Developing abiotic resources from the ocean

The ocean holds a wealth of abiotic resources, including minerals and sediments found on the continental shelf and deep seabed. These resources, formed through natural processes like erosion and river transport, are increasingly seen as valuable due to rising commodity prices and advancements in technology.

Key abiotic resources in ocean environments

• Sediments on the continental shelf - Include materials like sand, gravel, and mud, which originate from eroded rocks carried by rivers to the sea.
• Precious minerals - Diamonds are located on the continental shelf near regions like Africa and Indonesia, while gold and manganese are found on the ocean floor.
• Economic incentives - Since the 1970s, higher industrial commodity prices have made mining these resources potentially profitable, leading to exploration licences being granted by the International Seabed Authority for deep-ocean seabed mining.
• Technological advancements - Improved mining technology, adapted from the offshore oil industry, has made deep-sea mining more feasible. For instance, a Canadian firm is exploring copper and gold extraction from the seabed near Papua New Guinea.

Challenges and impacts of extracting oil and hydrates

Beyond minerals, the ocean is a significant source of energy resources such as oil, gas, and methane hydrates. However, extracting these resources poses environmental and technical challenges that can impact marine ecosystems and coastal regions.

Oil and gas extraction

• Key locations - Vast oil and gas deposits lie beneath the continental shelf, with the Persian Gulf holding 66% of the world's proven oil reserves and 33% of gas reserves. The Gulf of Mexico has been a hub for exploration since the 1940s.
• Environmental risks - Oil spills frequently pollute coastal areas, damaging ecosystems. Acoustic prospecting for hydrocarbons can disturb marine mammals, while toxic effects from over 500 oil platforms in the North Sea harm deep-sea (benthic) communities.

Methane hydrates as an energy source

• Nature of hydrates - These are compounds of methane trapped in water molecules, found on continental shelf slopes deep below the ocean surface.
• Potential and debate - Some scientists estimate that hydrates hold more energy than all known fossil fuel deposits combined, making them appealing to energy-scarce nations like Japan and India. Others argue that the energy required to extract them may exceed the energy gained.

Trends in biotic resource use in global fisheries

The use of biotic resources, particularly fish, has seen significant changes over recent decades. Fisheries and aquaculture play a vital role in global food supply, with production trends reflecting both growth and challenges in sustainability.

Growth in fish production

• Capture fisheries - Traditional fishing (capture production) increased from the 1950s but has levelled off since the mid-1990s due to overfishing and stock depletion.
• Aquaculture expansion - Fish farming (aquaculture production) has shown rapid growth since the 1970s, contributing significantly to the total fish supply.
• Total output - By 2012, combined fisheries and aquaculture produced nearly 158 million tonnes of fish, with a market value exceeding £170 billion.

The state of world marine fish stocks and consumption patterns

The health of marine fish stocks is a critical concern, as overfishing threatens sustainability. Consumption patterns also vary widely across regions, reflecting cultural and economic differences.

Status of marine fish stocks since 1974

• Overfished stocks - The proportion of stocks classified as overfished (biologically unsustainable) has risen from around 12% in 1974 to approximately 32% by 2013.
• Fully fished stocks - Stocks at maximum sustainable levels (fully fished) have increased from about 48% to 58% over the same period.
• Underfished stocks - Stocks with potential for increased fishing (underfished) have declined sharply from roughly 40% to just 10%.

Global fish consumption patterns

• Regional variations - Fish consumption is lowest in Africa, while Asia accounts for two-thirds of the global total, consuming 87.2 million tonnes in 2012, with 43.5 million tonnes outside China.
• Protein contribution - Globally, fish provides nearly 20% of animal protein intake for about 3.1 billion people, underlining its importance in diets worldwide.

Strategies for sustainable ocean resource management

Balancing the exploitation of ocean resources with environmental protection is crucial for future sustainability. Both abiotic and biotic resource use require careful management to mitigate negative impacts and ensure long-term viability.

Managing abiotic resource extraction

• Regulation of mining - International bodies like the International Seabed Authority oversee deep-sea mining to prevent environmental damage, setting guidelines for exploration and extraction.

Sustainable fishery practices

• Implementing quotas and bans - Setting limits on fish catches and enforcing fishing bans in overexploited areas can help stocks recover.
• Closing fishing zones - Temporarily shutting down certain marine areas to fishing protects breeding grounds and allows fish populations to replenish.
• Reducing fleet size - Cutting the number of fishing boats and workers helps alleviate pressure on fish stocks, addressing the issue of too many fishermen targeting limited resources.
• Preventing immature catches - Regulations to avoid catching juvenile fish ensure populations can mature and reproduce, sustaining future yields.
• Embracing technology - Adopting efficient fishing technologies can reduce waste and bycatch, improving the overall sustainability of the industry.