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Whales and Shipping Lanes

Whale_and_Ship_CalamokidisRisk assessment of shipping activities and habitat use by large Whales

within the Gulf of the Farallones, Cordell Bank, and Monterey Bay National Marine Sanctuaries

Large whales (cetaceans) face increasing threats in our oceans including potential impacts of vessel traffic such as ship strikes and vessel noise. Recent observations indicate negative interations may be increasing. Our primary goal is to investigate the risk for Gray whales and endangered Humpback and Blue whales in an area of increasing shipping activities.

We used historical whale sighting data and Automatic Identification Systems (AIS) data in selected time-periods to identify types and numbers of vessels that transit the shipping lanes in the vicinity of the large cetacean foraging and transiting areas in central California. Our spatial analysis provided important details on critical habitat within the three central California National Marine Sanctuaries and Marine Protected Areas and the overlap of cetacean densities with ship densities.

2013 News – Spotter App, real-time crowd sourcing to reduce ship strikes on whales

Project results


Sighting locations of humpback and blue whales during summer and fall feeding season during 1989-1990 (Kieckhefer humpback whale data) and 2001-2008; 2010-2011 (Keiper data for blue and humpback whales).

New 2012 Result Summary ( 2 M pdf)

Results of humpback and blue whale habitat use patterns indicated greatest densities occurred near the continental shelf edge, along the inner side of the shelf edge and along the shelf slope, at Cordell Bank, and west, north and south of the Farallon Islands. Desities were also high on the continental shelf in the Gulf of the Farallones and Cordell Bank National Marine Sanctuaries. The observations made during whale watching cruises and other studies exhibited a similar pattern.

Results of San Francisco approach vessel traffic patterns during Aug-Oct 2009-2010 indicated the greatest numbers of vessels were cargo ships (52%) and tankers (24%); 14% were”other” (passenger, pilot vessel, search and rescue, port tender, military ops, underwater ops, law enforcement, sailing, pleasure, fishing, unidentified); and 10% were towing or tugs.

Overlap of whale density and vessel density results indicated the principal areas of relative risk were the western approach shipping lanes that intersect the shelf edge within the Gulf of the Farallones and in the Cordell Bank area where the (extended) northwest lanes pass through the shelf north of the Gulf of the Farallones.


Whales in Danger of Ship Strikes Gain Mobile App

Bay Nature, July 2013


  • Carol A. Keiper, Oikonos Ecosystem Knowledge
  • Janet Casey and Glenn Ford, R.G. Ford Consulting
  • Tom Kieckhefer, Marine Ecologist
  • Chris Miller, NPS Ocean Acoustics Laboratory
  • John Calambokidis, Cascadia Research



Pacific Life Foundation




Whale watching cruises (opportunistic data collected by Keiper) in

cluded the following:

  • Oceanic Society (
  • SF Bay Whale Watching (
  • Capt. Jim Roberts, Outer Limits
  • Capt. Mick Menigoz, Superfish
    Humpback whales south of the Farallon Islands.(Photos: © 2010 John Calambokidis, Cascadia Research) Graphic shows whale intersections within shipping lanes.

    Humpback whales south of the Farallon Islands.(Photos: © John Calambokidis, Cascadia Research) Graphic shows whale intersections within shipping lanes.