Noelle Swan

Archive for the ‘Wildlife and Ecology’ Category

Not all Seaboard communities are battling cicada infestations, but what if yours is?

In Science Education, Wildlife and Ecology on June 7, 2013 at 12:10 pm

This article first was published as a guest post on The Christian Science Monitor blog Modern Parenthood on June 7, 2013.

Photo Credit: MorgueFile Dodgerton Skillhause

Photo Credit: MorgueFile Dodgerton Skillhause

For months now, East Coast residents between North Carolina and Connecticut have kept a watchful eye on the cicada forecast. Bug lovers eagerly awaited one of nature’s biggest—and arguably weirdest—coming out parties, while more squeamish residents dreaded the impending infestation.

It seems that many areas, such as BaltimoreWashington D.C. and parts of New Jersey have been spared, while others are positively overrun with the flying critters. It turns out that the cicadas have spent the last 17 years burrowing in rather sporadic clusters. If you have not seen any cicadas yet, chances are you won’t see them this time around, though it’s possible they may hit your area in 2021 when Brood X make their debut; this year’s crew is known as Brood II.

If your area is teeming with cicadas and the idea of a swarm of insects sends shivers down your spine, a little background knowledge can go a long way to take control of those emotions. Framing the event as a fascinating phenomenon for kids could help calm their fears and prevent lasting insect phobias.

So, what are cicadas anyway?

Cicadas are herbivorous, flying insects that grow to be about 0.75 to 2.25 inches long. There are over 1,500 species of cicadas around the world and more than 150 different species in North America. The particular species making headlines this spring is the periodical cicada, or Magicicada.

While many species of cicadas are present throughout the year, periodical cicadas spend the majority of their lives underground. This particular species surfaces only once every 17 years, for four to six weeks in a mad dash to mate. .

What’s all that racket?

Cicadas are best known for a high-pitched buzzing sound that males make trying to attract a mate. The din created by a swarm of cicada suitors can be highly distracting and downright annoying; however it can also be a useful prompt for families to explore the properties of sound.

Male cicadas have plate-like membranes on their abdomens that vibrate like the skins of drums. Young kids can experiment with vibration and sound by placing the palm of their hands on their throats while humming, plucking a rubber band, or rubbing a comb back and forth over different surfaces. Older children can explore how different vibrations produce different sounds.

Cicadas don’t initiate their telltale symphony right away. First they emerge from small holes in the ground, about 0.5 inches in diameter. Then they climb onto tree trunks and shed their exoskeleton before they are ready to mate. If the timing is right, you might witness a newly emerged cicada wriggle free from its old skin during its final stage of metamorphosis. If you miss it, don’t worry, you’ll likely find many discarded carapaces, for kids to collect and examine.

Adult cicadas take shelter in the treetops for about five days while they wait for their new skins to harden into protective exoskeletons. Then they begin their noisy mating rituals; and they are hard to miss. Having lived most of their lives underground, they are somewhat bumbling fliers and tend crash into people, windows, and other objects. If you get caught in a swarm of cicadas flitting about to find mates, it helps to remember—and remind kids—that they are harmless. If you can move indoors until they pass.

When no amount of humor can quell the annoyance factor, remember that cicadas play a vital role in the ecosystem. While living underground, they tunnel through the earth in search of plant roots to munch and help to aerate the soil. Their decomposing bodies and discarded exoskeletons help to replenish the natural nutrient cycle of the soil.

And if you just can’t take it anymore, remember that they’ll soon be gone for another 17 years.


Horseshoe crab spawning: Take the kids on an after-bedtime adventure

In Marine Ecology, Science Education, Wildlife and Ecology on May 20, 2013 at 10:43 am

This article first was published as a guest post on The Christian Science Monitor blog Modern Parenthood on May 20, 2013.

Photo credit: Wikimedia commons author Hayden

Photo credit: Wikimedia commons author Hayden

Every year, ancient sea creatures resembling miniature armored tanks invade East Coast beaches with one mission — lay and fertilize as many eggs as possible before disappearing back into the sea.

