rocky shore ecosystem Flashcards
location
all over the planet where are the bedrock and large boulders exposed at low tides
what’s the substrate
rock
physical characteristic: intertidal air water
exposed to air and covered by water
temperature
wide variation especially in the air
light
lots in air, but it water varies with depth
energy
variable on location
chemical characteristics (salinity, oxygen, nutrients)
salinity: wide variation in air and in tidepools with precipitation and evaporation
oxygen: variation in tidepools, not very accessible to the most intertidal organism in the air
nutrients: moderate to high due to proximity to land
how is the distribution of organisms in the … bands
horizontal
how many zones are?
3! high, middle, and low zones
why there are 3 zones?
because of differing tolerances of organisms to stresses (biotic and abiotic)
what can you find in upper tidal?
periwinkles: limpets, lichens, encrusting algae
what can be found in middle intertidal?
barnacles dominant, mussels, seaweeds
what can be found in the lower intertidal?
seaweeds, surf grass
what are the limits of organisms for upper limits?
set by abiotic factors such as desiccation, temperature, salinity, food, oxygen availability
what are the limits of organisms for the lower intertidal?
set by biotic factors such as competition, predation, herbivory
what is desiccation?
water loss, drying out
when does desiccation occur?
during low tides due to air exposure
how can desiccation increase
with wind and temperature
what species are more tolerant to be in the air?
periwinkles, limpets, Fucus, Porphyra so can live longer in the intertidal zone
what kind of adaptation organisms develop due to desiccation?
- lose water then rehydrating
- Mucus (fucus, anemones)
- conserve water
- live in the tidepool
the temperature on rocky intertidal of air, water?
- water temperature varies slightly
- air temperature can vary drastically?
how does temperature impact organisms?
organisms out of the water are subject to greater variations in temperature
adaptations to temperature
- evaporative cooling in mussels and gooseneck barnacles
- mucus in anemones
- eurythermal enzymes(able to tolerate a wide range of temperatures) in barnacles but not in sea urchins/sea stars
how can salinity increase?
with evaporation or decrease with freshwater input
how can salinity decrease?
fresh water input
how are called the organism that is tolerant to wide variations in salinity
euryhaline (mussels, barnacles)
how are called the organisms that can tolerate a narrow range of salinity?
stenohaline (sea stars)
what are the adaptations to salinity?
close up (barnacles, mussels, anemones) ion pumps in gills crabs
where do the organisms get their food from?
from water (plankton), can only feed when underwater
where do organisms obtain oxygen from?
water
adaptations to food and oxygen availability
low activity levels at low tide
- feed/take in oxygen the whole time they are underwater (barnacles, mussels)
- scaleless fish can absorb O2 across the body
- modified O2 absorption
adaptations to UV light
- sunscreen natural compound that absorbs UV
- protective shells
- under rocks and overhangs
adaptations to wave exposure
hang on (mussels make byssal threads, some seaweeds are flexible)
biotic factors
competition, predators, herbivory
how is called the direct interaction type of competition?
interference
how is called the differential use of resources type of competition
exploitative
the between species type of competition
interspecific
between individuals of the same species type of competition
intraspecific
what are the 2 types of predators?
generalists (eat a wide range of food types) and specialists (eat a single prey type)
what are the adaptations to predation?
- protective shells (hermit crabs)
- camouflage
- chemical defenses in nudibranchs
- escape responses
- mutualistic associations
what are the adaptations to predation?
- protective shells (hermit crabs)
- camouflage
- chemical defenses in nudibranchs
- escape responses
- mutualistic associations (keyhole limpet and scale worm)
what are the refugees from predations?
- height in intertidal
- size (some mussels are too big to be eaten)
- space (limpets living on vertical surfaces to avoid predation)
is herbivory similar to predation interactions?
yes
what’s herbivory?
animals eating plants/seaweeds
what are the refugees from herbivory?
chemical defenses (sulphuric acid in desmarestia)
- physical defenses (calcium carbonate in coralline algae)
- height in the intertidal
what are the upper limits set by?
abiotic factors (desiccation, temperature, salinity, food and oxygen availability)
what are the lower limits set by?
biotic factors such as competition, predation, herbivory
