As temperatures and humidity rise in the United States, conditions are becoming more favorable for disease-carrying deer ticks.
The U.S. Environmental Protection Agency (EPA) reports that climate change has expanded the geographical range of ticks. Deer ticks specifically are most active when temperatures are above 45 degrees Fahrenheit and humidity is at least 85 percent. As temperatures and humidity rise in many parts of North America, so too are tick populations. The EPA reports that the incidence of Lyme disease in the U.S. has doubled since 1991.
The Northeastern U.S. has experienced the sharpest increase Lyme disease transmission. This part of the country is becoming more humid, making conditions better for ticks to emerge from the ground and latch onto hosts. New Hampshire, Maine, and Vermont have seen the largest spike in Lyme disease incidence since 1991, followed closely by Delaware and Massachusetts. On average, the EPA reports, these states now see 50 to 100 more cases per 100,000 people than they did in 1991.
The state Department of Natural Resources warns Iowans to consider how fish are affected when using chemicals and fertilizers.
The end of the summer is when fish are most vulnerable — temperatures are high, and dying and decaying plant life reduce dissolved oxygen in the water. Fish and other aquatic wildlife are stressed, meaning pollution can lead to more fish kills.
In 2016, the DNR reported 15 fish kills, 11 of which occurred in the latter part of the summer, after July 15. In the last two weeks, the DNR has investigated four fish kills around the state.
The DNR reminds farmers and homeowners that what they put on their fields or lawns will wash into waterways, where it could harm wildlife. Even a small amount of a chemical can cause serious damage.
“We have received several reports of small summer fish kills at many lakes, ponds, and a few streams throughout Iowa,” said Chris Larson, fisheries supervisor for the DNR in southwest Iowa, in a press release. “We have also had some fish kills caused by pollutants.”
Rarely, however, will all of the fish in a single body of water die at once. Usually the ecosystem can bounce back from a fish kill and balance its population again within a few years.
Farmers and homeowners can prevent pollution-caused fish kills by not applying chemical fertilizer or manure before it rains, and following disposal instructions on pesticide labels.
This week’s On The Radio segment provides details about restoration and improvement projects at Kent Park Lake in Johnson County.
Jenna Ladd | August 7, 2017
Transcript: The Iowa Department of Natural Resources is on track with its plans to improve water quality and recreational opportunities at Kent Park Lake in Johnson County.
This is the Iowa Environmental Focus.
In partnership with the Johnson County Conservation Board and Stanley Consultants, Iowa DNR plans to wrap up the first phase of park improvements this fall, which included restoring and constructing catch basins, adding ADA complaint facilities and installing bio-retention cells to keep storm water run-off from entering the lake.
Kent Park Lake was drained this spring in preparation for lake restoration projects. In the second phase, DNR plans to remove sediments from the lake basin, reshape parts of the bank and lake basin and add fish habitat. According to a press release from the department, the project’s aim is to remove the lake from the Iowa DNR Impaired Waters List and to provide more recreational activities for park visitors.
Project officials held a public meeting last month at Kent Park to discuss the preliminary plans for phase two with local residents.
For more information about the project, visit iowa-environmental-focus-dot-org.
From the UI Center for Global and Regional Environmental Research, I’m Betsy Stone.
According to the Union of Concerned Scientists, wildfires have become more likely and more intense since the 1980’s. They last nearly five times as long, occur almost four times as often and burn more than six times the land area on average.
Moving forward, residents of fire-prone regions can expect the wildfire season to lengthen. In the southwestern U.S., scientists predict wildfire season will increase from seven months to twelve months.
The economic impacts of wildfires are staggering. Since 2000, the U.S. Forest Service has spent more than $1 billion on fire suppression in one fiscal year on two occasions. During the first decade of the 21st century, wildfires cost an average of $665 million per year in economic damages.
In their full report on this issue, the Union of Concerned Scientists say it’s not too late for humans to slow the course of climate change. They write,
“The global temperature is increasing and the climate is changing due to the greenhouse-gas emissions we have already produced, leading to a likely rise in the incidence of wildfires. But it is not too late. What we do now has the power to influence the frequency and severity of these fires and their effects on us.”
Zika virus spread rampantly throughout the Americas in 2014 and 2015. While the infection itself presents with few noticeable symptoms, it has been linked to an increased number of babies born with microcephaly and Guillain-Barré syndrome, which can result in paralysis.
