Principal Investigator: Joseph Haxel (Pacific Marine Environmental Lab), Leigh Torres (OSU Marine Mammal Institute)
Co-Principal Investigators: Sharon Nieukirk, Robert Dziak, David Mellinger (Pacific Marine Environmental Lab)
External Collaborator: Todd Chandler, Leila Lemos (OSU Marine Mammal Institute)


Project title

Measuring physiological effects of changing noise levels on Pacific gray whales (Eschrichtius robustus)

Background

Over the past few decades increased shipping traffic has led to increased low frequency noise in the marine environment of the Northeast Pacific, which could be harmful to marine species that rely on sound production and reception s for critical life history functions and picking up cues from their environment, such as baleen whales. Limited information exists on how chronic, elevated ambient noise levels may impact the behavior, physiology, and ecology of cetaceans. This work proposes to assess stress response of whales to elevated noise by examining variation in stress hormone (glucocorticoids) levels.

Hydrophone setup

Research Objectives

Using PCFA gray whales along the Oregon coast as our study species we will collect data and conduct analyses aimed at addressing the following questions:

  1. Are whales exposed to significantly different anthropogenic and naturally influenced ambient noise environments depending on location and time?
  2. Do individual GC hormone concentrations vary relative to individual, body condition, prey availability or habitat (location)?
  3. Relative to samples collected in low-noise environments, do fecal samples from whales in noisy environments have higher GC concentrations, indicative of elevated stress? Furthermore is there an observed difference in GC concentrations between environments dominated by anthropogenic versus natural sound sources?
  4. What is the time scale of recovery for fecal stress hormone concentrations to baseline levels after an increased noise event?
Fecal sample collection

Significance

The proposed project addresses research topics 1, 2, and 3 of the RFP: (1) noise exposure and/or its effects on auditory ability, behavior, physiology, and/or communication, (2) ocean soundscapes and their natural and anthropogenic components, including characterizing levels and trends in ocean noise, and (3) animals’ use of underwater sound through production and/or reception of acoustic signals. Our project will continue to collect the data necessary to evaluate the role of ambient noise on marine mammal stress. The questions we are addressing in this project require a long-term dataset to account for environmental variability and re-sample individual whales over time and space. Through our multifaceted project we will build upon the success of our 2016 field season to progress our long-term dataset necessary to address issues concerning the impact and recovery of whales to ambient noise. This population of gray whales is logistically accessible, listed as non-threatened, and includes inter-annually re-sighted individuals, which are all factors that can facilitate a long-term study of ambient noise impacts on cetaceans. Findings from such a project will inform management decisions regarding allowable noise thresholds in the vicinity of baleen whales.


Pacific gray whale