STANDARDIZED SURVEY OF HUMAN ACTIVITIES AND MARINE MAMMALS
One
of the main suites of information needed for successful management
and planning is the spatial and temporal distribution of various
activities that take place within a sanctuary and the levels at
which they occur. Such information can then be used as a baseline
against which to measure future changes and to investigate the
degree to which such uses might interact with sanctuary resources
or other user groups. The productive waters encompassed by the
SBNMS are home to an impressive array of marine life and utilized
by an equally impressive array of user groups. Public input has
indicated high levels of concern over environmental issues such
as the potential for habitat degradation by mobile fishing gear
and the entanglement of baleen whales in fixed fishing gear.
In July, 2001, the SBNMS undertook a year-long study to quantify
and map the spatial and temporal densities of fixed and mobile
gear fishing effort and baleen whale sightings. Data were collected
during monthly standardized shipboard surveys that bisected the
sanctuary at 5 kilometer (2.5 nautical mile) intervals. Researchers
used a subset of those data and ArcView's Spatial Analyst program
to conduct an analysis of the density and distribution of fixed
gear (trap and gillnet) fisheries, mobile gear (otter trawl and
scallop dredge) fisheries and baleen whales (i.e., North Atlantic
humpback, right, fin and minke whales). A "user geography"
of the sanctuary based on patterns of use was then developed to
identify high use areas that might pose risk of environmental
damage. ArcView was used to develop an index of Relative Interaction
Potential (RIP) to identify where baleen whales might become entangled
in fishing gear; a known threat within the Sanctuary.
RIPs were capable of identifying interaction "hot spots"
and could provide managers with the opportunity to manage at scales
smaller than the entire sanctuary. The analysis identified a number
of areas that stood out in terms of entanglement risk and thus
are useful for targeting specific areas for guidelines and regulations
such as fishery closures and/or gear modifications, or intensive
surveillance to facilitate rescue attempts. RIPs are also valuable
to facilitating dialogue and information exchange between interest
groups seeking solutions to whale-fishery interactions.
Partial funding for this research was provided by an Environmental
Leadership Award from the Switzer Foundation to David Wiley.
Survey
design.
Distribution
of baleen whales based on standardized survey 2001-2002.
Distribution
of fixed fishing gear based on standardized survey 2001-2002.
Relative Interaction Potential as determined by analysis of standardized
survey data for 2001-2002 (Figure credit: Michael Thompson).
PUBLICATIONS/PRESENTATIONS
Wiley, D. N., Moller, J. C., and Zilinskas, K. A. 2003. The distribution
and density of commercial fisheries and baleen whales within the
Stellwagen Bank National Marine Sanctuary: July 2001-June 2002.
MTS Journal 37(1), 35-53.
Wiley,
D. N, Moller, J. C. Zilinskas, K. A, and Thompson, M. A. 2003.
Quantifying the relative spatial and temporal risk of baleen whale
entanglement within the Stellwagen Bank National Marine Sanctuary.
15th Biennial Meeting, The Society for Marine Mammalogy, Greensboro,
North Carolina; December 14th-19th.
Anthropogenic
mortality caused by entanglement in commercial fishing gear and
ship strike are serious problems for endangered whale species.
Under the Marine Mammal Protection Act and the Endan
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