Eutrophication Key Terms Flashcards

1
Q

Eutrophication

A

An increase in the external nutrients to an ecosystem that results in an increase in plant growth. Affects ecosystems, recreation, economies and lives.

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2
Q

Eutrophic

A

Lake or body of water rich in nutrients and so supporting a dense plant population, the decomposition of which kills animal life by depriving it of oxygen

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3
Q

Nutrient

A

Essential elements that tent to limit plant growth. Plants need oxygen but it is not considered a nutrient - nutrients are things that limit

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4
Q

Phytoplankton

A

Increased nutrient supply can result in increased phytoplankton growth -> more phytoplankton .. this can cause problems

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5
Q

Limiting nutrient

A

C, N, P, Fe (fertilizer ingredients)

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6
Q

Liebigs Laws

A

Tells us which nutrient to reduce, the limiting nutrient is the one in shortest relative to need - must control this to reverse eutrophication

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7
Q

Control (in an experiment)

A

One that is limited

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8
Q

Paleo-reconstruction

A

Shows us lake aging - history of algae production

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9
Q

Sediment core

A

Collected during reconstruction

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10
Q

Point source

A

Comes from points - pipes, domestic sewage - is easier to measure

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11
Q

Non-point source

A

From water shed activities, live stock production, urbanization

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12
Q

Biological Oxygen Demand (BOD)

A

The amount of oxygen consumed by respiration per unit time - depends on 2 main things: concentration of organic matter in water & how easily organic matter is decomposed (labile)

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13
Q

Labile

A

Readily digested, easily decomposed by bacteria - raw sewage

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14
Q

Refractory

A

Poorly digested, not easily decomposed by bacteria - leafs and wood

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15
Q

Cyanobacteria

A

Fresh water toxic phytoplankton

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16
Q

Dinoflagellates

A

Marine toxic phytoplankton - huge issue can kill a lot animals

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17
Q

Toxic Red Tide

A

Harmful algal bloom caused by dinoflagellates

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18
Q

Fish Kill

A

More nutrients aren’t always a good thing - increased nutrients leads to increased fish

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19
Q

Dead Zone

A

Areas of large bodies of water where the bottom water is anoxic. These are occurring in many areas along the coast of major continents, large rivers and large lakes.

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20
Q

Anoxic

A

Very low or completely zero concentrations of dissolved oxygen

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21
Q

Sewage Diversion

A

Lake Washington success story

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22
Q

What 4 elements limit plant growth?

A

C, N, P, Fe

23
Q

Why do we need to determine which nutrient is limiting to control eutrophication?

A

The limiting nutrient is the one thats shortest in supply - this is how reverse it, limiting one is the one that will have the effect.

So we can limit the growth of phytoplankton and potential dead zones

24
Q

Where does C, N and P come from externally in lakes

A

c: atmosphere & watershed, n: watershed & atmosphere, p: watershed

25
Q

Which element was it surprising to find was limiting in lake water using lab experiments? Why was this not correct? How did it not represent what was actually happening in the lake?

A

Carbon - in nature Carbon is found in the air (wind + air = carbon gets in through air) - in the lab/flask the top is too small for this to happen - When water is in a flask, ripples are eliminated and waves are non existent

26
Q

Why is iron limited in the ocean but not inland lakes?

A

Fe limited in the ocean because it far from dirt and run off

27
Q

Is Eutrophication a natural process? What evidence was used to support the answer?

A

Mostly, no - in class question about roads and run off, see graph below (showed no natural Eutrophication for centuries until Romans built roads near lake) -

28
Q

What is the main way building a road near a lake contributes to eutrophication?

A

Muddy water has lots of plant food in it, high P - building a road takes P out

29
Q

What are three negative things caused by dumping raw sewage? How does decomposition come into play?

A
  1. Decomp consumes oxygen (bad for river bc fish want the oxygen) 2. Decomp releases inorganic nutrients 3. Spreads disease

dump waste (inorganic matter) in lake–> Bacteria comes in to decomposes that stuff it uses oxygen

  • -> The more waste we dump will generate more bacteria to decompose and use up oxygen
  • -> Increasing the Biological Oxygen Demand because bacteria need oxygen to decompose these organic waste-
  • > AS they bacteria is decomposing the wastes, they are also respiring which releases inorganic nutrients(#2)
30
Q

What two main factors affect the BOD of organic matter in water?

A

Concentration of organic matter in water and how easily organic matter is decomposed

31
Q

Do we want sewage to have a higher or lower bod?

A

Lower BOD

32
Q

Preliminary, primary, secondary and tertiary phases of sewage plant. Know each and which reduces BOD.

