Humans have developed a surprisingly wide range of strategies that actively help the ocean recover from damage and build resilience against future threats. From designating vast stretches of sea as off-limits to fishing, to growing seaweed that counteracts acidification, these efforts are producing measurable results. Here’s how people are making a real difference.
Marine Protected Areas
The most straightforward way humans help the ocean is by drawing a line around vulnerable ecosystems and limiting what can happen there. Marine protected areas (MPAs) restrict activities like commercial fishing, drilling, and dredging within their boundaries, giving marine life space to recover. About 9.6% of the global ocean is currently covered by MPAs, and the international community has set an ambitious target through the UN Convention on Biological Diversity: protecting 30% of the ocean by 2030.
The 2023 High Seas Treaty, which entered into force in early 2025, gives this goal real legal teeth. For the first time, it creates a framework for establishing protected areas in international waters, the vast stretches of ocean that belong to no single country. The treaty also addresses how the genetic resources found in deep-sea organisms should be shared fairly, preventing wealthy nations from monopolizing discoveries. Inside well-managed MPAs, fish populations grow larger, coral cover increases, and biodiversity rebounds. The quality of protection matters enormously, though. A protected area that still allows industrial trawling does far less good than one with strict enforcement.
Coral Reef Restoration
Coral reefs support roughly a quarter of all marine species despite covering less than 1% of the ocean floor. When reefs degrade from warming, pollution, or storms, scientists now have techniques to help them recover faster than they would on their own.
One approach is coral gardening: fragments of healthy coral are grown in underwater nurseries and then transplanted onto damaged reefs. A newer and potentially more scalable method is larval seeding, where researchers collect coral spawn during mass spawning events, rear the larvae in controlled conditions, and then settle them onto reef surfaces. Recent work on improving larval settlement has achieved success rates between 47% and 51% on specially conditioned ceramic surfaces designed to mimic the texture of natural reef. Without those conditioned surfaces, settlement drops to under 1%, which highlights how much the technique depends on getting the details right.
Researchers are also experimenting with chemical cues that naturally trigger coral larvae to attach and begin growing. Compounds extracted from crustose coralline algae, the pink crusty layer found on healthy reefs, can push settlement rates above 70% in lab conditions. These methods are still being refined for large-scale use, and long-term survival after settlement depends on factors like water quality, wave action, and the presence of grazing fish that keep algae from smothering young corals. But the trajectory is encouraging: reef restoration has moved from small pilot projects to programs operating across entire reef systems in Australia, the Caribbean, and Southeast Asia.
Seaweed Farms That Buffer Acidification
As the ocean absorbs carbon dioxide from the atmosphere, seawater becomes more acidic, making it harder for shellfish, corals, and plankton to build their calcium-based shells and skeletons. Seaweed farms offer a surprisingly effective local remedy. Because seaweed absorbs CO2 during photosynthesis, large-scale farms measurably raise the pH of surrounding water, creating pockets of relief for nearby marine life.
Field monitoring of commercial seaweed farms has shown that kelp species can raise the pH within the farm area by 0.10 units, a meaningful shift in ocean chemistry terms. Other farmed seaweeds raised pH by 0.03 to 0.04 units. CO2 levels in the water inside seaweed farms were on average about 59 microatmospheres lower than in surrounding waters, with some farms pulling CO2 down by more than 113 microatmospheres. The pH fluctuations inside farms ranged from 0.14 to 0.30 units during monitoring periods, and some researchers suggest this variability could even help nearby organisms build tolerance to the more acidic conditions expected in the future. Seaweed farming is already a massive industry in East Asia, which means this buffering effect is happening at scale without requiring any additional infrastructure.
Mangrove Restoration and Carbon Storage
Mangrove forests are among the most powerful carbon sinks on the planet, storing carbon in their trunks, roots, and the thick organic soils beneath them at rates far exceeding most terrestrial forests per unit area. Replanting mangroves along degraded coastlines delivers a triple benefit: carbon sequestration, storm protection for coastal communities, and nursery habitat for commercially important fish and shrimp species.
A ten-year study of restored mangrove stands on Flores Island in Indonesia found that replanted sites sequestered between 29 and 70 metric tons of CO2 per hectare. That wide range reflects differences in species, planting density, and local conditions, but even the lower end represents significant carbon capture. The restored sites also saw the return of diverse animal communities, reinforcing the idea that replanting mangroves rebuilds entire ecosystems rather than just storing carbon.
Fishing Gear That Saves Marine Life
Commercial fishing inevitably catches animals it wasn’t targeting. Sea turtles, sharks, dolphins, and seabirds all get tangled in nets and hooked on longlines. But gear modifications developed over the past few decades have dramatically reduced this bycatch.
The clearest success story is the turtle excluder device (TED), a grid fitted inside shrimp trawl nets that directs turtles toward an escape opening while allowing shrimp to pass through. NOAA and the shrimp industry developed TEDs in the 1980s and 1990s, and making them mandatory in U.S. shrimp fisheries has resulted in close to 100% reduction in turtle deaths from shrimp nets. Similar innovations exist for other species: circle hooks on longlines reduce sea turtle hookings, acoustic pingers on gillnets warn dolphins and porpoises away, and weighted lines on lobster pots prevent whale entanglement. None of these devices eliminate bycatch entirely, but they represent a fundamental shift in how the fishing industry operates, from ignoring collateral damage to engineering it out of the process.
Offshore Wind Farms as Accidental Reefs
Offshore wind turbines are built for energy, but their underwater foundations create hard surfaces in areas that are often flat, featureless sand. Marine organisms colonize these structures rapidly, turning them into artificial reefs that attract fish and invertebrates. Research has confirmed that wind farm foundations draw significantly more fish to the area, with the effect varying depending on design. Monopile foundations surrounded by rock protection on the seabed attracted the most fish, while other designs like jacket foundations or those with sandbag protection drew fewer.
The reef effect is real but spatially limited, concentrated close to the structures rather than spreading across the entire wind farm footprint. Still, with thousands of offshore turbines planned worldwide, the cumulative habitat creation is substantial. This makes offshore wind one of the rare cases where climate change mitigation and local biodiversity conservation happen simultaneously, though getting the most out of this dual benefit requires thinking about foundation design and placement from the start.
Plastic Removal and Pollution Prevention
Large-scale cleanup operations are now pulling plastic from the ocean at an industrial pace. Organizations like The Ocean Cleanup have deployed collection systems in the Great Pacific Garbage Patch and in rivers that carry plastic to the sea, intercepting waste before it fragments into harder-to-capture microplastics. Coastal cleanup campaigns organized by nonprofits and local governments remove millions of pounds of debris from shorelines each year.
Prevention efforts are equally important. Bans on single-use plastics, improved wastewater treatment, and better waste management in coastal developing nations all reduce the flow of pollution at its source. Biodegradable fishing gear is being tested to address “ghost fishing,” where lost nets continue trapping and killing marine life for years. The combination of removing what’s already there and stopping new pollution from entering the water is gradually shifting the balance, though the sheer volume of plastic already in the ocean means this will remain a decades-long effort.