Behavioral responses of Sotalia fluviatilis (cetacea, delphinidae) to acoustic pingers, Fortaleza, Brazil

Published source details Monteiro-Neto C., Vila F.J.C.A., Alves-Jr T.T., Araüjo D.S., Campos A.A., Martins A.M.A., Parente C.L., Manuel A., Furtado-Neto R. & Lien J. (2004) Behavioral responses of Sotalia fluviatilis (cetacea, delphinidae) to acoustic pingers, Fortaleza, Brazil. Marine Mammal Science, 20, 145-151.
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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 controlled study in 1996–1998 at a coastal site in the South Atlantic Ocean, near Fortaleza, Brazil (Monteiro-Neto et al. 2004) found that float lines with active acoustic devices attached had fewer tucuxi dolphin sightings Sotalia fluviatilis around them than float lines with inactive acoustic devices or no devices. On average, fewer tucuxi dolphins were sighted in two quadrats on either side of a float line with active acoustic devices attached compared to float lines with inactive acoustic devices or no devices attached (data reported as statistical model results). The average number of dolphin sightings did not differ significantly between trials within seven other quadrats that were not immediately adjacent to the float line (see original paper for data). A float line (100 m long) was deployed with active acoustic devices attached (30 trials), inactive (silent) acoustic devices attached (20 trials) and with no devices (55 trials). Each trial lasted 1–7 h. Five acoustic devices (Dukane NetMark 1000) were evenly spaced along the float line. Two observers on the shore recorded dolphin sightings within nine quadrats (0.5–0.9 km²) in a 6-km² area surrounding the float line during each of the 105 trials between November 1996 and August 1998.

(Summarised by: Anna Berthinussen)