- > The seventh edition of the World Ocean Review focuses on the effects of climate change on the physics of the ocean and on its biotic communities; the consequences of fishing, shipping, resource extraction, energy production, and marine pollution; and the questions of how active substances from the ocean can be used and how the ocean can be managed in the future in such a way that both its protection and the participation of as many people as possible in its services and goods are ensured.
The Ocean, Guarantor of Life – Sustainable Use, Effective Protection
The outbreak of the coronavirus pandemic in January 2020 marked a turning point for the world ocean. International merchant shipping collapsed, at least for a time; cruise ships were forced to abandon their voyages; beach hotels stood empty; large-scale marine projects such as the construction of new oil and gas production facilities in the Arctic were delayed. The international negotiations on improved marine conservation and more sustainable use also stalled when major political conferences could not go ahead as planned.
However, the pandemic also turned the spotlight on the oceans to a greater and more varied extent than ever before. This interest was driven firstly by the rapid progression of global warming and the role of the ocean as a heat repository, and secondly by a new wave of digital publicity for marine topics. Conferences, lectures and symposia were suddenly all moved online and were often open to everyone. Researchers held webinars to share new information and their latest research findings; marine conservation organizations and societies shifted their campaigns and events to the virtual space. Anyone who wished to and who had a knowledge of the relevant language could access these information formats on a daily basis, including events run by small, local cooperatives which, before the pandemic, rarely had an opportunity to reach a transregional, less still an international audience.
This growing public attention to the issues affecting the oceans did not come a moment too soon. The ocean is in a parlous state, which means that one of the fundamental pillars of our human existence rests on shaky ground, for the truth is that every person on Earth relies on the ocean in one way or another. The seas regulate the Earth’s climate and ensure that our planet remains habitable and liveable. They distribute tropical heat around the globe, provide vapour to the water cycle, help to mitigate climate change by absorbing vast amounts of carbon dioxide and heat, and produce the oxygen for every second breath we take.
The ocean is the Earth’s largest and most diverse habitat. It supplies animal protein for more than three billion people and provides livelihoods for millions more – in fishing, marine and coastal tourism, shipping, resource extraction, the renewable energy sector, and branches of the economy which process materials or substances from the sea.
Around 40 per cent of the world’s people live less than 150 kilometres from the coast. For them, but also for the many visitors from further inland, the sea is a place for leisure and recreation, a source of inspiration and an element of identity. Today, it is clear that the healthier and more resilient the ocean, the greater human wellbeing will be, now and in future.
- Currently, however, the ocean cannot be described as being in a healthy state. On the contrary, like the rest of the planet, our seas are the setting for not just one but three crises, all of which are entirely man-made – climate change, species extinction and growing pollution. On its own, each one of these three crises represents an existential problem for the ocean; taken together, the effects of this “trilemma” are amplified, reverberating, tsunami-like, far beyond their place of origin. The dramatic effects of these crises can now be felt not only in every area of the sea – from the surf zones to the deep-sea trenches, from the tropics to the remote polar regions – but also, and above all, on land, home to millions of people who are increasingly being denied the services that the ocean would normally provide.
In many regions, climate change is now the greatest threat, for it is altering living conditions in the oceans and coastal zones at a rate never previously experienced in human history. The oceans absorb more than 90 per cent of the excess heat and around 25 per cent of anthropogenic carbon dioxide emissions. As a consequence, the chemical and physical properties of the water masses are changing.
The ocean is currently warming more rapidly and to greater depths than at any time since the end of the last Ice Age. In 2020 alone, the upper 2000 metres of the water column in the world’s oceans absorbed up to 20 more zettajoules of heat than in 2019. This is enough heat to boil 1.3 billion kettles, each containing 1.5 litres of water. Sea surface temperature has increased by an average of 0.88 degrees Celsius since the start of the 20th century. In 2020, 84 per cent of the global sea surface was affected by at least one marine heatwave.
Due to this warming, mixing of the water masses has decreased. As one outcome of this decline, the world’s oceans lost around two per cent of their oxygen content between 1970 and 2010. Over the past four decades, their pH value has also fallen to the lowest level in 1000 years – a new record – while the global sea level is now rising by 3.7 millimetres per annum. In short, the seas are getting warmer, higher, more acidic and more oxygen-depleted, and their water masses are no longer circulating around the globe by their normal routes and at the normal speed. At the same time, the frequency and intensity
of extreme events such as heatwaves and storms are increasing. Oxygen-depleted zones are now emerging in increasingly eutrophic coastal waters and, due to the more pronounced stratification of the water masses, in the open sea as well.
