8 Ocean Resources and Sustainability

Why ocean resources matter

Ocean resources provide food, materials, energy, transportation routes, and habitats that support human societies and marine life. Sustainable use means meeting human needs while maintaining healthy ocean ecosystems and preserving options for future generations.

Living and nonliving resources

Ocean resources include Living resources and Nonliving resources. Living resources are organisms or populations that people use or value, including fish, shellfish, seaweeds, and other marine organisms. They also include the habitats and ecological relationships that sustain them. They can replenish themselves, but only if harvest and other pressures do not outpace reproduction and recovery.

Nonliving resources include seabed minerals, sand and gravel, oil and natural gas, and energy from waves, tides, currents, and differences in ocean temperature. Some are finite: extracting a mineral or burning a fossil fuel depletes the resource. Renewable ocean energy is replenished by natural processes, although developing it can still affect habitats and wildlife.

Fisheries and seafood

A Fishery is an activity, industry, or area associated with catching fish and other seafood. Fisheries provide food, jobs, and income, but excessive harvest can reduce populations and disrupt food webs. Fishing can also affect ecosystems through Bycatch—the unintended capture of other species—and through habitat damage or lost fishing gear.

Sustainable fishery management uses monitoring and stock assessments to estimate population condition and set harvest limits. Other tools include seasonal or area closures, size limits, gear rules that reduce bycatch, and plans to rebuild depleted populations. Effective management also considers habitat, predators and prey, climate conditions, and the needs of fishing communities rather than focusing only on the target species.

FAO’s 2025 global assessment found that 64.5% of assessed marine fish stocks were fished within biologically sustainable levels. This illustrates both the value of management and the continuing challenge of overfishing.

Aquaculture—raising aquatic organisms in farms—can supplement wild fisheries. Its sustainability depends on factors such as feed, disease control, waste, escape of farmed organisms, and effects on nearby habitats.

Energy from the ocean

Ocean energy technologies can capture energy from waves, tides, and currents, or use temperature differences between warm surface water and colder deep water. These resources are renewable, and tides and some currents are predictable. Many marine-energy technologies are still developing, so projects must be designed and sited with attention to navigation, marine habitats, and wildlife.

The ocean also supplies oil and natural gas from offshore deposits. These fuels provide energy but are nonrenewable. Their extraction, transport, and spills can harm marine environments, and their use releases greenhouse gases that contribute to climate change.

Mineral resources and seabed impacts

Marine minerals include sand and gravel used in construction, mineral-bearing sands, phosphorites, and deposits on the deep seafloor. Deep-sea deposits include polymetallic nodules on abyssal plains, cobalt-rich crusts on seamounts, and polymetallic sulfides associated with hydrothermal vents. They can contain metals such as manganese, nickel, copper, cobalt, and zinc.

Finding and extracting these materials can disturb seafloor habitats, create sediment plumes, and affect organisms that are poorly understood or slow to recover. Potential impacts and ecosystem recovery remain uncertain. Assessing environmental effects and applying precaution are therefore important parts of decisions about seabed mining.

Pollution and resource health

Much marine pollution originates on land and reaches the sea through runoff, rivers, and wastewater. Fertilizers can add excess nitrogen and phosphorus, fueling algal growth. When algae die and decompose, oxygen in the water may be depleted, creating conditions that harm or kill marine animals.

Plastic debris, including lost fishing gear, can persist in the marine environment and fragment into smaller pieces. It can also entangle or injure wildlife. Other pressures include oil and chemical pollution, sewage, and sediment runoff.

Preventing pollution at its source—through better waste handling, wastewater treatment, and careful use of fertilizers and chemicals—is generally more effective than trying to remove pollutants after they disperse.

Principles for sustainable management

Sustainable ocean management balances ecological health with social and economic needs. It uses the best available science by monitoring resources and ecosystems, assessing risks, and revising decisions as evidence improves. A precautionary approach is important when serious harm is possible but knowledge is incomplete: a lack of evidence does not establish that an activity is safe.

Management should treat ocean ecosystems as connected systems, considering habitats, food webs, climate, pollution, and human communities alongside individual resources. It can set limits and reduce harm through measures such as harvest limits, protected areas, pollution controls, and lower-impact technologies where appropriate.

Affected communities—including fishers, Indigenous peoples, and local residents—should be involved alongside scientists and other stakeholders. Management also requires tracking outcomes, enforcing rules, and changing decisions when conditions or evidence change. Reusing and recycling materials where possible, and preventing waste and pollution at their sources, can reduce demand for extraction.

Ecosystem-based management explicitly accounts for ecological, physical, economic, and social interactions. For example, a fishery plan that sets catch limits but ignores spawning habitat may fail to protect the population. Combining catch limits with habitat protection, bycatch reduction, monitoring, and community participation offers a more complete approach.