For three nights, curious onlookers will have the opportunity to witness one of the oldest mating rituals in the world as scores of horseshoe crabs scuttle up onto the shores of Delaware BayCape Cod, and the coastal beaches along the East Coast.

The horseshoe crab, officially known by its scientific name, Limulus polyphemus, has been making annual pilgrimages out of the sea for hundreds of millions of years. Most wait for the full and new moons of late May and June to perform their mating dance.

This year marine biologists expect that the biggest horseshoe crowds will emerge on May 24, June 9, and June 23.

While some horseshoe crabs come ashore during the day, the majority will wait for the cover of night. Then, scores of them will emerge from the sea to begin their moonlit dance on the beach. The females will come first, many with males already in tow in search of a bit of sand to lay their eggs. The females are considerably bigger than males to accommodate the thousands of eggs beneath each helmet-like shell. The females dig nests in the sand before they drop off their young and return to the water. The males pace back and forth over the nests, fertilizing as many eggs as they can before they too return to the cool shallows of the water.

For families interested in gaining a front row seat to the show, Delaware Bay is the world’s largest spawning ground, but they have been spotted up and down the east coast. Citizen scientists can report sightings online to the Ecological Research and Development Group. InDelaware and New Jersey, volunteers can help count the horseshoe crabs as part of a survey during the several weekends this spring and summer. Some horseshoe crabs have already been tagged as part of monitoring projects conducted by the US Fish and Wildlife Service. If you come across a horseshoe crab with a circular or square white tag attached to the corner of the shell, make note of the number on the tag and report it to the US Fish and Wildlife Services online or by calling 1-888-LIMULUS.

Not really a crab at all, Limulus polyphemus is actually an arthropod and is more closely related to scorpions and spiders than any crab.

Limulus is a favorite species for marine biologists and teachers to share with children. The helmet-shaped shells, or carapaces, that protect them from predatory birds in the wild also make them hardy enough to thrive in aquarium touch tanks. While their blade-like tails may look menacing, they serve solely as a rudder for steering in the sand and helping the horseshoe crabs to right themselves should they become overturned by the tide.

Observant beachgoers may come across the discarded shells of horseshoe crabs that have outgrown their carapace and molted. These ghostlike shells can be great fun for kids to explore.

For families that cannot get to the shore, there are many non-fiction books for children describing these prehistoric creatures. Children’s book author Ruth Horowitz offers some moonlit magic in “Crab Moon”, a picture book illustrated by Kate Keisler and recognized by the National Science Teachers Association as an outstanding science trade book.

Violence halts UD researcher’s snow leopard project in its tracks

In Wildlife and Ecology on February 11, 2013 at 5:42 pm

Snow leopardWhen University of Delaware graduate student Shannon Kachel headed to Tajikistan last summer in search of the endangered snow leopard, he was prepared to contend with rugged terrain, high altitudes, and even possibly Afghan drug and weapons smugglers. However, he did not expect to have to take shelter in a bathtub while government troops swept through the streets and mortar shells streaked by his hostel window.

Kachel was in bed when machine gun fire erupted outside his window.

“I rolled off of the bed and onto the floor then belly-crawled over to the bathtub. I spent 13 hours huddling there with shrapnel and bullets flying through windows, buildings burning, and tanks rolling through the streets below,” he said.

The UD wildlife ecology major had come to Tajikistan two months earlier as part of a research project funded by the University of Delaware and Panthera, an international wildcat conservation organization. He aimed to piece together a rough census of snow leopards, mountainous wildcats known for their gray-white fur and black rosette markings, and to explore the effect of human hunting of hoofed animals, or ungulates, on the predatory cats.

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Underwater robots track sand tiger sharks

In Wildlife and Ecology on November 25, 2012 at 12:56 pm

This article first was published by, Delaware’s NPR News Station on November 25, 2012.

Photo Credit: Tim Sackton

The sand tiger shark’s telltale silhouette and jagged rows of teeth may strike fear into the hearts of aquarium visitors, but Delaware State University fisheries biologist Dewayne Fox thinks this large gray fish with reddish-brown spots on its back is “just absolutely awesome.”

