MAFS 110: Aquatic Resources - Water as an Environment

Study Notes

Water covers three-quarters of the Earth's surface, existing in three physical states: liquid, solid (ice), and gas (water vapor).
Water is essential for life on Earth, being a critical component of all biological processes.
The unique chemistry of the water molecule allows it to exist in all three physical states.

Water molecules consist of two hydrogen and one oxygen atom, which creates an asymmetry in the molecular structure.
This asymmetry leads to strong bonds between water and other polar molecules.
Cohesion, the ability of water molecules to stick together, helps plants take up water at their roots and contributes to water's high boiling point.
Water is an excellent solvent, capable of dissolving a wide variety of molecules, earning it the term "universal solvent."

Water plays a crucial role in cell transport and use of substances like oxygen, nutrients, and drugs.
Water helps maintain cell shape by creating pressure in the cell.
It also contributes to the formation of cell membranes.

The hydrologic cycle is a natural system where water is constantly recycled through the atmosphere, rivers, and oceans.
Water is an essential, renewable resource that occurs naturally on Earth.

Aquatic ecosystems can be divided into two main categories: marine and freshwater ecosystems.
Freshwater ecosystems can be further divided into:
- Aquifers and springs (groundwater)
- Rivers and streams
- Lakes and ponds
- Wetlands
- Lagoons and estuaries
Aquatic ecosystems support aquatic plant growth, provide habitats for animals, and offer nutrients and minerals necessary for aquatic life.

Biotic factors are living elements in an ecosystem, including producers, consumers, and decomposers.
Abiotic factors, such as light, temperature, oxygen, nutrients, and pH, determine where organisms live in water.
Temperature affects the activity levels of organisms in water, with optimal temperatures varying among species.