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Monterey Bay National Marine Sanctuary Vessel Traffic Management Executive Summary


The Monterey Bay National Marine Sanctuary (MBNMS) is the largest marine protected area in the United States. It includes over 6,000 square miles of water off central California, spanning nearly 300 miles of coastline from Cambria to the Marin Headlands. The area was given sanctuary protection by Congress in 1992 in recognition of its national environmental importance and its unique, sensitive and abundant biodiversity. The Sanctuary is home to an extraordinarily diverse array of marine mammals, sea birds, fishes and invertebrates, including many species that are particularly sensitive to the impacts of spilled oil or other hazardous materials. The Sanctuary is also located in an area of critical importance to the conduct of maritime commerce, which is a major component of the regional and national economy.

Vessel traffic within the Sanctuary was a major issue of concern raised during the Sanctuary designation process. The historical record of spills for the Pacific Coast indicates that the total number of spills from transiting vessels is relatively small in number, but the potential impacts can be enormous given the number and volume of these vessels and the potential size of a spill. Congress directed the Secretaries of Commerce and Transportation to evaluate potential threats from spills of oil or other hazardous materials to Sanctuary resources and possible ways to reduce those threats. The United States Coast Guard (USCG) and the National Oceanic and Atmospheric Administration (NOAA) established a workgroup of key stakeholders in the issue, including representatives from federal, state and local governments, environmental groups and industry to review existing practices and risks, and recommend a package of strategies which could be presented for public review. The workgroup's goal was to provide a vessel traffic management system that maximizes protection of Sanctuary resources while allowing for the continuation of safe, efficient and environmentally sound transportation. The workgroup's regional recommendations were presented to the public in 1998. They have been scrutinized over the past two years by a variety of national and international organizations to arrive at the final required international approvals announced on May 31st, 2000.

Management Measures

figure 1: Previous Patterns of Vessel Traffic
figure 1: Previous Patterns of Vessel Traffic

There are approximately 4,000 coastal transits of the Sanctuary each year by large vessels. Approximately 20% of these transits are crude oil tankers. The majority of the remainder are large commercial vessels (LCVs) such as container ships and bulk product carriers. Previous patterns of vessel traffic transits are shown in Figure 1 ( LCVs are of particular concern for spills since they currently travel as close as 2 miles to shore and can carry up to 1 million gallons of bunker fuel, a heavy, viscous fuel similar to crude oil, which they use to power themselves. Recognizing that spills can potentially occur from any transiting vessel carrying crude oil, bunker fuel, or other hazardous material, the workgroup focused its recommendations on four major categories of vessels: a) LCVs greater than 300 gross tons; b) Hazmat ships carrying hazardous materials in bulk, such as chemicals, explosives/munitions, ore concentrates, liquefied gases, and refined petroleum products; c) barges carrying oil or hazardous materials in bulk; and d) laden tankers carrying crude oil, black oil or other persistent liquid cargo in bulk.

The work group's recommended set of strategies reflects a balance of factors combined to provide protection for the Sanctuary, reduced risk of vessel groundings and collisions, and efficient vessel operation, while minimizing the economic burden to industry. The strategies rely on distances offshore which are in part based on an analysis of the anticipated response time for existing rescue vessels. That is, if a vessel that follows the routing measures loses power or steering capabilities, it will almost certainly be reached by a rescue vessel before it drifts ashore and creates a spill. Also of concern was shifting large commercial vessels away from nearshore waters and enhancing the predictability of their locations to reduce collisions and interference with smaller fishing or recreational vessels. The comprehensive package is outlined below:


Distance from Shore

Distances offshore of Point Sur and Pigeon Point strengthen informal patterns of current practices, and where necessary, shift certain types of vessels further offshore to reduce the level of threats to resources.



Large Commercial Vessels (LCVs):

12.7 nautical miles (nm) northbound/16 nm southbound off Pigeon Point and

15 nm northbound/20 nm southbound off Point Sur



Hazmat Ships:

25 nm (northbound) and 30 nm (southbound) from shore off Pigeon Point and Point Sur




25 nm




50 nm

  Implementation of these distances for LCVs and Hazmat Ships will be through Recommended Tracks approved by the United Nation's International Maritime Organization (IMO), an organization of the world's key shipping nations. Following the IMO final approval given at their meeting in London on May 26, 2000, these routes will be marked on the nautical charts mariners use for navigation. Implementation will begin December 1, 2000.

Barges will be addressed by development of an industry agreement with domestic barge companies. Implementation of the 50 nm distance offshore for tankers will involve negotiation of an industry agreement covering all foreign and domestic carriers of crude oil, building on the existing Western States Petroleum Association agreement covering the Alaskan trade.

Traffic Separation Schemes (TSS)

Modifications for two TSSs, the lanes which help organize vessels as they approach major ports, were also recommended by the workgroup and have recently received final approval. The "southern approach" of the San Francisco TSS will shift slightly offshore to the west and an 18-mile extension will be added to the western end of the Santa Barbara Channel. These revisions will reduce risk of groundings along the San Mateo coastline and Point Arguello, and will improve north-south alignment with the proposed Recommended Tracks for LCVs. The USCG published the Final Rulemaking on these revisions in April 2000 and implementation of the TSS shifts began July 15, 2000.


Monitoring and Reporting

Timely implementation of an Automated Information System (AIS), an electronic system that reports a vessel's position, is also recommended to increase capabilities for tracking and communicating with these vessels as they transit the Sanctuary and for assessing compliance with the recommended tracks.


Rescue Vessel Network

Development of a Rescue Vessel Network is recommended to enable response agencies to more quickly identify and direct the nearest potential rescue vessel to the location of a distressed vessel.


Near-miss Reporting

Timely implementation is recommended for a national "near-miss" reporting system which is currently being planned by the USCG, the Maritime Administration, and industry groups. This system would provide valuable insight into dangerous conditions before they precipitate an accident.



The overall vessel management package will include a strong education campaign for mariners to provide information on the sensitivity of Sanctuary resources, details on the new management measures and the importance of compliance.

The overall package of strategies will work together to ensure safe, effective, and environmentally sound vessel traffic management in the Sanctuary region. Completion of this agreement among diverse agencies, environmental groups and the shipping industry, and its subsequent approval at the international level is an excellent example of the collaborate approach to resource management in National Marine Sanctuaries.

Reviewed: April 11, 2024
Web Site Owner: National Ocean Service

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