Sounds of the Tropics: Part 3:
Can you hear me? How do dolphins in Bocas del Toro, Panama communicate in a noisy habitat?
Acoustic technology helps us understand the impact of boat activities on coastal dolphins.
Imagine living in a world where your vision is limited to a few tens of meters, a world where you rely mostly on sound to figure out where you are, what to eat, who to partner with, and who out there might eat you. Now imagining having to do it all in a very noisy space!
Sound plays a key role in the lives of marine mammals. Whales, including dolphins, have evolved the most sophisticated ways to use sound in conveying and extracting information from the environment and conspecifics (or members of the same species). Most whales use echolocation signals to navigate, locate food, and detect predators, and all species have evolved a wide repertoire of social sounds for finding mates, coordinating group formation, and building alliances by identifying family groups and individuals.
Over the last 60 years, the acoustic space in which whales communicate has been changing. Man-made underwater noise from activities like shipping is increasing noise levels by 3.3 dB per decade. Given the role that sound plays in the survival and reproduction of these animals, there are growing concerns about the interference of man-made noise, such as boat traffic, on whale communication and habitat quality.
Why should we care about the impact of boat traffic on dolphins? Dolphins are an integral part of marine ecosystems. They are top predators, and as such are important indicators of ecosystem health. They are also economically valuable. Dolphin-watching activities in Latin America are growing 3 times faster than in the rest of the world, providing coastal communities with an economic alternative to fishing.
In this case, we evaluate the status of a resident population of bottlenose dolphins in Bocas del Toro, Panama. These dolphins were saved from extraction (to supply dolphinariums) only to become the number one target of unregulated dolphin-watching activities in Panama. We will share the findings from the Dolphin Project about the impact of unregulated dolphin-watching boat activities and discuss a number of mitigation efforts to regulate this activity.