A WARNING FROM OUR OCEANS
The United Nations has designated 8 June 2021 as World Oceans Day – a day for humanity to celebrate the ocean. Astrid’s timely reprint from our Spring 2020 issue of The Plain Truth highlights how important oceans are for every human being on the planet, with a close look at coral.
In recent years, much media attention has focused on the events of the vast expanse of water which covers more than 70% of the Earth’s surface – our oceans. And although many studies and investigations have taken place beneath the waves, a staggering 80% of our oceans still remains unexplored?
Oceans are vitally important to the very existence of mankind. Containing around 97% of all the planet’s water and regulating much of Earth’s climate, oceans are essential for our very survival.
The Bible’s opening chapter (Genesis 1) describes God creating every living creature that moves in the waters, instructing them to multiply and fill the waters. The oceans were designed to be bustling with life.
But the focus of this article is not to look at the abundance of a thriving sealife, but rather the harm which mankind is afflicting upon it. Pollution, overfishing and shipping are only some of the activities that are accumulating and causing unimaginable damage.
Apart from being the largest ‘carbon sink’ on the planet, the ocean also absorbs an estimated third of the additional carbon dioxide put into the atmosphere by the burning of fossil fuels. When this happens, the oceans become more acidic as well as increasing the sea surface temperature. Bearing the brunt of these man-produced activities are the small and decorative creatures called ‘corals’.
Whilst appearing very similar to plants, most people – including myself, until recently – are not aware that corals are in fact animals. Corals are colonies of invertebrates called polyps. These start off as larvae, settling permanently on existing colonies by building skeletal homes using calcium carbonate mineral from the seawater. And, equipped with small stinging tentacles, corals capture passing plankton to eat, but the main meal comes from the algae living in symbiosis with the corals.
Basically, the algae receive shelter and carbon in order to photosynthesize, and in return, give the corals energy and nutrients. Amazingly, the algae are also responsible for the beautiful colours often associated with corals – browns, oranges, reds, greens, blues, etc.
There are two main types of coral; ‘soft corals’, which are flexible and resemble plants and trees; and ‘hard reef-building corals’. The latter having harder skeletons as they contain more calcium carbonate mineral than the soft corals. Even the way that corals reproduce is fascinating and varied, where corals can be male, female, both or neither! Some species only breed at specific times of the year, for example around the time of a full moon. During so-called ‘spawning events’, the corals release small sperm and egg parcels, which break up in the water and mingle with sperm and eggs from nearby colonies, to create larvae. Meanwhile, other corals increase by creating clones, which are added to the existing colony or broken off to join or create other colonies.
With an original base of submerged stones and rocks, hard corals build their skeletal homes on top of previous coral skeletons, slowly building up the reef. While only covering a minuscule percentage of the ocean floor, coral reefs are among the most diverse and productive ecosystems on earth providing food, shelter and breeding grounds for around 25% of all known marine species. And, the world’s current living reefs are thought to be between 6,000 and 8,000 years old. Acting as barriers, coral reefs are mainly found in tropical and subtropical waters, where the algae has good access to light for photosynthesizing. As one of the largest living organisms on earth, the well-known Great Barrier Reef off Australia’s coast can even be seen from space. And, just as rainforests prevent soil erosion on land, coral reefs help prevent coastal erosion by providing a buffer from waves, storms and floods.
Bleaching events 
But all is not well for our coral reefs, and many are in mortal danger. As I write, the latest headlines read that Australia’s Great Barrier Reef has suffered another mass bleaching event – the third in just five years. Data shows that warmer sea temperatures – particularly in February this year – are feared to have caused huge coral loss across the world’s largest reef system. When the ocean becomes more acidic, due to increased carbon dioxide uptake (as mentioned at the beginning of this article), the calcium carbonate mineral in the seawater starts to dissolve, making it harder for corals (and other shell animals) to build their skeletal homes. And, when the sea’s surface temperature rises the corals get stressed and expel the indwelling algae, thus losing nutrients and colour.
So-called ‘bleaching events’ leave the corals white, and vulnerable to starvation, disease and death. Even though corals are resilient, bleaching events are reported to have increased nearly five-fold in the last four decades, leaving corals inadequate time to recover. According to the UN Environment Programme, up to 50% of corals have died in the last 30 years, while the rest remain under threat. Many scientists fear that most coral could be gone as soon as 2050, if conditions do not change.
Restoration of coral reefs
For this reason, marine scientists all over the world are working on ways to restore coral reefs. As part of ‘Project Coral’, scientists have already produced 24 species of coral at the Horniman Aquarium in London. The organisation is the first institution in the world to successfully induce predictable broadcast coral spawning by assimilating the time of year, the light and other conditions for reproduction.
In Australia, the Reef Restoration Foundation collects corals which survived the major bleaching events in 2016 and 2017. Considered more resistant to heat, the mother cuttings are put into nurseries underwater close to the damaged reef, where they are regularly monitored. And, once the corals have grown large enough, they are reattached to the reef.
Additionally, the importance of the ocean and the sensitive coral reefs are now receiving attention on many political agendas. Just before Blue Planet II was released in 2017 – highlighting the plastic scourge in the ocean – the UN held its first ocean conference setting goals for achieving a healthy ocean. Then in December 2019 the EU presented the European Green Deal which incorporates environmental goals and principles into all EU policies, with the aim of permeating other agreements with neighbouring countries around the Mediterranean Sea.
Throughout the Bible, starting with the creation story in Genesis 1, the importance and abundance of life in our environment – including the oceans – are seen as opportunities to celebrate the creation and its creator, God.
And God said, ‘Let the water teem with living creatures, and let birds fly above the earth across the vault of the sky.’ So God created the great creatures of the sea and every living thing with which the water teems and that moves about in it, according to their kinds, and every winged bird according to its kind. And God saw that it was good. God blessed them and said, ‘Be fruitful and increase in number and fill the water in the seas, and let the birds increase on the earth.’ And there was evening, and there was morning – the fifth day. (Genesis 1:20 – 23)
And a final word from Psalms 96:11:
‘Let the heavens rejoice, let the earth be glad;… let the sea resound, and all that is in it.’
 See accompanying box for definition.
 Interaction between two different organisms living in close physical association, typically to the advantage of both.