Climate change leaves wolverines on slippery slope

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Wolverines, those vociferous, marathon-climbing, fearless relatives of the sea otter may soon face a foe that no amount of bravery can outlast — climate change.

Climate model results from the National Center for Atmospheric Research (NCAR) in Boulder, Colorado, show wolverine habitat in the Lower 48 warming significantly from climate change during the second half of the century. The pending warmer climes threaten snow cover that is vital to the wolverine’s survival.

“It’s highly uncertain whether wolverines will continue to survive in the lower 48, given the changes that are likely to take place there,” said NCAR scientist Synte Peacock in a press release, and the lead author of a paper, which appears in Environmental Research Letters.

Wolverine Den (Photo/Wikimedia Commons,Ernst Vikne)

Wolverines dig snow dens for their kits 8 to 10 feet deep, and are specially adapted to run and hunt across the snow. Snow pack also helps preserve carrion that the wolverines rely on for sustenance throughout the winter. While about 15,000 wolverines are estimated to live across Canada and Alaska, only a few dozen are thought to still live in Montana, Wyoming and Washington State, according to the press release.

If the plight of the wolverine is not the kind of thing that gets your hair on end, there’s still reason to care. The study also found that a side effect of the loss of snow melt means big impacts for people as well. The projected lack of snow could reduce the amount of water in Idaho, western Montana and western Wyoming by as much as three or four-fold by the end of the century. Get those water-saving shower heads now.

The study is not meant to bring only doom and gloom. Researcher say this kind of analysis could help us think preventative. “This study is an example of how targeted climate predictions can produce new insights that could help us reduce the impact of future climate change on delicate ecosystems,” said Sarah Ruth, program director for the NSF’s Directorate for Geosciences in a press release.

Wolverine (Photo/U.S. National Park Service)

A critter of unique character — to really understand what makes the wolverine such a remarkable creature, check out Douglas Chadwick’s book, The Wolverine Way. Even if you’re not a wildlife lover, this is an adventurous read that will leave you in awe of what a creature will do to survive.

NCAR Study available here.

Changing Chesapeake Bay acidity endangers oysters

New research shows that the shell growth of Crassostrea virginica from Chesapeake Bay could be compromised by current levels of acidity in some Bay waters. (Photo/Chris Kelly, UMCES Horn Point Laboratory)

Growing up at the mouth of the Lynnhaven River in Virginia, where the river meets the Chesapeake Bay and the bay meets the ocean, I can’t tell you how many mornings I woke up and looked out my window to see neighbors wading in rubber boots, harvesting oysters from the beds just off our riverbank. For some, like my neighbors, oysters were a way to connect with the land and make a little extra dough. For others it was their livelihood. The act was something that just was. It never occurred to me that the oysters could one day be gone.

That’s why I was especially alarmed to read this new report from the University of Maryland Center for Environmental Sciences. Rising acidity levels in the Chesapeake Bay are making it harder for oysters to grow their shells. I’ve heard the news before that rising ocean acidity from sources such as carbon dioxide can spell disaster for marine wildlife, but this new study shows that acidity is rising faster in the Chesapeake Bay than in the ocean and having a measurable impact on Bay wildlife.

“With oyster populations already at historically low levels, increasingly acidic waters are yet another stressor limiting the recovery of the Bay’s oyster populations,” said marine biologist Dr. Roger Newell of the UMCES Horn Point Laboratory in a press release.

But don’t turn around to blame climate change just yet. The story is a bit more nuanced than that, though the source of the problem still has to do with us. In the saltier areas of the bay, the acidity is going up, leading to thin shell growth that makes oysters more vulnerable to predators, including crabs. But in more freshwater portions of the Bay, acidity is actually going down, said the study, which looked at more than 20 years of historical water quality data from the Bay.

The difference seems to be not atmospheric carbon dioxide, but the base of the food chain. In freshwater areas along the upper Chesapeake, sewage and agricultural runoff cause phytoplankton blooms, which consume carbon dioxide and lower acidity, said the study. Sounds good at this point right? Here’s the catch. As phytoplankton drift through the Bay, they are eaten by animals and other bacteria, releasing the carbon dioxide that the plankton so diligently consumed in the first place. This carbon dioxide lingers in the water, leading to spikes in acidity in the saltier regions of the Bay near the ocean.

“While these variations in acidity may improve conditions for shellfish in some areas, they may also magnify detrimental impacts in others,” said lead author Dr. George Waldbusser of Oregon State University in a press release. “What our study indicates is there may be an important shifting baseline and without better measurements we will fail to fully understand impacts on estuarine biota.”

Beyond the science itself, this study highlights how connected and varied our environment is. It lays out a pathway of human-induced consequences to an ecosystem, and teaches that we need to look beyond one-to-one cause and effect. Erin Voigt, an undergraduate student who worked on the study puts it well. “The complex response of oyster shell formation to temperature, salinity, and acidity highlights the need to understand how the entire ecosystem is changing, not just acidity,” she said.

And that ecosystem includes us.

You can view the article online in the journal Estuaries and Coasts.

Looking to the skies to predict hantavirus outbreaks

Captive bred Peromyscus maniculatus (Deer Mouse). Originally published at RodentFancy.com (Photo Courtesy 6th Happiness)

When faced with plagues of deer mice and outbreaks of deadly hantavirus, checking in with the weatherman probably isn’t on most people’s minds. But new science shows that maybe it should be.

