrictions.

A Statistical Model for Vessel-to-Vessel Distances to Evaluate Radar Interference

2017 ◽  
Vol 70 (5) ◽  
pp. 1098-1116 ◽  
Author(s):  
Gaspare Galati ◽  
Gabriele Pavan ◽  
Francesco De Palo ◽  
Giuseppe Ragonesi
Keyword(s):  
Solid State ◽  
Density Function ◽  
Coast Guard ◽  
Automatic Identification ◽  
Identification System ◽  
Limited Area ◽  
Maritime Traffic ◽  
The Mean ◽  
New Generation ◽  
Italian Coast

Maritime traffic has significantly increased in recent decades due to its advantageous costs, delivery rate and environmental compatibility. With the advent of the new generation of marine radars, based on the solid-state transmitter technology that calls for much longer transmitted pulses, the interference problem can become critical. Knowing the positions and the heights of the ships, the mean number of the vessels in radar range can be estimated to evaluate the effects of their mutual radar interferences. This paper aims to estimate the probability density function of the mutual distances. The truncation of the density function within a limited area related to horizon visibility leads to a simple single-parameter expression, useful to classify the ships as either randomly distributed or following a defined route. Practical results have been obtained using Automatic Identification System (AIS) data provided by the Italian Coast Guard in the Mediterranean Sea.

scholarly journals A Marine Autonomous Surface Craft for Long-Duration, Spatially Explicit, Multidisciplinary Water Column Sampling in Coastal and Estuarine Systems

2015 ◽  
Vol 32 (3) ◽  
pp. 627-641 ◽  
Author(s):  
Daniel L. Codiga
Keyword(s):  
Water Column ◽  
Collision Avoidance ◽  
Rhode Island ◽  
Coast Guard ◽  
Research Quality ◽  
Spatially Explicit ◽  
Automatic Identification ◽  
Identification System ◽  
Current Profile ◽  
Material Transport

AbstractThe Surveying Coastal Ocean Autonomous Profiler (SCOAP) is a large catamaran marine autonomous surface craft (MASC) for unattended weeks-long, spatially explicit, multidisciplinary oceanographic water column profile sampling in coastal/estuarine waterbodies. Material transport rates/pathways, crucial to understanding these ecosystems, are typically poorly known. SCOAP addresses demanding spatiotemporal sampling needs and operational challenges (strong currents, open coastal sea states, complex bathymetry, heavy vessel traffic). Its large size (11-m length, 5-m beam) provides seaworthiness/stability. The average speed of 2.5 m s−1 meets the representative goal to traverse an 18-km transect, sampling 10 min at each of 10 stations 2 km apart, nominally 4 times daily. Efficient hulls and a diesel–electric energy system can provide the needed endurance. The U.S. Coast Guard guidelines are followed: lighting, code flags, the Automatic Identification System (AIS), and collision avoidance regulations (COLREGs)-based collision avoidance (CA) by onboard autonomy software. Large energy reserves obviate low-power optimization of sensors, enabling truly multidisciplinary sampling, and provide on-demand propulsion for effective CA. Vessel stability facilitates high-quality current profile observations and will aid engineering/operation of the planned winched profiling system, performance of an anticipated radar system to detect/track non-AIS vessels, and potential research-quality meteorological sensor operation. A Narragansett Bay test deployment, attended by an escort vessel, met design goals; an unattended open coastal deployment is planned for Rhode Island Sound. Scientific and operational strengths of large catamaran MASCs suggest they could be an important cost-effective complement to other sampling platforms (e.g., improved spatiotemporal coverage and resolution, extending farther inshore, with a broader range of sensors, compared to underwater gliders) in coastal/estuarine waters.

AIS The Cornerstone of National Security?

2003 ◽  
Vol 56 (1) ◽  
pp. 31-44 ◽  
Author(s):  
Jay A. Creech ◽  
Joseph F. Ryan
Keyword(s):  
National Security ◽  
Coast Guard ◽  
International Maritime Organization ◽  
Automatic Identification ◽  
Identification System ◽  
Automatic Identification System ◽  
The Us ◽  
Pros And Cons ◽  
Technical Issues ◽  
Maritime Domain Awareness

The International Maritime Organization has mandated carriage requirements for VHF Automatic Identification System (AIS) on vessels over 300 tons by 2007 (IMO SOLAS: 1974 and IMO Resolution MSC.99(73)). The AIS will transmit a vessel's position and voyage data to other AIS-equipped vessels and shore-based authorities. It was envisioned that AIS data could enhance the safety of navigation by allowing vessels to quickly identify each other and use Digital Select Calling (DSC) to arrange maneuvers. We will discuss the history and the development of AIS, the technical issues surrounding its use by the mariner as a navigation tool and the pros and cons of the proposal by the US Coast Guard (USCG) to use AIS as a means of surveillance for Maritime Domain Awareness.

