Preserving and restoring riparian forests, wetlands, mangroves, and open areas can mitigate nutrient pollution by creating and maintaining natural nutrient sinks. These policies can take many forms, including:
Protected areas. Establishing protected areas through legal measures can serve to protect and preserve critical ecosystems. In 1998, 6,264 km2 of the Danube Delta (Romania and Ukraine) were protected as part of the UNESCO Man and Biosphere program. The Danube Delta lies on the coast of the Black Sea and is Europe’s largest wetland and reed bed. It is a critical ecosystem for capturing and cycling nutrients (UNESCO 2007).
Land purchases and establishment of conservation easements. Public and private purchases of ecologically valuable land as well as establishment of conservation easements (i.e., the purchase of development rights) can help reduce nutrient pollution by protecting ecosystems that capture and cycle nutrients.
Fig 2. Lamesley Wetlands is an experimental sewage treatment system in Northumbria, UK. Here, reed beds are simultaneously efficient in treating phosphate rich wastewater effluents and water from mine workings. The experimental system is efficient, inexpensive and provides habitat for a number of species.
Image Credit: Chrish Heaton | Geograph.org.uk
For example, the Worcester Land Protection Partnership is a partnership between the city of Worcester (Massachusetts, U.S.) and the Trust for Public Land, a nonprofit land conservation organization, aimed at identifying and acquiring priority watershed land for the purpose of improving and maintaining water quality within the rivers and reservoirs (Trust for Public Land 2008).
Habitat restoration. Often the aquatic ecosystems most severely impacted by eutrophication are the ones that have been already degraded due to other causes (Mee 2006). Human pressures on fish stocks, shoreline erosion, and loss of submerged aquatic vegetation make ecosystems more vulnerable to the impacts of eutrophication. In the United States, Maryland and Virginia have both funded restoration efforts aimed at restoring submerged aquatic vegetation and replenishing oyster beds in the Chesapeake Bay.