Posts Tagged 'public radio'



A Blue View: Bringing Oysters Back from the Brink

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.

August 21, 2013: Bringing Oysters Back from the Brink

A Blue View podcastClick here to listen to John discuss the critical role
oyster reefs play in maintaining a healthy
Chesapeake Bay! 

Oysters are a huge part of the Chesapeake Bay culture—its past, present, and future. Even the name “Chesapeake” means “great shellfish bay” in Algonquin. Yet since the early part of the 1900s, oyster populations have been in crisis.

The health of oyster populations in the Bay is critical to providing habitat for aquatic animals, supporting feeding grounds for migratory birds, and enhancing water quality as oysters filter their food from the water. An adult oyster can filter up to 50 gallons of water per day. To put this in perspective, the National Oceanic and Atmospheric Administration points out that oysters once were able to filter the entire Chesapeake Bay in a week. Today, it takes a year.

Researchers are beginning to understand the importance of oyster reefs in protecting coastal areas. Along with coral reefs, wetlands, dunes, and other coastal habitats, oyster reefs actually help prevent erosion, reduce the impact of storm surges, and protect against sea level rise. In fact, part of New York City’s $19-billion-dollar plan to combat the effects of climate change includes building large underwater oyster reefs around the harbor.

Over time, oyster populations have been devastated by overfishing, disease, pollution, habitat destruction, and urban runoff. NOAA reports that the oyster population of the Chesapeake today is less than 1 percent of its historical level. In fact, oyster harvesting peaked in the 1880s, when 20 million bushels were harvested in a single year. In 2012, only 135,000 bushels were harvested from the Bay…less than one percent of those historic levels.

Still, all hope is not lost, and efforts are underway to solve the Chesapeake Bay’s oyster problem. These include an ambitious plan to restore oyster populations throughout the area by spreading hundreds of thousands of tons of granite and old oyster shells along Harris Creek, a tributary of the Choptank River. Shells seeded with baby oysters are then placed on this substrate using a high-pressure hose. Then, nature is left to do its work. Watch this video to learn more about the project:

[youtube http://www.youtube.com/watch?v=U8TNeusghYs]

The Chesapeake Bay region isn’t the only one looking to improve the prospects for oysters. In New Jersey, for example, an advocacy group called ReClam the Bay is caring for seven oyster nurseries in the hopes of helping populations in Barnegat Bay to recover. Protected nurseries allow the oysters to grow without the risk of predators dining on them. Visitors are welcome to come by these nurseries and get their hands wet in what ReClam the Bay hopes will be an educational opportunity that will encourage people to make better choices for the health of the shellfish populations and the bay.

Out on the West Coast, efforts to save Oregon’s only native oyster species, the Olympia, have proven largely successful. Though previously declared “functionally extinct,” after 8 years of work by the Nature Conservancy and watermen, the 1.5 million oysters now inhabiting Netarts Bay seem to be reproducing successfully.

In Maryland, a “No Shell Left Behind” oyster recycling tax credit of one dollar a bushel became official on July 1. Its aim is to encourage the recycling of valuable oyster shells to help restore oyster populations in the Chesapeake Bay. Empty shells, which are necessary for hatcheries to replenish the oyster population, are extremely valuable, as each shell can host up to 10 young oysters, known as “spat.”

You can play a part in this, too! Whether by recycling oyster shells, participating in Chesapeake Bay conservation events, or even running in next year’s “Sprint for Spat” 5K race, sponsored by the Oyster Recovery Partnership, get involved! A healthy oyster population helps us all.

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A Blue View: Jellies – Oceans Out of Balance

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.

August 14, 2013: Jellies – Oceans Out of Balance

A Blue View podcastClick here to listen to John discuss how the rapid increase in jellyfish
populations has 
negatively impacted the health of our oceans. 

Beautiful, eye-catching, and otherworldly, jellyfish are dazzling creatures to look at, though not something you want to run into at the beach.

Not technically fish, jellies have drifted through our seas for more than 500 million years. They range in size from that of a pinhead to more than 8 feet in diameter, with tentacles 130 feet long. Most species have tentacles that sting, even when they become detached from the jelly’s body. And, as many a beach-goer can attest, those stinging cells can make for some less than pleasant experiences when our paths accidentally cross.