Fox started studying sand tiger sharks in the Delaware Bay in 2006, in an effort to understand why their numbers have declined between 70 and 95 percent in recent years.

This fall, thanks to some high tech support from researchers at the University of Delaware, Fox got his first real-time glimpse of the migration patterns and environmental preferences of these elusive sharks – information that may help him find answers to the shark’s dwindling presence.

Continuing a longtime partnership between Delaware’s two land-grant universities, Fox called upon University of Delaware assistant professor of oceanography Matt Oliver to convert a remote-controlled underwater glider used to monitor water conditions into a satellite receiver and transmitter.

Over the last six years, Fox has tagged more than 500 sand tiger sharks with acoustic transmitters that send radio signals to an array of 70 receivers positioned along the Atlantic coastline as the sharks swim by them.

By combining data gathered through those acoustic transmitters with sightings reported by marine biologists in other coastal states, Fox has started to piece together an outline of the sand tiger shark’s migration habits.

Mother sand tiger sharks seem to prefer to give birth off the coast of the Carolinas. Young pups spend their summers in Cape Cod before graduating to Delaware Bay, Fox said. Both young and adult sand tigers spend the winters in the warmer waters of Florida and the Gulf of Mexico.

“One of the things we have been able to figure out is that the Delaware Bay probably has the largest concentrations of sand tiger sharks in the summer,” Fox said.

The sand tiger sharks likely fill a vital ecological niche at the top of the bay’s food chain, Fox said. Should their numbers continue to decline, he said he worries that the ecosystem as a whole could suffer.

This wouldn’t be the first time the declining shark populations rippled down to impact neighboring species, Fox said. The decline of sand bar sharks in the Chesapeake Bay led to an explosion of cownose rays that in turn decimated the bay’s oyster population, and fractured Maryland’s oyster industry.

While Fox’s acoustic transmitters have provided a rough sketch of the sand tiger sharks’ migration path, many questions linger about what environmental cues might trigger migration and reproduction, Fox said.

That’s where Oliver’s suped-up glider comes in.

Known as OTIS, short for Oceanographic Telemetry Information Sensors, the glider resembles a bright yellow rocket with fins and houses multiple sensors capable of measuring temperature, salinity, oxygen levels, and chlorophyll concentrations in the water.s

Oliver’s adaptation can also pick up signals given off by special Radio Frequency Identification (RFID) tags attached to marine animals, alter its course to follow those animals, and head to the surface to place a satellite telephone call to Oliver’s lab with information about which animals it has encountered and the corresponding environmental conditions.

“The idea is to actually get the data that shows what types of water conditions sharks are using so that you can eventually build a model and make predictions based on water parameters,” Oliver said.

University of Delaware graduate student of oceanography Danielle Haulsee also helped to broaden the kind of information available to Fox by internally implanting sand tiger sharks with VEMCO mobile transceivers (VMTs).

These high-tech tags are capable of not only transmitting their location but also of receiving information from other VMTs implanted in other marine life, such as other sharks, striped bass, or sturgeon.

“[I]f anything with a [VMT] tag swims by a shark, it can pick that up and tell us about it. By looking at the data that comes from those tags, you can start to see not only where the shark goes but what else is around that shark,” Haulsee said.

Haulsee received special training from marine veterinarians from the Georgia Aquarium to surgically implant VMT tags into sand tiger sharks. This summer, she, Fox, and Oliver headed out into the bay fishing for sharks.

The three drew sand tiger sharks alongside the boat, one at a time, in a kind of underwater stretcher that folds around the animal and holds it in place just under the surface of the water. Haulsee made a small incision in the abdomens of 20 sand tiger sharks, placing tags in the body cavity, before stitching them back up and sending them on their way.

Fox hopes that gathering diverse data about sand tiger sharks from OTIS and the VMT tags could not only expand knowledge about sand tiger shark behaviors and habits, but also lead to the identification and reduction of factors that might be contributing to their decline.

However, because sand tiger sharks have one of the lowest reproductive growth rates of all sharks, recovery likely will be slow.

