Sea rewilding (also known as marine rewilding) is an area of

environmental conservation *Environmental protection Environmental protection is the practice of protecting the natural environment by individuals, organizations and governments. Its objectives are to conserve natural resources and the existing natural environment and, ...

activity which focuses on

rewilding Rewilding may refer to: *Rewilding (conservation biology), the return of habitats to a natural state ** Rewilding Europe, a programme to do so in Europe *** Pleistocene rewilding, a form of species reintroduction ** Rewilding Institute, an organi ...

, restoring ocean life and returning seas to a more natural state. Sea rewilding projects operate around the world, working to repopulate a wide range of organisms, including giant clams, sharks, skates, sea sturgeons, and many other species. Rewilding marine and

coastal ecosystems A marine coastal ecosystem is a marine ecosystem which occurs where the land meets the ocean. Marine coastal ecosystems include many different types of marine habitats, such as estuaries and lagoons, salt marshes and mangrove forests, seagrass ...

offer potential ways to

mitigate Mitigation is the reduction of something harmful or the reduction of its harmful effects. It may refer to measures taken to reduce the harmful effects of hazards that remain ''in potentia'', or to manage harmful incidents that have already occur ...

climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to ...

and

sequester carbon Carbon sequestration is the process of storing carbon in a carbon pool. It plays a crucial role in limiting climate change by reducing the amount of carbon dioxide in the atmosphere. There are two main types of carbon sequestration: biologic ( ...

. Sea rewilding projects are currently less common than those focusing on rewilding land, and seas are under increasing stress from the

blue economy Blue economy is a term in economics relating to the exploitation, preservation and regeneration of the marine environment. Its scope of interpretation varies among organizations. However, the term is generally used in the scope of internationa ...

– commercial activities which further stress the marine environment.

Seagrass

Seagrass meadows A seagrass meadow or seagrass bed is an underwater ecosystem formed by seagrasses. Seagrasses are marine (saltwater) plants found in shallow coastal waters and in the brackish waters of estuaries. Seagrasses are flowering plants with stems and ...

store

carbon dioxide Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is t ...

. More than 90% of the United Kingdom's historic seagrass meadows have been lost. Restoring meadows could offset carbon emissions and provide habitat for numerous fish and shellfish species. Research into seagrass, which covers about one percent of the sea floor suggests that it may be delivering 15–18% of carbon storage in the ocean. Meadows have been declining since the 1930s and are being lost at an alarming rate. Due to their scarcity they have been designated a UK habitat of principal importance. In the United States, a project at

Chesapeake Bay The Chesapeake Bay ( ) is the largest estuary in the United States. The Bay is located in the Mid-Atlantic (United States), Mid-Atlantic region and is primarily separated from the Atlantic Ocean by the Delmarva Peninsula (including the parts: the ...

is considered a success.

Native oysters

Oysters Oyster is the common name for a number of different families of salt-water bivalve molluscs that live in marine or brackish habitats. In some species, the valves are highly calcified, and many are somewhat irregular in shape. Many, but not al ...

filter water, recycle nutrients and help to protect against

coastal erosion Coastal erosion is the loss or displacement of land, or the long-term removal of sediment and rocks along the coastline due to the action of waves, currents, tides, wind-driven water, waterborne ice, or other impacts of storms. The landwa ...

. Oyster stocks have declined by 95 per cent in Europe due to over-harvesting, habitat loss,

pollution Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the ...

and disease. In

Rhode Island Rhode Island (, like ''road'') is a state in the New England region of the Northeastern United States. It is the smallest U.S. state by area and the seventh-least populous, with slightly fewer than 1.1 million residents as of 2020, but i ...

, US, "wild oyster populations are at an all-time low", according to Eric Schneider, the principal marine biologist with the Rhode Island Department of Environmental Management's Division of Marine Fisheries. He also states: "oysters provide a number of essential

ecosystem services Ecosystem services are the many and varied benefits to humans provided by the natural environment and healthy ecosystems. Such ecosystems include, for example, agroecosystems, forest ecosystem, grassland ecosystems, and aquatic ecosystems ...

, from

water filtration A water filter removes impurities by lowering contamination of water using a fine physical barrier, a chemical process, or a biological process. Filters cleanse water to different extents, for purposes such as: providing agricultural irrigation ...

to fish habitat and shoreline protection. By having oyster reef habitat absent from these systems, those services can be significantly depressed." It has been demonstrated that restoring historic oyster beds improves water quality.

Kelp forests

Kelp forest at Taranga pinnacles Hen and Chicken Islands PA232359

Kelp forest Kelp forests are underwater areas with a high density of kelp, which covers a large part of the world's coastlines. Smaller areas of anchored kelp are called kelp beds. They are recognized as one of the most productive and dynamic ecosystems on E ...

s are important habitats which have been lost over time in coastal waters. Kelp forests provide habitat for fish, protect coastlines from erosion and trap carbon dioxide from the ocean. They grow fast and absorb large amounts of carbon. Restoring kelp forests is a strategy to

address climate change Climate change mitigation is action to limit climate change by reducing emissions of greenhouse gases or removing those gases from the atmosphere. The recent rise in global average temperature is mostly caused by emissions from fossil fuels bu ...

and enrich ocean livestock.

Marine protected areas

Marine protected area Marine protected areas (MPA) are protected areas of seas, oceans, estuaries or in the US, the Great Lakes. These marine areas can come in many forms ranging from wildlife refuges to research facilities. MPAs restrict human activity for a conser ...

s are areas protected from certain activity. They are used to preserve and conserve areas where marine life has been disrupted or disturbed. Such disturbances could be

overfishing Overfishing is the removal of a species of fish (i.e. fishing) from a body of water at a rate greater than that the species can replenish its population naturally (i.e. the overexploitation of the fishery's existing fish stock), resulting in the ...

ocean pollution Marine pollution occurs when substances used or spread by humans, such as industrial, agricultural and residential waste, particles, noise, excess carbon dioxide or invasive organisms enter the ocean and cause harmful effects there. The major ...

, and other similar disturbances. In

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the eas ...

, environmental groups such as Rewilding Chile are campaigning to create new protected areas.

Carbon capture

Rewilding the sea has been described as "the new way to capture carbon".

Organisations

*Seawilding, a Scottish charity work with communities *

NatureScot NatureScot ( gd, NàdarAlba), which was formerly known as Scottish Natural Heritage, is an executive non-departmental public body of the Scottish Government responsible for the country's natural heritage, especially its natural, genetic and ...

Rewilding Britain Rewilding Britain is an organisation founded in 2015 that aims to promote the rewilding of Great Britain. It is a registered charity in England and Wales, and also in Scotland. History One of the people involved in setting up the charity was Gua ...