Rocky Shore Flashcards
The fate of the incoming sunlight over the sea
Most reflected or absorbed by atmosphere
Most hitting sea is used to heat water and promote evaporation
Only about 2% used by algae for photosynthesis
Important abiotic factors on the rocky shore
- Sunlight
- Wave action
- Rock type
- Tides
- Salinity
- Temperature
- pH
Advantages of wave action
Mixing of:
- Oxygen
- Food
- Nutrients
Disadvantages of wave action
- Abrasion
- Isolation and dehydration of organisms
Adaptations to deal with wave action
Behavioral:
- sheltering in crevices
- living high up or low down shore
Structural:
- flattened or streamlined shape e.g. seaweeds, mussels
- cementing/byssus threads to attach to rocks e.g. barnacles and mussels
- ability to roll in waves e.g. periwinkles
Some extreme factors in a rock pool
Rapid changes in:
- Temperature
- Salinity
- pH
Frequency of tides
- Roughly twice a day the tides rise and fall
- Every 14 days there are spring tides
Spring tides
- When the sun and moon align to pull together on the water
- every 14 days, full and new moons
- highest and lowest tide levels at these times
Cause of tides
- Gravitational pull on large water bodies by sun and moon
- Water bulges on both sides of the earth in the direction that the gravitational pull occurs
Adaptations to prevent drying out
Behavioural:
- sheltering in pools
- hiding in moist crevices or under seaweed
Body design:
- Small surface area to volume
- coverings to trap water e.g. operculum in winkles
Secretions:
- mucous to keep organism moist
Producers on the rocky shore
Red, green and brown algae
- Sea lettuce
- (Ulva sp.)
- Green algae - a producer
- Common in Balanoid Zone
- Limpets
- (Pattella sp.)
- grazers of algae
- Larger limpets an indicator species of Cochlear Zone
- Sea urchins
- grazers of algae
- Common in rock pools and in sublittoral zones
- Winkles or periwinkles
- Grazers of algae
- Larger ones found lower down shore, small ones called Littorina indicator species in the Littorina Zone
- Mussels
- Filter feeders
- Found in Lower Balanoid zone and
- Sea Anenome
- Predator - catches small prey with tentacles and stings
- Common in rockpools and sheltered rocks and crevices in Cochlear Zone
- Hermit Crab
- Scavenger
- Found in rock pools, uses discarded shells for shelter
- Shore Crab
- Scavenger/occasional predator
- Found in rockpools
- Phytoplankton
- Tiny, microscopic producers
- Found floating in top surface layers of the sea
- Zooplankton
- Tiny, microscopic animals
- Found floating in top surface layers of the sea
- Barnacles
- Filter feeders
- Indicator species of Balanoid Zone
- Klipfish
- Omnivor consumer
- Rockpools and Sublittoral Zone
- Black backed seagull
- Top predator / scavenger
Tolerance
Ability to survive specific conditions according to specific adaptations
Zones on the rocky shore
- Supralittoral Zone - splashed only occasionally
- Littorina Zone - covered only spring high
- Upper Balanoid Zone - covered neap high
- Lower Balanoid Zone - exposed neap low
- Cochlear Zone - exposed only spring low
- Sublittoral Zone - never exposed
Indicator organisms of Littorina Zone
- small black winkles (Littorina sp.)
- Purple Laver (Porphyra sp.)
Indicator organisms of the Balanoid Zones
Barnacles (Tetraclita sp.)
Indicator organisms of the Cochlear Zone
Cone and pear limpets (Patella sp.)
Indicator organisms of Sublittoral Zone
Kelp (Ecklonia sp.)
Red Bait (Pyura sp.)
Purple Laver