Related to sea anemones and corals, jellies have no heart, brain, blood, or bones, and are 95 percent water. Contrary to popular myths, jellies are not out to get you. As ocean drifters, they are carried along on ocean currents. But their vast numbers in certain places have made them a menace, and their unique ability to thrive in less-than-ideal conditions has scientists keeping a close eye on these fascinating creatures.

Jellies seem less susceptible to algae blooms, pollution, warming waters, and reduced oxygen levels, meaning that the more the environment deteriorates, the better it is for jellies. In an alarming phenomenon dubbed “jellification” by some scientists, jellies in some areas of the world are literally taking over the seas.

The role of jellies in the ocean ecosystem and whether or not their increasing numbers are displacing other ocean inhabitants are both matters of active debate in the marine science community. There are several reasons attributed to the rise of jelly populations. In addition to their ability to thrive in inhospitable conditions, jellies benefit when the fish, turtles, and other species that normally eat them are overfished. Then, as jellies eat zooplankton, fish eggs, larvae, and even fish, they further impact the food chain, perpetuating an imbalance that’s difficult to correct.

An overabundance of jellies isn’t good for tourism around the globe, particularly when they wash up on beaches. Depending upon the species, a jellyfish sting can cause anything from mild discomfort to severe pain and in rare cases, like the box jellies of Australia, even death. Jellies also affect fisheries—and fisherman—when they collide with nets, sometimes even killing the catch with their toxins. Jellies can also cause power outages and equipment damage at power plants by clogging cooling intakes.

Considered a delicacy in China, some see dining on these unique creatures as a creative and efficient way to control the jellyfish population. The European Union has embarked on an international research program to evaluate the spread of jellies in the Mediterranean and other regions and develop a coastal management strategy accordingly.

For all the issues that jellyfish blooms can cause, they are essential and active participants in the ocean ecosystem. They belong there. The best way you can keep bays and oceans healthy is to make smart choices at home. One important place to start is in your yard. Avoid overfertilizing your lawn and garden. Excess fertilizer washes into our waterways, reduces oxygen, and contributes to harmful algae blooms—conditions that are great for jellies but terrible for fish populations. You might even consider opening your mind to a new delicacy when jellies show up on a restaurant menu near you.

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A Blue View: Stormwater – A Search for Solutions

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.

July 31, 2013: Stormwater – A Search for Soluations

A Blue View podcast

Click here to listen to John and Halle Van der Gaag
from Blue Water Baltimore discuss stormwater runoff!

John: We hear a lot about stormwater, but many of us still don’t exactly know what it is and why we should care. In Baltimore and all across the country, however, stormwater runoff is a major problem. To help us understand what this issue means to our community, Halle Van der Gaag, executive director of Blue Water Baltimore, is with me in the studio. Hi, Halle.

Halle: Hi, John. Thanks for having me.

J: There’s a lot of misinformation out there about stormwater, but at its most basic, what is stormwater, and how does it relate to our community and our waters?

H: Stormwater runoff is actually rainwater that hits our pavement, roofs, and parking lots, and flows downstream, carrying pollutants, animal waste, fertilizer, and pesticides. What a lot of people don’t realize is that it actually carries air pollution that lands on our pavement, and washes that downstream as well.

J: Why is our stormwater situation so critical here in Baltimore?

H: For a long time, no one paid attention to stormwater. We were focused on industrial pollution and agricultural pollution. The reality of it is that pipes that carry stormwater are old, deteriorating, and breaking. They have not been maintained and they need an infrastructure overhaul.

J: Do we have a lot of impervious surfaces here? Describe what those are.

H: Impervious surface is just a term for hardscape or pavement – hard surfaces where you get no infiltration of rainwater. If you look around Baltimore, you’ll see that we have lots and lots of pavement. Not all of it is actually being used. Some of it is streets, but some of it is parking lots.

J: How does this whole situation manifest itself in our city these days?

H: What we’re seeing a lot is pipes bursting, streets collapsing, pollution in our waterways and in our harbor. It’s a real problem, not just for our waterways but as an inconvenience to commuters and people who are living and working in Baltimore.

J: It’s obviously a very costly and labor-intensive problem to solve, but what kind of work is being done now to help with this issue?

H: Recently, people have probably heard about a stormwater utility fee that has been passed in Baltimore and across the state. This allows Baltimore to finally be proactive and actually have the resources it needs to fix stormwater pipes before they break.

J: I know this is a really important issue, and some people have mis-characterized the stormwater fee as a rainwater tax and things like that. Help us understand more what these fees will help accomplish and how that might help the Chesapeake Bay.