In a study published recently in the journal Frontiers in Microbiology, researchers developed a way to predict Zika outbreaks before they happen. The scientists used climate data from Zika-prone areas to build computer models for Aedes mosquito populations.
One of the study’s authors, Dr. Ángel Muñoz of Princeton University, said, “Both the mosquitos that transmit Zika and the virus itself are climate-sensitive.” He continued in an interview with E & E news, “High temperatures, like the ones observed during the record-breaking years 2015 and 2016, generally increase the virus replication rates and also the speed of mosquito reproduction. The overall effect of high temperatures is an increase in the potential risk of transmission.”
The researchers used their computer model to test how well their projections of the virus spreading matched with what actually occurred in 2014 and 2015. They found that their model could consistently predict a Zika outbreak one month before it occurred. In some areas, the model predicted an epidemic three months in advance.
Their computer model is not without its limitations. First, the study notes that scientists can only confidently make predictions for entire countries and regions, not cities or towns. Second, Aedes mosquitos also carry dengue and chikungunya, so the model does not distinguish whether the mosquitos are carrying Zika or another vector-borne disease. It simply indicates when conditions for disease transmission are highly suitable.
Dr. Benjamin Beard is deputy director of the Centers for Disease Control and Prevention’s Division of Vector-Borne Diseases. Referring to the changing climate and increased international travel, he said in an email, “We are seeing an accelerated threat from mosquito-borne diseases overall. Over the past few decades, we have seen a resurgence of dengue and the introduction of West Nile, chikungunya, and now Zika virus into the Western Hemisphere.”
International demand for sand has skyrocketed in recent years thanks to rapid urbanization in Asia. Sand is used to make the concrete and asphalt for every new building, road, and residence. More than thirteen billion tons of sand were mined for construction last year, 70 percent went to Asia. According to a report from the BBC, China used more sand in the last four years than the U.S. used in all of the 20th century. It’s not just Asia, though, the number of people worldwide living in cities has quadrupled since 1950.
Sand is formed when rocks are pulverized by natural forces and then transported to shores by wind and water over the course of millions of years. At present, it is being extracted at a rate much too fast for natural systems to keep up with.
To keep pace with exploding demand, sand miners are dredging lakes and rivers, chipping away at coastlines and disappearing entire small islands. Sand extraction in rivers often deepens the channel, making bank erosion more likely. Similarly, when miners remove sediments, they often also remove plant life, which can have adverse impacts on aquatic food chains. The practice can have disastrous effects for infrastructure too. For example, for many years, sand for construction in Shanghai was mined from the Yangtze River. The practice was banned in 2000 after entire bridges were undermined and 1,000 feet of riverbank fell into the river.
Many other countries are imposing regulations on sand mining. In the United States, sand cannot be mined near large residential areas or offshore. Export limits and mining restrictions are in place in several Asian countries like Myanmar, Vietnam, Cambodia and India, but the “sand mafia” in India is making regulators’ job difficult. The illegal sand mining industry is expected to be worth more than $2 billion a year.
The department announced on Wednesday that it terminated the Forest Bureau Chief Paul Tauke. All other foresters were reassigned to other divisions within the DNR. Alex Murphy is a spokesperson for the department. In an interview with Iowa Public Radio, he said, “We’ve moved these employees under different areas and actually eliminated the bureau itself, although all the functions of the bureau exist, just in different bureaus or divisions.” The changes saved the department around $277,000.
The DNR Trail Crew program was abolished along with two full-time program DNR employees. The Trail Crew team was comprised of 15 Americorps members that traveled around the state with DNR employees to develop and improve Iowa’s 500 miles of nature trails. Other Americorps programs within the department were eliminated as well.
State Geologist Bob Libra also lost his job. The state plans to contract UI geologists to take over geological research projects. Among the other positions eliminated are the department safety officer, animal feeding operations coordinator and art director for the DNR’s magazine.
UI environmental science program graduate Megan Henry warned that the elimination of positions in environmental sciences may drive more young people out of Iowa. Her letter to the editor in the Des Moines Register reads,
“Now the university will likely also equip natural science students in geology with even more hands-on experience, because “without a state geologist, the DNR will contract with the University of Iowa for geological research and technical assistance.” The only problem: How do you attract students to this vital work, if the jobs only exist while they are paying tuition?”