Environmental Benefits of Shellfish

• Oysters are keystone species because they have a disproportionately large impact on the natural environment and other species in an ecosystem. Oysters are also ecosystem engineers because they significantly modify and create new habitat for other species by forming reefs. A conservative economic evaluation estimated oyster reef benefits at $5,500-$99,000/hectare/year, excluding the value of oyster harvesting.
• Shellfish are filter feeders, which remove particles and nutrients from the water column through their natural feeding process. Market-sized oysters can filter up to 45 gallons/day!
  • Shellfish feed on phytoplankton, but can also accumulate marine biotoxins; chemical contaminants; and pathogenic microorganisms, such as bacteria and viruses; effectively removing them from the water column. 
  • Shellfish help control harmful algal blooms, such as red tide, by removing algal cells before they accumulate to harmful levels.
  • Improved water quality makes the environment more suitable for vegetation and organisms that require high water clarity, such as eelgrass.
• The nooks and crannies of shellfish beds create structure and habitat for invertebrates and juvenile fish, which are a food source for predatory fish and other marine species. Healthy shellfish populations help to support finfish populations. Watch how oyster reefs form and organisms use the reefs.
• Shellfish help to minimize the impacts of climate change. Climate change will cause shoreline erosion, increased storm intensity and frequency, and coastal flooding. Shellfish beds stabilize sediments, helping to protect the shoreline from erosion and storms. Additionally, oyster reefs can sequester carbon, and protect surrounding habitats like salt marshes from erosion, aiding carbon sequestration in these habitats. 

Environmental Benefits of Shellfish Aquaculture

• Shellfish aquaculture is a sustainable and green industry. Read more about seafood sustainability and how aquaculture supports sustainability through NOAA.
• Sustainable aquaculture helps to reduce harvesting pressure, and can even reduce disease impacts, on wild populations
• Aquaculture gear can also have beneficial ecological impacts by creating structure and habitat. Watch how different Long Island Sound fish species interact with aquaculture gear.
• Excessive nutrient loading can result in eutrophication, which can deplete areas of oxygen or cause harmful algal blooms. Shellfish naturally remove nitrogen from the environment. Shellfish aquaculture in Greenwich Bay, Connecticut removes nitrogen at an estimated value of $2.3-5.8 million/year.