Drivers of Decline

Drivers of Decline


The Global Ocean Commission identified five interconnected drivers of ocean decline:

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Rising Demand for Resources

Minerals and Energy
Global oil consumption has doubled since the late 1960s, and natural gas consumption has more than tripled. Demand for copper has quadrupled since 1960, while rare earth elements – hardly used before 1950 – are in increasing demand for ‘clean’ technologies. As resources on land dwindle, businesses turn to the ocean.

Genetic Materials
Marine genetic resources show great promise for application in pharmaceuticals and biotechnology. There is breakthrough activity in the fight against HIV, cancer, tuberculosis and malaria.

Living Marine Resources
The global fish catch has quadrupled since the 1950s and contributes roughly 16% of the animal protein consumed globally. Deep-sea species such as corals and sponges are being studied for use in medicines for cancer, arthritis and other conditions. Around 18,000 products are already made from marine organisms.


© Nigel Marple / Greenpeace

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Technological Advances

Deep-sea access and exploitation
One-third of oil is extracted from under the seabed, and deep-sea rigs produce 5% of total hydrocarbons, with some wells deeper than 3km. Deep-sea mineral mining is now technically feasible. Bottom trawl fishing extends below 2,200m across all oceans. The next logical steps for the fossil fuel industry are expansion into the Arctic as summer sea ice disappears, as well as exploitation of methane hydrates. The cost of sequencing a genome fell from above US$10 million to below US$10,000 in a decade.

Vessels (distance and depth)
Since the 1950s, increasingly powerful engines, bigger equipment and refrigeration have allowed vessels to travel progressively further and catch greater quantities of fish. Engine power facilitates the use of bigger trawls and longer lines; bottom trawling would be impossible with less power.

Increased (over-)extraction
The sophistication of equipment has increased the industry’s efficiency. Longlines up to 60km in length are now deployed in the high seas. Fish are detected and corralled using sonar and fish aggregation devices (FADs).


© Nautilus Minerals

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Decline of Fish Stocks

FAO estimates that about two-thirds of fish stocks are exploited to their maximum sustainable limit, and one-third beyond that limit. Two-thirds of high seas stocks are overexploited and/or depleted. Many stocks of the largest fish (such as tuna and swordfish) are below 10% of their historical level. The World Bank calculates that mismanagement of fisheries costs the world economy about US$50 billion per year.

The global catch increased from 18 million tonnes in 1950 to nearly 94 million tonnes in 1994. The global fleet’s overall engine power grew 10-fold over the period. The catch is now falling due to declining stocks, but capacity continues to rise; ships use twice as much energy to catch a tonne of fish as 60 years ago. Too many vessels are competing for increasingly exploited stocks, increasing the imperative to fish illegally.

Despite overfishing and overcapacity, countries grant at least US$30 billion a year in fishing subsidies, 60% of which directly encourages unsustainable practices. Fuel subsidies are the biggest component. Developed countries give 70% of fishing subsidies, with Japan, China, the EU, the United States and Russia the highest spenders.

Illegal unreported unregulated (IUU) Fishing
Illegal, unregulated and unreported fishing accounts for up to 35% of the global wild marine catch and causes annual losses of up to US$23.5 billion. One-half of the value of the illegal catch comes from the high seas. IUU fishing is linked to other international crimes such as drug and people smuggling.


© Alex Hofford / Greenpeace

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Climate Change, Biodiversity and Habitat Loss

Climate change and acidification
The ocean absorbs more than 90% of the energy trapped in the Earth system by greenhouse gas emissions and absorbs one-quarter of our carbon dioxide emissions. This has created a ‘deadly trio’ of impacts on the ocean – acidification, warming and deoxygenation. Today’s level of acidification is unparalleled in the last 300 million years. Biological impacts include displacement of organisms away from breeding and feeding grounds, reduced formation of shells and a reduction in the living space for large fish.

Destructive fishing
Bottom trawling drags nets and steel plates weighing many tonnes across the ocean floor, crushing features such as reefs. Target species are generally slow-growing and vulnerable to over-exploitation. Every year 15 million km2 of the sea floor is bottom-trawled. Other destructive practices include shark finning, the banned but still practised deployment of driftnets, as well as gear that catches unwanted species.

Over 80% of marine pollution comes from land-based activities, including fertilisers, pesticides, sewage, garbage, plastics and oil. Disposal at sea of the most toxic materials was banned by the 1972 London Convention, with more restrictions added in 1996. However, the toxins already present, combined with the unregulated dumping of ‘emerging chemicals’ and ubiquitous plastic pollution, remain a major challenge.


© Corey Arnold

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Weak High Seas Governance

Patchwork/sectoral governance
The existing high seas governance framework is weak, fragmented and poorly implemented. It is sectoral, with different bodies regulating different industries, and not based on modern ecosystem understanding. Regional fisheries management organisations (RFMOs) are legally charged with managing high-seas fisheries, but concentrate on a few commercial stocks. Their effectiveness varies widely; reviews have found flaws with all. No organisation has overall responsibility for conserving high seas biodiversity, and in most of the high seas there is no legal mechanism for establishing marine protected areas.

Compliance and enforcement
For fishing, there is little capacity for enforcement of regulations or sanctions for non-compliance. RFMO rules apply only to member States. Authorities have limited power to intercept vessels suspected of illegal activity. Fishing vessels are exempt from the requirement to carry an International Maritime Organization (IMO) number and use tracking equipment, which is mandatory on passenger and large merchant ships.

New and emerging issues
There is no governance framework for industries such as energy production and geoengineering that may emerge in the high seas. There is no equity framework for exploitation of genetic resources.


© United Nations

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