Date of Award

5-15-2015

Embargo Date

5-15-2016

Degree Name

Master of Science (MS)

Department

Biology

Advisor(s)

Susan E. Parks

Keywords

anthropogenic noise, foraging

Subject Categories

Life Sciences

Abstract

The humpback whale (Megaptera novaeangliae) is an endangered baleen whale species with a cosmopolitan distribution. The coastal habitat of this species result in significant exposure to anthropogenic noise from human activities. Previous research in the well-studied Pacific populations has demonstrated changes in calling behavior in response to noise, but noise impacts on other critical behaviors such as foraging have not yet been investigated. This study examines the impacts of ship noise on the nighttime bottom foraging behavior of humpback whales in the North Atlantic – a region with substantial human activity including high levels of noise from commercial shipping traffic. Data were collected from 2006 to 2009 in the Stellwagen Bank National Marine Sanctuary in the southern Gulf of Maine during June and July. Data included underwater behaviors and acoustic recordings of surrounding environmental noise collected using an archival tag attached to nine individual whales. Here I use series of linear mixed models to assess the effects of ship noise on eight metrics of nighttime feeding behaviors. Fixed effects included the presence versus absence of ship noise, received level of ship noise, and the before, during, or after ship noise exposure period. These variables had significant influence on three metrics: dive descent rate, ascent rate, and number of rolls indicative of feeding events. Descent rate decreased as noise level increased, while ascent rate was significantly faster in the during or after period when compared to the before period. The number of rolls significantly increased in the after exposure period, but at the greatest received levels, feeding rolls were completely absent during dives. These findings indicate that humpback whales on Stellwagen Bank show small, but significant, changes in foraging activity when exposed to ship noise. This study supports the hypothesis that environmental noise has an impact on the nighttime foraging activities of this species.

Access

Open Access

Included in

Life Sciences Commons

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.