L35 - Marine Ecosystems Flashcards
what are ecosystem services?
how ecosystems provide to the huamn population directly (food) or indirectly (filtering air)
how do marine ecosystems provide services?
by water purification, waste management and nutrient cycling
what ecosystem has the greatest phylogenetic level biodiversity?
marine ecosystem
why do marine ecosystems have the greastest level of biodiversity?
they have been there the longest, more time to evolve
what are biodiversity hotspots in marine ecosystems?
coral reefs - 9 million different species
what is ecosystem functioning?
nature provides us with clean water, air and food via biodiversity
what are advantages associated with sea weed?
source of biofuel production
food source
fast growth rate and absorbs CO2
aliginates from seaweed used for combatting disease by cellular reconstruction
what are estuaries?
regions of water where the river meets the sea
what is the hadal zone?
9000m below sea level
what is the most common estuary type?
eustatic sea level rise flooded u-shaped valleys)
example Chesapeake USA
what do offshore deposits cause?
barriers across bays and inlets/ bar built estuaries
what are 3 types of estuary?
1) coastal plains with eustatic sea level rise (flooded u-shaped valley)
2) bar built estuaries (off shore deposits)
3) sinking bays with flooding (isostatic variation driven by tectonic activity)
what effects tidal range?
the shape of the estuary
how can we classify estuaries?
tidal range:
microtidal <2m
macrotidal 4-6m
hypertidal >6m
what are estuaries a source of?
renewable energy
how is salinity in an estuary measured?
proxy equipment
how does salinity characterise estuaries?
it shows how well the water is mixed
what is sediment in estuaries?
soft fine silt rich in OM
how are species characterised within estuaries?
oxygen and salinity levels
what does sediment produce during anaerboic breakdown?
CH4 and H2S
what is zone 1 in relation to an estuary?
head of estuary river , low salinity (5)
what is zone 2 in relation to an estuary?
main mixing area of fresh river water and salinity ocean water
what is zone 3 in relation to an estuary?
salinity is 18-25
what is zone 4 in relation to an estuary?
increasing salinity of 25-35
what is zone 5 in relation to an estuary?
where the mouth of the river meets the sea, fully saline
what organisms are found in zone 1 (fresh water)?
fish
what organisms are found in zone 2?
polychaetes, nematodes, crustaceans and fish
what organisms are found in zone 3?
anthropoda
what organisms are found in zone 4?
filter feeders like mussels and oysters, eels and salmon (migrators)
what organisms are found in zone 5?
no plants, too salty, algae found
what effects Thames Fish Diversity (growth and abundance)?
climate change
