Clicks to Chaos: How Climate Shifts are Drowning Dolphins

Samudra Conservation
Sep 12
5 min read

Updated: Sep 12

By Sarah Drego, Samudra Conservation

Charisma. Energy. Delight

Nothing captures the spirit of ‘underwater-fun’ louder than dolphins. These socially intelligent mammals joyfully leap over the waves in synchronized pods with a zest for life, exuding what can only be described as pure “main character energy.”

With their clicks, flips and mischief - they bring the vibe!

But, though dolphins appear to be perpetually smiling - this grin hides an impending doom. As climate change continues to reshape our oceans, these aquatic acrobats struggle to perform, hunt, communicate and survive.

India's National Aquatic Animal - The Gangetic River Dolphin

WHY DOLPHINS MATTER

Dolphins are not just the entertainers of the sea. They are a ‘keystone species’ and apex predators, managing ecosystems by balancing fish populations and supporting marine biodiversity.

Their advanced social structures, problem-solving abilities, and unique communication strategies showcase a level of intelligence rivaling that of primates. Healthy dolphin populations are a sign of healthy oceans—and when dolphins struggle, it’s a red flag for the entire marine world, including us.

Every year, September 12th - World Dolphin Day is celebrated to highlight the threats and spread awareness about the perils faced by these playful marine mammals.

When we think of current threats to dolphins, a few obvious ones come to mind - accidental entanglement in fishing gear, pollution, habitat destruction, overfishing and hunting

Whilst these are still genuine concerns, another subtle, yet more deadly problem is brewing beneath the waves: climate change and particularly - ocean acidification.

YES, THE OCEAN SUFFERS FROM ACIDITY TOO

Just as our bodies have natural mechanisms present for digesting our food, the Earth too has a system to digest excess carbon dioxide CO2 - the ocean.

According to recent studies by the National Oceanic and Atmospheric Administration, the ocean absorbs up to 30% of anthropogenic carbon emissions acting as a crucial carbon sink and mitigating the effect of climate change.

Here’s a quick chemistry crash course:

Ocean acidification equation — The Ocean Acidification Process

When atmospheric Carbon Dioxide combines with Water it forms Carbonic Acid which dissociates into Bicarbonate and Hydrogen ions

The concentration of these free hydrogen ions in the water determines the pH of the ocean . Adding more hydrogen ions to the ocean water lowers the pH and makes it more acidic.

Ocean pH is an important factor supporting marine life and has historically been at 8.2. However, post the industrial revolution this pH has dropped to 8.1

Whilst this may not appear as a significant decrement in pH, it indicates a 30% increase in ocean acidity - a chemical change with enormous ecological consequences!

The more carbon dioxide we release into the atmosphere, the more acidic our oceans become.

Graph showing ocean acidification, with pH decreasing while dissolved CO2 rises from 1850 to 2100. — Co-relation between ocean pH and carbon dioxide levels

UNDERWATER COMMUNICATION BREACH

Dolphins have one of nature’s most incredible inbuilt features for navigation and communication - echolocation.

They emit high-frequency clicks from their nasal passages, which are then focused and amplified by an organ in their forehead called the melon. These sound waves travel through the water, bounce off nearby objects, and return as echoes. The echoes are picked up by specialized acoustic fat in their jaw, which channels the information straight to their brain.

The result? A 3D soundscape - allowing them to “see” their surroundings.

This unique feature or ‘biosonar,’ inspired scientists to invent SONAR - SOund Navigation and Ranging, a technology used across almost every marine vessel which uses sound waves to study, navigate and locate objects underwater.

Dolphin echolocation diagram: Sound waves from dolphin to fish — How dolphin echolocation works

Our oceans aren’t as quiet and peaceful as we’d imagine. Dolphins and other cetaceans are already suffering from tremendous noise pollution due to shipping vessels, underwater mining and construction.

For us folks, it's equivalent to living amidst the constant cacophonous din of traffic. Let’s be real - most of us are unfortunately accustomed to it and just plug in earphones.

