slide1
Download
Skip this Video
Download Presentation
Environmental Factors Affecting Corals and Coral Reefs

Loading in 2 Seconds...

play fullscreen
1 / 46

Environmental Factors Affecting Corals and Coral Reefs - PowerPoint PPT Presentation


  • 104 Views
  • Uploaded on

Environmental Factors Affecting Corals and Coral Reefs. Environmental Factors Correlated with Healthy Reef Coral Growth. Warm tropical water Normal seawater salinity Appropriate solar radiation Low organic nutrients (oligotrophic) Low turbidity Low sedimentation Vigorous water motion.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Environmental Factors Affecting Corals and Coral Reefs' - fredericka-miller


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide2

Environmental Factors Correlated

with Healthy Reef Coral Growth

  • Warm tropical water
  • Normal seawater salinity
  • Appropriate solar radiation
  • Low organic nutrients (oligotrophic)
  • Low turbidity
  • Low sedimentation
  • Vigorous water motion
the electromagnetic radiation spectrum
The Electromagnetic Radiation Spectrum

Only green and blue wavelengths pass through water a great distance.

p hotosynthetically a ctive r adiation
Photosynthetically Active Radiation

PAR

(i.e., visible light)

slide5

Primary Production Limitations

  • light
  • water
  • nutrients

Photosynthesis

Photic Zone

No Photosynthesis

Aphotic Zone

slide6

Light Absorption in the Ocean

Light Intensity

  • decreases with depth
  • 100 meter = depth limit of hermatypic corals primarily a result of the overall reduction in light
  • many studies have focused upon how changing light intensities with depth affect the photosynthesis of zooxanthellae of corals
slide8

Primary Productivity

The rate of production of organic matter by autotrophs

slide9

Primary Productivity

Photosynthesis

  • Involves the use of light energy in the conversion of inorganic carbon into organic carbon.
photosynthesis

Photosynthesis

6H2O + 6CO2 + light  C6H12O6 + 6O2

slide11

Primary Producers

Common Name

Blue-green algae (cyanobacteria)

Red algae

Brown algae

Green algae

Coccolithophorids

Dinoflagellates

Diatoms

Seagrass

slide12

Primary Productivity

Chemosynthesis

  • Involves the use of energy released by the catalysis of certain inorganic reaction to convert inorganic carbon into organic carbon.
cellular respiration

Cellular Respiration

C6H12O6 + 6O2 6H2O + 6CO2 + energy

slide15

Measuring Primary Productivity in the Ocean

Standing Crop Estimates

  • weigh out total plant material
  • measure concentration of chlorophyll in the water
  • use satellite imagery

Measure Actual Rates of Primary Productivity

  • measure oxygen production and consumption by plants (e.g., light-dark bottle technique)
slide16

Table 1. Average net primary production and biomass of aquatic habitats. Data from R.H. Whittaker and G.E. Likens, Human Ecol. 1: 357-369 (1973).

slide17

Primary Productivity

Gross Primary Productivity (GP)

  • The rate of production of organic matter from inorganic materials by autotrophic organisms

Respiration (R)

  • The rate of consumption of organic matter (conversion to inorganic matter) by organisms.

Net Primary Productivity (NP)

  • The net rate of organic matter produced as a consequence of both GP and R.
slide18

Primary Productivity

NP = GP + R

Note that R is a negative value because it results in the reduction of organic matter.

slide21

Plankton Size

  • Picoplankton (.2-2 µm)
  • Nanoplankton (2 - 20 µm)
  • Microplankton (20-200 µm)
  • Macroplankton (200-2,000 µm)
  • Megaplankton (> 2,000 µm)

microplankton

picoplankton

nanplankton

slide22

Plankton Sampling

Mesh

5 in

Collecting bottle

Avoidance ability- this is a function of reactive distance, radius of net, speed of tow, burst of speed of larvae

To reduce net clogging:

  • pick correct mesh size
  • use longer net
  • tow at slower speeds
  • tow for shorter time
  • change configuration of net
  • Picoplankton .2-3um
  • Nanoplankton 2-20um
  • Microplankton 20-200um
slide23

Rates of primary production regulated by LIMITING FACTORS:

  • major limiting factors in ocean (inorganic nutrients, light) differ from those on land (moisture, temp, inorganic nutrients, light)
  • primary production measured via change in O2 concentrations in “light” and “dark bottles”
slide24

Phytoplankton

Zooplankton

slide25

zooplankton

phytoplankton

decomposition

Light & Dark Experiments

Photosynthesis:

light + 6CO2 + 6H2O C6H12O6 + 6O2

Respiration:

C6H12O6 + 6O2

6CO2 + H2O + ATP

slide26

light bottle

photosynthesis

+ respiration

dark bottle

respiration

weight

slide27

Sources of Error

  • Respiration rates are not equal between light and dark bottles.
  • The glass wall of the light bottle filters light.
  • The bottle may not be representative of the water as a whole.
slide28

Photoadaptation in Corals

Changes in pigment concentrations and algal densities in response to light intensity

A coral (Acanthastrea) under high magnification. Focus stack. Fluorescent pigments emphasized with full-spectrum lights

slide29

Colony Morphology Responses to Irradiance

Hemispherical Branching Colonies

Plate-Forming Colonies

slide32

Effects of UV on Living Things

  • damage to DNA resulting in mutations
  • damage to other biological molecules
    • proteins: enzyme inactivation
    • lipids: disruption of cell membranes and membrane transport systems
slide33

Corals and UV Radiation

  • decreased growth
  • decreased rates of calcification
  • transplantation experiments (deep corals brought to the surface) demonstrate corals may be UV-sensitive (exhibit bleaching and increased mortality)
  • coral sperm appears to be UV-sensitive (note spawning normally takes place at night)
slide34

Ultraviolet Absorbing Compounds in Corals

  • mycosporine-like amino acids (MAA’s)
  • MAA’s apparently produced by zooxanthellae but stored in the animal tissues
  • concentrations greater in shallow water corals than in deeper ones
  • transplantation experiments demonstrate adaptational changes in pigment concentrations
  • positively buoyant eggs exhibit higher concentrations of pigments than do negatively buoyant eggs
effects of uv on the coral zooxanthellae symbiosis
Effects of UV on the Coral-Zooxanthellae Symbiosis

PAR + UV

MAAs

PAR

PAR

Coral pigment

Photosynthesis

slide37

The hole in the ozone

Oct. 1979

Sep. 2013

temperature
Temperature
  • Lethal Limits
    • <17 and > 33oC for extended periods of time
    • physiological effects = bleaching (expulsion of zooxanthellae from coral tissues)
  • Ecological Limits
    • 18 - 32oC (low limit correlates with 20o N & S latitude limit of reef corals)
    • some exceptions exist
    • reasons for differences between lethal and actual limits
      • secondary effects of temperature on feeding or on reproduction
      • synergistic effects of other environmental factors (e.g., UV irradiance)
slide43

Other Factors

  • Salinity
  • Sedimentation
  • Aerial Exposure at Low Tide
  • Water Motion
  • Inorganic Nutrients
  • Currents
slide46

Acid Rain in Marine Environment

  • reduces ability of marine organisms to utilize calcium carbonate
  • Coral calcification rate reduced 15-20%
  • Skeletal density decreased, branches thinner
ad