A field test of acoustic deterrent devices used to reduce interactions between bottlenose dolphins and a coastal gillnet fishery

Published source details Waples D.M., Thorne L.H., Hodge L.E.W., Burke E.K., Urian K.W. & Read A.J. (2013) A field test of acoustic deterrent devices used to reduce interactions between bottlenose dolphins and a coastal gillnet fishery. Biological Conservation, 157, 163-171.
Share Tweet Email

This study is summarised as evidence for the following.

	Action	Category
	Use acoustic devices on fishing gear Action Link

Use acoustic devices on fishing gear

A randomized, controlled study in 2004–2005 across two coastal areas in the North Atlantic Ocean, off the coast of North Carolina, USA (Waples et al. 2013) found that when active acoustic devices were used on fishing nets, common bottlenose dolphins Tursiops truncatus interacted with the nets less and echolocated more compared to when inactive devices were used. Fewer dolphins approached within 500 m and interacted with nets with active acoustic devices than nets with inactive acoustic devices (data reported as statistical model results). Dolphins spent more time echolocating near to nets with active acoustic devices than nets with inactive or no devices. In 2004–2005, commercial fishers deployed 83 gill nets with active acoustic devices (SaveWave devices attached to the float line, 100 m apart, emitting sounds at frequencies of 5–90 kHz and 30–160 kHz) and 68 gill nets with inactive (silent) devices. Gill nets (300 m long) were deployed perpendicular to the shore. An onboard observer recorded dolphin behaviour around each of the 151 nets. In 2004, a research vessel towing a hydrophone recorded the echolocation clicks of seven dolphins within 500 m of four nets with active acoustic devices, two nets with inactive devices and one net without devices deployed by another fishery.

(Summarised by: Anna Berthinussen)