Answer:
Young individuals have a high
probability of dying, but older individuals have a relatively low probability
of dying.
Survival rate for adult sea
urchins are very high while there is a lower survival rate for younger sea
urchins due to higher predation rates and high stress levels associated with
warm sea water temperatures. During the spring, the sea urchins spawn and the
female sea urchin releases millions of tiny, jelly-coated eggs into the water
that are then fertilized by the sperm of the male sea urchin. The tiny sea
urchin eggs become part of the plankton and the sea urchin babies (larvae) do
not hatch for several months. The sea urchin young will not become large enough
to retreat from the plankton and down to the ocean floor until they are between
2 and 5 years old. Due to dredging on the ocean floor and pollution in the
water, the sea urchin populations are declining especially the young sea urchin.
