Posts Tagged 'coral reefs'

A Blue View: Clownfish

A Blue View is a weekly perspective on the life aquatic, hosted by National Aquarium CEO John Racanelli.

From the smallest plants and animals invisible to the human eye to entire ecosystems, every living thing depends on and is intricately linked by water.

Tune in to 88.1 WYPR every Tuesday at 5:45 p.m. as John brings to the surface important issues and fascinating discoveries making waves in the world today.

April 9, 2014: Clownfish

A Blue View podcastClick here to listen to John discuss
clownfish and the important role
they play in the health of coral reefs!

Parents of young children know a thing or two about clownfish. These adorable orange and white fish rocketed to stardom in the animated classic Finding Nemo, which featured an adventurous clownfish hero.

Finding Nemo

Clownfish popularity, however, extends far beyond the preschool set. The movie led to an upswing in their demand within the exotic pet trade – they are now one of the most popular saltwater aquarium fish.

That was the downside of the Nemo-effect. The upside? More people became interested in coral reef conservation. It is an ecosystem of tremendous importance, fragility and interdependence, and clownfish are an indicator species for reef health.

Further, they are truly fascinating creatures. When Nemo’s dad, Marlin, names all of the eggs Marlin Junior, the moviemakers got the science right: all clown fish are born male. Many fish species are able to change sex, almost always from female to male. But the clownfish is different, changing gender only to become the dominant female of the group, and that change is irreversible. In a clownfish group living in an anemone the largest fish is female, the second largest a male. They are the mating pair.

But the adventure story of Nemo’s dad traveling far and wide to find his son? Unscientific. In the wild, clownfish never venture far from their anemone. It’s home…and pantry. It’s this interdependence that has earned the fish their full name: the anemone clownfish.

national aquarium clownfish

The relationship between anemones and anemone clownfish is a classic oceanic partnership of mutualism.

In science, mutualism is defined as a relationship between two species in which both benefit from the association. In fact, clownfish and anemones probably couldn’t live without each other, which qualifies them as “obligate symbionts.”

They couldn’t be more different, yet they need each other to survive. The clownfish is a vertebrate, while a sea anemone is an invertebrate, closely related to corals and jellyfish. And like them, its sting is deadly to most other creatures.

So how does the clownfish manage to live among the anemone’s lethal tentacles? Well, very cautiously. As the clownfish gets to know its anemone, it does an elaborate ballet of tentative darting movements, touching the anemone’s stinging tentacles gently, working up immunity and a protective layer of mucus.

Once they’ve acclimated to each other, they eat each other’s food scraps. The anemone’s tentacles provide the clownfish with protection from predators. The clownfish protects the anemone from predators like the butterfly fish and nibbles the anemone free of parasites. Cozy, right?

But scientists have recently discovered that there is additional complexity to the relationship.

The anemone benefits from the clownfish’s ammonia-rich waste. It’s like anemone fertilizer: it helps the animal grow.

After all, a bigger anemone is better for both; its larger tentacles can snare larger, more nutritious prey and the clownfish gets better leftovers and more spacious living quarters.

There’s also a fascinating nocturnal half to the anemone-clownfish routine. Scientists used to think that at night the clownfish snuggled quietly inside the anemone. But Dr. Nanette Chadwick and her team at Auburn University recently discovered that the clownfish moves around more than was suspected, reminiscent of a dog trying to get comfortable on its dog bed.

The clownfish’s movements oxygenate the water deep within the anemone’s tangle of tentacles. In effect, the clownfish helps the anemone breathe.

Clownfish and anemones literally cannot live without one another. In the sea, as in Hollywood, they call that chemistry!


Animal Update – February 28

national aquarium animal update

Graysby in Atlantic Coral Reef exhibit! 

A graysby has been added to our Atlantic Coral Reef exhibit!

national aquarium graysby

Did you know? Graysby fish are solitary and secretive animals. The often spend most of their day hiding in spots within the coral reefs where they make their home.

Graysbys vary in coloration from light grey to brown. These fish are covered in many small reddish spots!

national aquarium graysby

The graysby’s range includes the Western Atlantic Oceans from North Carolina to southern Florida, as well as the Gulf of Mexico and the Caribbean Sea.

Be sure to check back every Friday to find out what’s happening!