Marine organisms can barely cope with these additional stresses, which far exceed their physiological boundaries, often resulting in local mass mortality. Scientists are therefore observing fundamental changes in life in the ocean: mobile species such as cod, lobster, krill and many others are abandoning their traditional territories and migrating poleward or to greater depths; sedentary or less mobile species such as molluscs face death from heat exposure.
As a result of these two developments, biodiversity, especially in previously species-rich tropical waters, is declining dramatically, species composition in the middle latitudes is changing and the cold-adapted organisms which inhabit the polar seas are now rarely able to find suitable refuges.
- Key events such as algal blooms are occurring earlier in the year in response to the warmer temperatures, disrupting the sea’s biological calendar and adversely affecting vital predator-prey relationships. Biodiversity hotspots such as kelp forests, seagrass meadows, mangroves and tropical coral reefs are dying off. The general fitness and reproduction statistics for many species are declining, as is the body mass of individual animals. This shrinking of stocks and populations causes a drop in biomass production. The ocean thus produces less food and material for potential human use. Modelling shows that all these trends will continue unless humanity succeeds in drastically reducing its greenhouse gas emissions and curbing global warming.
Fisherfolk are clearly feeling the effects of climate change already. As a result of marine warming, ocean acidification and oxygen depletion, the productivity of many marine fish species decreased from 1930 to 2010 and in parallel, the global fishing potential shrank by 4.1 per cent over the same period. This is a substantial reduction if it is considered that marine fish and seafood are a staple part of the diet in many regions of the world and that according to official figures, around 179 million tonnes of fish are caught wild or raised in aquaculture facilities annually. Some of the worst-affected regions, such as the North Sea, the Sea of Japan and the Asian seas around the Pacific, have even recorded productivity decreases of 15 to 35 per cent. In other words, as a result of climate change, local fishing communities – assuming that they manage their stocks in accordance with FAO criteria – are catching around one third less fish than their predecessors 90 years ago.
However, this development does little to change the status quo in marine fishing. Oversized fishing fleets continue to chase declining fish stocks, while numerous countries still subsidize the depredation of the seas. In 2018 alone, the ten largest providers of subsidies granted more than USD 5.3 billion in financial support for the operation of their fishing fleets in foreign waters. It is difficult to quantify the resulting damage because half of the fish caught come from stocks that are not subject to any kind of scientific monitoring. According to FAO data, more than one third of the scientifically assessed stocks are now considered overfished. Other studies which also take illegal, unreported and uncontrolled fishing into account assume an even higher figure.
New technologies and information portals now make it easier to control industrial marine fishing. Local projects in the USA, Chile and the Philippines show that previously overfished fish and mollusc populations are often capable of recovering if sustainable, science-based management strategies are introduced or local cooperatives are granted exclusive fishing rights. By contrast, depletion of fish stocks due to overfishing mainly affects regions where there are no controls, and no regulation of industrial fishing.
Will it be possible for the world’s growing appetite for marine fish and seafood to be satiated primarily from marine aquaculture in future? Only time will tell. For decades, the construction and operation of aquaculture facilities have resulted in large-scale environmental degradation, and the vast demand for fishmeal has led to the overfishing of wild stocks. What’s more, the impacts of climate change are already taking their toll. For these reasons, intensive research is being conducted on strategies, feedstuffs and technologies that would support sustainable and resilient aquaculture. Integrated or ecosystem-based approaches with closed nutrient cycles currently offer the best prospects of success. Major growth potential is also currently predicted for the cultivation of macroalgae – at least in areas where marine warming, ocean acidification and oxygen depletion still allow this to take place.
- Macroalgae such as seagrass and kelp not only produce oxygen and sequester carbon; they also filter out nutrients from the water and thus help to clean the ocean. With eutrophication and marine pollution increasing, however, these natural filtration systems are overwhelmed. According to United Nations estimates, every year, around 400 million tonnes of pollutants are discharged into the sea. They include thousands of chemicals, nutrients, plastics and other synthetic materials, toxic heavy metals, pharmaceutical substances, cosmetic products, pathogens, radioactive substances and many more. The drivers include the increasing production and use of these substances, but also their incorrect disposal. Around 80 per cent of pollutants identified in the sea originate from land-based sources.
