KOROR STATE GOVERNMENT MARINE TOUR GUIDE ... - C3

Usually, spawning occurs 3-5 days after the full moon. The process actually begins six
months before as the eggs and sperm start to develop within the polyps. Mass spawning
usually lasts about a week, with different species of corals spawning at different times
during the night and on different nights. Eggs and sperm float on the water’s surface,
where they combine and develop into a planula, the free-swimming planktonic larval
stage of a coral.
Depending on the coral species, the planula may stay as part of the plankton from
weeks to months. When it is time to settle, the planula attaches itself to a vacant patch of
reef and starts to grow into the ‘founder’ polyp for a new coral colony.
Human Impacts and Use
Coral reefs are under threat world wide. Increased nutrient levels in the sea, caused by
agriculture, industry and urbanization supports algal growth. Algae may eventually out –
compete and smother corals. Increased sediment loads from rivers and run-off not only
decreases water clarity, but also physically smothers coral. On a localized scale,
anchors and divers, particularly in high-use areas can cause high levels of damage.
Coral Color
Many visitors are surprised that corals do not appear as colorful as they do in pictures in
magazines. This is because these photos were taken using a flash.
White light is made up of all the
colors of the rainbow, but water
filters out these colors at
different depths with red and
yellow disappearing first, leaving
green and blue. This gives the
reef a predominantly blue-green
appearance at depths over 10m.
The bright colors of corals can
be seen in the shallows, but in
deeper water, an underwater
flashlight or flash on a camera is
needed.
PCS
Coral Identification
The easiest way to classify hard corals is by their appearance as follows:
• Branching
• Table
• Plate
• Boulder
• Vase
• Bushy
• Solitary
• Mushroom
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