Assembling an acoustic catalogue for different dolphin species in the Colombian Pacific coast: An opportunity to parameterize whistles before rising noise pollution levels

Abstract

Growing ship traffic worldwide has led to a relatively recent increase in underwater noise, raising concerns about effects on marine mammal communication. Many populations of several dolphin species inhabit the eastern Pacific Ocean, along the coast of Colombia. Noise pollution levels in the Colombian Pacific coast (CPC) are very low. Currently, the CPC is slated for the construction of a port in the Gulf of Tribugá. Previous port construction in other countries have shown that this will change the acoustic environment and will compromise marine fauna, such as dolphins. This is the first study focused on the whistle acoustic parameters from several dolphin species in the region before any disturbance. Opportunistic recordings were made in two different locations alongside the coast, reporting five different delphinid species. The results show that the repertoire of four species is different when compared to other populations in more disturbed areas around the globe. An LDA was used to cluster the acoustic parameters and it supported the acoustic niche hypothesis, finding that these species may avoid whistle overlapping. If constructed, the port could force species to adjust their vocal repertoire engaging in an inter-specific whistle overlapping, or could lead to area abandonment, which would cause economic and ecological disasters for the region.