Female sand tiger sharks do not fully mature until their teens and typically only live until they are around 25 years old. Sand tiger embryos begin learning to hunt in the womb, first eating unfertilized eggs, and then their would-be siblings until only one remains. Females give birth to a single pup every two years or more. That means a single female probably will only have four pups in her lifetime.

“This is an animal that even if everything is right, it’s going to take a long time for them to come back,” Fox said.

Honeybee experts worry uptick in urban beekeeping could compromise health of honeybee populations

In Honeybees, Wildlife and Ecology on October 25, 2012 at 9:47 am

This article first was published by under the title Explosion in Urban Beekeeping Raises Concerns for Honeybee Population on October 25, 2012.

Photo Credit: FLICKR/dni777

Millions of buzzing residents have moved into Utah, as the number of new beekeepers registering with the state has increased eightfold since 2006.

That’s good news for local farmers and gardeners who depend on honeybees to pollinate their crops. The bad news is that the new arrivals could be bringing with them a rash of problems.

Several honeybee experts worry that in the hands of novice beekeepers, all those hives could become incubators for viruses and pests ready to hitch a ride to any of the thousands of commercial hives around the state.

Clint Burfitt suggests that this concern has been fueled by a fundamental shift in the scale of risk that face beekeepers today. “In the past, a [commercial] beekeeper could keep 1000 hives and might lose a few [to disease], but now a commercial beekeeper can have losses of 60 percent.” Burfitt is a state entomologist at the Utah Department of Agriculture and Food.

Colony Collapse Disorder, the nationwide phenomenon that first hit the news in 2006, contributes to these losses. By some estimates, the disorder is blamed for killing one quarter of the nation’s bees, resulting in a $12 billion loss to the agricultural economy.

Some beekeepers fear that should pest and viral infection spread to commercial apiaries, the results could be similarly devastating. “If one person isn’t knowledgeable or just doesn’t understand how to recognize or treat for [pests and pathogens], that jeopardizes everybody in that system,” says Burfitt.

The greatest opportunity for contamination comes when honeybees rob nectar from each others’ hives, inadvertently taking fungal spores, mites, and viruses with them. The varroa mite, the most common problem facing beekeepers, introduces viruses and bacteria directly into the bloodstream of bees. A rarer threat, the American foulbrood turns normally glistening, white honeybee larva into brownish goo that smells like dirty socks

“People get all fired up about [starting their new hives]. It goes pretty well at first, but summer gets busy and they let it languish. If it craps out, this time of year, robbers come looking for weak hives. Robber bees come in, pests jump ship and join the new hives,” says Chris Rodesch, Salt Lake County bee inspector. This activity can initiate a cycle that quickly infects an entire neighborhood of hives.

However, Rodesch maintains that commercial bees experience more risk of exposure when they are rented to farmers to pollinate crops, a common and lucrative practice. They are often trucked long distances and forage alongside bees from other parts of the country.

Should an outbreak of a particularly pernicious virus occur, the Department of Agriculture and Food is equipped to notify registered beekeepers and offer advice on symptoms and treatment. The Utah Bee Inspection Act mandates that all beekeepers register their hives with the department within 15 days of setting them up.

Nevertheless, there are shortcomings to the system. The inspection act does not require beekeepers to submit notification of hive losses. Such a requirement could make a big difference in identifying pests and pathogens before they reach the level of outbreak.

Further, many of the state’s beekeepers are either unaware of the registration requirement or unwilling to register their hives. Rodesch says that only half of the hives that he visits are registered with the state.

“Unless you see a lot of hives it’s hard to know if what’s happening in yours is normal or something that needs to be addressed,” says Rodesch. “That’s why the [beekeeping] clubs are really important.”

Cory Stanley, an entomology professor and honeybee specialist with Utah State University gives live demonstrations of various hive management techniques throughout the state, “I think that it is important to let the young beekeepers know the value of asking questions.”

UD Apiary research aims to take sting out of nationwide bee colony collapse

In Honeybees, Wildlife and Ecology on August 2, 2012 at 1:56 pm

This article first was published by, Delaware’s NPR News Station on August 2, 2012.

