As animal rights increasingly gain momentum in public discussion, activists are shedding light on the deplorable living conditions that are destructive to their existence. Without urgent action, each day, thousands of animals will continue to lose their lives.
When scientists conducted a study on the communication patterns between dolphins, their findings sent shockwaves around the world, revealing that humans have disturbed the marine ecosystem in an unexpected way.
An Intelligent Species
At least 39 species of dolphins populate the ocean waters, according to the United Nations Convention on the Conservation of Migratory Species of Wild Animals. Not only are dolphins a highly intelligent marine species, but they also play an important role in ecology. Any drastic change in their ecological existence could cause irreparable damage to their ecosystem and ours.
Ocean Water Helpers
Dolphins play a vital role in the underwater life, often preying on ill or old fish. By eating these fish, the dolphins rid the water of them, helping to cut down on infectious disease among fish populations. This keeps more fish species healthy and alive to reproduce.
Think of dolphins as the “sanitary police” of the ocean as killing them results in more disease and lower fish populations. For example, dolphins may eat fish afflicted with the toxin ciguatera. Since ciguatera-infected fish cause food poisoning if people eat them, dolphins help keep these fish off our dinner table. But, sadly, the underwater equilibrium of dolphins is drastically changing due to humans.
The Threat to Their Existence
Dolphins absolutely suffer threats to their life from natural disease and shark attacks. However, the main threat to dolphins comes from human beings. The Dolphin Institute states that Bottlenose dolphins and other marine mammals face a number of conservation threats due to human induced impacts on the marine environment. Among the common threats to dolphins’ existence are habitat degradation, boat traffic, fishing interactions, and pollution.
An Entire Species Extinct
Worldwide, dolphins, like countless other animals, face a variety of impacts that threaten their existence due to humans. In recent history, the Baiji, a beautiful river dolphin, was recently declared extinct. The increase in construction of dams and boat traffic in its river habitat had been detrimental to the dolphin population, wiping it out as a whole.
A Shocking Study
One recent study on the marine creatures has raised major concerns among ecologists and animal activists. As if humans weren’t already doing enough to destroy the planet and harm our fellow creatures, the study has revealed that human-caused noise is hindering the ability of dolphins to communicate with one another.
Researchers from the University of Maryland Center for Environmental Science laid underwater microphones on the bottom of the Atlantic Ocean to find out more about the ambient noise levels in the area off the coast of Maryland. They found that dolphins are altering the way they communicate with one another to be heard over noise from boats and other vessels in nearby shipping lanes.
Like a Noisy Bar
“It’s kind of like trying to answer a question in a noisy bar and after repeated attempts to be heard, you just give the shortest answer possible,” said Dr. Helen Bailey, a marine biologist with the University of Maryland Center for Environmental Science who studies protected species in order to understand their habitat use and informal conservation and management. “Dolphins simplified their calls to counter the masking effects of vessel noise.”
Noise Caused by Ships
Bailey’s assistant, Leila Fouda, added, “The simplification of these whistles could reduce the information in these acoustic signals and make it more difficult for dolphins to communicate.” The researchers, who gathered data by putting microphones on the ocean floor, noted in the study that while it’s possible for ambient noise to occur naturally, the noise they recorded underwater was “mainly” caused by ships.
Dolphins’ Whistle Patterns Destroyed
Naturally, dolphin calls have a complex sound pattern with rises and falls in the pitch and frequency in their whistles. However, in the recent study, these researchers found that human induced noise had changed their natural whistling patterns. With background noise, such as the low frequency chug-chugging of a ship’s engine, their usually complex whistle signatures completely flat-lined.
Dolphin Dependence On Sounds
Dolphins are highly social animals, and they produce calls for many different reasons. They talk to each other to stay together as a group, they whistle when they feed, and they even call out their names when different groups of dolphins meet. “These whistles are really important,” Bailey said. “Nobody wants to live in a noisy neighborhood. If you have these chronic noise levels, what does this mean to the population?”
Noise Frightens Dolphins
Noise travels far further in water than in air. Oil drilling, navigational sonars and ship engines have shown to frighten, and confuse dolphins. Noise pollution may cause marine mammals to beach themselves and may also force dolphins to move away from their normal feeding and breeding grounds.
Like Human Speech
A dolphin’s complex array of whistling communication techniques has been compared to human speech by some scientists. As a species, dolphins have an incredible sense of hearing and rely largely on sound to navigate the ocean, locate food, maintain awareness of threats, keep track of their children and pod members and communicate to one another.
Robbed of a Normal Life
Whistling is also produced for a dolphins’ desire to mate, to alert others when there is nearby danger, to socialize with one another, and to let their pod know that they have found food nearby. Their survival depends on this method of communication, without it, they will be robbed of a normal underwater life.
Each dolphin has their own unique sound. They can communicate in a slightly different pitch so that other pod members know which dolphin in the group is speaking and to make it easier for pod members to keep track of each others location. While sound plays a similar role on land it can be even more important for survival in the ocean.
A Rising Concern
The study reveals that while dolphins have an excellent sense of hearing, their ability to listen to sounds are drastically decreased by man-made ambient noises from submarines, loud boat engines, explosives and low flying aircraft. These man made noises are all becoming more and more common leaving marine biologists and researchers with concern in regards to the dolphins ability to survive in its environment.
Leave Water to Alleviate Stress
These sounds can make it difficult for dolphins to communicate with one another, accurately locate food, and navigate a sometimes pitch-black ocean. Aside from these possible issues, other concerns include the possibility of dolphins beaching themselves due to difficulty navigating the ocean. Their reluctance to be in the water is due to the distress from the human-induced noise.
The worst of its effects are the permanent damage to hearing and hemorrhaging near the dolphins ear and brain tissue. This becomes possible from developing decompression sickness from raising to the surface too quickly and difficulty locating food because of ambient interruption during the use of echolocation.
Other Marine Life Effected
Their findings echo another study also published this week. Japanese scientists found that humpback whales around the country’s Ogasawara Islands are reducing their famous whale songs in response to noise caused by passing ships. And, as the site Inverse notes, a 2016 study on orcas also found that sound from ships hindered their ability to communicate.
What Can We Do?
“We need to be working to engineer quieter boats,” said Bailey. The sound from the ships that were recorded had decibel levels up to 130, just like being near a noisy road. “We need to ask, ‘Is there a way shipping can do it that is more environmentally friendly’.” Regulations and voluntary incentives to reduce the sound from vessels, with speed limits or quieter engines, could help to decrease the effects on dolphins and other species sensitive to sound.