human impact unit 3. algae algae basics the base of the food chain (largest producer) produces...
TRANSCRIPT
Human ImpactUnit 3
Algae
Algae basics
• the base of the food chain (largest producer)
•produces 70-75% of O2 for the earth’s atmosphere and earth’s water
•can be unicellular (1 cell) or multicellular
Normal algae cycle
reproduce + create O2
nutrients released by bacteria, reabsorbed by algae, cleans water, causes succession
% die in winter, aerobic bacteria break down the dead material, use up O2
algae grow, photosynthesize to create O2
Plenty of O2 for aquatic life, and releases into air
lakes/ponds are transformed
A healthy pond begins to have aquatic vegetation; other inhabitants die, increasing organic matter, and it becomes shallower.
Algae cycle + human impact = eutrophication
eutrophication – too much algae, sometimes called “bloom”
How humans add nutrients:1. wastewater, septic2. farming waste3. fertilizer (golf courses, residential)4. car washes, soap5. composting (leaves, grass) → good thing
Algae reproduce + create O2
nutrients released by bacteria, reabsorbed by algae, toxic stuff added, succession
% die in winter, aerobic bacteria use up all of O2
Too much algae grows, photosynthesize to create O2
No O2 left for fish and toxic gases
Algae cycle + human impact = eutrophication
Toxic anaerobic bacteria take over, create CH4 and H2S
Nutrients added by human activities
Tons of dead algae
• new• bigger, deeper• low nutrients• low biodiversity• cold, clear• EX: great lakes
• old• shallow• warmer, cloudier• green algae• high nutrients• high biodiversity• EX: farm pond
Classifying water sources
Eutrophication
Eutrophication
Eutrophication
Eutrophication
Eutrophication
Different Types of Algae
• green algaegreen algae– contains chlorophyll a, b (green color) which
captures light to create energy
• brown algae– do photosynthesis, but use chlorophyll c
(brown)– diatoms (unicellular) are similar
• Diatoms– unicellular organisms with yellow-brown
chloroplast that enables them to photosynthesize.
• red algae– found in the oceans– use chlorophyll a, but have red pigment– sushi wraps, thickening agents (ice cream)