Oceanography Chapter 1

 Salinity is the amount of salt dissolved  in a liquid.

The salinity in most ocean water is 35 salt per gram; in places such as the Dead Sea, where a great deal of evaporation takes place, the salinity is higher, around 40 salt per gram.

Most icebergs are made up of fresh water.  Large icebergs float in ocean water because they are less dense; ocean water is more dense than fresh water.

SCUBA divers do not venture to depths lower than 300 feet because the pressure is too great.

Divers don't return quickly to the surface after venturing to the depths of the ocean because nitrogen bubbles can form in their blood and tissues, causing a condition known as the bends.

Ocean life is classified into 3 groups:

• Plankton - animals and plants that are microscopic and float at the surface.  Animal and plants in this group include larval lobster, krill, and phytoplankton.

• Nekton - animals that swim.  The octopus, turtle, and whale are part of this group.

• Benthos - animals and plants that live on the ocean floor.  The clam, sponge, and coral are included in the Benthos group.

These groups are based on the depth at which they live.

Phytoplankton produce 80 percent of the oxygen on our planet through a process called photosynthesis.

About 98 percent of ocean life lives on the ocean floor.

All ocean food chains start with phytoplankton.

	Ocean Properties
	Light	Temperature	Density
Surface of the Ocean	High	High	Low
Depths of the Ocean	Low	Low	High