H: In addition to fixing pipes, we also see lots of opportunities for green infrastructure, for opportunities to create stormwater practices that will help beautify the city, but are actually functional, beautiful spaces where you’re using plants and trees to filter and slow down stormwater before it hits the streets. It can be happening on public right-aways and in parks, but there’s a lot that people can do in their own backyards – installing rain gardens, rain barrels, planting conservation landscaping, lots of things that folks can actually do. Then they can offset and ask the city for credit for the stormwater fee. The goal here is to reduce pollution, not just collect fees that go into a big giant pipe.

J: Reducing pollution is something that’s good for all of us. Thank you so much for joining me, Halle. To learn more about Blue Water Baltimore and how you can reduce your stormwater impacts at home, visit aqua.org/ablueview.

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A Blue View: Rainforests of the Sea

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.

July 24, 2013: Coral Reefs: Rainforests of the Sea

A Blue View podcast

Click here to listen to John discuss the importance of 
protection coral reefs.

Sometimes called the rainforests of the sea, coral reefs are colorful, intricate ecosystems—among the most incredible natural wonders in the world. Their brilliant hues and diverse inhabitants make them a favorite of scuba divers and ocean enthusiasts around the world. But, coral reefs are also in grave danger—and saving these ancient splendors is both a necessary and feasible goal.

blacktip reef

Our newest exhibit, Blacktip Reef, is the re-creation of a vibrant Indo-Pacific reef!

According to a report by the World Resources Institute, 75 percent of the world’s reefs are considered threatened due to a combination of risks. Climate change has made bleaching, which is a massive die-off of coral polyps, and disease outbreaks more common. Increased carbon in our oceans results in ocean acidification, which, in turn, destroys the very structure of the reef. Overfishing and destructive fishing practices are disturbing the balance of these complex ecosystems. Coastal development, pollution, coral mining, and unsustainable tourism activities are adding additional stresses to an already challenged habitat. Some scientists fear that at this rate, living coral reefs could vanish from earth within a generation unless drastic action is taken.

Surprisingly, while coral reefs make up just two-tenths of a percent of the ocean floor, they support about 25 percent of all marine animals. They are critical spawning, nursery, breeding, and feeding grounds for thousands of species.

Many people don’t realize that corals are in fact animals, closely related to jellyfish and anemones. There are both hard and soft corals, and all live together in colonies, creating a foundation for all the other inhabitants of the reef, from tiny darting fishes to large apex predators like sharks and everything in between.

There’s no question that these ecosystems are environmentally critical, but they are also important economic drivers, creating millions of jobs and providing a sustainable tourism resource when properly managed. Coral reefs also serve as natural barriers for islands and other communities, helping to prevent erosion and minimizing the impact of waves and storms. In fact, according to the National Oceanic and Atmospheric Administration, up to 90 percent of the energy from wind-generated waves is absorbed by reefs.

NOAA also estimates that ocean temperature will rise nearly two degrees within this century from the greenhouse gases already released, which will undoubtedly threaten these critical ecosystems even more. As marine scientists explore just how coral reefs will cope with increasing acidity in the world’s oceans, it is abundantly clear that we must act to save these oceanic treasures.

Scientists are now studying coral reefs along Mexico’s Yucatan Peninsula, where underwater springs naturally lower the pH of the surrounding seawater. There, researchers are learning how corals respond to higher acidity in a natural setting. On the other side of the world, a U.S. climate scientist is conducting an experiment on Australia’s Great Barrier Reef to see whether antacid could boost coral growth by slowing seawater acidification.

These researchers are taking threats to our coral reefs seriously, and we need to do the same. The single biggest thing you can do to slow the deterioration of reefs is to reduce your own carbon footprint by driving less and conserving energy at home. We can also to make sustainable seafood a priority and vigorously support steps to enforce proper management of these resources. We do well to remember that our actions on land—our stormwater, trash, and yard runoff—all eventually work their way to the sea and impact coral reefs. We can all keep coral reefs in mind as we go about our daily lives—and remember that water connects us all.

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A Blue View: The Unfair Attack on Sharks

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.

July 10, 2013: Sharks Unfairly Attacked

A Blue View podcast

Click here to listen to John discuss the bad
reputation sharks have gotten over the years. 

Sharks have long captured the imagination of the public. These days, even shark sightings make national news. Just this past June, great white shark sightings in Massachusetts and New Jersey cleared beaches and were widely reported across the country.