Scientists report in the Journal of Animal Ecology that they have been able for the first time to quantify the link between weather events, like El Niño, and booms in potentially hazardous deer mouse populations. Best take this news seriously. We’re in the middle of an El Niño season.

Their findings may help public health officials develop better hantavirus prevention strategies as well as enable scientists to predict how climate change could affect the severity and locations of deer mouse outbreaks.

The Sin Nombre hantavirus is an illness not worth wishing on your worst enemy. It’s a zoonotic disease, meaning it can be transferred from animal to human. The first recognized U.S. outbreak occurred in 1993 in the Four Corners region, and on average, 20 to 40 cases are reported each year, according the U.S. Centers for Disease Control. Unlucky victims can look forward to flu-like symptoms and respiratory and heart failure, and survivors face recurring symptoms for the rest of their lives. The disease is transferred by deer mouse droppings, urine and the animal itself.

Biologist Angela D. Luis with Pennsylvania State University, Richard J. Douglass at the University of Montana and colleagues combined capture-release, climate and vegetation data with computer models to find out if deer mouse population and disease presence were influenced by weather. 15 years and more than 4,700 mice later, Luis and her colleagues found the connection.

At first glance, it sounds like more rain means more food, more mice and more hantavirus, as rainy years create better food crops for the cute but pesky disease carriers. But the relationship is not so straightforward. The “more rain equals more everything else” scenario is partially influenced by season. Luis found that higher temperatures and rain in the summer through early winter months bode well for mouse populations, but not so well during the spring.

This could be particularly key for the Southwest, as during El Niño years, this region typically experiences significantly more rainfall. The study isn’t perfect, factors like predation, migration, and competition could also be affecting deer mouse outbreaks, but the weather connection appears to be strong.

Right now Luis and her colleagues are expanding their study. So far they’ve looked at habitat in Montana only. They are looking at more types of environments throughout the state, including sagebrush and pine forests, which will help determine whether their model could be applied to multiple regions.

The Mangrove Forests of Mexico’s Yucatan Peninsula

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Along the Yucatan Peninsula, in a land of heat and drenching humidity thrives a rare mangrove ecosystem, important for coastal life and home to jaguarundi, hundreds of bird species and, yes, maybe a mosquito or two.  I hope you enjoy this short jaunt into the mangroves, sans the mosquitoes, near Celestun in Mexico’s Yucatan Peninsula. One afternoon doesn’t do a place like this justice, but it is a glimpse into this vulnerable ecosystem that is increasingly under threat from climate change, deforestation, pollution and coral reef degradation.

Family dining right whale style

 

For a month after birth, Southern right whale mothers and their calves rest and nurse. Then, like the pair shown here off Argentina, they start to swim faster and farther as they prepare for a long migration in the South Atlantic to reach their feeding areas. A University of Utah study found mother whales teach their calves where to eat, raising concern about whether the whales can adapt as global warming disrupts feeding grounds. (Photo/John Atkinson, Ocean Alliance)

Mom right whales know best when it comes to mealtime it seems. They lead calves to grub at traditional feeding grounds teaching their offspring generations of knowledge about when and where to find food. In fact whole clans of whales will dine together in the cetacean version of a family-owned dining spot. But this is one family tradition that could lead to starvation for an already vulnerable whale species if climate change causes shifts in food distribution.

Previous research by Vicky Rowntree, research associate professor of biology and a coauthor of the new study at the University of Utah, has already shown the impacts of climate change on right whale populations. When sea temperatures rise, krill disappear and right whales respond by giving birth to fewer offspring. Now these new studies into whale behavior could highlight another problem for the whales when it comes to food.

“A primary concern is, what are whales going to do with global warming, which may change the location and abundance of their prey?” asked Rowntree in a press release. “Can they adapt if they learn from their mother where to feed – or will they die?”

Rowntree and her colleagues collected skin samples from right whales and, using a novel technique in science, combined DNA and isotope analysis to determine whale lineages and where they tend to chow down. They found that related whales congregated in designated areas to feed, and that mothers teach calves in their first year of life where to find food.

Here’s to hoping that right whales will be quick to adapt if the buffet moves elsewhere.

An upside to climate change?

They’re the five “dirty words” of the West — cheatgrass; spotted knapweed; yellow starthistle; tamarisk; and leafy spurge — but the battle against these pervasive troublemakers could receive a boost from an unlikely ally, climate change. Scientists from Princeton University have determined that climate change will very likely cause massive die-offs of these invasive plants across the West, creating unprecedented opportunities to restore millions of acres of infected wilderness to native vegetation.

The findings, released this month in the journal Global Change Biology, will help land managers develop long-term invasive plant recovery projects. The restorative potential comes at a price however, as the model used in the study also predicts that some populations of invasive plants may simply shift their ranges to new areas — yellow starthistle will likely move from its current range in California, Oregon and Washington to a new ranges in California and Nevada for example.

Either way, the study forecasts a new picture of the western landscape, and may help researchers treat or possibly prevent invasive plant infestations. Whether the prognosis is good or bad, this is potentially important news for land managers and residents.