Tag-based Heart Rate Measurements of Harbor Porpoises During Normal and Noise-exposed Dives to Study Stress Responses.

摘要

Marine mammals face potentially dramatic changes in the environment, as well as continued disturbances of their ocean habitat from shipping, sonar, fisheries, oil exploration and other ocean activities. To predict and quantify how marine mammals will respond to natural and anthropogenic stressors, it is essential to understand their physiological limits, the potential plasticity of their diving physiology, and their physiological responses to stress. The typical mammalian startle or stress response to an acoustic stressor is increased heart rate, cardiac output and ventilation rate (Graham 1979), all which are contrary to the typical marine mammal dive response (Scholander 1940). Information on the acute stress response during diving is essential to predict how potential stressors effect oxygen and nitrogen management and can provide information on the level of stress the animals routinely experience. Here we propose to examine the dive heart rate, ventilation rate and activity in both captive and wild porpoise to better understand the dive response and how it may be overruled by noise exposure. We will access the acute stress response to an acoustic stressor by comparing heart rate, ventilation rate, and activity between control and exposure dives.