This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
Most of us experience the ocean looking out from a beach during vacation or maybe flying over it in a plane. It seems vast, ancient and invulnerable. It is hard to imagine that up to 80 percent of life lives below the waves, throughout 1.3 billion cubic kilometers of water and across a seabed comprising mountain ranges, vast plains and trenches reaching to nearly 11,000-meters-deep.
The ocean spawned life, it gave rise to the biological revolution of photosynthesis that pumped our atmosphere full of oxygen and with the first crawling upon the land by our vertebrate ancestors, led to us. With the ocean now providing nearly 50 percent of Earth’s oxygen, every second breath we take originates from the marine environment. The ocean feeds billions of us and, through other services it provides, plays a critical role in supporting the ecology of Earth that we ultimately rely on. Many of these services we do not recognize and certainly do not value. For example, the ocean has absorbed up to 50 percent of the carbon dioxide produced by burning fossil fuels, mitigating the greenhouse gas’s role in global warming.
Our relationship with the ocean has become an abusive one. Industrial fishing has led to a catastrophic collapse of both the species we target and those taken as by-catch. Populations of many of the iconic predators of the oceans—tuna, swordfish, sharks and even cod—have been reduced to less than 10 percent of their unexploited abundance. Our inexorable appetite for profit from fisheries has led us to trawl deep and remote seamounts and other deep-sea ecosystems for fish that can live for more than 100 years whilst also destroying vulnerable marine ecosystems such as deep-sea coral reefs and sponge gardens that support an enormous diversity of life.
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Pollution has now reached every part of the ocean. We can see that plastic debris kills through ingestion or entanglement a variety of animals including seals, turtles (which mistake it for their jellyfish food), whales and seabirds. What is not so obvious are the microplastic particles that are now found everywhere in the ocean and which may be introducing toxins into food chains.
The effects of climate change are now taking hold on the oceans. Warming, ocean acidification and declining oxygen levels are all symptoms that in ancient oceans have been associated with severe disturbances to the carbon cycle. They have often been associated with cataclysmic extinction events including some of the “big five” major extinctions on Earth. As a result of our greenhouse-gas emissions, changes in marine ecosystems are occurring globally. Some species are on the move to stay within waters of their preferred temperature, the timing of events such as spawning is changing, and mass mortality of marine life are occurring as a result of extreme warming events or the sudden encroachment of deoxygenated waters on coastal ecosystems.
It is easy to be overwhelmed by the tragic spiral of degradation that we are witnessing in the oceans. However, it is still the greatest wilderness on Earth. Many of the human activities that are damaging the oceans can be modified so they are less harmful, and reduced so the ocean can recover. Fishing, for example, is an activity where we have a clear understanding of the causes and results of overexploitation and damaging practices. There are achievable fixes such as simple modifications to fishing gear to eliminate some forms of by-catch. Making all fishing vessels carry a mandatory identification number, as other merchant vessels do, could make enforcement of fishing regulations much easier. Dealing with overcapacity in fishing fleets and subsidies that lead to overfishing is possible.
Why are these measures not being implemented? The ocean is governed mainly through the principles of the United Nations Convention on Law of the Sea. However, implementation of the provisions of the international law is spread across a plethora of sector-specific organizations that focus on the exploitation of marine resources rather than their conservation. This has made it easy for the interests of single states and industrial concerns to undermine the management of the ocean for the maximum benefit of humankind collectively. Nowhere has this been more acute than in the high seas, the waters that lie beyond 200 nautical miles from the coast and which are subject to international rather than state-based regulation.
Given the degradation of the oceans and a burgeoning human population predicted to reach 9 billion or more by the middle of the century, we cannot allow 19th-century-style politics to rule the waves. It is time to act collectively to rescue the oceans so that they continue to provide critical services and inspiration for our children and for generations thereafter. On June 24, the Global Ocean Commission launched “A Rescue Package for the Global Ocean,” which comprises eight sets of recommendations for practical solutions to the causes of degradation of high seas and lays out an agenda to move the oceans from decline to recovery. It is nothing less than a “Marshall Plan” for the oceans, a reflection of the scale of the emergency we face.
All images courtesy of Alex Rogers.