• have a metabolism (the use of energy)
• react to the external environment
• grow
• reproduce

• Contain Carbon, Hydrogen, Oxygen
• Other elements in lesser amounts
• Contain energy
• Takes energy to make them, yields energy when you break them apart

• Photo/Chemo - synthesis
• "Food", breakdown of organic compounds

• "self-feeders"
• includes photosynthetic and chemosynthetic organisms
• primary production

• "other feeders"
• feed on other organisms

• Light energy is captured and converted in chloroplasts: pigments
• different species have different ones
• all that have chloroplasts have Chlorophyll a

e.g., Cu, Zn, Ni, Co, Fe, Mo, Mn, B, Na, Cl

Generally, these are required to act as cofactors in enzymes

Iron is well recognized as being in short supply over large parts of the ocean. It is particularly important in Nitrogen Fixation. Copper, Zinc and Nickel have also been implicated in influencing the growth of open-ocean phytoplankton. Trace element interactions are complex, and incompletely understood.

• Phytoplankton are most abundant where there are nutrients
• Nutrients are highest near coastal regions and in upwelling zones

• rivers, streams, and agriculture (runoff)
• upwelling
• recycling (messy eaters)
• atmosphere (CO2, N2)

• advantage of small size
• simple diffusion to supply nutrients and remove wastes - large SA/V ratio

Surface area increases as the square of the diameter.

Volume increases as the cube of the diameter.

• Nutrients and waste products must pass through the cell membrane
• Most phytoplankton cannot rely on passive diffusion!

Diffusion Mechanisms:

• Passive Diffusion - (based solely on the gradient of concentrations)
• Facilitated Diffusion - "channels" allow ions to move through the cell wall
• Active Uptake - There are transporters on the cell wall

• time spent in the photic zone
• nutrient availabillity (e.g. nutrients sink)
• the photic zone is often shallower than the mixed layer but cells circulating in the mixed layer are continually brought into the photic zone
• pycnocline limits vertical mixing to the upper regions of lakes and oceans, once cells sink below it they are lost from the population

• Trophic levels: each level of organism
• Trophic transfer: percentage of energy

• Carbon - present in all organic molecules
• Nitrogen - found in proteins and nucleic acids
• Phosphorus and silicon - found in rigid parts of organisms
• Iron and trace metals - used for electron transport

Biological factors also affect living organisms in the ocean. Some biological factors that affect ocean organisms:

• feeding relationships
• crowding (competition for space)
• Metabolic wastes
• Defense of territory

• Diffusion - mixing due to random molecular movements
• Osmosis - diffusion of water through a membrane
• Active transport - the transport of a substance against a concentration gradient. It requires energy input.

High tide to 200 m depth
Characterized by :

• Shallow water, so large fluctuations in temperature and salinity
• Tides expose/submerge the shallow neritic
• Breaking waves disperse a lot of energy

Pelagic --> Oceanic zones

Everything seaward of the Neritic Zone

Divided by Depth:

• Epipelagic 0-200 meters (only zone with enough light for photosynthesis! Bottom of the surface waters)
• Mesopelagic 200-1000 meters
• Bathypelagic 1000-4000 meters
• Abyssopelagic 4000-6000 meters
• Hadalpelagic >6000 meters

Mesopelagic 200-1000 meters

• Usually includes the oxygen minimum zone
• Also has the nutrient maximum (700-1000m)
• Bioluminescence is most common here
• Includes the Deep Scattering Layer (DSL)

Bathypelagic 1000-4000 meters

Abyssopelagic 4000-6000 meters

• Includes over 75% of the living space in the oceanic environment
• There is essentially no light
• Most fish are blind or rely on bioluminescence
• Oxygen concentrations increase due to cold, deep polar water masses

• Subneritic Province: extends from high tide line to 200m, and approximately equals the continental shelf
• Suboceanic Province: Everything seaward of the Subneritic Province