|Noise from human activities like shipping interferes with the underwater animal's ability to hear ocean's natural sound / Photo by: hwdbzxy via 123rf|
Every day, marine life is ultimately threatened by a harsh cacophony of industrial noise from seismic exploration, shipping, and other human activities in our waters. The waste and problems brought by humans have also been slowly destroying their natural habitats. The ocean, once considered the safest place for marine animals, is now turning into a hub for danger.
The Ocean is Getting Louder
Sound is the most efficient way to communicate and survive in the ocean. However, over the past few centuries, human activity has become destructive towards marine mammals. Shipping, recreational boating, energy exploration, and other human activities produce noise that travels long distances underwater, which increases and changes the ocean noise levels.
According to an article by the National Ocean Service, ocean noise refers to the sounds produced by human activity and can interfere or destruct the ability of marine animals to hear natural sounds in the ocean. This is the reason underwater sounds getting louder can negatively impact ocean animals and ecosystems. Ocean noise can affect the ability of animals to communicate, and hear environmental cues that are vital for survival and protecting themselves from predators.
Unfortunately, as the ocean gets louder, marine mammals slowly change the way they communicate. In an article by The Washington Post, Janet Mann, an expert on bottlenose dolphins at Georgetown University, said that she suspects that calves now prefer staying near their mothers when ambient sounds are loud. This gives the calves fewer opportunities to explore their natural habitat and develop on their own.
A study titled "Impacts of anthropogenic noise on marine life: Publication patterns, new discoveries, and future directions in research and management" showed that ocean noise has experienced rapid growth and diversification since 1940. The researchers found that marine life forms can be very sensitive to sound, and ocean noise may elevate risks of starvation and predation.
As discussed in Science Direct, the researchers stated two ways to mitigate harmful effects: setting allowable harm limits at the level of the population, and marine spatial planning to identify priority areas for mitigation or 'Quiet Marine Protected Areas'.
How Significant Sound is to Marine Life
Wild forest animals like lions, tigers, and foxes usually use their sense of sight and smell to survive. But in the ocean, marine mammals depend on the sound that they produce for hunting, navigating and communicating. Strong echoes are always present underwater and project for many miles. Although this may sound easy, the truth is, this method can be tricky at times. The listener has to sort through various sounds and echoes to hear a message correctly.
According to an article by the Discovery of Sound in the Sea, sound is essential in conveying information quickly and over long distances. The messages marine animals send each other differ in terms of rate, pitch, and structure of sounds. They also use sound to convey messages about reproduction, territoriality, and the maintenance of group structure. For instance, some whales use sound to localize, detect, and characterize objects. The process of locating distant objects using the reflection of sounds is called echolocation. Marine mammals such as dolphins and whales use this process to locate food. This can be an effective way for marine animals to find prey and analyze their environment.
|Sounds of human activities like shipping interferes with the underwater animal's ability to hear ocean's natural sound / Photo by: hwdbzxy via 123rf|
Additionally, other aquatic invertebrates and species of fish use sounds such as grunts, croaks, clicks, and snaps to attract mates and to protect themselves from predators. So much research still needs to be conducted on how marine invertebrates use sound for their survival. However, initial studies have found that spiny lobsters and fiddler crabs produce sounds for defensive and courtship purposes.
Indeed, marine mammals rely on sound to communicate, locate food, and ward off predators underwater. In an article by the Fast Company, Michael Jasny, director of the Marine Mammal Protection Project at the Natural Resources Defense Council, said, “The most important thing to understand in thinking about noise in the ocean is that the ocean is a world of sound. Marine mammals, fish, and other marine species have evolved to depend on hearing as their primary sense."
Turn Down the Volume in the Ocean
There is so much that humans can do to reduce the destructive activities affecting marine mammals. With enough research and preparation, humans could actually bring back life in the ocean. This will not just benefit marine life but also secure the balance in our ecosystem. Fortunately, the National Oceanic and Atmospheric Administration (NOAA) is developing and monitoring networks underwater considered integral to the ocean. NOAA created "The Ocean Noise Strategy Roadmap", which also aims to conduct more studies to determine the impacts of the noise pollution inflicted in the ocean.
In an article by the Hawai'i Public Radio, Michael Jansen, the director of the Natural Resources Defense Council’s Marine Mammal Protection Project, said that the program will not only reduce the impact of noise pollution underwater, but will also spark change in how governments approach and address this serious environmental issue.