Evidence of this worsening persistent pollution can now be found in all regions of the world’s oceans. Wastes and substances toxic to the environment are not only a hazard to marine life; they also pose a threat to the health and livelihoods of anyone who relies on the ocean as a source of food or income. Particular damage is caused by toxic substances which are not readily degraded in nature and therefore bioaccumulate in food webs. These and other pollutants cause disease, deformities and behavioural changes in marine organisms, impair reproduction and can cause the death of affected individuals. Plastic pollution is particularly significant nowadays: experts have identified at least 700 animal species for which plastic in the ocean can be a deadly hazard. Like water and nutrients, microplastic particles now migrate in their own separate cycle through all the individual components of the Earth system.
Although various initiatives have been launched, the international community has not yet succeeded in curbing the input of pollutants into the seas, partly because the environmentally harmful effects of new chemicals are generally recognised far too late. Only the global ban on selected persistent organic pollutants (POPs) is having an effect – the concentrations of these pollutants in the sea are gradually declining. Long-term progress in tackling marine pollution will therefore only be achieved once there is a substantial reduction in fertilizer use, a large proportion of households and businesses around the world are connected to well-functioning sewage and solid-waste management systems, substances toxic to the environment and oil-based plastics are replaced by biodegradable alternatives, and the use of chemicals and plastics is limited to closed-loop systems.
In view of the crises facing the planet, a radical transformation of international merchant shipping is necessary as well. This ever-expanding branch of the economy accounts for around three per cent of global greenhouse gas emissions, while noise from ships, sewage, garbage and invasive species put pressure on coastal ecosystems around the world. Equipping the merchant fleet, comprising almost 100,000 vessels, with low-emission propulsion systems or replacing the fleet with new ships would be a mammoth, global-scale project in both technological and financial terms.
It would require very substantial investment in the development of new propulsion systems and alternative fuels, as well as legal and fiscal measures to provide investors with planning security, a supranational tax on greenhouse gas emissions and strict controls by the flag and port states to verify compliance with uniform regulations.
The International Maritime Organization (IMO) aims to reduce the merchant fleet’s carbon dioxide emissions by 2050 to half of the amount released in 2008. At the same time, coastal nations are facing the challenge of protecting their ports from the impacts of advancing climate change while minimizing greenhouse gas emissions from port operations. Some of the direct environmental impacts of shipping are already being addressed through international regulation; with others – noise pollution from shipping traffic, for example – there is still a great deal of catching up to do.
- The more the Earth warms, the more important the ocean becomes for humanity, for it is clear that the ocean has a vital role to play in achieving the greenhouse gas emissions reductions that are such an urgent necessity. The world’s oceans are needed for at least two transformation processes – as a direct source of energy, and likely also as a source of raw materials. Despite the expansion of renewable energies, the age of offshore oil and gas production is far from over. New marine deposits are still being developed, most of them at greater depths than before, and at greater distances from the coasts. More than a quarter of global fossil resource production now comes from the sea. Another option being considered at present is to make more use of exhausted subsea natural gas deposits as storage sites for liquefied carbon dioxide. The necessary technologies already exist and initial pilot projects are under way, with more currently at the planning stage.
At the same time, more offshore wind farms are being constructed worldwide, also at increasing distances from the coasts to take advantage of better wind conditions on the open sea. Due to technological advances, modern wind turbines are much larger and produce more power than earlier models. As a consequence, the prices of green offshore wind power are falling and demand is growing.
Due to the immense potential of offshore wind energy, it is one of the key technologies for sustainable energy production. Alternatives such as wave and current power plants, offshore photovoltaic arrays, and biofuel production from algae are all still in the developmental stage but play a significant role in long-term forward planning.
However, the expansion and large-scale use of renewable offshore energy will fail unless an adequate and appropriate infrastructure and storage systems are in place. Their manufacture requires vast amounts of raw materials, whose extraction on land destroys habitats for human communities and wildlife.
Resource extraction in the ocean, especially in the deep sea – where deposits contain a great variety of metals and minerals – is a conceivable alternative. The exploitation of these deposits is becoming increasingly likely, despite worldwide protests by environmentalists. The International Seabed Authority (ISA) has already issued 31 licences for the exploration of mineral resources on the sea floor. Initial extraction technologies have been tested on site and studies on environmental impacts and environmental monitoring have been conducted. The ISA is currently drafting a set of rules for deep-sea mining in international waters, which, according to experts, could commence within five to ten years.
