Buscando cetáceos no Oceano Atlântico Sul através da bioacústica

Abstract

Cetaceans have great biological importance, and in view of the growth of anthropogenic activities that affect, or the interest for their conservation has been occurring. For many species, no information is yet available to define which threat category can be found, so further research on cetacean information is needed. And this research is challenging due to the environment in which cetaceans live. Because most of your life is submerged, there is an inherent difficulty in accessing information about cetaceans. The most commonly used survey mode is visual observation in linear transects, but like every method, it has its advantages, such as the need for animals to be allowed on the surface for use, a need for sunlight, a suitable climate, a survey, and a rely on specialized staff and be costly. An acoustic search is an alternative that can find some of these problems. It does not depend on sunlight, can run 24, is more weather independent, is one of the few methods capable of detecting underwater animals, and is less so. Because users use or form a vast form in their ecology, it is possible to use this method for a range of studies with different intentions. Acoustic monitoring is also among the most commonly used methods for tracking cetaceans today, but few comparative studies between the two methods performed. Structures were compared as monitoring when executed simultaneously, and identified as cetacean detection, and how visual monitoring behaves in relation to time of day and sea state. The number of detections was generally higher in acoustic monitoring, but did not have a significant value (p> 0.05) in the permutation test. The acoustic method allowed to detect detections at night, which made it impossible to see because of the lack of light and had a greater number of detections when the sea state was higher. The results are as expected, showing that acoustic monitoring can be a complement or an alternative method to visual, increase the number of detections and maximize effort, enable the increase of information about cetaceans.