Lecture 1 - Intro Flashcards
Deep Sea by Volume
78.5%
Deep Sea by SA
62.2%
Deepest part of the ocean
Marianas Trench, Challenger Deep
10,911 m, 35,798 ft
Average depth of the ocean
3808 m, 12460 ft
Properties of the deep sea (7)
Dark Cold High Pressure Salinity Low O2 Stable Food Poor
Why is the deep sea dark?
Which ocean is colder?
Pacific
Average temp of the ocean
3.5*C
Variation in Salinity
little variation 34.7-36.5%
Important for defining land masses
Areas of low O2
O2 minimum layer
Anoxic basins
Hydrothermal vents
Anthropogenic hypoxia
Over time (millions of years) what has happened to temp and O2?
Both have decreased over time
Why is the deep sea food poor?
Food originates at the surface and sinks
Declines by 10x each km
Deep Sea Habitats (6)
Pelagic realm Soft bottom (B) Hard bottom (B) Hydrothermal vents (B) Hydrocarbon seeps (B) Fall of large organisms (B)
What defines the Pelagic realm?
little structure/surfaces
only microhabitats are biological
widest variety of higher taxa
What defines soft bottom?
extremely fine mud
rich infauna as well as epifuana
What defines hard bottom?
exposed rocks where little grows expect for in strong currents
What defines hydrothermal vents?
unstable, short-lived habitats
hot, sulfide rich waters
high animal biomass
What defines hydrocarbon seeps?
longer lived and colder than hydrothermal vents
Two types of adaptations
Adaptations for survival
Adaptations due to relaxation of selection factors
Adaptations for survival deal with…
low food high pressure darkness mate-finding etc.
Adaptations for relaxation deal with…
absence of turbulence
absence of visual predation
stability (restricted temp tolerance)
Deep Sea by SA
62.2%
Deepest part of the ocean
Marianas Trench, Challenger Deep
10,911 m, 35,798 ft
Average depth of the ocean
3808 m, 12460 ft
