Erica Cirino: Our Medicated Surface Waters

Ars Technica:

The United States of America is a highly medicated country: almost seven in 10 Americans take prescription drugs. That translates to 4.4 billion prescriptions and nearly $310 billion spent on medication in 2015. Painkillers, cholesterol-lowering medications, and antidepressants top the list of drugs most commonly prescribed by doctors.

Americans aren’t just putting these drugs into their bodies; they’re also putting more drugs into the environment. A growing body of research suggests all types of drugs, from illegal drugs to antibiotics to hormones, enter the environment through sewage and cesspool systems across the country. And while pharmaceutical drugs—when used as prescribed—are capable of curing disease and alleviating symptoms in people, they can wreak havoc on nature.

There, they persist for long periods without breaking down. Hormones in medications like birth control cause changes such as intersex development in fish and amphibians. Antidepressants have been found in the brain tissue of fish downstream from wastewater treatment plants. Research on the presence of illegal drugs in water bodies has revealed some interesting trends: drug concentrations are highest on weekends and skyrocket after social events, such as music festivals, where large quantities of drugs are often consumed.

Diana Gitig: New Hypothesis about Declining Monarch Butterflies

Ars Technica

Anurag Agrawal ... has written a book about them called Monarchs and Milkweed: A Migrating Butterfly, a Poisonous Plant, and Their Remarkable Story of Coevolution. Monarches and their sole food source, the toxic milkweed plant, provide a great example of coevolution. Monarch caterpillars are born on milkweed leaves, where their mothers deposited them as eggs. They grow fat eating the plant. They are not pollinators; the milkweed gets nothing out of the relationship. In fact, the plant goes to great lengths to fight the monarchs. Milkweeds exude latex (the “milk” responsible for the eponym), which contains a noxious chemical cocktail suspended in the sticky rubber. A newly hatched monarch caterpillar’s teeth and feet can, and often do, get easily mired. “More than 60 percent of monarchs died in the burst of latex that accompanied their first bites into the plant,” Agrawal tells us. “Less than 10 percent make it to full size.”

Because monarch butterflies are disappearing. They have experienced a 75-percent drop in their numbers over the past 25 years, and a number of reasons for this decline have been suggested. One is that their overwintering grounds, already quite small, are being threatened by logging, hunting, cattle grazing, and climate change.

But the prevailing idea is that monarchs are disappearing because milkweed is disappearing due to urbanization, the expansion of agriculture, and especially the indiscriminate overuse of herbicides enabled by the advent of herbicide-resistant crops. Monarch caterpillars have nothing to eat, this idea goes, and so they die.

Despite the popularity and the appeal of this hypothesis, Agrawal does not buy it.

Scott Johnson: Lakes Soaking up Road Salt

Ars Technica:

Road salt became common in the 1940s, and the amount used has increased over time. The US puts down around 18 million tons of salt each year. Roadsides along highways obviously get dosed with more than their fair share of salt, but salt also runs off (sometimes via storm drains) into streams and lakes where it can accumulate. That makes road salt a common target in local efforts to protect bodies of water. Although this has sometimes been studied on the local scale, there hasn’t been much big-picture analysis. A new study led by the University of Wisconsin-Madison’s Hilary Dugan works to fill in that gap by estimating how widespread salt contamination is in North America.

The researchers used data from 371 lakes that covered at least four hectares and had chloride measurements going back at least 10 years. That’s not a purely random sampling, but it’s the best way to find trends. Most are in the US Midwest and Northeast, with a handful from southern Canada and some spread over the rest of the US. One-third of the 371 lakes showed a significant upward trend in salt concentration.

Boom times for fish populations

NSF:

We’re all familiar with the idea of extreme events. Meteorologists keep us up to date on hurricanes, floods and high temperatures. Economists watch the stock market for signs of crashes or rallies. Researchers spend a lot of time trying to better predict these events, yet are often surprised by the outcomes. According to a new study in the journal Limnology & Oceanography Letters, when it comes to nature’s extremes, nothing seems to beat what happens underwater.

