The Unique and Fragile Habitats of Bays and Estuaries

The environmental problems facing beaches are a more well-known and triumphed cause than the issues facing the less glamorous water habitats of bays and estuaries. Bays and estuaries are unique and fragile habitats that provide a home to a number of species, however, and their destruction is just as concerning. Take a minute to read about these other near-shore marine sanctuaries and the challenges they face.

Estuaries

Estuaries are places where freshwater meets oceanwater, forming a briny mixture that is neither river nor sea. These areas create a sort of nursery for many types of animals. They tend to be shallow and grassy, and they are not subject to the full blows of the ocean, since they are protected by sandbars, barrier islands, mud flats or some other natural formation. The near-shore location of these animal nurseries puts them face to face with human development, and these resulting environmental concerns.

  • Nutrient overloading: Runoff can bring excess phosphorous and nitrogen to estuaries. These nutrients are crucial for healthy plant life, and that’s why they are key components in chemical fertilizer mixtures. Having too much phosphorous and nitrogen can lead to algal blooms and hypoxia, however—a state of low oxygen content in the water. This can lead to the death of seagrass and any animals that depend on seagrass for life.
  • Pathogens and bacteria: Just like beaches, estuaries can be impacted by the bacteria commonly found in urban runoff. This bacteria can concentrate in mussels and other shellfish, making the animals toxic and unfit for human consumption.
  • Habitat degradation: Think of any type of human development near sea areas, and it probably affects estuaries through creating excess runoff and sediments. Filling in low-lying wetlands destroys these eco-systems, as does highway construction, forestry, and damming.

Bays

Think of some of the famous bays in America: from San Francisco to Tampa, these convenient inlets are magnets for urban development. All that development can put serious strain on the body of water that invited all those residents and businesses in the first place.

  • Water Diversion: Agriculture is a major culprit here. While we all need to eat, diverting too much water from rivers that feed a bay can result in lowered water quality and disastrous effects for fish and wildlife.
  • Residential Water Use: With all those people enjoying life in the bay area, residential water use can also put a significant strain on the rivers and streams that originally replenished the bay and kept the water fresh and clean.
  • Sediment Contamination: Did you know that the silty sand and muck at the bottom of any body of water is actually an important part of the ecosystem? The tiny organisms which inhabit this sediment are the base of the food chain. Chemicals and other toxic elements from urban runoff can collect in the sediment, however, and make it uninhabitable—hurting all animals further up the food chain.

 

Sources:

The Green Gate. (2010) NRDC’s Environmental Guide to the SF Bay Area.

Common Estuarine Environmental Problems. (2009) Environmental Protection Agency.