Transcript Our Backyard Waterways: Eutrophication

Our Backyard Waterways:
Eutrophication
Presented by: Rachel Martin
©MathScience Innovation Center
Day 2
Eutrophication
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Nutrients
• Nutrients, like nitrogen and phosphorus,
occur naturally in the water, soil & air.
• Just as the nitrogen & phosphorus in
fertilizer aids the growth of grass, trees
and agricultural crops, both nutrients are
vital to the growth of plants in our local
waters & beyond.
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http://www.chesapeakebay.net/Info/nutr1.cfm
Nitrogen (N)
• The most common gas found in the earth's
atmosphere.
• Nitrogen enters the ecosystem in several
chemical forms & also occurs in other
dissolved or particulate forms, such as
animal waste and tissues of living & dead
organisms.
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http://www.chesapeakebay.net/Info/nutr1.cfm
Phosphorus (P)
• Phosphorus is found in dissolved organic &
inorganic forms, often attached to particles
of sediment.
• Once attached to sediment, phosphorous
can be moved 100s to 1,000s of miles from
were it was released by flowing through
streams & rivers.
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http://www.chesapeakebay.net/Info/nutr1.cfm
Phosphorus (P)
• It is a vital component in the process of
converting sunlight into usable energy forms
for the production of food and fiber.
• It is also essential to cellular growth and
reproduction for organisms such as algae &
bacteria.
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http://www.chesapeakebay.net/Info/nutr1.cfm
Nutrients
• Sources: sewage treatment
plants, industries, vehicle
exhaust, acid rain, & runoff from
agricultural, municipal,
recreational (ex., golf courses),
residential and urban areas
www.chesapeakebay.net/Info/nutr1.cfm
www.epa.gov/oppefed1/models/water/drt_april2005.htm
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www.applegreens.com/photogallery6.htm
http://www.ens-newswire.com/ens/dec2002/2002-12-09-01.asp
Skeletonema costatum
How does it work?
• Excess amounts of N & P cause rapid growth of algae
(phytoplankton), creating dense populations, or blooms.
These blooms become so dense that they reduce the
amount of sunlight available to underwater grasses.
• Without light, plants cannot photosynthesize & produce
the food they need to survive, eventually killing the
grasses.
• Algae may also grow directly on the surface of these
grasses.
Large photo: www.mdsg.umd.edu/SAV/ ©MathScience Innovation Center
Inset photo: www.dnr.state.md.us/Bay/cblife/algae/diatom/skeletonema_costatum.html
• Unconsumed algae will ultimately sink & be
decomposed by bacteria in a process that
depletes the water of oxygen.
• All animals need oxygen to live, so when
oxygen levels get low, fish swim away if they
can - other aquatic animals that cannot move
(ex. oysters) may die if oxygen levels get too
low.
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Photo: www.gotalgae.com/temperature_solutions.htm
Eutrophication Activity
Pea Soup Ponds
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Summary
Students will learn how water can be
polluted by algal blooms. They will grow
algae with different concentrations of
fertilizer or nutrients and analyze their
results as environmental engineers
working to protect a local water resource.
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Engineering Connection
• Goal = to create useable water sources
• Test and monitor water sources
• Implementation of pollution control
strategies or water treatment technology
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Green Algae: What is it?
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It is a MICROSCOPIC PROTIST!
It is NOT a plant! But evolved from plants.
Can photosynthesize, have chloroplasts.
Mostly single celled, some form colonies.
Many have flagella.
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Algal Blooms
• Too many nutrients cause algae to
reproduce quickly, causing the lake to
turn a greenish color.
• When algae die in large numbers, the
BACTERIA will start to DECOMPOSE
the dead algae, using up vital oxygen in
the water.
©MathScience Innovation Center can cause
• Low oxygen concentrations
How will you set up an experiment to
test the effect of fertilizer on algal
blooms?
Materials
• Algal culture
• 4 petri dishes
• Lawn fertilizer
• Water
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