Lecture 10 - Community metabolism, O2 minimum layer, metabolic rates

Question 1

General idea of metabolic rates of Deep-sea Animals

Answer 1

Rates of processes are slow in the deep sea because of energy limitation (very low concentration of food at depth)

Question 2

What does food limitation mean?

Answer 2

Starving individuals = individuals limited

Adaptations for food = population limited

Question 3

What evidence is there for low community metabolism rates in the deep sea?

Answer 3

O2 in the deep sea even thought O2 replenishment is very slow (about 1/2-1/3 air saturation)
Alvin sandwich still intact after 1 year (community microbial activity very low)
Bell jar and grab respirometers - in situ measurements of benthic comminity metabolism

Question 4

Decrease in benthic community metabolism with _____ is primarily due to what?

Answer 4

depth

decreased community biomass

Question 5

Community rates are lower when?

Answer 5

at greater depths
farther away from land
under less productive regions
(due to low inputs of organic matter)