The most harmful ocean pollutant is - far and away - carbon pollution. In the last decade, the oceans have absorbed nearly a third of the carbon dioxide emitted by industrial activity. This has slowed climate change, but at great cost to ocean health. When carbon dioxide is absorbed by seawater it increases acidity levels, and threatens ocean life ranging from the microscopic snails that feed salmon to the coral reefs that support tourism. Plastics are another particularly insidious form of ocean pollution; according to the non-profit Ocean Conservancy, coastal nations generate 275 million metric tons of plastic waste every year (and 8 million metric tons of plastic enters the oceans). The Ellen MacArthur Foundation and the World Economic Forum jointly predicted that there will be more plastic than fish (by weight) in the oceans by 2050, and the United Nations Environment Programme has recorded more than 817 species of ocean animal that have encountered plastic pollution. Plastic pollution has also been detected in seafood sold for human consumption; a 2015 study by a team of University of California, Davis and Hasanuddin University researchers flagged man-made debris in 25% of seafood market fish, and 67% of all species sampled in the US.
According to a report published in the journal Science Advances in 2018, only 9% of plastic waste has been recycled globally - highlighting a need to re-think design and regulation in a way that incentivizes re-use. Potential solutions include policies that curb the use of single-use plastics like bags or straws, or improving the capture of plastics that leak out of waste systems. Researchers have found that just 10 of the world’s rivers are the source of 90% of the plastic pollution entering the oceans, pointing to a possible focus for efforts to curb plastic pollution as a matter of policy and industrial reform - by stopping pollution at its source. Another major source of ocean pollution is the runoff of fertilizers used in agriculture, which are carried down rivers into oceans where they create population explosions of algae and bacteria. This in turn depletes oxygen levels, killing fish and creating inhospitable conditions for marine life. As a result, more than 400 low-oxygen “dead zones” have been documented in the oceans worldwide. The spread of these areas could be limited, in a way that also saves money for the agriculture industry, by deploying a more strategic and responsible application of fertilizers.
Mass Extinction
Ocean life is sitting on an extinction cliff
As far as life on land is concerned, we are rapidly approaching what scientists have dubbed the “Sixth Mass Extinction” - as human-caused extinction rates approach levels last experienced during the era that saw the end of many dinosaur lineages. The situation in the oceans is a little brighter, for the moment. According to the International Union for Conservation of Nature, about 17 ocean animal extinctions have occurred in the last 500 years (during the same period, more than 500 land animal extinctions have occurred due to human activity). A 2016 report in the journal Science projected that rates of extinction in the oceans could increase dramatically, however - particularly as climate change accelerates. Ocean animals that are under threat include Monk Seals (both the Hawaiian monk seal and the Mediterranean monk seal), Blue Whales (which were depleted in the early 1900s), and all six species of sea turtle found in US waters. Without a change to business as usual in ocean management, we could therefore soon initiate an additional Sixth Mass Extinction in the oceans.
An industrial revolution is beginning in the oceans, with parallels to the industrial revolutions that have taken place on land. This involves a rapid expansion of marine industries such as ocean farming, marine energy, and marine transport, and a nearly five-fold increase in the amount of ocean area being explored for deep sea mining. According to the International Union for Conservation of Nature, by May 2018 the International Seabed Authority had issued 29 contracts for the exploration of deep-sea mineral deposits, and more than 1.5 million square kilometres of international seabed (about the size of Mongolia) had been set aside for mineral exploration in the Pacific and Indian oceans and along the mid-Atlantic ridge. Mining in international water is expected to begin in 2025, according to the IUCN. On land, animal extinction rates began accelerating rapidly during the first two industrial revolutions, when there was much less awareness of the link between human health and the environment. Now, the oceans present an opportunity to intelligently move a marine industrial revolution forward without associated spikes in animal extinction that would compromise the oceans’ nourishing resources.
