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  2. National Estuary Program (NEP)

Exploring Estuaries: Glossary

Illustration of a horseshoe crab
  • Algae. Plants without roots that grow in estuaries and "feed" on nutrients (such as nitrogen and phosphorus) in the water.
  • Algae blooms. Occurs when algae grows very fast because too many nutrients enter the water. Algae blooms color the water a deep red-brown.
  • Barrier island. Refers to a long, narrow island running parallel to the mainland, built up by waves and currents and protecting the coast from erosion by surf and tidal surges.
  • DDT. A group of colorless chemicals, no longer made today, that was used to kill insects. DDT is toxic to people and animals when swallowed or absorbed through the skin.
  • Drought. A period without rain that can damage crops such as wheat and corn.
  • Ecosystem. A community of plants and animals, like a neighborhood.
  • Endangered species. A plant or animal that is in immediate danger of becoming extinct and needs protection to survive.
  • Erosion. The process where soil and other matter are worn away by rain, stream currents, and wind.
  • Estuary. A partially closed coastal body of water where freshwater and saltwater mix.
  • Fertilizers. Substances, such as chemicals or animal manure, used to provide nutrients to help plants grow. Many people use fertilizers on their lawns and gardens.
  • Fisheries. A place where large numbers of fish are caught.
  • Fish kills. Refers to large numbers of fish being killed, usually because there is not enough oxygen in the water or because of a chemical spill.
  • Food chain. The relationship between who eats whom among plants and animals.
  • Freshwater. Refers to water from rivers, lakes, reservoirs, underground streams, and other sources. Water is continually lifted from the oceans by evaporation and then returned to the land as ice, snow, or rain. Ice and snow melt from mountains to release freshwater to our rivers, streams, lakes, and to resupply underground streams.
  • Habitat. The place in which a plant or animal normally lives.
  • Heavy metals. A group of highly toxic metals that are generally harmful to plants and animals.
  • Hypoxia. A condition where there isn't enough oxygen in the water. This forces fish to either swim away or die and can suffocate plants living in the water. Hypoxia occurs when there are too many nutrients in the water.
  • Nonpoint source. Refers to pollution that enters estuaries from many places, such as when rainwater washes over parking lots, lawns, or farms and brings pollutants from all these sources into the estuary.
  • Nutria. Animals with reddish brown and black fur, webbed feet, orange front teeth that stick out, and long tails. Nutria live throughout Louisiana in coastal swamps, brackish marshes, ponds, streams, rivers, and lakes. They eat plants and grass and can grow up to 4 feet long.
  • Nutrients. Refers to the "food" that plants need in order to grow. Examples include nitrogen and phosphorus. Too many nutrients in the water can cause problems in an estuary, such as hypoxia.
  • Pathogens. Tiny disease-causing microorganisms such as viruses, fungi, and bacteria.
  • Pesticides. Chemicals used to destroy or control plant, fungus, or animal pests.
  • Point source. Refers to pollution that enters estuaries from a single point, such as a factory pipe.
  • Reefs. Skeleton-like ecosystems made up of colonies of limestone-producing, living animals. Coral reefs tell us about water quality and the health of an estuary.
  • Runoff. Water that flows across the surface of the land and empties into a body of water.
  • Seawater. Water that comes from the ocean and is very salty.
  • Sediment. Mud, sand, silt, clay, shell debris, and other particles that settle on the bottom of rivers, lakes, estuaries, and oceans. Sedimentation refers to the build up of sediment.
  • Septic systems. Systems that carry wastewater away from our homes when we turn on a faucet or flush a toilet.
  • Sewage. The wastewater generated by people in homes and businesses.
  • Sewage treatment plants. Places where wastewater is treated with chemicals and bacteria to produce clean water that can be returned to rivers and other waterways.
  • Shellfish. An animal such as a mollusk (clams, oysters, and snails) or crustacean (crabs and shrimp) that have a shell or shell-like external skeleton.
  • Stormwater. Refers to rainwater as well as water from washing cars, overwatering lawns, and other sources. Stromwater washes down storm drains on the curbs of roads and leads directly into lakes, rivers, and streams untreated. Stormwater can carry pollution directly into our natural water resources.
  • Tides. The rise and fall of ocean waters produced by the gravitational pull of the moon and the sun.
  • Threatened species. A plant or animal that is likely to become endangered if not protected.
  • Watershed. The area of land that drains into a particular body of water.

National Estuary Program (NEP)

  • National Estuary Program (NEP) Home
    • Basic Information about Estuaries
  • Funding Resources
  • Learn about the National Estuary Program
    • Overview of the NEP
    • National NEP Results
    • Exploring Estuaries
    • NEP Library
      • National Estuary Program Reports
  • Local Estuary Programs
    • Individual Estuary Program Websites
    • Comprehensive Conservation and Management Plans
    • NEPs on Social Media
    • State of the Bay Reports
    • NEP Videos, Virtual Tours and Photo Gallery
  • NEP Success Stories
    • Fact Sheets
    • Habitat Plans
    • How NEPs Address Environmental Issues
      • Aquatic Nuisance Species
      • Climate Change
      • Declines in Fish and Wildlife Populations
      • Habitat Loss and Degradation
      • Nutrient Loads
      • Pathogens
      • Stormwater
      • Toxics
    • Progress Evaluation
    • Successful Watershed Management: NEP Lessons Learned
    • Sustainable Financing Examples
      • Casco Bay Estuary Partnership
      • Coastal Bend Bays & Estuaries Program
      • Partnership for the Delaware Estuary
      • Indian River Lagoon National Estuary Program
      • Narragansett Bay Estuary Program
      • Peconic Estuary Partnership
      • Tampa Bay Estuary Program
Contact Us about National Estuary Program
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on April 17, 2025
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