But what can dolphins do?

These sensitive animals live in a world of constant acoustic static, which disrupts their natural way of hunting, navigating, and socializing

And to add another trumpet to the band - ocean acidification makes this noise louder.

Studies show that as seawater becomes more acidic, the absorption of low-frequency sound waves decreases. As their absorption reduces, the sound waves travel further

That means sounds like shipping noise, submarine sonar, and even whale calls - normally confined to certain distances - can now travel farther, adding to the already overwhelming acoustic clutter.

Imagine trying to have a private conversation in the middle of a rock concert - where every speaker is blasting at full volume, and the sound keeps reverberating off the walls, drowning out your own voice.

This is the reality our dolphins are living!

Dolphins now have to work harder to talk, hunt, and navigate - spending extra energy just to do basic things. Over time, this adds up to high stress levels, poor health, trouble reproducing, and eventually - population decline.

SILENT HUNGER CRISIS

And it’s not just their communication - but their food supply as well!

As ocean acidification silently reshapes marine ecosystems, the very foundation of their food chain is crumbling.

At the base of every marine food web lies a microscopic organism - plankton. Though invisible to the naked eye, plankton support the entire marine ecosystem.

Small fish feed on plankton, big fish feed on the small fish and dolphins eventually feed on the big fish. They form a delicate food chain where every link matters.

Food chain diagram: plankton to small fish to bigger fish to dolphin. Labels: Primary Producer to Tertiary Consumer, — A marine food chain showcasing the links between dolphins and plankton

But what happens if plankton - the initial link, disappears?

It’s simple - they all perish.

When seawater becomes more acidic, plankton struggles to survive and reproduce. They rely on calcium carbonate to build their shells and skeletons — an ability that weakens as ocean acidity rises.

Studies show that acidified waters lead to - thinner, fragile plankton shells and slower growth and lower reproduction rates. Without healthy plankton populations, small fish and other marine animals begin to dwindle.

So while dolphins don’t directly ‘taste’ the acidity, they feel the domino effect when their food supply shrinks.

WAY FORWARD

India is home to several dolphin species - from the playful Indian Ocean Bottlenose to the iconic Ganges River dolphin. Climate change, unsustainable fishing, and noise pollution are gradually pushing these charismatic animals into troubled waters.

Number of Ganges River dolphins were estimated to be around 4,000-5,000 by the end of the 20th century, and has now dropped to about 1,800 individuals

But, there is hope. Across India and even the globe, conservation groups are innovating to protect them.

One big step forward comes from the Coastal Conservation Foundation (CCF) in Mumbai. CCF recently received a major grant from The Habitat Trust to scale up its Coastal Cetacean Project, dedicated to monitoring and protecting dolphin populations along the west coast of India.

Other initiatives include the National Mission for Clean Ganga (NMCG), which focuses on conserving the endangered Gangetic river dolphin - India’s National Aquatic Animal. In Chilika Lagoon, Odisha, strict eco-tourism guidelines have been set to protect Irrawaddy dolphins from boat strikes and harassment.

A particularly innovative tool in the arsenal is Dolphin Gemma - an open-source AI-powered software designed by Google to decipher dolphin communication.

Together, these measures highlight a key truth - saving dolphins isn’t just about one species. It’s about protecting entire ecosystems.

Three dolphins leap through the ocean at sunset, with calm waves and a pinkish sky in the background.

THE FINAL SPLASH

Ocean acidification is a silently growing, invisible threat. Yet, its impacts on dolphins - through sound, stress, and starvation - are an alarming signal we cannot ignore.

We can all contribute to a less acidic ocean by actively choosing sustainable living practices. Transitioning to greener and cleaner energy sources helps reduce our carbon footprint - reducing carbon dioxide input.

From Gujarat’s coastline to the mangroves of the Sundarbans, every small effort leads to big changes.

Because when dolphins thrive - the ocean thrives as well.

And really, what’s the ocean without its ultimate showstoppers?