Bee colonies across the country began mysteriously collapsing in 2006, and have had scientists urgently seeking a cause of the meltdown ever since. Now, researchers at the University of Delaware believe they’ve uncovered clues to solving this problem that threatens the delicate natural balance on which the nation’s food supply depends.

At UD’s Newark apiary, where 22 hives are home to more than 1.3 million bees, researchers are focusing on an invasive parasite that can be as devastating to a bee colony as its Latin name, Varroa destructor, implies. The mites are one of several culprits that may be combining to cause Colony Collapse Disorder, which has resulted in the die-off of tens of billions of bees nationwide.

Debbie Delaney, a UD assistant professor of entomology and wildlife ecology, says combating one possible source of the decline might be as simple as mimicking a bee’s natural behavior, at least for small-scale beekeepers like the 300 apiarists in Delaware who host the majority of the state’s honeybees in their backyards.

While State Apiarist Robert Mitchell describes the status of the honeybee population in Delaware as “adequate,” he adds that colony losses have taken a toll at a time when the demand for pollination services continues to grow.

“Honeybees are responsible for the pollination of $10 million worth of wholesale fruit and vegetable value in the state,” said Secretary Ed Kee of the Delaware Department of Agriculture in an email reply. “This valuable resource must be protected.”

UD Apiary research aims to take sting out of nationwide bee colony collapse
Various stages of varroa mites.
Photo by Zachary Huang,

The varroa mite is one of the “primary forces behind the decline of the honey bees,” said Katy Evans, a UD graduate student spearheading Delaney’s study.

These little external parasites attack both adult honeybees and their brood, or young, by latching onto them and feasting on their blood. That may sound familiar to people used to swatting at mosquitoes, but varroa mites are no minor nuisance.

Although we can just barely see them with the naked eye, Delaney explains that it is a whole different story from a bee’s perspective.

“It’s as if we had a dinner plate attached to us sucking our blood,” she said.

To get to that blood, mites have to penetrate the bee’s exoskeleton, leaving behind a wound that is open to infection from additional pests and pathogens. When feeding on drones, or male bees, the mites deplete the drones’ protein and sperm levels and eventually render the bee incapable of flying. In addition to feeding on drones, the mites attach themselves to the brood of young bees in the early stages of their development.

“To make it even more awful, they vector viruses,” Delaney added. Just like a mosquito carrying malaria, or a tick bearing lime disease, these mites can transport and deliver new diseases directly into their hosts’ bloodstreams.

Delaney’s research at the UD apiary stems from observations she made in her backyard hives. So far, her bees have been healthy: no signs of virus, good honey production, and a strong population. She says that some of her bees have varroa mites, but they haven’t damaged the colony overall. She believes that the few mites on her bees at home have not had a chance to multiply because she employs a technique called hive splitting, which is modeled after bees’ natural tendency to swarm and establish two separate hives if their population outgrows the hive.

UD Apiary research aims to take sting out of nationwide bee colony collapse
Bee larva with 5 varroa mites on one side.
Photo by Zachary Huang,

Delaney is currently testing a theory that some natural beekeepers have claimed for years. During a hive-splitting period, bees don’t reproduce, and varroa mites have no baby bees to feed on. So the mite population dies off and takes so long to rebound that they never achieve numbers large enough to harm the colony.

Bill Leitzinger, amateur apiarist from Middletown and president of the Delaware Beekeepers Association has used the hive-splitting technique to control varroa mites in his hives for ten years. Leitzinger says when he was growing up, his father used chemicals to address mites and other problems around his few hives. He decided to do things differently.

“I have never used chemicals,” he said. “It used to be I was the weird one. Now most beekeepers are trying not to use chemicals.” He noted that the natural beekeeping movement evolved in response to research showing that chemicals applied to the hive can seep into the wax and remain in the hive for several years.

Delaney points out that miticides are not the only chemicals that remain in the wax. Pesticides and fungicides applied to plants miles away can stick to honeybees’ bodies during nectar collection and hitch a ride back into the hive where they, too, remain in the wax for years to come.

Recent research indicates that insecticides and parasites in non-lethal amounts can have a combined effect that becomes lethal. Delaney speculates that the combination of miticides and insecticides could have a similar effect. She hopes that her research will confirm that hive splitting is a viable alternative to chemical miticide application.

