The many dangers facing world oceans | The World Weekly
Life on earth began in the ocean. These vast expanses of salty, nutrient-filled water are the reason life exists in such abundance. Oceans cover 70% of the world's surface and constitute 99% of habitable space.
The seas are a lifeline, accounting for 97% of the earth's water supply and emitting more than 50% of the world's oxygen. Around the world, roughly 1.25 billion people rely on fish as their primary source of protein.
Oceans are vital to life on earth in countless ways. But now a toxic cocktail of climate change, irresponsible fishing and careless consumption is putting marine life and biodiversity in danger.
“You can reduce the threats to the ocean to two things,” Roderic Mast, president and CEO of the Oceanic Society, a nonprofit organisation dedicated to marine conservation, told The World Weekly. “Everything people put into the oceans and everything they take out of them.”
Carbon dioxide is one of the most harmful substances to our oceans. The seas have absorbed one third of the carbon dioxide that humans have put into the atmosphere since the industrial revolution. The rise in carbon levels has left our oceans warmer and more acidic than ever before.
The negative effects of warming waters are most evident at the two poles. In these high latitude seas, temperatures are changing three to four times more quickly than anywhere else, elevating sea levels, altering underwater habits and changing migration patterns.
Oceanographer and climate scientist Erik van Sebille uses the metaphor of a “gigantic game of musical chairs”. As the waters warm up, ecosystems shift towards the poles, seeking the same temperatures they enjoyed before. However, for the organisms that prefer the coolest temperatures, there is nowhere left to go. No chairs remain empty. “They simply can’t move away from the warming,” says Dr. van Sebille, “so now these ecosystems are in a very dire situation.”
Ecosystems elsewhere suffer from higher levels of ocean acidity. This reduces the concentration of carbonate ions, affecting creatures that grow external skeletons such as coral and shellfish. As a result, organisms form weaker skeletons and expend more energy in the formation process. The debilitation of these species has a significant effect on the entire marine food chain.
Increased levels of carbon dioxide have also led to a rise in plankton growth. Bacteria eat the dead plankton, a process which consumes a lot of oxygen. “To some extent this is natural,” says Dr. van Sebille, “but in a changing climate it is accelerating and areas with too little oxygen to be inhabitable are expanding.”
National parks of the ocean
Marine protected areas, experts say, may be the key to curbing the damaging effects of climate change. “When we leave natural systems alone, they have a chance at bouncing back from decades of human impacts,” Anna Cummins, Co-Founder & Global Strategy Director of 5 Gyres Institute, a nonprofit organisation combatting plastic pollution, told TWW.
These areas act as “national parks in our oceans”, receiving close protection and monitoring. Fishing is prohibited and ecosystems are kept healthy. Last month, Mexican authorities created the largest ocean reserve in North America around the Revillagigedo archipelago, Mexico’s answer to Ecuador’s famous Galápagos Islands. Due to commercial fishing, populations of the 400 species of fish around the archipelago have declined in recent years.
Currently, only 6% of the global ocean is set aside for marine protection but the UN convention on biological diversity aims to expand this to 10% by 2020. The positive impacts of such conservation projects can reach far beyond the small areas to which they are contained.
“If we plan carefully, ecosystems downstream may become more resilient as well because of the constant flux of ecosystems and larvae of animals,” says Dr. van Sebille.
Climate change is affecting the oceans in many harmful ways, often undetectable to the eye. One substance, however, is having a very visible impact on the wellbeing of the world’s oceans.
The problem with plastic
Plastic now has an abundant presence in seas across the globe. “Every minute the equivalent of a garbage truck worth of plastic is dumped into the world’s oceans,” David Pinsky of Greenpeace USA told TWW.
One-use plastics such as water bottles, straws and food packaging are used for an average of just 15 minutes. Once in the ocean, that one straw or plastic bag can take up to 400 years to decompose.
Huge amounts of plastic circulate in strong ocean currents or gyres. The largest of these vast "plastic soups" is found in the north Pacific, known as the Great Pacific Garbage Patch. Such concentrations of plastic disrupt habitats and wildlife, disfiguring some of the most beautiful parts of the planet.
“Plastics act as magnets to chemical toxins,” Julie Andersen, executive director of the Plastic Oceans Foundation, told TWW. “Larger-sized plastics break up into micro-plastics which are ingested by plankton and even coral.”
Consumption habits need to change urgently, observers say. At the current rate of production, “plastic will outnumber fish in our oceans in just a few decades,” says Ms. Andersen, whose organisation uses media and film to raise awareness around plastic pollution in the world’s seas.
Some organisations are embarking upon large cleanup operations. Boyan Slat is the founder and CEO of Ocean Cleanup, a company that plans to use a giant V-shaped barrier to collect rubbish with the help of sea currents. The collected waste is then sold to organisations who will reuse the waste. The system will launch in 2018 and, according to Mr. Slat and his team, will remove 50% of the Great Pacific Garbage Patch within five years.
Some, however, are sceptical of such cleanup projects and believe preventative action is the way forward. A large-scale cut in the consumption of one-use plastics could reduce plastic pollution by 50%. Another option is to use independent fishmongers who prioritise sustainable seafood and environmentally-friendly packaging.
However, to bring about change in individual human behaviour on such a vast scale remains a difficult task. Information-based campaigns can prove ineffective. After all, people are aware of the negative consequences of smoking or eating fast-food, but many continue to do both.
“You need to tune in to mechanisms which help us move from awareness to action,” says Mr. Mast. “This involves creating incentives, economic and otherwise, and long-term monitoring of what works and what doesn’t.”
Support from the governmental level is a crucial supplement to individual action. States can implement far-reaching educational programmes, as well as placing limits on fisheries and protecting key areas. Government efforts can also tackle the root of the problem, beginning at the design level of plastic production.
“This would help propel us towards a truly zero-waste, circular economy,” says Ms. Cummins, “one where products are destined for reuse and reintegration, rather than for the landfill and the environment.”
The future of the world’s oceans is, by many counts, not all that bright. Nevertheless, there remains a glimmer of hope. Ocean ecosystems and various species of fish and marine life are hugely resilient, capable of coping with highly difficult conditions.
As sea levels rise, record-breaking temperatures cook the globe, industrial fishing fleets expand, and plastic pollution chokes the world’s oceans, the time for action is now.” - David Pinsky, Greenpeace USA Oceans Campaigner
Optimism accompanied by a call for urgent action is a common attitude among many oceanographers, experts and campaigners. While more action is required, a lot of the technology and expertise needed to tackle the issue already exist.
The oceans may be under threat, but they are by no means finished. As Dr. van Sebille puts it, “the ocean is still a beautiful place, just fantastic. It doesn’t all have to be negative.”