Book Description

This dissertation concerns the southern resident killer whales (Orcinus orca), a genetically isolated population of fish-eating killer whales that frequent the international waters of the Salish Sea between the United States and Canada in the eastern Pacific Ocean. Research was conducted from June 1 to October 31, 2007 and from June 7 to October 31, 2008, between geographic coordinates: 48°12' to 49° N latitude by 122°43' to 123°50° W longitude. The southern resident killer whale population has experienced multiple fluctuations since population surveys were initiated by the Center for Whale Research (CWR) in the mid 1970's. In November 2005, the U.S. National Oceanic and Atmospheric Administration's National Marine Fisheries Service (NMFS), Northwest Regional Office listed the southern resident killer whales as an endangered distinct population segment of the species Orcinus orca under the United States Endangered Species Act (ESA). Several risk factors including reductions in the quantity and quality of prey (salmon), exposure to persistent toxins, and disturbance from vessel presence and associated noise were identified as contributing to the decline of this already small population. With the listing under the ESA, critical habitat was designated in the inland waters around the U.S. San Juan Islands, Washington State and the Canadian Gulf Islands, British Columbia, Canada. Chapter one, Managing Vessel-based Killer Whale Watching: A Critical Assessment of the Evolution from Voluntary Guidelines to Regulations in the Salish Sea, provides background on the southern resident killer whales and the robust international whale watching industry in the region. This chapter also provides a detailed history of local, state, federal and international vessel laws and guidelines for watching whales in the Salish Sea. Chapter two, Non-invasive methods to study southern resident killer whales and vessel compliance with regulations, describes a novel equipment package, consisting of a differential GPS integrated with a digital compass and laser rangefinder that allowed me to collect accurate geo-referenced locations and behavioral data on whales and vessels throughout the whale's critical habitat. To improve both the spatial and temporal data on whale-vessel interactions, the information collected with this equipment was used to assess vessel compliance with local, state and federal laws and the regionally accepted best-practices Be Whale Wise Guidelines. Chapter three, The effects of vessels on group cohesion and behavior of southern resident killer whales (Orcinus orca), discusses research investigating changes in killer whale group cohesion in response to vessel density, distance and mode of operation. Future cetacean studies would benefit from using the equipment and methods presented here, especially in areas that are not conducive to land-based theodolite collected data.