Scientists at the National Science Foundation (NSF) North Temperate Lakes Long-Term Ecological Research (LTER) site — one of 28 NSF LTER sites — are routinely measuring everything from water temperature to nutrient concentrations to fish populations in Wisconsin lakes.

Taking advantage of several decades’ worth of data, Ryan Batt, the paper’s lead author, and a team of researchers compared data on various physical, chemical and biological variables — 595 variables in total. They found that as the lakes’ temperatures rose and their nutrient concentrations increased, so did the number of organisms living there.

Natalie Sopinka: Fish Habitat Loss in Canada

Canadian Science:

Favaro and Olszynski quantified a net loss of over 2 million m2 of fish habitat. This loss of habitat was calculated assuming perfect compliance of habitat compensation requirements. The net loss of habitat jumped to almost 4 million m2 when only 80% of required habitat compensation occurred.

An overall loss of fish habitat suggests effectiveness of policies should have been enhanced not reduced; the former Act did not go beyond conservation goals (e.g., no net loss of habitat) as the goals were not even being met. If the HADD regime as previously set out in the Fisheries Act was not adequately protecting habitat why change what the law says? Why change the rigor of how projects causing harm are reviewed? Favaro and Olszynski contended the language of the former Act (i.e., inclusion of HADD) should be reinstated and that future amendments be informed by data accessible to all stakeholders. The authors obtained data for the study through the Access to Information Act and recommended a public registry of DFO authorizations be created. Favaro and Olszynski published their findings earlier this year in the Canadian Journal of Fisheries and Aquatic Sciences (CJFAS) and submitted them to FOPO.

Todd Reubold: The Biggest Sources of Nutrient Pollution in Cities

University of Minnesota:

New research from the University of Minnesota points to lawn fertilizers and pet waste as the dominant sources of nitrogen and phosphorus pollutants in seven sub-watersheds of the Mississippi River in Saint Paul, Minnesota.

The study — published in the Proceedings of the National Academy of Sciences — is the first to compare the urban watershed budgets of nitrogen and phosphorus. And the results can be applied to urban watersheds around the world impaired by excess nutrients.

The research team — led by Sarah Hobbie, Distinguished McKnight University Professor in the Department of Ecology, Evolution & Behavior and an Institute on the Environment Fellow — discovered households are the main sources of nutrient pollutants in the Twin Cities urban watershed. Household nitrogen fertilizer use in particular is more than 10 times greater than commercial fertilizer use by golf courses, college campuses and other non-residential locations, and pet waste is the leading source of phosphorus to these watersheds.

Steven Maier: Study of a Lake Trout strain

Great Lakes Echo:

Elk Lake in Northwest Michigan is home to a strain of that fish that researchers believe can contribute uniquely to restoring it. Elk Lake trout have been self-sustaining and reproducing for years. That’s unusual in the Great Lakes Basin...

Researchers have collected data for over seven years from acoustic transmitters inserted into captured adult Elk Lake trout. That data and thermal profiling indicate that the strain likes colder water than trout from both the Great Lakes or the Finger Lakes in New York.

Steven Maier: Mudpuppies

Great Lakes Echo:

A joint research team from Southern Illinois University and Shedd Aquarium in Chicago has recently taken on the mystery of the elusive mudpuppy. Their study, published in the Journal of Great Lakes Research in December, provides some answers.

The mudpuppy is a fully-aquatic salamander thought to be on the decline–though the extent of that decline is unknown. The foot-long amphibians are classified a “threatened species” in the state of Illinois and considered a concern throughout the Great Lakes region.

The team was able to assess effective capture techniques for the first time. The discovery that trapping should take place in the winter is especially critical for future researchers.

They were also able to learn about the mudpuppy’s diet–which consisted of pretty much anything that would fit in their mouth...

Samantha Oliver: What Two Frozen Lakes Taught Me

Center for Limnology

A. Hinterthuer

Today, I woke up at my favorite place on earth – Ten Mile Lake, in Hackensack, Minnesota. On the coldest day of the winter thus far, the frozen lake is so bright, so sparkly, it is almost hard to look at. And when you are from a place where 30 below is often the actual temperature (NOT the wind chill), you rely less on the calendar to define the seasons and more on observations of specific events that are tied to the climate.

