1 of 35

Aquatic Ecology

Terrie Looney, Ph.D.

Environmental Educator

Big Thicket Association

2 of 35

Program Objectives

  • Water characteristics
  • Water quality
  • Water testing
  • Nutrient cycles

​

​

3 of 35

Water is special!

​

  • All 3 states in nature.
  • Tetrahedron
  • Hydrogen bonds

​

4 of 35

5 of 35

Solid vs liquid

6 of 35

7 of 35

Surface tension

8 of 35

Capillary action

9 of 35

10 of 35

11 of 35

Igor Shiklomanov's chapter "World fresh water resources" in Peter H. Gleick (editor), 1993, Water in Crisis: A Guide to the World's Fresh Water Resources (Oxford University Press, New York).� 

Water source

Water volume, in cubic miles

Water volume, in cubic kilometers

Percent of�freshwater

Percent of�total water

Oceans, Seas, & Bays

321,000,000

1,338,000,000

--

96.54

Ice caps, Glaciers, & Permanent Snow

5,773,000

24,064,000

68.7

1.74

Groundwater

5,614,000

23,400,000

--

1.69

    Fresh

2,526,000

10,530,000

30.1

  0.76

    Saline

3,088,000

12,870,000

--

  0.93

Soil Moisture

3,959

16,500

0.05

0.001

Ground Ice & Permafrost

71,970

300,000

0.86

0.022

Lakes

42,320

176,400

--

0.013

    Fresh

21,830

91,000

0.26

0.007

    Saline

20,490

85,400

--

0.006

Atmosphere

3,095

12,900

0.04

0.001

Swamp Water

2,752

11,470

0.03

0.0008

Rivers

509

2,120

0.006

0.0002

Biological Water

269

1,120

0.003

0.0001

12 of 35

Water Quality

  • pH
  • Alkalinity
  • Turbidity
  • Oxygen

​

13 of 35

pH

  • Acidity or baseness of water
  • Optimum range 6.5 - 7.5
  • < 6.5 fish stress, low reproduction
  • < 6 most fish die
  • Linked to alkalinity

14 of 35

Alkalinity

  • Measure of CaCO3 concentrations
  • Optimum range 50 - 150 mg/l
  • Related to water clarity

15 of 35

DO - Dissolved Oxygen

  • Measure of O2 in water
  • Optimum > 6 ppm
  • At 4 ppm fish stress
  • < 3 ppm fish die
  • Related to temperature,

BOD, and turbidity

16 of 35

Turbidity

  • Clarity of water
  • Amount of suspended solids

​

17 of 35

18 of 35

What causes turbidity?

​

  • Physical factors-

​

  • Chemical factors-

​

  • Biological factors-

​

19 of 35

Turbidity

  • Definition
  • Causes
  • Measurement
  • Effects on water quality

20 of 35

21 of 35

Biological turbidity

  • Caused by algae or plankton bloom
  • High algae = high BOD
  • High BOD + High temp = O2 Depletion

​

22 of 35

Physical turbidity

  • Caused by erosion, animals, run off
  • Impacts photosynthesis
  • Impacts benthic organisms

​

23 of 35

Chemical Turbidity

  • Caused by water chemistry
  • Impacts photosynthesis
  • Impacts benthics
  • Impacts aquatic animals

24 of 35

Secchi tube

25 of 35

Nutrient cycles

  • nutrients increase plankton growth
  • plankton feeds forage fish

​

​

26 of 35

Nitrogen cycle

27 of 35

Phosphorus cycle

28 of 35

Phosphorus

29 of 35

30 of 35

Checking populations

31 of 35

Aquatic Invasive Species

  • Adapt to a wide range of habitats.
  • They have superior ability to acquire food.
  • They reproduce prolifically.
  • They have few natural predators in the new habitat.

32 of 35

Economic Impact

  • Estimated $137 billion/yr for the U.S. (Pimentel et al, 2005)
  • Aquatic invasives $100’s of millions/yr+ (NOAA)

​

​

​

​

33 of 35

Things you can do

  • Check your boat- Clean and dry boat, trailer, motor and live wells.
  • Do not transport bait/water to other ponds.
  • Do not release non-native animals/plants.
  • Dispose of unwanted plants properly.
  • Buy wisely. Purchase native species.

34 of 35

Questions?

Terrie Looney, Ph.D

nribedu@gmail.com

409-656-0559

35 of 35

Catch Records

  • Help track fish growth
  • Track fish numbers
  • Monitor fish health