scholarly journals The Next Wave of Passive Acoustic Data Management: How Centralized Access Can Enhance Science

2021 ◽  
Vol 8 ◽  
Author(s):  
Carrie C. Wall ◽  
Samara M. Haver ◽  
Leila T. Hatch ◽  
Jennifer Miksis-Olds ◽  
Rob Bochenek ◽  
...  
Keyword(s):  
The United States ◽  
Sound Level ◽  
Reference Station ◽  
Anthropogenic Noise ◽  
Coastal Zones ◽  
Central Pacific ◽  
Acoustic Data ◽  
First Order ◽  
Sound Levels ◽  
Passive Acoustic

Passive acoustic data collection has grown exponentially over the past decade resulting in petabytes of data that document our ocean soundscapes. This effort has resulted in two big data challenges: (1) the curation, management, and global dissemination of passive acoustic datasets and (2) efficiently extracting critical information and comparing it to other datasets in the context of ecosystem-based research and management. To address the former, the NOAA National Centers for Environmental Information recently established an archive for passive acoustic data. This fast-growing archive currently contains over 100 TB of passive acoustic audio files mainly collected from stationary recorders throughout waters in the United States. These datasets are documented with standards-based metadata and are freely available to the public. To begin to address the latter, through standardized processing and centralized stewardship and access, we provide a previously unattainable comparison of first order sound level-patterns from archived data collected across three distinctly separate long-term passive acoustic monitoring (PAM) efforts conducted at regional and national scales: NOAA/National Park Service Ocean Noise Reference Station Network, the Atlantic Deepwater Ecosystem Observatory Network, and the Sanctuary Soundscape Monitoring Project. Nine sites were selected from these projects covering the Alaskan Arctic, Northeast and Central Pacific, Gulf of Mexico, Caribbean Sea, and Mid and Northwest Atlantic. Sites could generally be categorized into those strongly influenced by anthropogenic noise (e.g., vessel traffic) and those that were not. Higher sound levels, specifically for lower frequencies (<125 Hz), and proximity to densely populated coastal zones were common characteristics of sites influenced by anthropogenic noise. Conversely, sites with lower overall sound levels and away from dense populations resulted in soundscape patterns influenced by biological sources. Seasonal variability in sound levels across selected decidecade bands was apparent for most sites and often represented changes in the presence or behavior of sound-producing species. This first order examination of levels across projects highlights the utility of these initial metrics to identify patterns that can then be examined in more detail. Finally, to help the PAM community collectively and collaboratively move forward, we propose the next frontier for scalable data stewardship, access, and processing flow.

scholarly journals Slower Ship Speed in the Bahamas Due to COVID-19 Produces a Dramatic Reduction in Ocean Sound Levels

2021 ◽  
Vol 8 ◽  
Author(s):  
Charlotte Dunn ◽  
James Theriault ◽  
Leigh Hickmott ◽  
Diane Claridge
Keyword(s):  
Sperm Whale ◽  
Mitigation Measures ◽  
Automatic Identification ◽  
Identification System ◽  
Density Level ◽  
Underwater Sound ◽  
Sperm Whales ◽  
Ship Traffic ◽  
Sound Levels ◽  
Ship Speed

As underwater noise from ship traffic increases, profound effects on the marine environment highlight the need for improved mitigation measures. One measure, reduction in ship speed, has been shown to be one of the key drivers in reducing sound source levels of vessels. In 2017, a study began to assess the impacts of increasing commercial shipping traffic on sperm whales in Northwest Providence Channel, northern Bahamas, an international trade route that primarily serves the southeast US. Ship data were collected from an Automatic Identification System (AIS) station combined with recordings from an acoustic recorder to measure underwater sound levels and to detect the presence of sperm whales. Here we analyze a subset of these data to opportunistically investigate potential changes in ship traffic before and during the COVID-19 pandemic. These data span one calendar year from October 2019 to October 2020. A pre-COVID-19 dataset of 121 days, from a recorder approximately 2 km from the shipping route was compared to a 134-day dataset collected during COVID-19 from the same site, comprising 2900 and 3181 ten-minute recordings, respectively. A dramatic decrease in ocean noise levels concurrent with changes in shipping activity occurred during the pandemic. The mean pre-COVID-19 power density level in the 111–140 Hz 1/3-octave band was 88.81 dB re 1 μPa (range 81.38–100.90) and decreased to 84.27 dB re 1 μPa (range 78.60–99.51) during COVID-19, equating to a 41% reduction in sound pressure levels (SPL). After differences in seasonal changes in wind speed were accounted for, SPL decreased during the pandemic by 3.98 dB (37%). The most notable changes in ship activity were significantly reduced vessel speeds for all ship types and fewer ships using the area during the pandemic. Vessel speed was highly correlated to SPL and the only ship-based variable that predicted SPLs. Despite the opportunistic nature [i.e., not a standard before-after-control-impact (BACI) study], this study provides a unique opportunity to assess the effectiveness of ship traffic management strategies, such as slowing ships down, to mitigate impacts on marine life in the study area, including local sperm whale populations.

