Physiological Ecology

= mechanisms/morphological features that allow organisms to respond to and maneuver their environment.

Physiological Ecology Sediments - adaptations to sediments Irradiance (Light) - photosynthesis -  pigments -  pigment distribution/activity Temperature -  metabolic processes -  tolerance Salinity Water movement Nutrients

Sediment types

Rocky Shores Mobile = dinoflagellates, cyanobacteria Attached = macroalgae

Sandy or muddy environments

Mobile = flagellates, diatoms, benthic algae

Attached = generally angiosperms, algae

Irrandiance or Light

Life with Light evolution of life = primarily due to interaction of photosynthetic organisms and light absence of light = photosynthesis could not occur, O2 would not be available

1m

10m

50m

70m

100m

50% of light = end red

20% of light = end yellow

no surplus energy

end green

0.5% of light = end blue

Absorption = long wavelength absorbed first (by water) Scattering = high energy due to molecules and particles

Euphotic Zone Positive net photosynthesis rate. What are the limiting factors other than light?

Aphotic Zone Negative net photosynthesis rate.

10

1 Net Photosynthesis

Biological Production - +

Photosynthetic Pigments

Pigment Distribution

Chl a! Chl b! Chl c! Carot α!

Carot β!

Fuco! Phyco!

Euglenophyta! +! +! +!Cyanobacteria! +! +! +!Chrysophyta! +! +! +! +! +!Rhodophyta! +! +! +! +!Phaeophyta! +! +! +! +!Chlorophyta! +! +! +!

*

*

Chlorophyll a

Carotene Fucoxanthin

Phycobilins

Pigment Activity

Engelmanns Theory of Chromatic Adaptation (1884)

Appealing, but not always correct

dept

h

Green Light Only

Predicts that: -  Green seaweeds = shallow water -  Reds deepest = blue range

Phycobilins

Fucoxanthin Chl c

Chl b

Phaeophyta