Download Aquatic Ecosystems 1

Aquatic
Ecosystems
Photograph by Steve Sieren
Introduction
• Ecosystem - collection of all organisms
living within their environment.
– Aquatic ecosystems: centered around water
and the organisms who inhabit these
ecosystems are specifically adapted for such
survival.
Photograph by Steve Sieren
The Hydrosphere
• The Earth is divided into different spheres.
– Hydrosphere: relates to the entire mass of water on the planet.
– Biosphere: includes all living things; including life on land, in
water, and in air.
• The organisms within the biosphere interact closely with
the hydrosphere for survival.
Photograph by Steve Sieren
Streams and Rivers
• A river is a stream of moving water that follows a definite
course.
• Creek, brook, stream, and river quality is directly related
to the health of other bodies of water, as these moving
bodies of water drain into larger lakes and some
eventually lead to oceans.
• These environments are characterized by higher levels of
oxygen (due to the waters movement) and little plant life
until the speed of the river slows.
Photograph by Steve Sieren
Streams and Rivers
• Recent EPA findings (summarized below) show that the health of
the nations streams is poor
– polluted with phosphorous and nitrogen
– with nearby land disturbed by pipes, pastures, or pavement.
Photograph by Steve Sieren
Freshwater Lakes & Ponds
• A lake is a body of water of considerable size surrounded by land.
• The EPA states that freshwater inland lakes and reservoirs provide
our nation with 70% of its drinking water and supply water for
industry, irrigation, and hydropower.
• Lake ecosystems support complex food web interactions and provide
habitat for threatened and endangered species.
• The United States has a 19 billion dollar freshwater fishing industry
dependent on the health of lakes, and many states’ tourism industry
centers rely on these freshwater reservoirs.
Photograph by Steve Sieren
Wetlands
• Wetlands are characterized by
regular saturation of the soil;
either totally covering the soil or is
present at or near the surface for
at least part of the year.
• They are found on every continent
except Antarctica.
• They can include swamps, bogs,
and marshes and can be fresh,
salty or brackish (a mixture of
fresh and salt water).
http://www.tpwd.state.tx.us/learning/webcasts/seacenter/images/txhab/wet-types.jpg
Photograph by Steve Sieren
Estuary
rivers meet the sea are
known as estuaries, a
combination of fresh and
salt water (brackish water).
• A delta is the fanned build
up of sediment from river
deposits which often covers
the center of the estuary.
Photograph by Steve Sieren
http://www.texasep.org/assets/images/estuary2.GIF
• Wetlands formed where
Relationships Between Pollutants &
Aquatic Environments
http://www.epa.gov/owow/oceans/nccr3/pdf/nccr3_entire.pdf
Photograph by Steve Sieren
Marshes
• Marshes - wetlands frequently or
•
•
•
•
continually flooded with water, with
soft-stemmed vegetation.
Can be fresh or salt water.
Nutrients are plentiful leading to an
abundance of plant and animal life.
Marshes recharge groundwater
supplies, help to limit damage from
flooding and coastal storms, and
most importantly, clean the water of
pollutants.
As water moves slowly through a
marsh, sediment and other
pollutants settle to the floor of the
marsh.
Photograph by Steve Sieren
• Swamps are wetlands
Swamps
characterized by woody plants
with water soaked soils during
the growing seasons and
standing water at times.
• The soils are thick, black,
nutrient-rich and grow watertolerant trees such as Cypress,
Atlantic White Cedar, and
Tupelo.
http://www.nwrc.usgs.gov/factshts/2004-3019/images/figure4.gif
• Plants, birds, fish, and invertebrates such as freshwater shrimp,
crayfish, and clams require the habitats provided by swamps.
• Many rare species, such as the endangered American Crocodile
depend on these ecosystems as well.
Photograph by Steve Sieren
Texas Swamps
• Caddo Lake State Park
– the only natural lake in Texas
– created by a mass of trees and flood debris known historically as the
Great Raft of the Red River. It obstructed the river channel for more
than 100 miles above Shreveport, Louisiana until 1874, when it was
successfully removed to
clear the channel for
navigation.
– lake slowly drained away,
leaving a swamp
- A modern dam has
recreated the lake
Photograph by Steve Sieren