Ocean Water and Life

Salt in the Ocean Salinity is the total amount of solid material dissolved in water. Salinity is expressed by the amount of salt found in 1,000 grams of water. Therefore, if we have 1 gram of salt and 1,000 grams of water, the salinity is 1 part per thousand, or 1 ppt.

Salinity The average ocean salinity is 35 ppt or 3.5% Dead Sea is 300ppt or 30 % SALT

Where does the salt come from Chemical weathering of rocks Earth’s interior.

Ocean Temperature The ocean’s surface water temperature varies with the amount of solar radiation received, which is primarily a function of latitude.

Temperature Variation with Depth The thermocline is the layer of ocean water where there is a rapid change of temperature with depth. The thermocline is a very important structure because it creates a barrier to marine life

Marine Organisms

Classification of Marine Organisms Marine organisms can be classified according to where they live and how they move.

Plankton Organisms—algae, animals, and bacteria—that drift with ocean currents.

Plankton Phytoplankton are algal plankton-microscopic algae Zooplankton are animal plankton Ex: fish, sea stars, lobsters, & crabs

Nekton Animals capable of moving independently of the ocean currents, by swimming or other means of propulsion.

Benthos Organisms living on or in the ocean bottom.

Divisions of the Ocean and Feeding Relationships

Ocean Depth and Light Euphotic – where photosynthesis occurs Disphotic- where light can still be measured Aphotic- NO light reaches

Water Depth Pelagic zone– open ocean of any depth -animals in this zone swim or float freely Benthic zone- includes sea-bottom surface regardless of distance from shore -mostly benthos organisms that attach to, crawl upon, or burrow into the seafloor Abyssal zone- subdivision of benthic zone -this zone is characterized by extremely high water pressure, low temps, no sunlight, and sparse light.

Giant Squid Very RARE to actually see them Can grow well over 60 feet

Bioluminescence is the production and emission of light by a living organism as the result of a chemical reaction

Feeding Relationships A trophic level is a nourishment level in a food chain.

A food chain is a sequence of organisms through which energy is transferred, starting with the primary producer. A food web is a group of interrelated food chains