Oceanic Biology and Chemistry Flashcards
What are Plankton?
Organisms that are unable to control their position against the action of the current
What are the three size categories of Phytoplankton?
Ultraplankton; Nannoplankton; Microplankton
What are the typical members of the Ultraplankton size?
Heterotrophic bacteria, autotrophic bacteria, cyanobacteria.
What are the typical members of the Nannoplankton size?
Coccoliths, silicaflagelattes
What are the typical members of the Microplankton size?
Diatoms; Radiolaria
How to phytoplankton such as diatoms protect themselves?
Elaborate silicon shells that are porous to let materials in and out
Most abundant form of phytoplankton?
Diatoms
What is the importance of phytoplankton frustles
They do not dissolve and they fall to the seafloor to form part of the sediments such as siliceous oozes
What is the importance of dinoflagellate pigmentation and bio luminescence?
Formation of red and brown tides - pale blue at night from bio luminescence
What is importance of coccolithophorid CaCO3 shell?
Shed during death ans sink to form carbonate ooze
What are two important zooplankton groups that ultimately form sediments?
Radiolaria - Silica walls; Foraminifera - Carbonate shells
How to radiolarians produce their glass like exoskelatons?
Absorb silica compounds through their lives and secrete well defined geometric networks called tests.
How can planktonic forams be used to provide useful infomration for past seawater temperatures?
Individual species often only tolerate a very narrow temperature range. Sea surface species can indicate sea temperatures unlike benthic species which stay relatively stable due to low climate variations
How is life distributed from the surface zone to the deep zone
Many herbivores in surface and pycnocline - decrease rapidly to deep zone. Little omnivores in surface zone, increase in pycnocline and decrease half way through deep zone to increase largly in bottom deep zone. Carnivores most abundant in middle of deep zone - fairly similar bottom deep zone and pycnocline to surface.
What is max depth of euphotic zone
~200m
Where can respiration take place and why
Everywhere in oceans as does not require light
What is photosynthesis equation
H2O + CO2 + Nutrients –> CH2O (organic matter) + O2
When is organic matter produced in relation to photosynthesis and respiration
When P > R
Explain the Marine Biological Pump
Phytoplankton use CO2, sunlight, water and nutrients - produce carbohydrates and oxygen - animals eat phytoplankton - leading to oceanic food web - dead phytoplankton and animals sink to deep ocean - some land on sea floor - material of dead organisms is called reduced carbon - carbon oxidised to yield energy, water and CO2 - 0.4% reduced carbont buried and stored - most is used by animals and bacteria and returned to deep ocean.
What general marine areas are net primary productivity per unit area at its highest? And where is production mostly distributed
Coastal zones and upwelings per unit area - mostly distributed in the open ocean
What is conservative and non-conservative properties in respect to seawater composition and classification?
Conservative means it is just affected by mixing and non - conservative means it is affected by chemical/biological processes
What are the major constituents of ocean sea water (each over 100 ppm)
Choride (Cl-), Sodium, (Na+), Sulfate (SO4-^2), Magnesium (Mg^+2), Calcium, (Ca^2+), Potassium, (K+)
What is the average salinity of the worlds oceans
34.7 (34.7 grams of dissolved solids per 1000g sample)
What are the ocean trace elements, (<1ppm)
Nitrogen; Lithium; Rubisium; Phospherous; Iodine; Iron; Zinc; Molybdenum
How can seasonal changes influence primary production?
Storm weather, light limitation, nutrient limitation - seasonal outflows
Why does the Deep Pacific Ocean have more N, P and Si than the Deep Atlantic Ocean?
Deep water concentration increase in response to deep water conveyor/circulation of nutrients
