The distribution and density of commercial fisheries and baleen whales within the Stellwagen Bank National Marine Sanctuary: July 2001-June 2002

Research in a national marine sanctuary provides the ability to monitor, assess and understand changes in, and threats to, the area. In July 2001, the Stellwagen Bank National Marine Sanctuary undertook a year-long study to quantify and map patterns of human and marine mammal use. Data were collected during monthly standardized shipboard surveys that bisected the Sanctuary at 5 km (2.5 nm) intervals. We 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. We used this to develop a user geography of the Sanctuary based on patterns of use and identify high use areas that might pose the risk of environmental damage. We also used ArcView 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. The RIP identified a number of areas that stood out in terms of entanglement risk. Information from the study will allow managers to identify future changes in Sanctuary use and investigate current areas of intense use for potential harm.