Human Well-Being and Oceans
The fates of the oceans and humanity are increasingly intertwined
The oceans are more than a beautiful home to inspiring ocean wildlife; they are a critically important source of nutritious food, income, jobs, and global stability. The oceans yield $2.5 trillion annually in goods and services, according to a “conservative” estimate published in 2017 by the consultancy BCG, making them equivalent to one of the largest single economies in the world. The oceans provide millions of jobs in fishing, aquaculture, tourism, energy, transportation, and biotechnology. The value of ocean resources is particularly important for poor countries. Fishery net exports from developing countries alone have been valued at $37 billion, or more than value of meat, tobacco, rice, and sugar exports combined, according to a report published in 2018 by the Food and Agriculture Organization (FAO). Wealthier nations are also dependent on ocean resources. The collapse of cod stocks along the east coast of Canada, for example, sparked the largest mass layoffs in the country’s history and prompted large-scale migration from affected provinces. Canada spent almost $2 billion between 1994 and 1998 on aid and recovery programs aimed at coping with this social and ecological disaster.
The oceans act as a massive refrigerator of free-range, highly nutritious food fit for human consumption. According to the FAO, fish provide more than 3.1 billion people with at least 20% of their animal protein, and serve as a critically important source of nutrients essential to good health like iron, zinc, and omega-3 fatty acids. Researchers estimate that if current trajectories for fishery decline persist, 845 million people could become at risk of diseases associated with malnutrition. Ocean health and human health intersect in other important, but sometimes less obvious ways. Fishery declines have been linked to human trafficking when, for example, child and slave labour is used to capture increasingly rare fish. Another example: some analysts suggest that piracy in Somalia and West Africa can partially be explained by disenfranchised fishermen turning to violence in order to protect decreasing offshore fish stocks. In situations where overfishing has depleted potentially lucrative species, organized crime has also escalated. In Mexico’s Sea of Cortez, for example, it is believed that drug cartels may be involved in an illicit industry that is both depleting a critically-endangered fish and threatening to trigger the extinction of the Vaquita (a small porpoise).
Aquaculture
We are shifting from being ocean hunters to ocean farmers
In 2014, for the first time in history, the global population ate more farmed fish than wild fish; this was a development as transformative as our forebears’ long ago shift from hunting and gathering on land to becoming able to rely on agriculture. Aquaculture in the ocean is a booming industry. According to a report published in 2018 by the Food and Agriculture Organization of the United Nations, global aquaculture production excluding plants increased by roughly 30% between 2011 and 2016, to 80 million tonnes. Production of finfish alone during 2016 was valued at $138.5 billion, according to the FAO report. While growth has been geographically diverse, the vast majority is currently centred in Asia. China alone represents more than 60% of global aquaculture production. The industry’s expansion could help meet a growing global demand for food from animal sources that may increase by 80% by 2050 - fuelled by global population growth, and by increasing amounts of wealth in developing countries.
Aquaculture could play an important role in promoting global food security. But there are challenges involved in keeping the nutritious products produced in lower-income nations within domestic markets, where they can help fight malnutrition and undernutrition; that’s because farmed seafood like shrimp is now often exported from developing to developed nations. In addition, just like farming on land, farming in the ocean can be environmentally destructive. While proponents of aquaculture note that it can take pressure off of frequently-overfished wild stocks, the negative effects of aquaculture include pollution, the harvesting of at-risk wild fish to feed farmed fish, and the destruction of wild fish nursery grounds (like mangrove forests) in order to build fish farms. Innovation could better enable more responsible fish farming, particularly as an increasingly crowded and protein-hungry world looks to the oceans for nourishment. The challenge will be to make ocean aquaculture something that can successfully meet food shortfalls - without also inflicting damage on ecosystems.