Often thought of as mindless, aggressive killers, sharks—and their toothy jaws—are featured prominently in movies and TV shows, always adding drama with a hint of fin visible above the water’s surface. Despite the fascination that we all feel for sharks, these important apex predators remain seriously misunderstood.

Most people think of great whites when they think of sharks, but there are actually more than 375 shark species, ranging in size from the 8-inch dwarf lantern shark to the 65-foot whale shark.

Here are just a few shark species that can be found at the Aquarium:

The vast majority of sharks are carnivores, but exactly what they eat depends on what they can catch. Larger shark species may prefer seals or large fish. Other species may opt for mollusks, clams, squid, and other small marine animals. One thing is certain—humans are not the preferred menu choice—far from it.

Of the hundreds of shark species, only 12 are considered even potentially dangerous to people, with great whites, bull sharks, and tiger sharks responsible for most attacks on humans. In 2012, approximately 80 shark attacks occurred worldwide, with seven fatalities. When one considers how fearful the general public is of sharks, it’s remarkable to learn that as many as 100 million sharks are killed by people each year. The fact is, sharks have far more to fear from humans.

While sharks may be at the top of the food chain, they are susceptible to threats such as shark finning, overfishing and bycatch. As top predators, most shark species produce relatively few offspring and take years to reach reproductive maturity. The whale shark, for example, doesn’t reproduce until the age 30. When killed in great numbers, sharks don’t have the opportunity to reproduce, and the long-term viability of the population is threatened.

So why should we worry about sharks? Let’s start with the fact that they’re absolutely critical to healthy ocean ecosystems. Scientists refer to sharks as a keystone species, meaning that the whole complex food web relies on them. From their perch at its top, sharks keep populations of other fish in check, naturally select out old and sick fish, and control populations so that other prey fish can’t cause an imbalance in the ecosystem. By doing the essential job of population control, sharks actually ensure adequate biodiversity in marine habitats.

Besides regulating the food web, sharks are believed to keep coral reefs, sea grass beds, and other vital habitats healthy. Essentially, sharks regulate the behavior of other species by intimidating them, preventing any one species from over-consuming critical habitat.

Because of the severe population decline of many shark species, several states, Maryland included, have taken steps to protect sharks by prohibiting the sale, trade, and transfer of shark fins, and many conservation organizations are advocating for even greater protection of these ocean-dwellers.

This summer, if you’re fortunate enough to spent time at the ocean, don’t let fear of sharks prevent you from enjoying the water. Be sensible, but not afraid. As you’ve no doubt heard, you face much greater risk driving to the shore than you do from the sharks that live there!

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A Blue View: Rising Seas

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 pm as John brings to the surface important issues and fascinating discoveries making waves in the world today.

June 26, 2013: Rising Seas

A Blue View podcast

Click here to listen to John discuss the impact
climate change is having on rising sea levels. 

On these hot summer days, our thoughts tend toward ice cream cones and tall glasses of ice water on a sweltering afternoon rather than the melting of ice sheets around the world. But just as the ice melting in your glass causes the water level to rise, so too does the melting of the world’s ice shelves.

Perhaps you’ve seen the incredible videos of massive chunks of ice breaking away from a glacier, causing crashing impressively into the sea. Until recently, it was thought that this was the primary cause of ice loss in Antarctica. But in fact, a study by NASA and university researchers indicates that warming oceans are also dissolving the ice from underneath the ice shelf at unprecedented rates, causing the greatest loss of Antarctic ice shelf mass. Scientists plan to use these data to help determine how ice shelves melt, improving projections of how the ice sheet might respond to a warming ocean and contribute to sea level rise.

Ice loss is not just occurring at the poles: NASA researchers have discovered that glaciers outside of the ice sheets of Greenland and Antarctica lost an average of 571 trillion pounds of mass each year during the six-year study period, causing sea levels to rise almost two-tenths of an inch during that time. This actually matches the sea level rise attributed to the combined ice loss of the Greenland and Antarctica ice sheets.

Ice melting isn’t the only contributor to sea level rise. Warming temperatures cause waters to warm and expand. In turn, warming waters take up more volume. This phenomenon is called thermal expansion. The combination of ice melting and thermal expansion means that sea level rise is not just a possibility…it is happening now, and the only question is how fast it’s going to rise.

Many scientists now believe that sea levels will rise by no less than one to two feet by 2100. And without dramatic reductions of greenhouse gas emissions, the threat could be much more substantial.