“If we can reduce in any possible way any type of pest that gets into the hive matrices or that the bees come in contact with, then I think that’s a very good thing,” Delaney said.

Digging Deep into the Chesapeake: UD Researchers Seek Clues to Curing Annual Dead Zone

In Marine Ecology, Wildlife and Ecology on June 4, 2012 at 5:50 pm

This article was first published by DFM News on June 4, 2012 under the title UD researcher seeks clues to curing annual Chesapeake Bay dead zone.

Dr. Deb Jaisi, Plant & Soil Science does work on sediment at the bottom of the Chesapeake Bay with the help of graduate students Sunendra Joshi (male) and Kiran Upreti (female). Photo courtesy: University of Delaware/Kathy F. Atkinson

Each summer in Chesapeake Bay, huge algal blooms, fueled by nutrient pollutants, blossom and die. Their remains sink to the bottom and are quickly devoured by bacteria that monopolize the Bay’s stores of dissolved oxygen, stressing or suffocating entire communities of marine life, such as clams, oysters and sponges.

“Restoration efforts in recent decades have helped improved water quality and ecological conditions in the Chesapeake Bay. However, the extent and severity of [the dead zone] has not improved as expected,” said Deb Jaisi associate professor of plant and soil science at the University of Delaware.

This past summer, in 2011, the Chesapeake received its worst report card yet from EcoCheck, a partnership between NOAA and the University of Maryland Center for Environmental Science, despite concerted efforts to reduce the amount of nutrients released into the bay through human activities.

The U.S. Environmental Protection Agency has named phosphorous as one of two major nutrient pollutants (along with nitrogen) contributing to the annual “dead zone.” Phosphorous is an essential element for life. It is found in every cell in the human body and nearly every food we eat. Humans, plants, and animals consume and excrete it. However, as with many things, too much phosphorous can be deadly.

Jaisi believes that a hidden record of phosphorous concentrations lies buried in the Bay floor. By decoding that record, he hopes to learn how concentrations have changed over time, and potentially pinpoint when and how a nutrient found in the bay for centuries became a pollutant capable of threatening the health of the entire bay.

Oak Ridge Associated Universities, a consortium of PhD-granting institutions, and the University of Delaware have awarded matching grants to support this research.

Something of a molecular detective, Jaisi plans to examine sediment cores provided by oceanography professor and eminent scholar David Burdige of Old Dominion University for traces of excess phosphorous that have settled on the bay floor year after year. Each source of phosphorous, from various fertilizers, to sewage treatment discharges, has its own atomic structure, similar to a fingerprint.

This summer, Jaisi will be installing a thermo-chemical element analyzer to help identify these fingerprints. Assuming he can get his lab up and running by mid-summer, he hopes to have some answers by the end of the year.


The first signs of trouble — depleted dissolved oxygen in the depths of the bay — began to show in the 1930s. By the 1950’s the dead zone started making annual appearances and has grown larger with each passing summer.

Because the Chesapeake Bay watershed is 64,000 square miles — nearly the size of the country of Cambodia — the problems and solutions likely originate far beyond the bay shores.

While half of the phosphorous in the bay comes from terrestrial sources, the U.S. Geological Survey estimates that nearly 10,000 metric tons of phosphorous enters the Bay through the watershed each year. Sources can include excess fertilizers applied to farmland, discharges from sewage treatment plants, and leaching from septic systems. One third of Delaware lies in the Bay’s watershed, so its farms, sewage treatment plants and septic systems contribute to the problem.

While Pennsylvania, Maryland, Virginia, and the District of Columbia have been attempting to improve the health of the Bay for thirty years, the EPA widened the approach in 2010. It required other states in the Chesapeake Bay watershed to submit plans to curb nutrient pollution. Delaware, New York, and West Virginia each completed the second phase of planning this spring and are preparing to implement new anti-pollution measures.

For Delaware, “it’s not just about trying to improve the bay 100 miles away. It’s about trying to improve waterways in our own state.” said Delaware Department of Natural Resources and Environmental Control Secretary Collin O’Mara.