Climate Change Impacts
Oceans are extremely vulnerable in the face of climate change
The oceans are being hit hard by climate change. Effects include ocean warming, ocean acidification, and oxygen depletion. A future ocean that is hotter, more acidic, and a more difficult place for ocean life to breathe presents serious challenges. The oceans have absorbed more than 90% of the heat produced via greenhouse gas-associated warming since the 1970s - and according to the National Oceanic and Atmospheric Administration, the five warmest years on record have all occurred since 2010. Ocean life is largely accustomed to stable temperatures, and is vulnerable to related changes. Coral reefs, for example, which can house millions of species, are being bleached from overheating. Back-to-back extreme ocean heat waves in 2016 and 2017 caused massive bleaching of the Great Barrier Reef off the coast of Australia, killing half of its coral. Potential related economic impacts, not to mention environmental impacts, are significant - a 2013 Deloitte study found that the Great Barrier Reef was generating about $7 billion in revenue for Australia, largely via tourism.
As an ocean warms, its oxygen levels drop. Oxygen content in the oceans declined by an estimated 2% between 1960 and 2010, according to a study published in the journal Nature in 2017. In addition, since the First Industrial Revolution, the acidity of the oceans has increased by roughly 30% as a result of carbon dioxide dissolving in marine waters; this makes it more difficult for many organisms to form healthy skeletons and shells. Scientists from the University of British Columbia's Institute for the Oceans and Fisheries have predicted that if climate change continues unchecked, global fisheries may suffer $10 billion in annual revenue loss by 2050. Global warming-driven sea level rise may be the most impactful form of ocean-related climate change - scientists predict that half of the population in 25 megacities (cities with more than 10 million inhabitants) will be affected by sea level rise if climate change is not slowed; Miami, Shanghai and dozens of other cities have already suffered related effects. Climate change must be aggressively checked in order to enable natural adaptation and evolution, and scientists typically agree that the best way to do this is to confront the difficult task of directly reducing global carbon emissions.
Shifting Ocean Governance
Current regulation does not adequately address the changes now impacting oceans
The oceans have always been difficult to govern; they cover 90% of the habitable space on the Earth, creating an immense, supranational domain with unique regulatory challenges. Unlike most natural assets on land, many ocean resources (such as the bluefin tuna that is prized for sushi) regularly swim across jurisdictional boundaries. In addition, damage incurred within one nation’s jurisdiction (like plastic pollution) can impact nations many thousands of kilometres away. Meanwhile climate change is driving seafood stocks towards the planet’s poles, to escape warming waters. This can create worrisome volatility in less-developed regions - as fish travel out of the reach of countries that need them most. Unfortunately, policies that can properly address these issues have been deferred. Two thirds of the oceans are on the high seas, or outside of the jurisdiction of any single country. The United Nations has committed to developing a first-of-its-kind, legally-binding treaty to better manage biodiversity and resources on the high seas by 2020. If it is successfully implemented, this could be a significant boon for ocean biodiversity.
The cross-border migration of valuable seafood has the potential to not only deprive developing economies of resources, but also spur regional conflict. Research published in the journal Science in 2018 suggested that as many as 70 countries will see new fish stocks in their national waters by the year 2100, as a result of climate change. New international agreements are needed to govern the sharing of fishery resources, and to prevent countries from overharvesting stocks when they realize their assets are migrating beyond their borders. One positive development in the world of ocean governance has been the establishment of marine protected areas. These can buy time for at-risk ecosystems to better adapt to climate change. However, based on a review of 144 studies, researchers at the University of York have concluded that about 30% of the oceans would need to be placed within protected areas in order to meet ocean health management goals - though just over 7% is currently protected. The United Kingdom has protected an area of ocean larger than the country’s own land mass, and Chile, the US, and Kiribati have established protected areas that are collectively larger than Italy - now, other countries need to catch up.