Humanity’s growing claims on the sea are also the subject of negotiations on a new international agreement to regulate the conservation of marine biological diversity. One of the topics being discussed in this context is the question of who should benefit, and to what extent, from marine genetic resources, i.e. the blueprints encoded in the genome of marine organisms that determine the unique diversity of their forms and functions. Nowadays, scientists are successfully decoding this information ever more rapidly in order to extract the formulas for marine natural products or active ingredients. The range of their potential applications is substantial, as are the profits which, it is hoped, will be generated as a result.
Marine natural products and substances are already found in a wide variety of applications. They are active ingredients in 17 licensed pharmaceuticals and are used in food supplements and fertilizers. They provide raw materials for cosmetics manufacturing and various other industrial applications. It is likely that many more applications will be feasible and sustainable in future. However, the international community must agree collective rules on conservation and use which would guarantee that the benefits of marine biodiversity are shared as widely as possible rather than accruing to a few select individuals.
- f the pressure of human use increases while the three crises facing the ocean continue unabated, the collapse of marine ecosystems is surely only a matter of time. And yet the ocean’s biotic communities often show remarkable resilience. They are able to recover if humanity gives them enough time and space and drastically reduces all the various stress factors.
For nearly four decades, the United Nations Convention on the Law of the Sea (UNCLOS) has provided the overarching legal framework for governance of the ocean. It classifies the marine areas into zones and regulates in which zones coastal states may exercise sovereign jurisdiction and in which areas international rules apply. It also requires the international community to protect and preserve the marine environment and establishes mechanisms for conflict resolution.
Detailed provisions on the sustainable use of the ocean are absent from the Convention. Instead, this topic is regulated in numerous national, transregional and international conventions or agreements, which generally focus on a single issue or economic sector and do not take interacting factors into account.
The same tunnel vision also afflicts many marine management organizations. A lack of cooperation and coordination across sectors causes conflicts of interest and lessens the prospects that any action taken will be successful. Furthermore, poorer coastal states in particular often lack the expertise, financial resources and the necessary technologies and structures to implement international rules in their national waters.
The lack of transparency in decision-making on marine policy and the failure to provide for the – crucial – involvement of local communities have been identified as other drivers of the crises facing the seas.
If the current crises affecting the ocean have taught us anything, it is this: they cannot be viewed in isolation from what is happening on land, in the atmosphere and within society. Ocean recovery will therefore only succeed if humanity makes change happen on multiple fronts. Sustainable marine management faces a mammoth task: it must overcome multiple challenges simultaneously. For example, it must:
In short, humanity must decide collectively how it wishes to strengthen the marine environment and make sustainable use of its many spaces and resources.
- be designed, funded and implemented on a trans-zonal, trans-sectoral and, where appropriate, transboundary basis;
- genuinely involve all stakeholders – including affected local communities, above all – in decision-making from the outset;
- be transparent, socially just and open to innovative niche solutions;
- aim to strengthen marine ecosystems and, as far as possible, restore degraded marine and coastal habitats;
- apply measures that offer the greatest benefits for climate change mitigation, biodiversity conservation and local communities;
- abolish environmentally harmful subsidies and invest the funds in projects that focus on sustainability;
- ensure that as far as possible, all decisions are science-based, and that evaluation measures are planned to ensure regular monitoring of progress.
Expert opinions differ on the scope of the structural changes required to initiate this process and achieve all the goals. While some experts believe that a radical transformation of our economic and value systems is necessary in order to halt global climate change, species extinction and the pollution crisis, others argue that the existing rules and regulations pertaining to the marine environment should first be implemented consistently. Only then, they say, will it be possible to assess whether more far-reaching changes are necessary in ocean governance.
- Whichever path is chosen by those responsible, progressing ocean recovery can only succeed through collective action. A further prerequisite is recognition of the acute problems facing the ocean, along with an understanding of how the effects of the many anthropogenic stress factors are amplified through their interaction and which potential solutions are available. Just like ten years ago, when we published the first World Ocean Review, we hope that this new edition will “make at least a small contribution towards steering a sustainable course”.