Coastal Services Center

Evaluating Zoning Alternatives in the Stellwagen Bank National Marine Sanctuary

Stellwagen Bank National Marine Sanctuary (sanctuary), located off the coast of Massachusetts, is recognized as one of the primary feeding grounds of the humpback whale and seasonal habitat for the endangered northern right whale. The sanctuary is also used for fishing, boating, and marine transportation, each having the potential to negatively impact marine mammals. As a result, concerns were raised related to human use impacts on marine mammals during the ongoing management plan review process. As a potential mitigation measure, it was proposed that limiting high-speed traffic through regions of high whale density could have the dual benefit of less total strikes (given the additional time to react) and a lower probability that a given strike would be fatal. Still, staff must balance these potential benefits with the interests of disparate user groups and attempt to mitigate the economic impact imposed by potential speed zoning.

The sanctuary began to investigate the speed zones as a potential management measure. Based on guidance from sanctuary staff, the CSC was able to design and automate spatial analyses that allow for the design and evaluation of a suite of zoning alternatives based on the potential of each to reduce the risk of injury and mortality to cetaceans while minimizing the economic impact to the user community. Designed for use by the sanctuary advisory committee, the tool allows the design of speed zones to be tested against any number of vessel routes, speeds, and operating costs. It returns relative economic impact values that will facilitate discussion, encourage stakeholder participation, and identify the most effective speed zone schemes with the lowest economic impact.

To read about this project in greater detail, please see:

• Evaluating Vessel Speed Restrictions to Mitigate Impacts to Marine Mammals in the Stellwagen Bank National Marine Sanctuary (PDF, requires a plug-in such as Adobe ® Reader ® to view).