Ambassadors of the Environment

Dorado Beach, Puerto RicoA collaboration between

Dorado Beach on Puerto Rico, with its coral reefs and forests, is a perfect place to connect people the wonders of nature. Jean-Michel Cousteau’s Ambassadors of

the Environment Program is dedicated to immersing people in these tropical ecosystems and helping everyone appreciate the value of nature.

In the Ambassadors program, we use the City Under The Sea metaphor to understand the ecological roles of the reef creatures. As in human cities, everyone has a job and together all of the work done by residents keeps the community health and running smoothly.

Coral reefs are like cities under the sea because they have power plants, farms, recycling, public housing, public health,

advertisement, managers AND corals are the construction crew that creates the buildings.

Each resident of the reef has a job and all those residents do the work necessary to keep the reef functioning in ways similar to our communities.

These round things are brain corals. Corals are colonies of small animals, called coral polyps, and they are the architects and construction crews of the reefs because their hard skeletons are what coral reefs are made of.

Some of the coral buildings look like skyscrapers.

They grow toward the surface for a reason. Do you know why?

Reef-building corals need sunlight. Sunlight powers tiny algae living inside the coral’s tissues. These algae, called zooxanthellae, perform

photosynthesis and make food that helps corals build the reef structure and food that also supports the reef food web.

This elkhorn coral reaches up toward the surface to get more sunlight for its algae partners. So the coral buildings of this

city under the sea have roof-top gardens or power plants

AND the waste of the animal serves as fertilizer to help the

algae grow.

Brain corals have another way to get sunlight. They use the same strategy as our brains – have lots of meanders to create more surface area for more

cells. In our case, more cells to do more thinking and in corals it’s more space for more algae .

There are many types of corals but they all are green or brown because of the algae living

inside them.

In the day, corals keep their stinging tentacles withdrawn so

their algae can make food.

DAY Coral polyps closed

At night when there is no sun, corals extend their tentacles

to catch tiny animal plankton that drifts by.

NIGHT Coral polyps open

So corals act like plants in the day and animals at night.

There are many types of algae that grow on their own. Like

zooxanthellae, they create food from raw materials and

sunlight. These algae are then food for many reef creatures,

such as damselfish, parrotfish, and sea urchins.

This farmer damselfish has a garden of fuzzy algae, lower left. It sees its reflection as an intruder and attacks the fish that

it thinks might eat the algae.

Parrotfish are the lawn mowers of the coral reef. They graze on algae and keep it from overgrowing the reef. As they graze

they scrape off part of the reef. See the scrape marks lower right.

Parrotfish grind up the algae along with bits of reef and then poop sand. This parrotfish can make 200 pounds of sand each year.

So when you stroll along a beautiful sandy beach remember that part of what you are walking on

has passed through the digestive tract of a parrotfish!

There is a clean up crew in this city under the sea. Lobsters eat dead fish and other stuff on the bottom. Sea cucumbers, right, swallow sand and

digest the dead organic matter, releasing clean sand.

Sponges are also part of the clean up crew. They filter water through their bodies to catch food like plankton and

bacteria. They are like air/water conditioners, keeping the water clean.

This is a queen conch snail. The conch in the upper right has been turned over, center, to show its beautiful shell with two eyes peeking out on the

right. When this conch dies its shell will remain on the bottom.

An empty conch shell is not wasted but instead used as a mobile home for a hermit crab.

In the coral city there is no waste, everything gets recycled.

This Christmas tree worm bores a hole into the coral below it to create a safe place to live. Since there’s no waste on the reef, what do you think is

going to happen to this hole when the worm dies?

The worm’s empty hole becomes a recycled home for another animal, like this blenny!

Just like in our world, the coral city has lots of advertising. This queen angelfish advertises with bright colors to let other fish

know who it is and that this part of the reef is its home.

Bright colors are advertising but there is also false advertising. Notice how these fish either hide their eyes or have

false eyes near the tail. This confuses predators and gives these fish a better chance of escape.

Camouflage is another type of false advertising. This trumpet fish has both color and shape to help it hide

Not only are scorpionfish the color of the bottom but notice how the fish is covered with projections to hide its outline.

Large predators like groupers and sharks are the managers of the city under the sea.

As predators, such as sharks, prey on smaller fish they keep the populations under control and maintain

ecological balance on coral reefs.

In the coral city there is a public health system where doctors help their patients get well.

This is a sick fish because it has a parasite on its head.

This isopod parasite is eating the cheek of this grouper who needs medical help.

These two gobies are the “doctors” and they pick off parasites and dead scales from their patients. They eat what they take from their patients. This is a mutualistic relationship because both parties benefit: the fish “patient” gets its parasites removed and the doctor gets an easy meal.

This cleaner shrimp is also a reef doctor. These cleaners or doctors are safe because it is not smart to eat your

doctor particularly if the doctor provides free health care.

The mutualistic relationship is even more interesting. The chub on the left has changed color to make sure the doctors

know it needs attention.

All of the reef residents have important jobs and together the work they do keeps the reef ecosystem functioning smoothly

Unfortunately, increasing carbon dioxide in the atmosphere, from burning petroleum, is heating up the oceans and making healthy brown corals

(center) get sick and turn white (upper right).

When the oceans become too warm the algae that live in the

corals are lost and the corals turn white. This can kill the

corals and make the entire reef ecosystem sick. The carbon dioxide can also make the

water acidic, preventing corals and other animals from making a hard skeleton.

Many reefs around the world look like this because of what people are doing to the environment.

Notice there is not one resident fish around these dead corals.

We can all help protect these amazing cities under the sea. Healthy coral reefs support healthy oceans and healthy oceans

support a healthy planet for us all!