Vessel Impacts
Greater Farallones

humpback whale with injuries from a ship's propeller
Deep cuts from a ship's propeller are telltale signs on this young humpback whale that it was killed by a ship striking it. Credit: Jan Roletto, GFNMS, NOAA

Why is it a concern?

Visitors, scientists, fishermen, commercial shippers, and other stakeholders access the sanctuary through the use of recreational and commercial vessels. These vessels are an important part of the "blue economy" and also provide a safe way for many visitors to experience some of the sanctuaries most iconic places. However, there are several impacts from vessels that can affect biological and archaeological resources within the sanctuary. These impacts include ship strikes, ship groundings, lost containers from shipping vessels, and discharge of waste water and other materials from ships.

Three major shipping lanes converge in the Greater Farallones National Marine Sanctuary (GFNMS) just west of the Golden Gate Bridge at the entrance to San Francisco Bay and ship strikes of whales have been recognized as a growing concern. The volume of traffic in and out of San Francisco Bay is large; in 2008, nearly 4,000 tank and non-tank vessels made this transit.  Documented ship strikes from NOAA NMFS data from 2004--mid 2015, occurring within or near the sanctuary (including San Francisco Bay, and outer coast from Sonoma through Monterey Counties); a total 20 whales were confirmed to have been killed by ships. There have been at least four confirmed ship strikes since the new vessel traffic lanes have been in effect, July 2012. The combination of high traffic, feeding areas, and migratory whale routes result in a marked increase risk of ship strikes to whales that can result in serious injury or death to whales.Four primary species of whales (blue, fin, humpback, and gray) have been killed by ship strikes in the GFNMS region. The impact of ship strikes on blue whales may be of greatest concern, given their smaller population, lack of population recovery and the high proportion of their mortality attributed to ship strikes. Conversely, the gray whale population has recovered even though they are struck and killed by ships, annually.  Their recovery could be a reflection of their larger population size,  their coastal distribution, and/or lack of foraging within shipping lanes, therefore resulting in a successfully recovered species.

In 2012 the Traffic Separation Scheme was modified at the approach to San Francisco Bay to help reduce co-occurrence of ships and whales. Further studies will be needed to determine the level of compliance of commercial vessels to the modified lanes. The sanctuary also began voluntary speed reductions in 2012, requesting vessels slow down to ten knots or less in one or more of the three lanes that approach San Francisco Bay.

Overview of Research

Research conducted by Sanctuary scientists and partners provides critical information to address existing and emerging resource conservation and management issues. The Overview of Research highlights some, but not necessarily all, of the research activities completed or ongoing at the Sanctuary.

Project Name PI and contacts Links

Applied California Current Ecosystem Studies

Jan Roletto, Jaimie Jahnke, and Dani Lipski

Monitoring Whales by Cascadia Research Collective

John Calambokidis

Cetacean & Ecosystem Assessment Survey of the California Current

Jay Barlow


Science Needs and Questions

The best available science is used by Sanctuary scientists and managers working to address priority resource conservation and management issues. As priorities change and new issues emerge, each Sanctuary develops new science needs and questions and works with partners to address them.

  • Identify "hotspots" of foraging and transiting blue and humpback whales?  How and when do these "hotspots" vary throughout the year and inter-annually?
  • Identify "hotspots" of foraging and transiting large cetaceans (i.e. Risso’s dolphins and larger)?  How and when do these "hotspots" vary throughout the year and inter-annually?
  • How has the risk of co-occurrence of whales and ship changed, since the vessel traffic scheme was modified in 2012?  Has there been a reduction in the risk to ship strikes?
  • Is there greater risk of ship strikes to younger whales?  Is there greater risk of ship strikes to foraging blue and humpback whales?
  • What is the population impact from one, two, or five know ship struck blue or humpback whale(s)? 
  • How do whales use the water column and how can this information inform policies to mitigate collisions between whales and shipping?
  • How do whales react to the approach of vessels and how can this information inform policies to mitigate collisions between whales and shipping?
  • How much diel, annual and inter-annual variability exists in the underwater behavior of endangered whales and how can this information inform policies to mitigate the risk of ship strikes to whales?

Education and Outreach Material

Ship strike podcast with Sean Hastings

Two apps are available with the intent to prevent ship trikes and help save whales. Whale Alert is an app aimed for use by the general public and the Spotter Pro app is intended for use by researchers, commercial ship operators, charter fishing boat operators, whale watching naturalists, and recreational and commercial fishers. Both apps document whale sightings in real-time. Data collected through these apps helps NOAA fill in the formation gap needed to request the U.S. Coast Guard’s Vessel Traffic Service to ask ship operators to slow down or change course as they approach areas where whales are present.


Berman-Kowalewski, M., F.M.D. Gulland, S. Wilkin, J. Calambokidis, B. Mate, J. Cordaro, D.
Rotstein, J. St. Leger, P. Collins, K. Fahy, and S. Dover. 2010. Association between bluewhale (Balaenoptera musculus) mortality and ship strikes along the California coast.
Aquatic Mammals 36: 59-66.

Joint Working Group on Vessel Strikes and Acoustic Impacts. 2012. Vessel Strikes and Acoustic
Impacts. Report of a Joint Working Group of Gulf of the Farallones and Cordell Bank National
Marine Sanctuaries Advisory Councils. San Francisco, CA. 43 pp.

Office of National Marine Sanctuaries. 2010. Gulf of the Farallones National Marine Sanctuary Condition Report 2010. U.S. Department of Commerce, National Oceanic and Atmospheric Administration, Office of National Marine Sanctuaries, Silver Spring, MD. 97 pp.