Estuaries
1. What is an estuary?
a partially enclosed body of water where 2 different
bodies of water meet & mix.
Estuaries
2. Estuaries are formed where
fresh water meets & mixes with
ocean water.
3. Estuaries are found where
rivers meet the sea.
4. Estuaries are found where
rivers meet chemically distinct
lakes.
Estuary Features and
Landforms
5. Each estuary includes a
variety of habitats. Some
may be bordered by
marshes.
6. Estuary features such as
swamps or lagoons form
behind barrier islands and
beaches.
Estuary Features and Landforms
7. Bays, harbors, sounds,
and inlets are all estuaries.
8. Bayous are formed by
channels of slow moving
water leading from a river
or lake.
Estuary Features and
Landforms
9. Salt marshes form in estuaries
in areas protected from highenergy waves.
10. Tidal flats are part of many
estuaries. Oyster & clams are
harvested here.
Estuary Features and Landforms
11. Mangrove forests surround
wetland areas in southern
estuaries.
12. In mountainous areas,
estuaries may be found in seaside
fjords.
Estuary Life
13. Many types of plants
grow in estuaries.
14. Estuaries provide food,
shelter, and water to variety
of plants and animals.
15. Why is an estuary a spawning & nursery grounds
for many organisms?
a. Few predators, abundant food, diversity of
habitats, high turbidity
b. Filters pollutants from water
c. Buffer to mainland during storms (absorbs excess
water)
16. Estuaries are :
a. Food & resting place for migratory birds
b. Source of commercially important species; clams,
oysters, blue crabs
c. Food & habitat for many organisms
d. Popular sport & recreation areas; fishing, sailing,
swimming
a. Landfill – draining & filling in to build homes, etc.
(destroys habitat)
b. Mining – for minerals, oil, sand, & gravel
c. Construction – dams/channel dredging (changes
spawning migrations, water circulation, & local
salinity)
d. Sediments – from construction, dredging, &
erosion (increases turbidity which inhibits
photosynthesis & smothers gill breathers)
e. Chemicals – pesticides/sewage (decrease species
diversity)
f. Overharvesting – clams, oysters, mussels, & fish
g. Thermal Pollution – industries use water as
coolant; heated water returned to estuary (incr. water
temp = decrease O2)
Threats to Estuaries
Estuaries Additional Details
18. Nutrient-rich river water spills into the estuary
and mixes with nutrient-rich ocean water which
makes them a productive ecosystem in which
organisms raise their young.
19. Large amount of plankton feed small fish, etc.
20. Birds, mammals, & larger fish feed on the smaller
fish and plants.
21. Migratory birds rest & breed here.
22. Pollution & rising sea levels threaten most
estuaries.
23. North Carolina estuaries are threatened by runoff
from urban development & agricultural areas.
Estuaries of NC
Survival in an Estuary
https://www.youtube.com/watch?v=XLumSN4G5P4
Life in a Transition Zone