The effects of noise disturbance from various recreational boating activities common to inland waters on the cardiac physiology of a freshwater fish, the largemouth bass (Micropterus salmoides)

Abstract

Abstract Recreational boating continues to grow in popularity, yet little is known about the effects of noise disturbance from boating on fish. Therefore, this study evaluated the organism‐level cardiovascular disturbance associated with different recreational boating activities using largemouth bass (Micropterus salmoides) as a model. Cardiac output and its components (heart rate and stroke volume) were monitored in real time, allowing for the determination of the magnitude of disturbance and the time required for recovery. Fish responses to three noise disturbances (canoe paddling, trolling motor, and combustion engine (9.9 hp)) for 60 s were contrasted using a Latin squares design. Exposure to each of the treatments resulted in an increase in cardiac output in all fish, associated with a dramatic increase in heart rate and a slight decrease in stroke volume. The level of change in cardiac output and its components increased in magnitude from the canoe treatment to the trolling motor treatment with the most extreme response being to that of the combustion engine treatment. Furthermore, time required for cardiovascular variables to recover varied across treatments with shortest periods for the canoe paddling disturbance (∼15 min), the longest periods for the combustion engine (∼40 min), and intermediate recovery periods for the trolling motor (∼25 min). Collectively, these results demonstrate that fish experienced sublethal physiological disturbances in response to the noise propagated from recreational boating activities. This work contributes to a growing body of research that has revealed that boating activities can have a number of ecological and environmental consequences such that their use may not be compatible with aquatic protected areas. Future research should evaluate how free‐swimming fish in the wild respond to such stressors relative to frequency of exposure and proximity to noise as most research to date has occurred in the laboratory. Copyright © 2008 John Wiley & Sons, Ltd.