Tide Pool Flashcards
The intertidal borders the ?
Subtidal zone which is always submerged
The intertidal zone is exposed during ?
Low tide
The substrate in an intertidal zone can be ?
Soft or rocky
Soft v. Rocky
Sand silt or mixture (mud)
Type of rock present and the degree or height of the slope
Epifauna
Organisms that live on the surface of a substrate
Mud snails on soft
Barnacles on hard
Infauna
Organisms that live in the substrate
Clams burrowed in soft bottoms
Meiofauna
Organisms that are so small they live in between the grains of soft substrate
Attached: sessile
Or motile
Organisms face a variety of challenges including
Desiccation Temperature changes Salinity changes Interrupted feeding Wave action oxygen availability and build up of CO2 Limited space
Water loss is more pronounced on what kinds of days , they deal with this potential water loss by?
Hot dry windy
Clamming up
What does a snail use to clam up into or breathe ?
Operculum
A motile organisms may move where to not lose water ?
Tide pool or area with more moisture
Hiding may also mean that organisms live in places where postures remains like ?
Crevices in a rock or low spots in soft bottoms
What is the downside of clamming up
No exchange of gas or feeding
What are some mechanisms marine animals have to keep cool
They have a light color so it’s cooler
They have ridges in their shells to increase surface area
How dramatically can salinity change , what is normal ocean salinity , estuarine salinity
40+ ppt
33-35 ppt
5-30’
Organisms in the intertidal zone are ?
Organisms in the sub tidal zone are ?
Euryhaline : can tolerate large changes
Stenohaline: can tolerate little changes dealing with salinity
Salinity may start at what ?
20-25
Goes down because of thunderstorm
Goes up because of water loss when intertidal is exposed
When does feeding cease for filter feeders
When exposed to air, like barnacles
How do snails feed at low tide
Scraping algae off surfaces
For communities with semi diurnal tides an organism could?
Nearly half of their day in submerged and not feeding
The degree of impact of waves affects , waves conform to shoreline in order of
Their distribution
Decreasing depth
Waves are a disturbance to organisms living directly exposed by? Which type of shoreline is often exposed to them harsher, in soft bottom communities who is exposed to them ? Marsh communities?
Dislodging them from their habitat
Rocky shorelines
Open beaches
Not exposed to a lot because positioned behind open beach
When can oxygen be exhausted
When an organisms clams up during low tide or if there are a lot of organisms living there
When does carbon dioxide build up? Some species have
When organisms cannot exchange these gases with their environment
Evolved the capability to exchange gases in air and water-crabs
Where is space the most limited , in soft bottoms space is limited why ?
Rocky intertidal environs,tons where surface area is limited
Organisms prefer hard substrate like oyster reef so that they don’t need to worry about washing away because of wave action
Intertidal zone is the area between
Mean low tide and mean high tide
Zonation consists of what levels
Upper intertidal
To middle and lower intertidal
What is normally on the upper intertidal zone
Periwinkle , lichen , encrusting algae, limpets
What is normally on middle
Barnacles , mussels, seaweed
What is normally in lower intertidal
Seaweeds , surf grass
Where is competition greater and why , it is always more …. Rich?
In lower intertidal because it is the least severe and exposed less
Species
What is distribution determined by
Toleration, competition, predation
Little gray barnacles v. Rock barnacles
Gray can tolerate being higher up because can tolerate desiccation, however can’t go too low because of competition from rock barnacles.
Rock barnacles can’t go high up because can’t tolerate desiccation, don’t go too low because predation of dog whelks and competition with mussels
When one organism is a better competitor of another , it will outgrow the other when the environment is ?
Un disturbed
If a habitat is disturbed , organisms move in and are later excluded in a predictable pattern known as
Succession
What will form when the community is undisturbed for and extended period of time ?
Climax community
Does a climax community have the highest diversity ?
No
Low disturbance means
The organisms best suited to resource acquisition will dominate
High disturbance
The organisms most resisted to disturbance or rapidly colonizing will dominate
Intermediate disturbance hypothesis
Suggests that the highest diversity will occur when a middle or moderate amount of disturbance occurs
The smaller the particles size the less ?
Oxygen that can fit in these spaces
Clay , silt , sand , gravel
.004,.062 ,2 mm
The size also affects how ?
Water drains
I’m coarse it drains quickly ,min fine it drains slowly
In poorly sorted water is blocked
The grain size in most intertidal communities is so ….. That all except the top few inches will be ?
Small , anoxic (without oxygen)
In fauna must maintain a connection with oxygenated zones via
Tube, siphon, extended burrows
What exists in the anoxic zone
Anaerobic bacteria the break down organics
What forms the basis for soft bottom communities
Chemoautotrophs, detritus, photo autotrophs (producers)
Who are the consumers in a soft bottom community
Detritus, suspension feeders( crabs sand crabs polychaetaes) , deposit feeders (polychaetes crabs) , carnivores (fishes birds moon snails)
The food web in the rocky intertidal zone is based on
Autotrophs such as sea grasses, algae and diatoms
Top carnivores in any community that have the ability to?
Change community composition significantly are known as keystone species