Underwater City: The Hustle and Bustle of Coral Reefs


Bright, beautiful and overflowing with life, coral reefs are among the most incredible natural wonders in the world. 

national aquarium coral reef infographic

Often thought of as rocks or plants, corals are actually made up of invertebrates called polyps. These polyps can range in size from a millimeter to a foot in diameter. The polyps group together, forming a colony, and use calcium carbonate from the ocean to build a protective skeleton.

Generally, corals are classified as either hard or soft corals. Hard corals are the framework of the reef. As these corals grow in colonies, they create skeletons. Soft corals are soft and bendable, looking more like plants. These organisms form a visually stunning and biologically important foundation for many ocean inhabitants, from tiny fish to large apex predators like sharks.

Though coral reefs constitute less than one percent of the ocean floor, they support an estimated 25 percent of ocean life. They are incredibly bio-diverse, and provide critical spawning, nursery, breeding and feeding grounds for thousands of species. And, according to a report by the World Research Institute, 75 percent of the world’s reefs are considered threatened.

The Value of Coral Reefs

The loss of thriving coral reefs has real consequences, and not just to their many inhabitants. Besides being essential habitats for fish, coral reefs have a measurable value to those who live on land.

Because they essentially serve as mountain ranges for the ocean’s coastlines, they deflect the energy of brutal storms that might otherwise decimate coastal communities. In fact, in areas where we have experienced tsunamis, the areas with coral reefs fared much better than those without.

Chemical compounds unique to coral reefs are especially useful for medicinal purposes. Researchers have used coral amalgams to treat ailments including ulcers, skin cancers and heart disorders. Once the correct formula is identified, the medicines can be mass-produced synthetically.

And of course, the natural beauty of coral reefs makes them attractive for tourists, too. Visitors from all over the world flock to the Florida Keys, Barbados, Indonesia, Australia and other destinations to get a closer look. Most of these areas rely heavily on tourism for economic growth and sustainability, so preserving coral reefs is vital for their economies.

All told, the economic value of coral reefs has been estimated to be $375 billion per year.

Reef in Danger

Sadly, coral reefs are highly threatened. Storm damage, invasive species, climate change, coastal development and commercial use are just a few of the threats. Corals are extremely sensitive, so even small sifts in light, temperature and water acidity can be detrimental. Many of the choices that we make every day contribute to the devastation of coral reefs. Coral is able to grow and repair itself, but needs precisely the right environment to do so.

In order for many coral species to thrive, they must have exposure to bright sunlight. Clear-water environments are necessary for corals to receive the maximum amount of direct light. Pollution in our water from runoff and other chemicals can cause excessive amounts of algae to grow on its surface. This process, called eutrophication, clouds the water and prevents coral from getting the sun that it needs.

In addition to chemical pollutants, coral reefs are also threatened by ocean acidification caused by the burning of fossil fuels. This process sends a deluge of carbon dioxide into the air, forming carbonic acid. Destructive fish practices, such as the use of cyanide to attract specific types of fish, also contribute to the devastation of coral reefs.

To respond to the threat of ocean acidification, the XPRIZE Foundation launched the $2 million Wendy Schmidt Ocean Health XPRIZE last year. This new contest, developed with help from the National Aquarium and other leading ocean healthy organizations, aims to spur innovators to develop accurate and affordable ocean pH sensors that will ultimately transform our understanding of one of the greatest problems associated with the rise in atmospheric carbon dioxide.

While the future of coral reefs may appear bleak, there’s still a lot we CAN do to protect these aquatic treasures! 

Jack Cover

2013 Re-cap: The Making of Blacktip Reef

This year, many of us here at the Aquarium had one thing on the brain – Blacktip Reef

From demolition to animal acquisitions, construction to animal introductions, countless hours of work from all of our departments went into the creation of this $12.5 million dollar exhibit!

As 2013 comes to a close, we’d like to take a moment to look back at how Blacktip Reef was made: 

Animal Transports

Before construction could begin on our new exhibit, the animals in our old Wings in the Water exhibit had to be safely removed!

Many of the animals that called Wings in the Water home, like our zebra sharks (Zeke and Zoe) and green sea turtle (Calypso) were moved behind-the-scenes, where they could patiently await the creation of their new home. Others were moved to other exhibits at the Aquarium or to other accredited institutions.