scholarly journals AIS data case Study : identifying AIS coverage gaps on the Ohio River in CY2018

2021 ◽  
Author(s):  
Patricia DiJoseph ◽  
Brian Tetreault ◽  
Marin Kress
Keyword(s):  
River System ◽  
Technical Note ◽  
Coast Guard ◽  
Automatic Identification ◽  
Identification System ◽  
Army Corps ◽  
Ohio River ◽  
Us Army ◽  
Inland River ◽  
The Us

This Coastal and Hydraulics Engineering Technical Note (CHETN) describes a method for evaluating the received coverage from Automatic Identification System (AIS) shore sites and the availability of historic vessel position reports along the Ohio River. The network of AIS shoreside sites installed and operated by the US Army Corps of Engineers (USACE) and the US Coast Guard (USCG) receive information transmitted from vessels; however, reception of these transmissions is generally line-of-sight between the vessel and the AIS site antenna. Reception may also be affected by factors such as the quality of the transceiver installation aboard the vessel as well as the state of the equipment at the receiving site. Understanding how to define and quantify coverage gaps along the inland river system can inform research utilizing AIS data, provide information on the performance of the AIS network, and provide guidance for efforts to address identified coverage gaps

Integrated Ocean Observing System (IOOS®) Supports Marine Operations: A Look from the U.S. Coast Guard

2010 ◽  
Vol 44 (6) ◽  
pp. 156-165 ◽  
Author(s):  
Jonathan M. Berkson ◽  
Arthur A. Allen ◽  
Donald L. Murphy ◽  
Kenneth J. Boda
Keyword(s):  
Data Acquisition ◽  
Coast Guard ◽  
The Arctic ◽  
Automatic Identification ◽  
Identification System ◽  
Real Time System ◽  
The North ◽  
Ocean Observations ◽  
Ocean Observing ◽  
The U.S

AbstractThe U.S. Coast Guard (USCG) is primarily a user of ocean observations but is also a provider of observations—especially in high-latitude regions. USCG has a long history of making ocean observations for mission activities and in support of other federal agencies. USCG uses the Integrated Ocean Observing System (IOOS®) to understand maritime conditions while conducting the Coast Guard’s roles of Maritime Safety, Maritime Security, and Maritime Stewardship. IOOS data are critical in planning search and rescue operations, ensuring safe navigation at high latitudes, responding to oil and hazardous spills, providing vessel traffic services, and maintaining maritime domain awareness (MDA). The International Ice Patrol makes and uses ocean observations to estimate drift and deterioration of icebergs. The North American Ice Service products are needed in polar and domestic ice operations. The National Oceanic Atmospheric Administration and the USCG are developing a way to disseminate the Physical Oceanographic Real-Time System data via the USCG Automatic Identification System. The Coast Guard provides personnel and vessel support for the National Data Buoy Center observational program, a component of the IOOS. Many key oceanographic, biologic, and geologic discoveries in the Arctic and Antarctic have been made from Coast Guard cutters. As oceanographic data acquisition moves from vessel observations to satellite remote sensing and unmanned in situ data acquisition systems, the USCG will continue to support this effort.

scholarly journals MAPPING SHIP TRAFFIC IN NARROW CHANNELS WITH BENDS USING AUTOMATIC IDENTIFICATION SYSTEM (AIS) DATA

2018 ◽  
pp. 14
Author(s):  
Jeffrey A. Oskamp ◽  
Eric D. Smith
Keyword(s):  
Open Water ◽  
The United States ◽  
Coast Guard ◽  
Vessel Density ◽  
Automatic Identification ◽  
Identification System ◽  
Narrow Channels ◽  
Automatic Identification System ◽  
Ship Traffic ◽  
Commercial Sources

Coastal, port, and waterway projects often require an understanding of the waterborne traffic in the site vicinity. Knowledge of what types of vessels transit near a project site, along with the vessel speeds and typical transit times/paths, can be valuable information to an engineer. Often the best available information for vessel traffic can be obtained from Automatic Identification System (AIS) data. AIS data includes information about the vessel type, position, course, and speed (IMO, 2014). Historic AIS data is available from a variety of free and commercial sources. Inside the United States, a large quantity of AIS data is available freely to the public from the United States’ Coast Guard datasets. AIS data can be summarized in a variety of tabular and graphic formats. For spatial planning and visualization, an intuitive format for communicating vessel traffic to non-technical audiences is a vessel density map. Straightforward methods are available (BOEM/NOAA, 2015) for producing vessel density maps in relatively open water and away from sharp channel bends. This paper addresses challenges with preparing vessel maps in areas with narrow channels and around bends.

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