QUANTIFYING THE ECOLOGICAL PROCESSES UNDERLYING COLLISIONS BETWEEN LARGE BALEEN WHALES AND LARGE SHIPS TO EVALUATE RISK

Author

Sara Halley Williams

Year of Award

2017

Document Type

Dissertation - Campus Access Only

Degree Type

Doctor of Philosophy (PhD)

Degree Name

Fish and Wildlife Biology

Department or School/College

College of Forestry and Conservation

Committee Chair

Paul M. Lukacs

Commitee Members

Scott M. Gende, Michael S. Mitchell, Elizabeth C. Metcalf, Jedediah M. Brodie

Publisher

University of Montana

Abstract

The marine environment is a major interface for human and wildlife conflict. Humans use the world’s oceans for activities ranging from military operations, tourism and recreation, commercial shipping and transport, and resource extraction. These activities have a variety of impacts on marine wildlife, from alteration of the acoustic environment, displacement, changes to behavior and movement to direct physical injury or death due to collisions with vessels. Increasing awareness of human-associated negative impacts has called for research aimed at understanding the specific effects and consequences of human activity and marine wildlife overlap.

Large baleen whales are of particular research, conservation, and management interest. In past centuries, commercial whaling pressures decimated populations worldwide. Recent protection efforts and whaling restrictions have allowed for the recovery of some species, while others have yet to achieve substantial population growth (Magera et al. 013). Often, areas of intense human maritime activity heavily overlap critical large whale habitat, including feeding areas, breeding and calving grounds, and migratory routes (Block et al. 2011, Maxwell et al. 2013). Collisions between ships and whales (‘ship strikes’) have been documented across the globe and across large whale species (Laist et al. 2001, Jensen & Silber 2003, Neilson et al. 2012), and have grown to become one of the primary and most severe world-wide threats to baleen whale conservation (Clapham et al. 1999, Thomas et al. 2016).

Substantial research has laid the groundwork for understanding the occurrence, causes, and circumstances surrounding ship strikes (Vanderlaan & Taggert 2007, Vanderlaan et al. 2009, Gende et al. 2011, Gende et al. 2012, van der Hoop et al. 2012, Conn & Silber 2013, Redfern et al. 2013, Bezamat et al. 2014), the probability of and relative risk of ships strikes in specific areas, and the effectiveness of mitigation efforts (van der Hoop et al. 2012, Laist et al. 2014). However, much of this work has approached ship strike research from a coarse spatial and temporal scale. Understanding of ship strike occurrence and ship strike risk at a more detailed resolution is still lacking, and the best mitigation methods to reduce ship strike risk are still uncertain.

In Glacier Bay National Park and Preserve and nearby waterways, I investigated the ecological processes that underlie the risk of ship strikes between large ships and humpback whales (Megaptera novaeangliae). Using spatially-explicit and observation-based methods, I evaluated density and occurrence, movement, and behavioral responses to anthropogenic activity of whales in real-time overlap with large ships. Results of these assessments were incorporated in a simulation framework to evaluate ship strike risk. My aim was to provide relevant and useful information to managers, conservation practitioners, and ship operators to reduce the negative impacts of human use of the ocean on large whales.

Recommended Citation

Williams, Sara Halley, "QUANTIFYING THE ECOLOGICAL PROCESSES UNDERLYING COLLISIONS BETWEEN LARGE BALEEN WHALES AND LARGE SHIPS TO EVALUATE RISK" (2017). Graduate Student Theses, Dissertations, & Professional Papers. 10985.
https://scholarworks.umt.edu/etd/10985