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How shellfish can help improve water quality
Citation:
Canfield, Katherine, S. Osinski, S. Ayvazian, K. Mulvaney, AND D. Cobb. How shellfish can help improve water quality. U.S. EPA Office of Research and Development, Washington, DC, 2021.
Impact/Purpose:
This infographic aims to build public awareness of the water quality benefits of eating shellfish, specifically among shellfish consumers. Nutrients are essential components of functioning ecosystems and human bodies and are only a problem when in excess. Excess nitrogen is the primary nutrient of concern for many coastal waterbodies. Oysters and other shellfish remove nitrogen from the marine environment in two ways and thus can be one tool in nutrient management. This graphic seeks to explain these complex processes and their value in cleaning up our waterways.
Description:
This is an infographic to explain the process of shellfish denitrification and the potential water quality benefits of shellfish aquaculture. Nutrients are essential components of functioning ecosystems and human bodies. Nutrients, like nitrogen and phosphorus, are only a problem when in excess. Excess nitrogen is the primary nutrient of concern for many coastal waterbodies. When there is more nitrogen in the environment than nutrient cycles can handle, consequences can include decreasing presence of marine plants, algal blooms that create reduced oxygen levels which can cause fish kills, and closure of waterways for recreational use and aquaculture farming. Oysters and other shellfish remove nitrogen from the marine environment in two ways, and thus can be one tool in nutrient management. Bioextraction¿is the removal of nitrogen via harvesting of bivalves in aquaculture and wild harvest.¿ Denitrification is the process of removing nitrogen in the form of nitrate from the environment, converting it into nitrogen gas that is permanently¿released into the air.¿Nitrate is a reactive form of nitrogen that is often associated with algal blooms. Nitrogen is broken down by bacteria on the sea bottom where the waste products fall and in the guts and on the shells of the shellfish. These bacteria change the forms of nitrogen to eventually release nitrogen as gas out of the water. Denitrification is a valuable process for cleaning up our waterways because it is the only nitrogen removal method that permanently removes nitrogen from the water column without removing shellfish from the water.