A

Preliminary - settle out large stuff
Primary - physical removal (screens, settling, floating); not effective at reducing BOD
Secondary - biological removal, sludge is separated out and brought elsewhere (greatly reduces BOD)
Tertiary - use chemical removal, add chemicals, not practiced everywhere bc its $$$

33
Q

What happens to inorganic and organic P in the secondary treatment? Is it a good or bad thing?

A
  • organic P decreases and inorganic P increases

its a bad thing

34
Q

What was Mr Floaty trying to convey to the public?

A

We need better regulations and should be flushing right into the river which happens w/ big storms

35
Q

How does green lawn syndrome and septic fields contribute to eutrophication?

A

Fertilizing lawn ends up in lake

36
Q

How does erosion contribute to eutrophication? Is point source on non-point source?

A

Erosion occurs with agriculture, livestock production and urbanization - these are all non-point sources that increase nutrients and contribute eutrophication

it has absorbed phosphorus particles
non-point

37
Q

There is a figure of increasing total P as a function of % watershed farmed or developed: What is it telling us?

A

Where people are P is higher, points on graph are lakes or ponds

38
Q

What organisms in the water increases with eutrophication? What particular kinds in freshwater and marine systems?

A

Phytoplankton blooms
Fresh - cyanobacteria
Marine - dinoflagellates
Difference between the two, dino can kill a lot of animals

39
Q

How does an increase in P affect the % of cyanobacteria in freshwater systems? How does the increase in P affect biodiversity of algae (algae = phytoplankton here)?

A

Adding more P along x axis is like more people, biodiversity decreases

40
Q

How does adding nutrients to lakes affect fish density? (note, it is different depending on the initial nutrient level in the lake (low or high), and how much is added).

A

Fish kill - slide 34, shows that more nutrients isn’t always a bad thing,

41
Q

Lake Eerie - what was dead about it? What organisms would argue that the lake is not dead? Why couldn’t the same solution be used from Lake Washington? What was the solution and did it work?

A

Solutions - removing P, Lake Eerie phytoplankton decreased, BOD went down, good for fish -> less dead zones (in 1960 it was declared dead due to P being too high)

Because it was caused by phosphorus loading from point sources

42
Q

By what % would doubling the concentration of PO4-3 increase phytoplankton growth rate in lakes given an initial concentration of e.g. 1, 5, 10 and 20μg/L (slide 12)

A

Example: 5 doubled -> 10
On the graph at 5 you have 1 unit of growth. At 10 you have around 1.3 so the change is .3 so 30%
At 20 its about .1 higher than 10 due to saturating curve

43
Q

Why do we need to determine which nutrient is limiting to control eutrophication

A

Because when you’re at the saturating curve it will no longer limit the growth. It is an essential element but we already have enough.

44
Q

What is the figure of chlorophyll vs total P of field observations of lake surveys telling us? (that is, what was the point of this figure?)

A

It shows us the relationship between phosphorus and chlorophyll. The more chlorophyll means the more plants. It shows that the higher the level of phosphorus the higher the level of chlorophyll.

45
Q

T / F
Higher levels of phosphorous lead to more phytoplankton growth

Increasing total phosphorous by 10 times leads to less than a 10 times increase in Chlorophyll

Phosphorous is limiting in the lakes surveyed

A

True

False

True

46
Q

How would you test whether a nutrient is limited using a laboratory experiment?

A

You would fill lake water into flasks and then add either C,N, or P into them with one remaining control. Then you would see which one produced the most phytoplankton

47
Q

What was the controversy concerning nutrient limitation?

A

“Junk Science” it was a selective use of evidence to support a pre-determined position. It was funded by companies that would be affected by the outcome.

48
Q

What nutrient(s) are most limiting in freshwater, coastal marine, and open water marine Systems?

A

FRESHWATER: Phosphorous
COASTAL MARINE: Nitrogen
OPEN WATER MARINE: Nitrogen, Phosphorus, Iron

49
Q

What is in raw sewage?

A

high in organic matter (called detritus)
high in N and P (organic and inorganic)
high in disease-causing microbes (bacteria, viruses, etc.)

50
Q

How do septic tanks contribute to eutrophication? Is this point or non-point?

A

septic tanks are mini-sewage treatment plants behind your house, The nutrients are going underground and eventually seep into the water system. They are basically inefficient mini-treatment plants.
non-point

51
Q

Medium nutrients in a lake affect fish in what part of the lake? Why?

A

The bottom because there is medium respiration, decreasing the level of dissolved oxygen at the bottom

52
Q

How do the figures of Lake Washington water indicated it was becoming eutrophic?
What happens to the phosphate in the summer?

A

The chlorophyll levels increased with the amount of phosphorus

53
Q

What was the solution to the phosphorous problem in Lake Erie? Did it work?

A

Improve watershed discharge -It shifted the main source to non-point source