Summer, to me, never began on the day with the most sunlight, but rather on the day the dock was installed (and ended, of course, when the dock was removed). Winter and spring were always announced by the day the lake froze and thawed.

Then I moved to the relatively tropical city of Madison, where the winter is shorter, but the lakes still provide a checkpoint in our urban phenology. But now my observations are set up as a study of contrasts: my asparagus came up two weeks sooner than my mom’s or simply subtract 10 degrees from Madison’s temperature to guess Hackensack’s temperature. On December 15th this year, I texted my mom: “Is Ten Mile frozen?” “Almost”, she responded. We have this conversation every year, but this year it felt different...

Dave Orrick: Walleye Decline with Global Warming

Pioneer Press:

Natural walleye lakes could be a rarity in Wisconsin by mid-century, thanks to climate change, a new study warns. And the largemouth bass shall inherit the warmer waters — and flourish, the government-funded study further predicts.

By as soon as 2040, a mere 4 percent of Wisconsin lakes might be able to support naturally sustained walleye populations — a 60 percent reduction from today — while the number of lakes conducive to high-abundance largemouth bass populations could rise to 89 percent, up from 60 percent today, according to the study, co-authored by researchers from state and federal agencies...

The bass-walleye transformation isn’t new. For 30 years, researchers have watched traditional walleye lakes become bass-dominated lakes, often to the chagrin of anglers and cabin owners. The root cause is not known for certain, but it correlates with lakes getting warmer as summers have grown hotter and winters have become shorter and less severe, said Gretchen Hansen, the study’s lead author. The warming climate is a likely culprit because biologists have long established that in similar lakes, walleyes dominate in cooler waters and largemouth bass in warmer waters.

Rae Ellen Bichell: Is it Safe to Eat Deer with Prions?

NPR:

Kuru showed that people could get a prion disease from eating infected people. Mad cow disease showed that people can get a prion disease from eating infected cow. But what about other prion diseases in other animals? Could, say, hunters get sick from eating infected deer? That’s what researchers in North America, including Belay, are trying to find out right now.

”Chronic wasting disease in North America is spreading fast,” says Belay. The disease causes infected wild deer and elk to starve to death. “In early 2000, we had about three states that reported CWD in the wild in deer and elk. Today, that number is 21.”

Belay says the disease is “a little bit concerning” because, unlike mad cow disease and kuru, where infectious prions were concentrated in the brain and nervous system tissue, in an animal with chronic wasting disease, the misfolded prions show up all over the body. They can even be found in saliva, feces and urine, which could explain how the disease is spreading so quickly among wild deer and elk.

The CDC is working with public health authorities in Wyoming and Colorado to monitor hunters for signs of prion disease.

”Unfortunately, because these diseases have long incubation periods, it’s not easy to monitor transmission,” says Belay.

Nathan Martin: Animal Migrations

The Atlantic:

Much of the current research on migration taking place in Wyoming stems, at least in part, from the work of Hall Sawyer, who grew up hunting and fishing in the state and has studied its wildlife for more than 15 years. In the late 1990s, Sawyer tracked the migration of a herd of pronghorn from Grand Teton National Park more than 100 miles south into the Upper Green River Valley. Then, in the mid-2000s, he stumbled upon a revelation when he was tracking mule deer herds in a southwestern part of the state called the Red Desert.

“We thought the mule deer just resided year-round in the desert or migrated short distances out there,” he said. “That’s when we discovered that half of those deer were migrating some 150 miles.”

The migration Sawyer revealed is the second longest recorded land migration in North America—only Arctic caribou go further. But these mule deer do not travel across barren tundra. Between the herd’s winter range in the windblown Red Desert and summer habitat among the granite and cool timber of the Hoback Canyon, they travel through oilfields and skirt residential developments, swim reservoirs and finger lakes, and cross three highways and more than 100 fences. The migration traverses a complex patchwork of public and private land controlled by people and agencies with diverse, sometimes conflicting interests.

