Select the correct answer.
A herd of sheep moves up the mountain to graze during summer, and migrates to the valley during winter. What type of migration do the sheep follow?
A.
one direction only
B.
seasonal movement
C.
daily movement
D.
one return journey

answer: - few nutrients

high pressure

low temperatures

explanation: 1. few nutrients:   open-ocean zone is located way far from the land, which is the main source of the essential nutrients.2. high pressure: pressure increases by 1 atmosphere for every 10 meters increase in depth.3. ample sunlight: a large fraction of the sunlight is reflected back to the atmosphere from the sea surface. 4. varying salinity: below the thermocline, the water is isolated from the atmosphere so the salinity remains stable over the year.5. low temperatures:   the temperature of open-ocean zone ranges from a low of -2°c to an average of 17°c

it's anything that aren't producers and consumers.

explanation:

you've got to be clear on what "this" is