Salt marshes at higher latitudes, including those in densely populated coastal regions of New England and Europe, are more vulnerable to the effects of eutrophication, which, if left unchecked, can trigger intense overgrazing by marsh herbivores that can destabilize marshes and reduce their ability to defend shorelines from erosion. The heavy flow of nitrogen and phosphorus into these marshes from upstream cities and farms can trigger a chain reaction that can lead to intense overgrazing by marsh herbivores. As nutrient-laden runoff from cities and farms flows into temperate salt marshes, it causes eutrophication increased plant growth and reduced oxygen levels in the water which kills many species of fish and other aquatic animals. As marsh populations of fish and other carnivores drop, populations of snails, crabs, insects and other herbivores or omnivores grow. These animals begin overgrazing the marsh grasses. As the grasses die off, the marsh becomes destabilized and, over time, may no longer be able to function as it once did.

• Share this page
• 
• 
• 
• 
• 
•