Because nutrients enter the bay from so many sources, O’Mara says that DNREC has had to enlist the help of local municipalities and industrial partners. “To achieve a healthy Chesapeake Bay is going to take the efforts of everyone from the local government to the county government, to the businesses and the farmers. We are going to have to work together so the bay can heal itself.”

O’Mara says the efforts will include upgrading wastewater treatment plants, improving storm water practices, and examining industrial sources of nutrient pollution.

However, 70 percent of Delaware’s nutrient runoff comes from agricultural activities, so individual farmers play a key role, says O’Mara. A cost-sharing program will encourage farmers to plant “cover crops” — ones that grow alongside desired crops and take up excess nutrients.

Doing more to reduce pollution in Chesapeake Bay will require significant financial investments, at a time when states are struggling to balance their budgets.

“The economic climate is tough, but efforts to clean up the Chesapeake Bay have been taking place for 20 to 30 years. We can’t delay implementation of additional pollution control measures because of costs,” said Nicholas DiPasquale, director of the Chesapeake Bay Program at the Environmental Protection Agency. “We must also consider the economic and non-economic benefits that will result from these efforts.”

Both DiPasquale and O’Mara point out that Delaware can expect some returns from these investments.

Improving storm water controls, using low-impact development techniques, and installing rain gardens will reduce flooding and the costs of responding to flood damage, says DiPasquale.

“If we’re able to improve the waterways to the point where more fish survive, it’s better for everyone,” said O’Mara.

Much of the seafood caught off the coasts of Delaware, Maryland, New Jersey, and the Carolinas started life in the waters of the Chesapeake. The success of Atlantic coastal fisheries—and the many livelihoods they support—depends directly on the health of the bay.

DiPasquale says he has started to see some success stories.

Numbers of striped bass, or rockfish, an important commercial and recreational sp that lives in the Chesapeake Bay and its tributaries dwindled in the 1980s, but since then the fish has recovered.

“We think we are starting to see the resilience of the bay restored,” said DiPasquale. “When you look at long term trends, you can see improvements in the health of the watershed, but we’re not there yet.”

National Epidemic Strikes Fort Delaware Bats; Visitors Helping Curb Spread

In Food Security, Wildlife and Ecology on May 8, 2012 at 4:55 pm

This article was first published online by DFM News on May 8, 2012.

Courtesy: Ryan von Linden/New York Department of Environmental Conservation

As Fort Delaware State Park kicked off its 2012 season last weekend, park rangers and guides started enlisting visitors to help the park’s seldom-seen bats. Visitors to the fort are being asked to assist in the effort to curb the spread of the disease known as white-nose syndrome (WNS) to other parts of the country.

Around 6 million bats have succumbed to a deadly fungus in just five years in the eastern United States and Canada. Some species, such as the little brown bat, have lost of 90-95 percent of their populations. This winter, the culprit took up residence in Fort Delaware State Park.

“Honestly science has never seen a mammalian disease catastrophe like this,” says Holly Niederriter, wildlife biologist for Delaware Division of Fish and Wildlife. “I’m not even sure that the Plague reached these proportions [in terms of percentage of the population killed] .”

Niederriter oversees the state park’s bat program. After finding a few sick bats at the fort this winter, her job instantly got more complicated.

Click here to read the full story.

Plastics in the Ocean May Be Grossly Underestimated

In Marine Ecology, Wildlife and Ecology on May 2, 2012 at 4:44 pm

This article first was published online by DFM News on May 2, 2012.

Photo Credit: Sea Education Association, Marilou Maglione

Surface trawling has long been used to estimate the level of plastic pollution in the ocean, from plastic soda bottles to disposable bags, but it turns out this method of measurement only scratches the surface of the problem… quite literally.

High winds cause plastic debris to mix well below the surface where more than half of the ocean’s plastic pollution has swirled about, uncounted, according to Tobias Kukulka, a University of Delaware assistant professor of physical ocean science and engineering.

In still water, plastic is buoyant, inevitably rising to the ocean surface, Kukulka explained in an email interview. “However, in a wind-driven turbulent ocean, this buoyant upward transport is balanced by a downward transport because plastic particles “catch a ride” with the turbulent motion,” he said.

