ålegrasenger

Ålegrasenger (eelgrass meadows) are underwater coastal habitats formed by seagrasses, especially eelgrass (Zostera marina), with additional species in some regions. These dense meadows occur in shallow, sheltered coastal waters where light can penetrate to the seabed, often in bays, estuaries and tidal zones. They grow in soft substrates such as fine sand and mud and can create extensive beds or patchy meadows depending on local conditions.

Eelgrass meadows are ecologically important. They stabilize sediments and reduce erosion by dampening wave energy, while also improving water quality by trapping sediments and filtering nutrients. The below-ground roots and rhizomes store carbon, contributing to blue carbon ecosystems. Above ground, meadows provide habitat, food and nursery areas for a diversity of species, including fish, crustaceans and invertebrates, and they support overall coastal biodiversity.

Geographically, ålegrasenger are found in temperate coastal regions of the Northern Hemisphere, including parts of Europe, North America and the North Atlantic. They are sensitive to water clarity and light levels, making them indicators of coastal ecosystem health.

Threats to eelgrass meadows include eutrophication, pollution, coastal development, dredging and bottom trawling, physical damage from boating and anchors, and climate-related changes such as warming waters and altered sediment regimes. In some regions, rapid declines have been observed, reducing ecosystem services and biodiversity.

Conservation and restoration efforts focus on protecting water quality, minimizing physical disturbance, and restoring meadows through transplantation or seed-based methods where light and habitat conditions are suitable. Monitoring and mapping help track recovery and guide coastal management.