Cycling Systems Essay, Research Paper
Decaying material sinks to the bottom of ponds/lakes/seas.
Problem ? the producers ( phytoplankton)
are at the surface ( where there is light ) so nutrients from decay must be
brought to the surface by water currents. 1.
Winter ? Water
circulates freely. Cold water at surface
sinks, circulating nutrients but cold temperatures and little light reduce
Spring ? Nutrients
are available , increased temperatures and increased daylight result in
increased productivity ( Spring bloom) 3.
Summer ? Warm water
rises and so colder water is trapped below a thermocline so nutrients are trapped at the bottom. Nutrients at top are quickly used up by
plants resulting in decrease in productivity and decreased number of consumers
dependent on plant life. 4.
Autumn ? Water at
surface cools and sinks allowing recycling of the nutrients and increased
productivity (Autumn bloom). Growth is limited by reducing temperatures and