FDSD: Species Interactions & Physical Factors Flashcards
What factors interact to control species distribution
Abiotic and biotic factors
What are the three zones on a shore
Littoral fringe (Cyanobacteria, periwinkles)
Eulittoral zone (barnacles, fucoid seaweed)
Sublittoral fringe (laminarian seaweeds)
What gives coral their colour
Zooxanthellae
What do reef-building corals have in their tissues
Zooxanthellae live at density of up to 1 million cells.cm-1 coral tissue.
These photosynthetic dinoflagellates live in symbiosis with coral
How do coral and algae symbiosis benefit
Coral provide protection nutrients (phosphates, nitrogenous and CO2)
Coral get O2 and food from photosynthesising Zooxanthellae.
What physical factors limit coral distribution due to Zooxanthellae requirements
Temps 18 - 30°C
Solid substrate for growth
Access to light - shallow clear water
Narrow range of salinity tolerance
What are the 2 main abiotic factors limiting species distribution
Temperature
Moisture
When does coral bleach
Changes in environment conditions such as salinity, light and mainly temperatures can kill algae causing the coral to expel them resulting in bleaching
What factors trigger coral bleaching
Increase/decrease in water temps (A change of 1 degree for 4 weeks can cause bleaching
Reduced pH (acidification)
Low salinity (increase freshwater input)
Pollution (nutrients, sediments)
Increase solar radiation
Non biodégradable chems in sunscreen
What does ocean acidification lead to
Weakening of CaCO3 skeleton of reef building corals
What temperature should waters be kept at to avoid bleaching
Temperature rises must be kept to less than 1.5°C to save >10% of the worlds corals
What coral species possesses an adaptation that allows it to survive in high temps and acidity
Orbicella faveolata
(Mountainous star coral)
What factors influence species distribution
Dispersal
Behavior
Other species
Physical & chemical factors
