Reducing Threats to Right Whales

Northern right whales.

Photo Credit: NOAA

by Gregory K. Silber and Shannon Bettridge

The North Atlantic right whale (Eubalaena glacialis) is one of the most critically endangered large whale species in the world. Early whalers called them the "right whale" to hunt because they were often found near the shore and they floated when killed. Today, collisions with vessels are the primary threat to right whales because their migration route crosses major East Coast shipping lanes.

An average of about two known "ship strike" related deaths occur each year in a total population of only 300 to 400 whales. But on October 2008, NOAA’s National Marine Fisheries Service (NMFS) announced landmark measures that will increase protection for North Atlantic right whales. For the first time, NMFS will require that ships 65 feet (20 meters) or greater in length reduce their speed to 10 knots (11.5 miles per hour) in areas where these whales feed, reproduce, or migrate.

Studies indicate that the likelihood and severity of ship strikes is related to ship speed. After analyzing cases where the ship speed and fate of the whale were known, researchers concluded that 85.5 percent of strikes occurred at vessel speeds of 10 knots or greater. They also found that the probability of a collision causing a whale’s death increased from 45 percent to 75 percent as vessel speed increased from 10 to 14 knots (16 mph), and it exceeded 90 percent at 17 knots (19.5 mph). Therefore, NMFS has routinely issued vessel speed advisories recommending speeds of 10 knots or less in specific areas and at times where right whales occur. Advisories are distributed through a variety of media, including NOAA Weather Radio, the Mandatory Ship Reporting systems, broadcast notices to mariners, and e-mail distribution. The new speed restrictions, however, will be mandatory.

A struck whale on the bow of a container ship.

Photo Credit: NOAA

Modification of shipping routes, notification of whale sightings, and mariner education are additional key components of the North Atlantic right whale recovery program. The NMFS ship strike reduction effort includes:

• Conducting extensive aircraft surveys for right whales and alerting mariners via e-mail, facsimile, the internet, U.S. Coast Guard (USCG) Broadcast Notices to Mariners, NOAA Weather Radio, and other outlets.
• Operating Mandatory Ship Reporting systems, in which all ships 300 gross tons and greater in size are required to report to a shore-based station when entering the two most important right whale aggregation areas. Reporting ships receive an automated return message providing information about the vulnerability of right whales to ship strikes and recent right whale sighting locations.
• Developing and distributing, in collaboration with its partners, printed material and a multi-media CD on ship strikes and the Mandatory Ship Reporting systems. NMFS has also developed training modules for mariner training academies, and NOAA navigational charts and related publications are routinely updated to include right whale advisories.
• Consulting with other federal agencies that operate vessels in right whale habitat. NMFS asked that federal vessels proceed at 12 knots (subsequently lowered to 10 knots) or less (or at "safe speed") when in right whale habitat, and most agencies have voluntarily complied when vital missions are not compromised. One such consultation involved the transport of liquefied natural gas (LNG) in Massachusetts Bay. Licenses authorizing the use of pipelines in fin, humpback, and right whale habitat require use of hydrophone arrays to detect vocalizing whales. Locations of acoustically detected right whale calls are transmitted to LNG vessels, which are required to travel at 10 knots or less anywhere within 5 miles (8 kilometers) of the location. Use of the arrays is mandated for the life of both LNG facilities, estimated to be 25 to 40 years.
• Rerouting vessels, where feasible. Moving ships from customary routes has been done in key locations where the benefits of rerouting can be demonstrated. In November 2006, NOAA established recommended shipping routes within Cape Cod Bay and off three ports in Georgia and Florida that minimize transits of key right whale aggregation areas. In addition, the United States submitted a proposal to the International Maritime Organization to reconfigure the “Traffic Separation Scheme” (TSS) that services Boston. The realignment, enacted in July 2007, involved only a minor shift in the TSS and traffic lanes, but it is expected to reduce the risk of ship strikes by 58 percent for right whales and 81 percent for other large whale species in the area. A subsequent action to further reduce the threat of a ship strike by narrowing an adjoining leg of the TSS went into effect in June 2009.

Efforts to recover a highly endangered migratory species often require an innovative, multi-faceted approach involving a variety of public and private interests. We have high hopes that our efforts to reduce the risk of ship strikes will aid in the eventual recovery of the North Atlantic right whale.

Additional information on this program can be found at www.nmfs.noaa.gov/pr/shipstrike/.

Gregory K. Silber (Greg.Silber@noaa.gov) and Shannon Bettridge (Shannon.Bettridge@noaa.gov) are with the NMFS Office of Protected Resources and can be reached at 301-713-2322.