The East Coast in particular is at greater risk from sea level than other areas of the world, mainly due to ocean currents and differences in seawater temperature and ocean salinity, according to climate scientists. The U.S. Geological Survey found that sea levels from North Carolina to Boston climbed by about 2 to 4 millimeters a year between 1950 and 2009 as compared to a global average of one-half to 1 millimeter.

These amounts may seem small and unimportant, but the repercussions from these rising levels are anything but. Imagine increased coastal flooding, shoreline erosion, loss of wetlands, and destroyed homes and businesses on the order of superstorm Sandy. Sea level rise does affect us all.

We need to take steps to control warming, as sea surface temperature and sea level rise are inextricably linked. According to the EPA, sea surface temperatures have risen at an average rate of 13 one-hundredths of a degree per decade since 1901. As small as that may sound, over 112 years, that’s an increase of one and a half degrees, which is already impacting not only sea level, but also coral reefs and other essential ocean habitats, migration and breeding patterns, the intensity of storms, and the spread of invasive species and marine diseases.

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A Blue View: Dolphin Earthquake Study

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 pm as John brings to the surface important issues and fascinating discoveries making waves in the world today.

June 19, 2013: Dolphin Earthquake Study

A Blue View podcast

Click here to listen to Dr. Mark Turner discuss how
our dolphins reacted to last year’s earthquake.

On August 23, 2011, a magnitude 5.8 earthquake occurred with its epicenter approximately 118 miles from the National Aquarium, Baltimore. A short time before the dolphin pavilion started shaking from the earthquake, an Aquarium volunteer logging the activities of four dolphins noticed that they all started to swim very quickly in close formation, something she could not recall ever having seen before. She had enough time to note this behavior in her handwritten log before the building suddenly started shaking. At the same time all this was happening, the underwater sounds in the dolphin pools were being recorded using a pair of hydrophones (i.e., underwater microphones). The combination of the in-person observation and the hydrophone recordings provides valuable insight into dolphin behavior.

When an earthquake occurs, seismic waves radiate out from the focus of the earthquake at different velocities. The fastest of these, called the primary wave or P-wave, can travel at speeds of 15,000 miles per hour. However, although very fast, P-waves often are unnoticed by humans. The S-wave and surface waves, the ones that shake everything and cause the worst destruction, travel at much slower speeds.

Although no humans at the Aquarium that day reported feeling the P-wave, its trace did show up in our hydrophone recordings almost 22 seconds before the arrival of the S and surface waves. In view of the P-wave’s appearance in the recordings and the dolphins’ behavior, marine mammal researcher Mark Turner believes the dolphins felt the P-wave, and the volunteer observed their reaction to it. Listen to the hydrophone’s recording: 

This is a clip of the underwater sounds in the dolphin pools when the August 23, 2011, Virginia earthquake occurred. Two hydrophones were recording at the time. The left stereo channel is the recording from the hydrophone in the front pool where a dolphin presentation was in progress. The right channel is from the back holding pool where fast swimming in an unusual configuration was observed. In the video that accompanies the sound clip, the top two panels show the raw signal picked up by each hydrophone. The top panel is from the front pool and the bottom one is from the holding pool.

The bottom two panels are spectrograms. A spectrogram is a visual representation of sounds in which the x-axis is time and the y-axis is frequency. In a spectrogram a dolphin whistle will appear as a dark, wavy line, and a squawk can sometimes appear as a stack of parallel wavy lines.

The sound clip begins at almost exactly the time the earthquake started in VA. The various seismic waves traveled from the earthquake’s focus to Baltimore at different velocities, with the P-wave arriving first, 27 seconds into the clip. Although the very low frequency vibrations induced by the P-wave are visible in the upper panels, they are inaudible, although you might hear some water splashing. The S and surface waves (the ones that are very loud and shook everything) did not arrive until almost 22 seconds later, 49 seconds after the beginning of the clip.

You may hear some of the presentation music, a bit louder in the left channel. If you listen carefully you will also hear (and see in the spectrograms) dolphin clicks, squawks and whistles. And, of course, you will hear the loud noises made by the earthquake surface waves as they sounded underwater.

An excellent overview of the different seismic waves with animations can be found by clicking here.

All signal displays were generated using Raven Pro, Interactive Sound Analysis Software, Bioacoustic Research Program at the Cornell Lab of Ornithology.

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