L5 Extreme Environments

Question 1

What are the factors of deep sea systems
Types of deep sea systems

Answer 1

• high pressure
• low temperature
• depth (lack of sunlight/photosynthesis and food)
  Types:
• soft bottom: abyssal plain
• hard bottom: sea mount, oceanic trenches
• vent habitats: hydrothermal vents and cold seeps

Question 2

What are the energy sources of extreme deep sea habitats ?

Answer 2

• Phytodetritus: falling products from algal blooms
• food falls: animal carcasses
• chemosynthesis: Methane and sulfur rich fluids (brine pools- cold seeps) provide energy for chemosynthetic bacteria

Question 3

Discuss hydrothermal vent formation and chimney forms

Answer 3

• formed as a result of cold seawater percolating through fissures in the ocean crust in areas of subduction, heated by magma and re-emerges as hot mineral rich waters
• high concentration of suffixes such as iron and manganese form chimneys
  Black smokers: formed from deposits of iron sulfide
  White smokers: formed from deposits of barium, calcium and silicon

Question 4

Discuss whale falls as a habitat

Answer 4

• Whale falls occur frequently along migration routes - support thriving communities
• Home to several crab species (tanner crab) which feed on flesh, osedax worms which feeds in oils from bones and sea anemones which colonise the skeleton