That a migration of such epic length existed in the first place—unknown, under science’s nose, in the 21st century—struck Sawyer as amazing. But as the excitement subsided, he started to think about how difficult it would be to ensure that such a migration could persist.

Fascinating story about animal migration and the research on elk migration in and around Yellowstone National Park.

France Diep: Water Use per Crop

ScienceLine (via street.mn chart of the day):

Homeowners have a “definitely significant” role in the nation’s water budget, says Cristina Milesi, an ecosystem modeling researcher now with NASA who led the 2005 Environmental Management study. “Each family may have only a small lawn,” she explains, “but once you add them all up they have a big impact.”

Watering the lawn generally accounts for 50 percent to 75 percent of a home’s water use during the summer. To save water and money, Milesi suggests choosing more drought resistant turf and adjusting your watering schedules to fit the weather and season. Many cities have suggested or required water schedules for different times of the year.

Some even advocate abandoning the great green lawn in favor of meadows, vegetable gardens, local native plants or just letting the grass die.

Sean Caroll: An Ecology Lesson

Nautilus:

Why is the planet green? Why don’t the animals eat all of the food? And what happens when certain animals are removed from a place? These questions led to the discovery that, just as there are molecular rules that regulate the numbers of different kinds of molecules and cells in the body, there are ecological rules that regulate the numbers and kinds of animals and plants in a given place. And these rules may have as much or more to do with our future welfare than all the molecular rules we may ever discover...

One major school of thought was that population size was controlled by physical conditions such as the weather. Smith, Hairston, and Slobodkin (hereafter dubbed “HSS”) all doubted this idea because, if true, it meant that population sizes fluctuated randomly with the weather. Instead, the trio was convinced that biological processes must control the abundance of species in nature, at least to some degree.

HSS pictured the food chain as subdivided into different levels according to the food each consumed (known as trophic levels). At the bottom were the decomposers that degrade organic debris; above them were the producers, the plants that relied on sunlight, rain, and soil nutrients; the next level were the consumers, the herbivores that ate plants; and above them the predators that ate the herbivores.

The ecological community generally accepted that each level limited the next higher level; that is, populations were positively regulated from the “bottom up.” But Smith and his lunch buddies pondered the observation that seemed at odds with this view: The terrestrial world is green. They knew that herbivores generally do not completely consume all of the vegetation available. Indeed, most plant leaves only show signs of being partially eaten. To HSS, that meant that herbivores were not food-limited, and that something else was limiting herbivore populations. That something, they believed, were predators, negatively regulating herbivore populations from the “top-down” in the food chain. While predator-prey relationships had long been studied by ecologists, it was generally thought that the availability of prey regulated predator numbers and not vice-versa. The proposal that predators as a whole acted to regulate prey populations was a radical twist...

Indeed, trophic cascades have been discovered across the globe, where keystone predators such as wolves, lions, sharks, coyotes, starfish, and spiders shape communities. And because of their newly appreciated regulatory roles, the loss of large predators over the past century has Estes, Paine, and many other biologists deeply concerned.

Luke Runyon: Causes of the Monarch Butterfly Decline

NPR:

Monarch butterflies are disappearing. Populations of these distinctive black and orange migratory insects have been in precipitous decline for the past 20 years, but scientists aren’t exactly sure what’s causing them to vanish.

So far, potential culprits include disease, climate change, drought and deforestation. Everyone from loggers to suburban developers has been implicated. But much of the blame has been placed on farmers and the pesticides they rely on — pesticides that have reduced the milkweed that monarch caterpillars feast on. Now, however, scientists say that may not be the full story.

Every spring, hundreds of thousands of monarchs sweep across the Great Plains from Mexico to Canada, and then back again in the fall. It’s an amazing journey, one that takes place over multiple generations for the butterflies. The insects breed while traveling north, expending four generations to make it to Canada. The final generation then flies all the way back to Mexico to spend the winter there.

Monarch populations are measured in hectares (roughly 2 1/2 acres). Surveys of their wintering habitats in the central mountains of Mexico show dense populations of monarchs at an average of more than nine hectares during the winters from 1995 to 2002. In 2014, monarchs took up less than one hectare.

