Question

1. what is the average salinity of seawater?
2. name the layer of the ocean that is warmed by the sun.
3. what causes ocean tides?
4. define ocean currents.
5. what happens to corals when ocean temperatures rise too much?
6. how does salinity affect the density of seawater?
7. what is the primary effect of ocean acidification on marine organisms?
8. what two factors drive ocean circulation?
9. describe what a thermocline is in simple terms.
10. why are coral reefs important to marine ecosystems?

Explanation:

1. The average salinity of seawater is about 3.5% or 35 parts per thousand. This is due to the presence of various dissolved salts like sodium - chloride.
2. The sun - warms the uppermost layer of the ocean, called the epipelagic zone or the photic zone.
3. Ocean tides are caused by the gravitational pull of the moon and the sun on the Earth's oceans.
4. Ocean currents are the continuous, directed movement of seawater, driven by factors like wind, temperature, and salinity differences.
5. When ocean temperatures rise too much, corals expel the symbiotic algae (zooxanthellae) living in their tissues, a process called coral bleaching.
6. As salinity increases, the density of seawater also increases because more dissolved salts add mass to a given volume of water.
7. The primary effect of ocean acidification on marine organisms is the interference with the formation of their calcium - carbonate shells and skeletons.
8. The two main factors driving ocean circulation are wind and differences in water density (thermohaline circulation).
9. A thermocline is a layer in the ocean where there is a rapid change in temperature with depth.
10. Coral reefs are important to marine ecosystems as they provide habitats for a vast number of marine species, protect coastlines from erosion, and are a source of food and income for many human communities.

Answer:

1. About 3.5% or 35 parts per thousand
2. Epipelagic zone/Photic zone
3. Gravitational pull of the moon and the sun
4. Continuous, directed movement of seawater driven by wind, temperature, salinity differences
5. Coral bleaching (expel symbiotic algae)
6. As salinity increases, density increases
7. Interference with formation of calcium - carbonate shells and skeletons
8. Wind and differences in water density
9. A layer with rapid temperature change with depth
10. Provide habitats, protect coastlines, source of food and income