COMMERCIAL SHIP BEHAVIOR AND RIGHT WHALE SIGHTING ADVISORY
Ship
collision is a major mortality threat to the endangered North
Atlantic right whale. To mitigate this threat, NOAA Fisheries
initiated the Right Whale Sighting Advisory System (RWSAS) that
designates advisory zones (AZs) around right whale sightings.
The program's goal is to have large ships route around or slow
down when transiting AZs, thereby reducing collision risk. The
efficacy of the program, however, had not been evaluated because
of difficulties documenting ship behavior.
With
the development and implementation of the United States Coast
Guard's Universal Shipborne Automatic Identification System (AIS),
a VHF tracking system that sends information about a ship's speed,
heading and position to other vessels and shore-based stations,
such evaluations became feasible. Researchers at the sanctuary
collaborated with NOAA Fisheries Northeast Science Center to quantify
and assess ship behavior. Coast Guard data for the Great South
Channel region were analyzed for May, 2005, concurrent with NOAA's
identification of a number of AZs. A GIS map was used to analyze
forty AIS vessel tracks. Two analyses were conducted: a visual
inspection for signs of rerouting, and a statistical summary of
a vessel's speed in and out of AZs. If vessels did not reroute
(i.e., steer around the AZs), researchers looked for indications
that vessels reduced speed or slowed to the twelve knots recommended
by the NOAA.
Only
one of the sampled vessels appeared to have rerouted to avoid
the highest concentrations of right whales. Only two vessels reduced
their speeds to below 12 knots while passing through AZs (5% compliance).
Five vessels reduced their speeds to an average that was below
12 knots (12.5% compliance). These data suggest that RWSAS information
was not adequately received and/or not responded to by vessels.
Improvements in information dissemination and/or incentives for
compliance are recommended.
Large vessel utilizing the Boston Traffic Separtation Scheme.
North Atlantic right whale (Eubalaena glacialis)
Right Whale Advisory Zones (red circles) were identified through
NOAA aerial surveys.
Example of vessel tracks (black lines) derived from the US Coast
Guard's AIS records.
Moller, J. C., Wiley, D. N., Cole, T. V. N., Niemeyer, M., and
Rosner, A. 2005. The behavior of commercial ships relative to
right whale advisory zones in the Great South Channel during May
of 2005. The 16th Biennial Conference on the Biology of Marine
Mammals, Society for Marine Mammalogy; San Diego, CA; December
12-16.
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