Ocean noise has increased exponentially over the past 20 years.
Soundscapes are a relatively new topic of study in the marine science world. Soundscapes describe the interaction of ocean physics and marine life for a region in the ocean. These descriptions give us insight into how sound functions in a particular area and how this may be affecting inhabiting marine life.
The world ocean is full of sounds – everything from a small bubble bursting to the deep groans of a blue whale. But more than just natural sounds exist in the sea, a myriad of human-generated sounds have become increasingly common.
The image to the left represents several examples of anthropogenic and animal sounds. If we take 1 example: small boats and mid-frequency cetaceans (e.g., dolphins), we see that small boats cover a similar frequency range for both dolphin sound production and their hearing range.
What does this mean? This means small boats can generate sounds that are at the same frequencies’ dolphins communicate at and are capable of hearing.
If we take in the whole graph, we can see more than 1 anthropogenic sound and animal sound overlap another’s communication and hearing range. All this compiled noise makes for a very noisy ocean and has the potential to mask animal communication.
Meaning all the noise might drown out one dolphin trying to communicate with another. This could lead to group members getting lost, reduced mating interactions, and other shifts in population dynamics.
Dolphin Click
160
dB re 1µPa @ 1 m
Modern Commercial Ship
188
dB re 1µPa @ 1 m
CAN YOU HEAR ME?!
Human noise may be drowning out cetacean sounds
Anthropogenic sounds have been suggested to cause negative impacts on marine mammal behavior and hearing thresholds. Pile driving is considered one of the loudest pulsed sounds. Take a look at what some of the science says about pile driving and bottlenose dolphin (Tursiops truncatus) populations