On this year's Africa Day, South African volunteers have headed to the beach. They spent Saturday cleaning up the coastline and raising awareness on marine conservation. Plastic waste is a growing environmental concern, particularly in the ocean. Let's take a closer look.

Groups of children, scouts and social clubs are celebrating Africa Day, by cleaning up Monwabisi Beach in South Africa.

This year's theme is a "Healthy Lifestyle Prolongs Life".

The volunteers, old and young, are trying to raise awareness for marine conservation.

HANNAH MOSES VOLUNTEER FROM GREENPOP "I believe what I'm doing today is cleaning up the ocean to make it safer for children to play, it's cleaner for the ocean so that most sea life are protected and not only sea life but us as well, the people who go on the beach."

HAYLEY MCLELLAN ENVIRONMENTAL CAMPAIGNER, TWO OCEANS AQUARIUM "When you just look across the beach, it looks pretty nice, pristine - it's not! There is deep, deep litter underneath the sand. You think you're seeing one little item, you pull on it and you pull on it and it's just heaps of plastic that is coming out actually entwined in fishing line."

Campaigners like McLellan are helping South Africans consider the impact of plastic.

She encourages the public to bring their own reusable bags when shopping.

According to McLellan, every marine organism is eating plastic, from the smallest mussel to giant whales.

PROFESSOR WENDY FODEN, MANAGER SOUTH AFRICAN NATIONAL PARKS "There's just been a big international report that has come out. The Intergovernmental Panel on Biodiversity and Ecosystems Services, that has been an international review of what has been published as the state of our biodiversity in the world. It's come out with some pretty scary facts. Some of the things they've come to show is that our natural systems have declined by 47%, a truly scary figure. Of the species we've assessed, 25% are threatened with extinction."

Many African countries are leading the way on limiting plastic usage.

Kenya, Rwanda, and Morocco have a total ban on single-use plastic bags.

But plastic is only part of the problem.

PROFESSOR WENDY FODEN, MANAGER SOUTH AFRICAN NATIONAL PARKS "One of the other big ones is pollution. We haven't been realizing all of the things we've been putting into our water systems, our soils and the air over all these decades of industrialization. The air is at an all time low in terms of its quality and we're putting so much carbon dioxide there. Also, a lot the pesticides that support our food system are very damaging for the biodiversity which it also relies. Then of course plastics are a huge problem, particularly in the ocean. They're finding their way right into the food chain and back to us in ways that are very concerning for our health."

Hopefully, as more governments and citizens take action against pollution and plastic waste, the world will be able to turn the tide on environmental degradation.

BO, CGTN.