marine environment 2 and 3 + microbes Flashcards
define the term biodiversity
- Includes all of the variety of all living organisms (all encompassing) and is short for biological diversity)
are there more marine species than non marine species in terms of macroorganisms?
no, there are signifcantly fewer then non- marine
15% are marine
80% is terrestrial
5% is freshwater
why are there many more non marine macro organisms than marine?
- the taxonomy of marine specied is relatively underdevelopmed and ther is a higher proportion of undescribed species.
- Nevertheless, the total amount of marine species is unlikely to even approach the number of non-marine ones
- Estimates vary but most suggest theta there are fewer than 500,000 species of marine eukaryotes
- Due to a few high diversity groups most noticeably insects (950,000 describes species with only a few marine species), flowering plants ( 250,000 describes species with only 100 marine species
- others suggest amount of productive habitats and low habitat complexity
state the number of animal phyla with species that are exclusively marine, marine and non marine and exclusivly non- marine
Exclusively marine
15
Eg. Echinodermata, ctenophora, chaetophora, chaetognatha
Marine and non marine
17
Eg. Porifera, cnidaria, Mollusca, bryozoa
Exclusively non-marine
1
onychophora
why is there a greater amount of phyla in marine species?
- Related to the fact that all animal phyla originated in the marine environment (‘default condition)
describe the difference between pelagic and benthic biodiversity.
- need to study animals and other heterotrophs to understand broad-scalepatterns (because most primary producers need light, which is only found in shallow waters)
- many more benthic than pelagic species 200,000+ versus <30,000
- e.g. all 32 of the marine phyla have benthic members; only 11 include species that are permanent residents in pelagic environments
- this is partly related to the fact that the marine fauna originated in the benthos (‘default condition)
describe how marine species diversity varies with latitude
- more good data is needed to understand patterns in marine species
- diversity tends to decrease with increasing latitude for some groups (eg gastropods)
- but there are other groups that do not show this pattern (macroalgae)
- There are many hypothesis by the reasons are not fully understood
- the gastropod study found that species diversity was correlated with solar input, and so possibly linked to some element of productivity.
relating to latitude where is the highest point of diversity?
at the equator and low diversity at the poles
where and why does water sink
poles have more salt and solder water as as it hits other water masses its more sense so it will sink and continue to do so
effects of temperature in the ocean
effects metbolic rate of ectotherms
organisms tliving in the mesopelagic and bthypelagic and deeper have a slow metbolic rate and appear sluggish
the effects of depth related pressure on marine organisms
1 atm for every 10m deeper
pressure with depth is linear
bathypelagic and deeper high to very high pressure
effects-
mostly unknown as it hard to replicate
- because most marine organiims are water and solids which are only slightly compressible and therefore resistnt to changes in volume
- however organisms with gas filled structure are highly susceptile to the effects of pressure
- when organisms are taken too quickly fromt heir pressure zone they can suffer from baroatrauma
- the very high pressure may also effect cell function eg. Membraines enzymes and other molecules
- bacteria most highest at high temp and low pressure
the effects of depth related ambient light on marine organisms
epipelagic = euphotic zone ( part of the environment where light is sufficent fro photosynthesis)
mesopelagic= twilight zone
bathypelagic of deeper = no ambient light
effects-
Food production
- no food ofr production beyond epipelagic zone
- oganisms below this zone typically rely on organic matter falling from above ‘marine snow’
- organic matter progressively used as it falls through water collum.
- mesopelagic, and especially bathypelagic and deeper environments tend to be food limited
- biomass decreases by about an order of magnitude (10X) per 1,000
how does dissolved oxygen vary with depth and what are efects on marine organisms?
epipelagic= highest
mesopelagi = ,ow/minimla
bathypelagic or deeper = intermedicate to high
this it because theres is a higher number of organisms to consumer the oxygen but as depth increases oxygen less biomass to consume this oxygen therefore oxygen levels are higher
effects/ adaptations
- Hemocyanin- picks up the oxygen and transfers it around the body found in organisms other than humans
- Gill surface area is larger for cephalopods to allow for more area for O2 to be diffused
define key marine microbeal groups
bacteria- is prokaryote,
fungi yeast, microalgae, slime moulds viruses
describe the main source of energy of bacteria
mainsource of energy for bacteria is from solar energy but some is also based on oxidation of H2S gas in hydrothermal vents
chemoautotrophs are non-photosynthetic and obstian nutrition from non-biological sources such as sulphur and methan
