Early Oceans and Ocean Acidification
- Early oceans were more acidic due to a carbon dioxide-rich atmosphere.
Impact on Coral Reefs
- Ocean acidification reduces carbonate ions needed by corals to build their skeletons.
- It causes biodiversity loss by harming corals and shellfish, leading to their deaths and reduced species variety.
Dissolved Oxygen and Aquatic Life
- Dissolved oxygen is oxygen gas mixed into water, crucial for organisms.
- Aquatic life requires dissolved oxygen for cellular respiration to produce energy.
- Biological Oxygen Demand (BOD) measures the oxygen needed by decomposers to break down organic material.
Cellular Respiration
- Cellular respiration equation: C<em>6H</em>12O<em>6+6O</em>2→6CO<em>2+6H</em>2O+ATP
- Contributes to oxygen depletion through carbon dioxide production.
Eutrophication and Dead Zones
- Eutrophication leads to overgrowth of algae followed by oxygen depletion.
- Excess nitrogen and phosphorus cause algal blooms that deplete oxygen, creating dead zones.
- Dead zones are common near agricultural areas due to fertilizer runoff.
Danger of Dead Zones
- Dead zones pose risks to organisms, especially in deeper ocean zones, due to low oxygen availability.
Ocean Layers
- The five main ocean layers from shallowest to deepest: Sunlight, Twilight, Midnight, Abyssal, Hadal.
- Photosynthesis occurs in the Sunlight Zone where sunlight penetrates for plant growth.
- Coral reefs exist only in specific layers that receive sunlight and thrive in shallow waters.