More than 80 Olive Ridley baby turtles have been spotted waddling across the sand of Versova Beach in Mumbai to get to the Arabian Sea over the past week, the Guardian reports.

It had been decades since the turtles were last seen on the beach. Their return continues a migratory journey that has been going on for centuries.

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“I had tears in my eyes when I saw them walking towards the ocean,” Afroz Shah, a lawyer and local community activist, told the Guardian.

Week 127 .



Fantastic news for Mumbai .



We got back Olive Ridley Sea Turtle after 20 years. Historic moment



Nested and Hatched at our beach. We facilitate their journey to ocean.



Constant cleaning helps marine species.



Marine conservation centre needed at @versovabeachpic.twitter.com/j79xCKamNh — Afroz Shah (@AfrozShah1) March 22, 2018

The migration is a sign that thousands of hours of hard work has paid off.

Two years ago, Versova Beach was essentially a landfill — pictures show legs sinking knee-deep into garbage.

"[The waste] was 5.5 feet high,” Shah told CNN at the time. “A man could drown in the plastic.”

Today, you can sunbathe on the pristine sand.

Read More: Scientists Want You to Help Map Plastic Waste on Beaches — From the Comfort of Your Sofa

That’s because a team of hundreds of volunteers led by Shah spent nearly two years picking up 11,684,500 pounds of trash, clearing upstream rivers, putting systems in place to prevent future trash from accumulating, and teaching locals about sustainable waste management.

They also cleaned 52 public toilets and planted 50 coconut trees, and Shah has plans to line coastlines with mangrove trees to prevent flooding and improve water quality.

The United Nations called it the “world’s largest beach clean-up effort” and awarded Shah the “Champion of the Earth” award.

“I am an ocean lover and feel that we owe a duty to our ocean to make it free of plastic,” he told the UN. “I just hope this is the beginning for coastal communities across India and the world.”

Read More: This Genius Man Is Using Plastic Bags to Pave Roads

Olive Ridley turtles lay eggs in the area, but had been unable to climb through the trash on Versova Beach, according to the Guardian.

#OliveRidleyTurtles make a come back to #VersovaBeach after 20 years. @ashupriolker takes a walk down Mumbai’s cleanest beach with the man who made it happen, @AfrozShah1@versovabeachpic.twitter.com/xfSXf7W9VH — CNBC-TV18 News (@CNBCTV18News) March 25, 2018

Now the same volunteers who cleaned the beach are camping out to make sure the baby turtles are protected from dogs and birds as they make their way to the water, the Guardian reports.

It’s an example of how collective action can revitalize communities and create environmental guardians.

Week 127 . #BeatPollution



Connect with nature gets a boost when connect with fellow humans happens



This is the routine in all our Clean-ups.



We bond over plastic pick up ; then over cooking and food .



Lovely cleanup of ocean and amazing bonding .



Ocean , we love you . pic.twitter.com/5NConfxhC5 — Afroz Shah (@AfrozShah1) March 25, 2018

Read More: A Seal Found With a Frisbee Cutting Into Her Neck Is Now Back in the Wild

Each year, 8 to 13 million tons of plastic make it into the world’s oceans — the equivalent of a garbage truck filled with plastic every minute. Throughout the world, there are about five plastic bags filled with plastic for every foot of coastline. By 2050, plastic could outweigh fish in the oceans.

Shah wants to bring his community clean-up methods around the world to make sure ecosystems stay safe for both humans and animals.

“There has been a loss of a sense of belonging,” Shah told the Guardian. “You can have laws, policies, regulations in place, but if the community doesn’t have a sense of belonging, you can see what happens.”

Global Citizen campaigns on ending plastic pollution around the world and you can take action on this issue here.