Overfishing
Fish are being removed from the sea faster than they can be replaced
The scientific philosopher Thomas Henry Huxley assured everyone in 1883 that it would be impossible to deplete populations of prolific fish like cod, mackerel, and herring. Within a century, he was proven wrong. The Food and Agriculture Organization of the United Nations reported in 2018 that about a third of global fish stocks are overfished - not least because fishing laws promote the philosophy that anything fishermen fail to harvest themselves will just be taken by others. Research published in 2016 in the Proceedings of the National Academy of Sciences suggested that replacing antiquated fishery governance systems with rights-based fishery management tools could increase fisheries’ collective annual profit by $53 billion. These tools can be used to allocate individual fishing rights to local fishermen and fishing communities, and their successful adoption has been documented in Australia, Iceland, and Mexico. Another issue is wasteful inefficiency; many fisheries capture, kill, and potentially discard marine species like sharks, dolphins, and sea turtles regardless of their suitability as potential food, and the damage that this causes imperils broader ecosystem health.
Illegal and unreported fishing exacerbates overfishing, and is a growing problem. According to a study published in 2014 in Marine Policy, up to a third of all wild seafood imported in the US is believed to be illegally caught. In the case of long-living, slow-growing marine species, a single incident of illegal fishing can set an ocean ecosystem back by decades. New surveillance technologies and platforms for data sharing are needed in order to rein in illegal fishing; one promising related development is the Agreement on Port State Measures, a global treaty that went into force in 2016 and can curb illegal fishing vessels’ access to ports. However, more countries are needed to back the agreement. There are a variety of other ways to combat overfishing, including a more strategic review of the billions of dollars spent globally on harmful fishery subsidies that, in many instances, promote economically-irrational overfishing (an effort is now underway at the World Trade Organization to pursue related reform). Replicating the European Union’s yellow/red card program for combating illegal fishing, which blocks market access to non-compliant foreign supply nations, is another potential option. Better controlling overfishing and illegal fishing is an increasingly critical element of safeguarding global food security, and of ensuring the health and prosperity of coastal economies.
Emerging Ocean Technologies
New opportunities for ocean-based industries are emerging, and so are challenges
Emerging technologies are changing the way we harvest food, energy, minerals, and data from the ocean. Rapid innovation in marine robotics, artificial intelligence, low-cost sensors, satellite systems, and methods for collecting and analysing data may yet create a cleaner and safer future - though these developments also present potential challenges for ocean health. Ocean mining is one example; portions of the seafloor are rich in gold, platinum, cobalt, and rare-earth elements, though these resources have up until now been out of reach. New, 300-ton mining machines have been developed that can harvest minerals in some of the deepest parts of the sea. Japan has completed its first large-scale mineral extraction from the seabed, and plans to begin commercial mining in its waters within the next decade. Meanwhile on the high seas, the Jamaica-based International Seabed Authority has issued more than 1 million square kilometres of mining exploration claims to 20 different countries. However, much of the seabed within these claims remains unexplored, and new species are frequently being discovered in the vicinity. It remains unclear if and how sediment plumes from seabed mining will affect the health of oceans generally, and fisheries specifically. Finding a way to properly balance mining interests against potential impacts on ocean ecosystems and marine industries remains a challenge.
A revolution in our ability to collect and process ocean data has now enabled the detection of illegal fishing from space, empowered sustainability-focused companies to more efficiently connect with people, and helped build intelligent zoning plans that better balance the needs of fishermen, marine transportation, and ocean conservation. In addition, new technologies are being developed to plug into the ocean’s enormous stores of green energy (possibilities include wave energy, tidal energy, thermal energy, and offshore wind). A record 4,331 megawatts of new offshore wind power was installed around the world during 2017, according to the Global Wind Energy Council, which increased the size of the market by 95%. While remaining hurdles to harvesting ocean energy include cost efficiency and the potential impact of new ocean power plants on ocean life, other exciting innovations are on the way: a robot that swims like a tuna, underwater data centres, autonomous self-driving ships, and geodesic spheres that can serve as offshore fish farms, for example. Properly embraced, disruptive technologies can help us take more from the oceans while damaging them less.