Global Warming Visual

Climate Lab:

The animated spiral presents global temperature change in a visually appealing and straightforward way. The pace of change is immediately obvious, especially over the past few decades. The relationship between current global temperatures and the internationally discussed target limits are also clear without much complex interpretation needed.

Click this link to go to the animated data graphic. An interesting way to present a lot of data!

Samantha Oliver: Altered Nutrient Flows into Lakes

UW-Madison Center of Limnology:

Humans have drastically changed the distribution of nutrients (nitrogen and phosphorus) across the landscape through urbanization, food production and burning fossil fuels. This has come at a cost to water quality; excess nutrients are transported to surface waters where they can fuel toxic algal blooms, foul drinking water and disrupt the ecosystem. We’ve made progress on point source pollution like sewage discharge since the Clean Water Act was established in 1972. But diffuse nutrient sources like runoff from agricultural areas are difficult to manage and still plague surface waters.

Jake Vander Zanden: Lake Dead Zones

Reporting from New Zealand:

UW-Madison’s Limnology Center: Earlier this year, Jake Vander Zanden rented his house out in Madison, packed his things, and headed with his family for a sabbatical in New Zealand. Under the auspices of a Fulbright scholarship, Jake is at the University of Waikato, studying ‘dead zones’ in lakes, where pollution reduces oxygen making it impossible for parts of lakes to support life.

Tell us about your research here in New Zealand
I’m looking at the phenomenon of lake ‘dead zones’. Lakes that in the past had a lot of oxygen in the bottom waters can lose that oxygen due to nutrient pollution – often from human activity – then they become an environment that can’t support life. You lose a lot of the value that would come from a lake, such as fisheries, when you have dead zones.

It seems like once you create dead zones they are difficult to turn back. Even if you remove nutrients and improve conditions, the healthy ecosystem never returns. That’s really worrisome because it is so difficult to fix the problem. Another consideration is that when you create a dead zone, the plant nutrient phosphorus is released from the lake sediments, which further contributes to the pollution problem.

Julienne Isaacs: The Benefits and Limits of Buffers

Manitoba Co-operator:

Sandi Riemersma, an environmental biologist with Palliser Environmental Services, says the effectiveness of buffers depends on several factors, including the slope of land, soil characteristics, buffer width, vegetation, season and management.

“A riparian buffer strip is a good tool to reduce sediment transport and often can reduce particulate phosphorus mobility,” she says. “But buffers are not effective in winter and early spring when vegetation is dormant, soils are frozen and microbial activity is low or absent,” she says.

Riemersma emphasizes nutrient application management as an essential aspect of protecting waterways from nutrient run-off. In addition, she says permanent cover should be maintained near waterways, steep slopes and on erodible and saline soils. “Riparian buffers help to maintain stable stream banks, thereby reducing soil erosion and associated sediment and nutrient transport in waterways,” she says.

Minnehaha Watershed District: Zebra Mussels Improve Water Clarity in Lake Minnetonka

Zebra mussels have caused significant changes in Lake Minnetonka’s water quality, according to findings of a study by Minnehaha Creek Watershed District (MCWD). The District has been monitoring the lake’s zebra mussel population since they were first detected there in 2010. Five years into the study, which was developed in partnership with Blue Water Science, MCWD released its findings on Thursdsay, April 21 at its AIS Spotlight, a gathering of community leaders at Minnetonka Community Center.

The District has discovered the biggest water quality changes are occurring among bays with the highest number of zebra mussels. In Wayzata Bay, which the population topped out at an estimated 200,000 zebra mussels per square meter in 2014, there has been an increase in water clarity and a decrease in algae (Chlorophyll) and Phosphorus. Those changes are not as prevalent in bays with lower zebra mussel populations. In Halsted Bay, which has 28 zebra mussels per square meter, there has been little change in water clarity, Chlorophyll and Phosphorus.

One suspects that some bays with improved water clarity may see an increase in aquatic plant habitat.