Passive acoustics uses the sounds produced by cetaceans when they communicate with each other or when they navigate. Acoustics recordings are collected with hydrophones, microphones developed specifically to listen to marine sounds. During boat campaigns, hydrophones can be towed behind the ship or immersed regularly. Hydrophones can also be fixed to the seabed to study the species present over a long period in a defined area, or a hydrophone can be fixed to an animal in a very temporary way to study communication between individuals. Acoustics has several advantages over visual observations: it facilitates the detection of discrete species, such as deep divers, it allows the collection of data at night, and greatly reduces the time spent in the field. However, acoustics is a relatively recent technique and it does not yet allow to collect as much information as visual observations; for example, it does not yet allow to identify all cetacean species nor to count individuals or to determine maturity status.

Acoustic station ©OSL

In recent years, several acoustic study programs have been conducted in the region, for example:
The CHAMP project (Caribbean Humpback whale Acoustic Monitoring Program) was implemented in 2016 and 2017. It aimed at strengthening the knowledge on humpback whales around 6 islands of the Caribbean with hydrophones fixed on the seabed. It was supported by NOAA. You will find the details of this study in their publication.


In 2019-2020, the association DSWP (The Dominican Sperm Whale project) and the Whitehead Laboratory of the University of Dalhousie (Nova Scotia) conducted boat campaigns with a towed hydrophone in the Lesser Antilles to study communication in sperm whales.


In 2020, the Interreg CARI’MAM project developed an acoustic observatory in the Greater Caribbean Region, with about twenty hydrophones deployed throughout the archipelago from Bermuda in the North to Bonaire in the South. They will be immersed at twenty meters depth for one year. The objective is to enhance managers knowledge on the species occuring in their waters all year round and to develop their acoustic skills. These hydrophones are "JasonBlue" models, developed by the University of Toulon, in the South of France. Their characteristic is to record a very wide range of sound frequencies; therefore, they should allow to collect sounds from all cetacean species living in the Caribbean (even those inaudible to the human ears).


Discover bellow some sound recordings of some of the most frequently observed species in the region:

The humpback whale (Megaptera novaeangliae)

The sperm whale (Physeter macrophalus)

The Atlantic spotted dolphin (Stenella frontalis)

Sounds from Watkins Marine Mammal Sound Database du New Bedford Whaling Museum