Things You Should Know About Oceans and Marine Biodiversity

Seventy per cent of the Earth’s surface is covered by the oceans. Its coral reefs are its rainforests and they teem with life, from minute plankton at the bottom of the food chain to giant whales, the largest animals that have ever lived. The biodiversity of the oceans is greater than that found on land and estimated to be between 50–80 per cent of the total. This rich marine biodiversity is suffering the same fate as its land-based cousins. Oceans play a major part in maintaining the CO2 balance, but like terrestrial ecosystems they suffer when this balance is disrupted.

Global warming is now creating this imbalance, as about 35 per cent of anthropogenic CO2 dissolves in the sea, which is more than it can cope with. This is causing the seas to become more acidic and is one more reason for the bleaching of coral reefs, causing the marine life that depends on them to be threatened.

Bleaching of Coral Reefs

Coral flourishes in optimum conditions in a symbiotic relationship with the algae that live in them and when these conditions are threatened by temperature changes and pollutants the coral turns completely white and dies off. At a local level there is a concern about poor fishermen threatening coral reefs with dynamite fishing, but even when this is hopefully dealt with the wider industrial-scale destruction of the coral reefs will continue.

The Great Barrier Reef, described as Australia’s natural wonder, is in mortal danger. Bleaching caused by climate change has killed almost a quarter of its coral this year and many scientists believe it could be too late for the rest. A survey of the reefs of the Maldives Islands in the Indian Ocean ‘found bleaching on a devastating scale.’ The survey found 60 to 90 per cent bleaching in some sites.

What can we do about this? As usual in these matters the finger always points to those of us who think we just sit at home causing no harm to anything or anyone. These events may occur in ocean habitats far away from where we live but the inter-connectedness of the natural world, and us to it, holds each one of us responsible for its welfare. And as The Nature Conservancy points out, ‘You don’t have to be a scientist to have a positive impact on coral reefs’.

Of the ten easy steps it proposes to protect coral reefs, six we can accomplish ourselves. They are conserving water, reducing pollution, putting a stop to the use of chemical fertilizer in our gardens and vegetable patches, disposing of waste sensibly and planting a tree. The tree connection should be obvious by now: the carbon the trees absorb would otherwise have found its way into the ocean.

Menace of Industrial Fishing

Industrial fishing methods now threaten existing fish stocks and it is estimated that there are enough trawlers to fish three planets the size of the Earth. Factory ships circle the globe, fishing with nets that stretch for forty kilometres. They not only do immense damage, as they scoop up everything from the sea bed, but they also deprive local fishermen of their birthright.

The catch is then cherry-picked for the most saleable items and the rest is thrown back into the sea, either dead or dying. Much of these dead discards are juvenile fish that cannot be sold and get dumped with little or no thought given to stock replenishment. Treating young fish like this leaves little scope for future fishing and future generations.

Tuna and cod are so overfished that they are now reaching non-recovery levels. According to the UN, 75 per cent of the world’s fish stocks have been depleted to non-commercial levels. One of the consequences of this type of mindless predatory fishing is that it doesn’t leave much for the small fishermen, who have relied for generations on local catches for their protein. The poor suffer once more at the grasping hands of the rich and powerful.

West African nations have some of the richest fishing grounds in the world; yet, their food security is under threat. European and Asian fishing fleets have moved into West African waters over the past thirty years after depleting their own fish stocks. Sub-Saharan Africa is now the only region on Earth where per capita fish consumption is actually falling, partly because foreign fishing fleets have removed so much fish. The same is true for the Indian Ocean fisherman of East Africa, and in this instance when the fish ran out, they turned to piracy.

The Scourge of Deforestation

One doesn’t have to be a gardener to know that when a plant or weed is pulled out of the ground a ball of soil attached to its roots comes with it. Magnify this a few million times and one gets an idea of what happens to the soil when a huge area of forest is clear cut or torched. The soil at the base of the trees is not just disturbed but totally destabilized. When the rains arrive, as they always do, the trees are no longer there to protect the soil and a whole ecosystem – that has taken millennia to form – is washed away.

This loosened soil then finds its way to the rivers and lakes and chokes them with nutrient-rich silt that kills the fish local people have relied on for their food supplies, and in extreme cases can divert rivers from their original course. Wooded slopes that are deforested can also be the cause of mudslides, which can bury whole villages and are now occurring with increasing frequency.

Vanishing Mangroves

Mangroves are coastal forests found in the tropics and sub-tropics and are part of coastal ecosystems. They thrive in saline environments and are a protection against coastal erosion. They are also a protection against storms, and although no data is yet available it has been proposed that much of the damage caused by the Indian Ocean Tsunami in 2004 could have been prevented had the mangroves in the coastal zones remained intact. About 35 per cent to 40 per cent of mangroves have been lost in the past thirty years. Nothing is free from commercial exploitation: 28 per cent of mangroves, amounting to 1,344,000 acres (544,000 hectares) was lost to shrimp farming in this period.61

The Iraqi Marshes atrocity shows us the consequences of using nature as a weapon. Generically known as wetlands, marshes and swamps are natural ecosystems that teem with life. These wetlands are losing their biodiversity as are the forests. Wetlands host indigenous bird species and provide resting places for millions of migratory birds. For example, waterfowl migration from Alaska and Northern Canada to southern wintering grounds have been reduced by more than half from 145 million to 64 million mainly due to human encroachment.

Note: The excerpt has been published from Fazlun Khalid’s latest book Signs On The Earth: Islam, Modernity And The Climate Crisis, published by Kube Publishing. The book can be purchased through the Amazon website.