Five ocean truths you need to hear

The ocean covers 71% of Earth’s surface. It is home to an estimated 95% of all life, and the planet’s longest mountain range lies under the waves. And yet, we know more about the surface of the moon than we know about our ocean. Misconceptions about the ocean can get in the way of us protecting some of the planet’s most vital resources.

Here are a few truths about the ocean to keep in mind:

1: No, the ocean can’t absorb all our mess

Pollution, particularly plastic pollution, is one of the most serious threats to the health of ocean ecosystems. One of the most effective ways of fixing this problem would be to eliminate single-use plastics: data collated for the United Nations from 5 010 dives that led to the collection of 3 000 pieces of plastic, metal, rubber and fishing gear showed that 89% of these were single-use products.

Plastic waste, including difficult-to-collect microplastics, has reached even the most remote parts of Antarctica and the Arctic. The United Nations Environment Programme says plastic pollution has been found in one of the deepest locations on Earth: the Pacific Ocean’s Mariana Trench, which reaches about eight kilometres down.

We have to change our ways. For centuries, humans have viewed the ocean as a bottomless pit that can absorb anything we don’t want: sewage, chemical runoff, crude oil and more. Nothing is further from the truth and even those of us who live as far away from the ocean as possible have an impact on its health because the water in most rivers ends up, ultimately, in the sea.

We’re polluting the engine room of our own home. The ocean truly is the lungs of the world, providing more than 50% of the oxygen we breathe and absorbing at least a quarter of our carbon dioxide emissions. They support countless livelihoods and provide us with food and medicinal products.

So think before you simply dispose of anything. It may be the final straw for the ocean, and you!

2: There are not plenty more fish in the sea

First, the good news: The message that global fish stocks are depleting and need better management appears to be getting through. A 2022 United Nations report estimates that more than 80% of fish caught, by volume, are from stocks the organisation believes to be sustainably fished.

The bad news? The decline in sustainably fished stocks continues, with 35.4% of fisheries worldwide overexploited in 2019. Here in South Africa, nearly 40% of fish stocks are overexploited, according to a 2020 report from the Department of Forestry, Fisheries, and the Environment.

Again, there’s good news – in 2020, the Department reported that 61% of stocks were considered not to be of concern; in 2012, 46%; in 2014, 49%; and in 2016, 52%. But illegal fishing and the poaching of lobster and perlemoen are still rampant.

We can all help by making sure the fish and seafood we eat are labelled “green” by the Southern African Sustainable Seafood Initiative or have the blue tick of the Marine Stewardship Council.

3: Corals are not plants

They look like glorious, multicoloured sea plants, but corals are colonies of invertebrate animals! What’s more, they need our protection.

Scientists have been making waves about their immense vulnerability for decades. They predict that 90% of coral reefs will be gone by 2055 - a mere 31 years from now.

To save corals, we must work to minimise global warming. Most corals need near-perfect temperatures to flourish. When the sea is too warm – and our seas are warming – they expel the symbiotic algae that live in them and cause all those brilliant colours. The problem? The algae is their main food source, so they are tossing out their food and then starving to death.

Ever had a whale of a time wafting around a coral reef, snorkel in mouth, delighting in the kaleidoscope of corals and fish to be seen? Corals play a pivotal role in our tourism economies. They are also home to 25% of marine life and provide nurseries for many fish we eat, coastal protection, medicines, recreation, and tourism.

“Coral reefs are the ocean equivalent of rainforests and are the most biologically diverse ecosystems in the ocean,” says Two Oceans Aquarium Conservation and Sustainability Manager, Helen Lockhart.

They are especially vital to the lives of the estimated 200 million people who depend on coral reefs to protect them from storm surges and sea-level rise, according to the California-based non-profit Coral Reef Alliance. Sadly, the extreme weather we’re seeing due to climate change can harm coral reefs: raging storms damage them, while the heavy rainfall that comes with the tempests can push more pollutants from the land to the sea, the alliance says.

4: There’s life down there

You may think that there isn't much life in the darkest depths of the ocean. But, believe it or not, life in the deep sea is plentiful and strange. The animals that live there are real survivors. They must withstand extremely harsh conditions, such as hundreds of bars of pressure, very little oxygen and food, and constant, extreme cold. Not anyone’s day at the beach!

What’s more, we’re only just discovering these fantastic life forms. Take the gummy squirrel, an odd-looking sea cucumber that trawls the ocean floor and was discovered about 5km below the surface of the Pacific in 2018. Or the 15cm yeti crab, which has hair-like structures on its huge pincers. It was only discovered in the South Pacific in 2005.

This is a place of mysterious-looking brine lakes, hydrothermal vents that reach more than 370℃ and cold seeps, where fluids and gases trapped deep in the earth filter through the ocean floor. The really weird thing: this is where most ocean species live, and scientists say we have yet to discover most of the 500 000 to 10-million species living in the deep sea.

5: Penguins in the coal mine

They’re cute and funny, so it’s heart-wrenching to realise that the International Union for Conservation of Nature classifies the African penguin as critically endangered, with predictions that they will be functionally extinct by 2035. The population of these unique penguins, found only in South Africa and Namibia, has declined by an estimated 93% since the turn of the 20^th century, says the Southern African Foundation for the Conservation of Coastal Birds (SANCCOB).

The African penguin is an indicator species. This means that their presence, or lack thereof, indicates the health of an ecosystem. African penguin poop fertilises the land around their colonies and is washed into the sea, influencing the growth of algae that shorebirds and marine invertebrates eat. They also improve access to food for birds and other sea creatures by herding fish into shoals, from where they can be picked off. Much like the canaries in coal mines which indicated to miners that a mine was no longer safe, African penguins are sounding the alarm that the ocean is in trouble.

Suppose the African penguin really does waddle off into extinction. In that case, it will affect us, and not only because of the death of the penguin-featuring tourist attractions at Cape Town’s Boulders Beach, Simon’s Town, and Betty’s Bay’s Stony Point Nature Reserve. By SANCCOB’S calculations, these bring in tourist revenue of around R311 million a year and generate jobs.

Serious action is needed to save the African penguin, which is one of only 18 penguin species across the world.