The Two Oceans Aquarium is committed to fostering love, respect and understanding of our oceans. Nothing makes us happier than meeting young people with an enthusiasm for unique solutions to our planet's biggest problems - learners Matthew Lewis, James Griffiths and Stefan von der Heyden have one such solution that they would like to share.

By now we all know that climate change is a huge global problem. One solution: whales.

Climate change is a human-made phenomenon whereby long-term seasonal changes have been caused due to the growing accumulation of greenhouse gases in the atmosphere. Every person leaves a "carbon footprint", CO 2 that is released into the atmosphere daily because of our routines and energy use.

Over the last couple of years, the evidence that humans are the main contributor to climate change has grown immensely, and these changes are posing many threats to the environment. These effects will be even worse if we do not protect the organisms that are vital to keeping the ecosystem stable and healthy.

How can whales solve this problem?

Whales move nutrients around in the ocean. They bring nutrients up to the surface of the ocean from the depths, where they are released into the "photic zone", stimulating the growth of tiny organisms that absorb CO 2 . This cycle is all thanks to whale poo - a true miracle of the ocean.

Whales produce vast quantities of poo that is very rich in iron and nitrogen - important but scarce minerals for the growth of phytoplankton. Areas such as the Antarctic where iron is very limited rely on whales to fertilise the surface waters for plankton to grow. As phytoplankton are plants, they remove CO 2 from the atmosphere through photosynthesis. Zooplankton, like krill, feed on the phytoplankton and when the zooplankton die, they sink into the deep, taking their stored carbon out of circulation.

Blooms of phytoplankton form the basis of the ocean’s ability to absorb greenhouse gases and store them away permanently. This is no small effect - as much as a third of CO 2 produced through our burning of fossil fuels is absorbed by the ocean, but this number is declining! Whale poo may not be responsible for all phytoplankton blooms, but in nutrient-poor waters like the Southern Ocean, it is a major contributor.

In simple terms: The more whales there are, the more they poop near the surface, the more phytoplankton there is, and the more CO 2 is removed from the atmosphere through this process. The role whales play in regulating plankton populations cannot be understated. Prior to 1986 whale hunting was commonplace and it was believed that the elimination of whales would result in population booms of their major prey - such as krill. This, however, has not proven true, and entire ecosystems collapsed with the disappearance of the whales.

A good example of whales' ability to remove carbon from the atmosphere: a 2010 study found that 12 000 sperm whales in the Southern Ocean permanently remove 200 000 tons of carbon from the atmosphere each year.

Whales are “ecosystem engineers” – they have the ability to modify their environment to improve their survival. We have yet to determine what the ocean's carrying capacity for whales is, but we do know that by taking hunting pressure off of whales, we have the potential to increase the oceans' capacity to absorb CO 2 and support even more life.

As the ocean absorbs more CO 2 , it becomes more acidic, reducing its ability to absorb more. For this reason, processes that allow carbon to be incorporated into the bodies of living organisms, like zooplankton, which carry it to the seafloor when they die are vitally important for removing CO 2 from the system entirely. Whale poo, fortunately, promotes exactly this kind of cycle.

Whales are not alone in their ability to influence the ocean's uptake of CO 2 , nor are their low population numbers the only contributor to the ocean's reduced ability to host life. Global issues like ocean acidification, pollution and unsustainable fishing are all playing a major role, but just like whales, a positive change can be made through global awareness and conservation efforts. To save the whales, we have to save our oceans, and if we save our oceans we can also make a huge dent in saving our atmosphere.

A solution under threat

The threats faced by whales are real. Despite modern efforts to conserve them, it will take decades for them to recover to their pre-whaling population numbers. We need to work on helping them now, so that we can help the entire world.

The WWF recognises several major threats still facing whales today - whaling by Japan, Iceland and Norway, ocean pollution in the form of abandoned fishing gear, plastic pollution and chemicals, and ship strikes.

How can you help whales?

South Africa is a member of the International Whaling Commision, and we are seeing a significant recovery of our local populations. Despite the historic slaughter of more than 2 million whales, we are seeing the recovery of most whale species - such as the southern right whale which, according to leading whale researcher Dr Ken Findlay, has numbers surpassing 15 000 individuals today, from as few as 100 in 1935.

But there is still work to be done, and YOU can help. Here's how you can make a difference to whales:

Spread the word about the importance of whales to our survival on Earth. Share this link with your friends and spread this message far and wide.

Support sustainable seafood - check your meals on the WWF SASSI list, or look for the MSC ecolabel. Not only does this protect the prey of whales, but it prevents fishing practices that cause harm to the whales themselves.

Say "no" to single-use plastic items like shopping packets, balloons and water bottles. Consider taking the #RethinkTheBag pledge.

Our government has recently ratified 20 new Marine Protected Areas - let's celebrate this achievement and encourage the establishment of even more.

About the authors

“Life Below Water” started with us, a group of grade 9 boys from Bishops Diocesan College: Matthew Lewis, James Griffiths and Stefan Von Der Heyden. At the end of the second school term, an opportunity was presented to the grade 9s of 2018 with the chance to work on an amazing new curriculum, “Big Ideas”.

We had to submit a motivational letter, revolving around the concept of the “4 Cs” - communication, collaboration, critical thinking and creativity - which are the vital skills needed for the future. A class of 30 was selected to trial the Big Ideas class, which uses the United Nation's 17 Sustainable Development Goals as a platform for lessons. The goal of this class is to provide us with the right knowledge to thrive in the 2030s - 2050s (our prime working days) and to research and develop a solution to one of the Sustainable Development Goals that we have chosen.