Primary productivity Flashcards
What are the different pelagic zones?
- epipelagic (0-200m)
- mesopelagic (200-1000m)
- bathypelagic (1000-4000m)
- abyssopelagic (4000-6000m)
- hadalpelagic (>6000m)
What are the different benthic zones?
- littoral/intertidal (partially exposed by air)
- sublittoral (low tide-200m)
- archibenthic (200-1000m)
- bathybenthic (1000-4000m)
- abyssobenthic (4000-6000m)
- hadalbenthic (>6000m)
Briefly define what plankton are
- small (0.2 um-2cm)
- limited locomotion
- rely on currents for movement
What are cyanobacteria?
- picophytoplankton
- domain Bacteria, phylum cyanobacteria, class cyanophyceae
- photosynthetic
- ## found solitary or in colonies in all latitudes
What are diatoms?
- nano/microphytoplankton
- domain Eukaryota, phylum ochrophyta, class bacillariophyceae
- contain chlorophyll a, c
- have a true nucleus
- unicellular and encased in silicon
- most dominant in polar and temperate waters
- make up half of organic material in oceans and much of earth’s biomass
- produce 20-50% of world’s oxygen yearly
What are dinoflagellates?
- unicellular and solitary
- micro/nanophytoplankton
- Domain eukaryota, phylum myzozoa, class dinophyceae
- covered in cellulose plating w/ 2 flagella
- contain chlorophyll a,c
- dominate tropical/subtropical latitudes
- are bioluminescent
- cause red tides
- are symbiotic with coral
What are coccolithophores?
- unicellular and solitary
- nanophytoplankton
- has 2 flagella and haptonema hunting threads
- covered in calcium carbonate plates (coccoliths)
- contains chorophyll a,c
- forms calcarous ooze and chalk cliffs after dying
- releases dimethyl sulfide which blocks the sun
What ratio of nutrients do phytoplankton uptake (Redfield ratio)?
106C : 16N : 1P : 0.0075Fe
In what areas is there low chlorophyll a concentrations?
Southern ocean, eastern equatorial ocean, subarctic northern pacific
Which phytoplankton can convert atmospheric nitrogen into its organic form (nitrogen fixation)?
cyanobacteria
Where is primary productivity highest and why?
- along coasts and in shallow sea
- upwellings and runoff
What are the parts of a seaweed body?
- blade
- thallus (body)
- holdfast
- stipe (foot)
Why are seaweeds/algae not plants?
- no vascular system
- no roots
- no true leaves
- absorbs water and nutrients directly from water
How do seaweeds (briefly) reproduce?
1) sporophytes release zoocytes (spores) from the sporangia
2) spores settle and develop into gametophytes
3) male gametophytes produce sperm and female gametophytes produce eggs
4) sperm and egg fertilize and form a zygote that later becomes a sporophyte
What algal genus has an opposite lifecycle to other seaweeds?
Mastocarpus
What is the compensation depth?
deepest depth of algal growth, provides the minimum amount of light provided for only growth
What are some characteristics of green algae?
- coenocytic growth (divided unicellular body)
- freshwater
- chlorophyll a,b + carotenoids
- uses calcium carbonate and toxins as defense against herbivores
What are some characteristics of red algae?
- marine
- various pigments and chlorophyll
- gelatinous cellulose based cell wall
- grows in tight spaces/uses calcium carbonate as defense
What are some characteristics of brown algae?
- marine
- chlorophyll + fucoxanthins for colour
- cell wall strengthened with alginate
- uses bladders and stipes to keep upright
- sargassum: species that forms large rafts in sargasso sea
- can be used as thickening agents in food
What services do seagrass meadows provide?
- carbon sink
- primary producer
- habitat/nursery
- sediment deposition + stabilization
- material supplies for rope, thatching
What important service do salt marsh plants provide?
run off filtration
What are the different parts of mangrove root systems?
above water:
- prop roots (lateral growth)
- drop roots (horizontal growth)
below water:
- anchor roots (lateral growth)
- cable roots (horizontal growth)
How do mangroves adapt to salty conditions?
- secrete excess salt
- shed salty leaves
- confines salt to xylem
What are the differences between GPP, NPP and NCP?
gross = total growth + respiration
net = growth - respiration of autotrophs
community = growth - respiraton by autotrophs and heterotrophs