Kukulka and co-lead author Giora Proskurowski, oceanography scientist at the University of Washington, published the results of a study of plastic pollution of the world’s oceans in the latest issue of Geophysical Research Letters.

Click here to read the article in full.

Harvard Study Shows Link Between Common Pesticide and Honeybee Colony Collapse Disorder

In Honeybees, Wildlife and Ecology on April 13, 2012 at 12:33 pm

This article first was published on on April 10, 2012.

Researchers at Harvard School of Public Health have linked imidicloprid, a common agricultural pesticide to honeybee Colony Collapse Disorder, a mysterious phenomenon resulting in devastation of entire hive colonies. The dramatic decline in honeybees because of this phenomenon has worried scientists, farmers, and beekeepers alike, as honeybees play a vital role in pollination and fruit production in both natural and agricultural ecosystems. The results of the study were announced in early April in a Harvard School of Public Health press release and will be published in the June issue of the scientific journal Bulletin of Insectology.

Colony Collapse Disorder

Florida beekeepers first reported the bizarre symptoms of Colony Collapse Disorder in the winter of 2006-2007. In 30-90% of beekeepers hives, the worker bees, or drones, spontaneously abandoned the hive, leaving behind their queen and their young. Without the workers to sustain the hive, the queen and young soon died. The phenomenon was like nothing beekeepers had ever seen before.

“If the honey bees died because of pathogen infection or disease you would see many, many dead bees both inside and outside the hives,” says Chengshen Lu, HSPH assistant professor of environmental exposure biology and lead author of the study. In cases of Colony Collapse Disorder, beekeepers have not found any dead bodies inside the hive and very few near the colony at all.

Lu says that he and his colleagues were able to replicate Colony Collapse Disorder in a study in Worcester County, Massachusetts. The study consisted of four bee yards, each containing four hives exposed to varying levels of imidicloprid and one hive left untreated as a control. After 23 weeks, all but one of the treated colonies collapsed. While those treated with the highest dose succumbed first, even those treated with low concentrations (smaller than the amounts used in agriculture) collapsed.

About Imidicloprid

Imidicloprid is a neonicitinoid, a class of pesticides designed to attack the nervous system of pest insects. Originally approved for landscaping in 1994, imidicloprid has since become one of the most widely used agricultural pesticides. Lu explains that when imidicloprid is applied to seeds, it will grow with the plant, finding its way into all parts of the plant, including nectar, pollen, and fruit. Bees foraging for nectar drink the imidicloprid-laden nectar and transport imidicloprid-rich pollen back to the hive.

In the case of commercial bees, beekeepers frequently supply the hive with high-fructose corn syrup during winter months to extend honey production. (Lu and his colleagues used this same technique to administer exact doses of the pesticide in their study). Because much high fructose corn syrup is derived from corn that has been treated with imidicloprid, these synthetic feeds are also a source of poison for the fuzzy pollinators.

All in the Timing

Lu believes timing has masked the link between imidicloprid and Colony Collapse Disorder. In his study, the hives appeared healthy for months after exposure. Twelve weeks after dosing, bees were buzzing around productively. He says that previous studies have looked for evidence of immediate toxicity. “If they don’t see an immediate problem, they wrap up the study and move on to the next,” he says. He adds that while understanding this delayed response brings a much-anticipated answer to one mystery, it begs an equally mysterious question: Why does it take so long for the poison in the imidicloprid to affect the honeybees?

Lu says that the delay between exposure and symptom expression is longer than the life cycle of a worker bee, typically 30-40 days. “It takes a couple of generations to make the toxicity occur in a dramatic way.” That means that the bees that are dying are not the same bees that were first exposed to the poison. Lu aims to investigate this delay this year in an additional study.

What’s Next?

The EPA already lists imidicloprid as toxic to bees in high doses, but in the absence of evidence that chronic exposure could be harmful, still permits its use. Lu says that he has sent the EPA a copy of this study as a courtesy and hopes that it will encourage the agency to consider its recommendations.