Want to see how we transport animals like our 500+ pound sea turtle? Check out our video:



After all the animals had been safely removed from the exhibit space and the necessary demolition was finished, the construction phase could begin!

Blacktip Reef‘s construction process included the installation of a 28 foot acrylic window and the individual placement of over 3,000 coral pieces, creating the perfect re-creation of an Indo-Pacific reef habitat.

Want to see how all of that coral was crafted by hand? Check out our video: 


Animal Introductions

The process of introducing animals into the exhibit began in early July, with the transport of Calypso!


After Calypso and a few hundred fish had acclimated well to their new home, all 20 of our blacktip reef sharks were added to the exhibit.

In October, our last animals were introduced into the exhibit! Over the period of two weeks, we added three wobbegong sharks and a huge Napoleon wrasse!

national aquarium humphead wrasse

It has been an incredibly busy and rewarding year. From all of us here at the Aquarium, we’d like to sincerely thank everyone for their continued support!

Here’s how YOU can support the continued growth and evolution of our newest exhibit!

Animal Update – November 1

national aquarium animal update

Yellow Tangs in our Pacific Coral Reef exhibit!

Several yellow tangs were recently introduced into our Pacific Coral Reef  exhibit!

national aquarium instagram yellow tang

Did you know? These fish are like little lawnmowers – they spend large portions of their day picking at rocks, quickly devouring any threads of algae.

Yellow tangs are a species of surgeonfish. Like the rest of their “family,” these tangs live in tropical habitats (ranging from the Hawaiian Islands to the coast of Florida).

national aquarium yellow tang

Be sure to check back every Friday to find out what’s happening!

The LAST Animal, a Napoleon Wrasse, Has Been Introduced into Blacktip Reef!

blacktip reef update national aquarium

We’re so excited to share that the LAST of our animals has been successfully introduced into Blacktip Reef!

Humphead Wrasse National Aquarium Blacktip Reef

Also known as a humphead or Maori wrasse (after a Polynesian group from New Zealand), this fish is found in reef habitats throughout the Indo-Pacific. This species of wrasse in particular can grow to be over six feet long!

This wrasse combs reefs in search of hard-shelled prey such as mollusks, sea stars and crustaceans – our aquarists keep the newest resident to Blacktip Reef on a similar diet!

National Aquarium, Blacktip Reef, Napoleon Wrasse

Napoleon wrasses have been known to live for over 30 years! It takes them 5-7 years to reach sexual maturity.

In the wild, this species’ population numbers have declined dramatically in recent years. This decline is due in major part to a high demand for this fish in the Asian luxury food market. Humphead wrasse meat can fetch up to $100 dollars per kilogram in Hong Kong. As a result of this recent and rapid population decline, the species has been listed under the Endangered Species Act and IUCN’s Red List.

 We hope you can stop by and meet the newest (truly stunning) resident of Blacktip Reef! In the meantime, look out for him on our live Shark Cam

Federal Government Donates Confiscated Coral to the National Aquarium

A shipment of illegally imported corals intercepted by Customs and Border Protection (CBP) has been donated to the National Aquarium.

The corals are being used as educational tools in our newest exhibit, Blacktip Reef, as well as for the Aquarium’s conservation outreach efforts, school science programs and fabrication templates.

blacktip reef education cart
The shipment, containing 20 pieces of Seriatopora hystrix (commonly known as birdsnest coral) and 22 pieces of Pocillopora damicornis (sometimes referred to as cauliflower coral), was intercepted by CBP at the port of Tampa, Florida. The corals were cut from the reefs off the coast of the Solomon Islands in the South Pacific.

Coral reefs are being threatened by human and environmental factors. Most species of coral are protected under the Convention on International Trade of Endangered Species (CITES) and require foreign permits. This international agreement between governments ensures that international trade of wild animals does not threaten their survival. CITES consists of 178 country signatories that protect species like coral worldwide.

As the nation’s border agency, CBP works closely with the Fish and Wildlife Service to ensure that laws protecting endangered species are enforced at every US port of entry.

Corals play a critical role in the ecosystem as they provide spawning, nursery, breeding and feeding  habitats for marine species, protect against shoreline erosion and provide local benefits for fishing and tourism industries.

These authentic coral pieces have become important tools for our educators, who able to bring coral reefs to life for thousands of visitors every day! We’re able to show visitors the beauty of coral and the important role that corals play in our world!

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