Human Impact Unit 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 algae grow, photosynthesize to create O2 Plenty of O2 for aquatic life, and releases into air % die in winter, aerobic bacteria break down the dead material, use up O2 nutrients released by bacteria, reabsorbed by algae, cleans water, causes succession

lakes/ponds are transformed

A healthy pond begins to have aquatic vegetation; other inhabitants die, increasing organic matter, and it becomes shallower.

possibly a marsh

Algae cycle + human impact = eutrophication Eutrophication: is a natural, slow-aging process for a water body, but human activity greatly speeds up the process. Water acquires a high concentration of nutrients, especially phosphates and nitrates. These typically promote excessive growth of algae. As the algae die and decompose, high levels of organic matter and the decomposing organisms deplete the water of available oxygen, causing the death of other organisms, such as fish.

Human Activities and Nutrients

Algae cycle + human impact = eutrophication Algae reproduce + create O2 Tons of dead algae Too much algae grows, photosynthesize to create O2 % die in winter, aerobic bacteria use up all of O2 No O2 left for fish and toxic gases Toxic anaerobic bacteria take over, create CH4 and H2S nutrients released by bacteria, reabsorbed by algae, toxic stuff added, succession Nutrients added by human activities

Classifying water sources 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

Eutrophication

Eutrophication

Eutrophication

Eutrophication

Eutrophication

Different Types of Algae green 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)