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Making Waves: Episode 72 (March 31, 2011)

You're listening to Making Waves. I'm Troy Kitch.

Today we’re going to talk about new algal bloom research and NOAA news from the U.S. Caribbean. Let’s do  it.

(UT Researchers Link Algae to Harmful Estrogen-like Compound in Water)

You may have heard stories in the news over the years about researchers discovering evidence that links manmade substances in our waterways to health and reproductive problems in animals … possibly including humans.

These compounds -– things like manmade hormones and pesticides -- are called endocrine disruptors, because there’s evidence that they mimic hormones, like estrogen, produced by the endocrine system -– a system of glands that produce hormones that regulate an organism’s bodily functions, such as reproduction.

While scientists have always thought that these kinds of damaging compounds only came from manmade sources, new NOAA-funded research shows that this may not be the case.

In a paper published in the American Chemical Society’s journal, Environmental Science & Technology, researchers at the University of Tennessee at Knoxville found that naturally occurring blue-green algae may be responsible for producing an estrogen-like compound. This natural compound appears to affect larval fish in a similar way as many manmade compounds.  

The study was led by researcher Theodore Henry, an adjunct professor for UT Knoxville’s Center for Environmental Biotechnology and faculty at the University of Plymouth in England.

He and his colleagues looked into the effects of a type of blue-green algae called Microcystis on zebrafish in their larval stage.  Microcystis algae frequently form what are known as harmful algal blooms. You may have heard of ‘red tides?’ Well, that’s one type of harmful algal bloom. These type of events happen when different types of algae in the water bloom out of control, producing  toxic substances as they do so. HABs are found in waters throughout the world and they’re a growing health and environmental concern.

During blooms of the particular blue-green algae known as Microcystis, a well-known and well-studied toxic substance is produced. What the researchers did was compare the affect this toxic substance alone had on the larval fish, and compare that to the effect of exposing the larvae directly to the algae that makes the toxin.

What they found was surprising. Only the fish in contact with the algae tested positive for exposure to estrogen from the environment. This led the researchers to conclude that the algae is producing a previously unknown substance -- an estrogen-like compound that acts as an endocrine disruptor, just like many manmade compounds.

While estrogen-like compounds released from algae in the environment haven’t conclusively been shown to affect reproduction in animals and plants, it’s an area of intense study. In a press release published by the University of Tennessee about the new study, Henry said that it’s possible that environmental estrogen-like compounds may lead to problems like physical feminization of male fish and behavioral changes. This is in addition to the possible human health effects of the toxins already known to be produced by these algae which may include skin rashes, fever, and liver damage.  Human activities may still play a role  because blue-green algal blooms are increasing due to enhanced nutrient pollution from human activities.


While more research is needed to better understand this phenomenon, the new study points out that researchers may have new harmful elements to consider as they investigate the effects of algal blooms on animal and public health. 

(U.S Caribbean News)

Next up, I want to tell you about two NOAA-related events that kicked off this week in the U.S. Caribbean. First, NOAA's Coral Reef Conservation Program and Fisheries Service released an ocean etiquette video to educate visitors to the U.S. Virgin Islands and Puerto Rico on how to be good stewards of the marine environment. One of the main goals of the new video is to get people to stop collecting corals and marine life as souvenirs.  

The six-minute Caribbean Marine Etiquette video and corresponding 30-second public service announcement are available in English and Spanish. They educate viewers on the impacts of throwing litter on the beach, kicking or standing on live corals, anchoring boats on corals and sea grass, and collecting corals and other animals as souvenirs.

The new video will air in hotels, dive shops and on television throughout the U.S. Caribbean to promote responsible tourism.

Corals are the slow-growing colonies of animals that form the foundation of the reef ecosystem. Collecting corals, sea fans and other invertebrates destroys the habitat such important marine species as spiny lobster, groupers and snappers need, and can do long-term damage to the larger reef community.

Regulations prohibit the taking without a permit of both living and dead coral and shells from beaches and reefs of the U.S. Virgin Islands and Puerto Rico. Despite these local laws, U.S. Customs Agents confiscate hundreds of pounds of such material every month from all major airports in the U.S Caribbean. Since 2007, NOAA has been working with local enforcement officers in partnership with the Caribbean Fishery Management Council to identify violations, and hopes the marine etiquette video and educational posters at airports and cruise ship terminals will reach visitors even before a violation occurs at the beach.

We'll have a link for more details on the new video in our show notes.

Also this week, NOAA researchers kicked off the eighth year of a mission to explore and map underwater realms of the U.S. Caribbean aboard the NOAA Ship Nancy Foster. For many of the areas visited during this expedition, it'll be the first time they've ever been studied or mapped.

During a cruise from March 28 through April 16, researchers from NOAA's National Centers for Coastal Ocean Science will be taking a close look at high-priority sea floor habitats between three and 30 kilometers off the southern coasts of St. Thomas and St. John. These areas were selected because of their ecological significance to commercially important fisheries and the need to update nautical charts in the region.

The data collected during the expedition will be used to paint a clearer picture of the U.S. Virgin Islands underwater habitats and the marine life they support. This info is critical for the resource managers charged with protecting these fragile ecosystems.

NOAA is undertaking this ongoing, multi-year mapping effort at the request of the Caribbean Fisheries Management Council, the National Park Service, and the University of the Virgin Islands. Check our show notes for a link to a site where you can get daily updates from the scientists during their Caribbean cruise.

And that’s all for this week.
If you have any questions about this week’s podcast, about the National Ocean Service, or about our ocean -- or if you have an ocean fact you’d like answered -- send us a note at
Now let’s bring in the ocean …
This is Making Waves from NOAA’s National Ocean Service.