Estuaries Hydrosphere I. What is an estuary?
A. An estuary is formed when two bodies of ________ and their _______ meet.
a. For example, when a ____ empties into the _____. b. Off the coast of NC, the ______ Sound is one of the
______ estuaries in the US.
B. They are very special because their waters are _________. a. This means the water is a _______ of _____water from
the river and _____water.
b. This mixture lowers the overall _______ content (typically less than 35 ppm).
C. Estuaries are some of the most ________ ecosystems in the world because many animals rely on it for _____, places to ____, and ______.
D. Humans also rely on estuaries for ____, ___, and _____! II. Characteristics of an estuary
A. They are a ________ between two very ________ environments.
B. The daily _____ (usually 2 high and 2 low tides each day) have a big impact on these environments, but depends greatly on its location, ____, _____, shape of the coastline, and anything that may ______ water flow.
C. Because estuaries are partially _________ by land, it is __________ from the full impact of the ocean waves, winds and storms.
D. No two estuaries are the same! They are classified by scientists by their ________ and how the salt and fresh water _____ in them.
A. Estuaries are home to lots of different organisms: _____, herring, horseshoe _____, bass, and _____ to name just a few.
B. These organisms come here to ___, ____, ____ and _____________.
C. They provide an estimated ___% of ________ fish and a larger percentage of the recreational fish catch for the US. D. Estuaries also are visited by ______ of people every year to
swim, boat, watch birds and other wildlife, and fish. IV. Estuaries are water filters!
A. As the water enters from the river and ocean, the _____ grasses and peat ____ out _________ like herbicides, pesticides, heavy metals, excess sediments and nutrients, storing them in the ____.
B. _______ will ___ some of these ___ things, collecting the contamination inside their bodies.
C. ________ also ___ the organic matter and _______ carbon dioxide, hydrogen sulfide, and methane into the __________. D. Because of the excess ___________ coming from the
________ and ________, it creates a highly fertile area to make it the “_______________.”
V. Estuaries Protect!
A. They are considered a ______ zone, stabilizing the shoreline and protecting the ______, inland habitats, and human
communities from ________ and storm surges from __________.
B. They also protect rivers, streams, and coasts from excess _________ by wind, water, and ice.
C. Sand bars buffer the impact of waves, and plants and shellfish beds _____ the shore against the _____.
VI. Types of Estuaries in NC A. _______ estuaries
a. Run __________ to the coast, in line with the rivers that feed them
b. Example: ______ River estuary B. ________ estuaries
a. Flow into trunk estuaries C. ________ estuaries
a. Lie ___________ to the coast, between the mainland shore and the barrier islands
b. This is what the _________ estuary is considered. VII. Characteristics of the Pamlico Estuary
A. The Pamlico Estuary is the _______ estuary in NC.
B. Water that ____ here are the Chowan, Roanoke, Pasquotank, Pamlico, and ______ rivers to name a few.
C. These rivers deposit ______ high in _____, which will settle on the sand and mud of the ________ of the estuary.
D. It is ____ than __ feet deep, so ________ can reach the bottom which allows plants to grow.
VIII.Threats to the estuarine system A. Changes to the land:
a. As the land is ________ for human use, it will change the _____ of water through this ecosystem.
b. _____ made of asphalt and concrete _______ water so that it runs off with all the _______ directly into the rivers, estuaries, and sea.
B. ________ were used for logging and farming before laws and restrictions were in place.
a. Nearly ____ of the NC wetlands were ________ before the laws went into place.
IX. More threats!
a. Dredging is when the bottom of the water is _____ and made _____.
b. This causes ______ to plants, oyster beds, and stirs up sediments that _____ the water.
c. When the water is cloudy, fish cannot ______ properly and may take in __________, and predators ______ see their prey to eat.
d. It can actually have the ______ effect on the water, where sediment __________ is increased and ________ has to continually occur.
B. _____________ is causing sea levels to rise as well as hurricanes, which causes a lot more _______ than can be handled.
X. And more…nutrients
A. Increase in ________ can have a ________ effect.
a. ______ treatment plants, septic systems, ________ air, and fertilizers deposit ________ like nitrogen and
phosphorus into rivers which make it into estuaries.
b. These ____ levels of nutrients can ________ the amount of algae at such a rate that the algae will _____ sunlight from reaching through the water, _______ off other plants.
c. When alive, the algae ________ a lot of _______ as a result of ____________, but once it dies off and __________, it _______ the oxygen which will
_________ and kill off fish and other organisms needing oxygen to survive.
XI. And more still…sewage & toxins
A. Sewage plants, septic tanks and _______ from farms into rivers carry ______ matter from humans and animals to the estuarine system.
B. _____ can also cause an __________ of plants, removing too much ______ from the environment, which kills fish and other organisms through ____________.
a. This can also happen when the salt and freshwater are not appropriately ______ together: salt water _____ and freshwater _____.
b. Bottom dwellers begin to live in very ______ conditions, which have less ______ and cause them to ___________. c. Dead organisms increase the amount of ________, which
