Julia Whitty

Julia Whitty

Environmental Correspondent

Julia is an award-winning author of fiction and nonfiction (Deep Blue Home, The Fragile Edge, A Tortoise for the Queen of Tonga), and a former documentary filmmaker. She also blogs at Deep Blue Home.

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Julia is a writer and former documentary filmmaker and the author of The Fragile Edge: Diving & Other Adventures in the South Pacific, winner of a PEN USA Literary Award, the John Burroughs Medal, the Kiriyama Prize, the Northern California Books Awards, and finalist for the Dayton Literary Peace Prize, and Deep Blue Home: An Intimate Ecology of Our Wild Ocean. Her short story collection A Tortoise for the Queen of Tonga won an O. Henry and was a finalist for the PEN Hemingway Award. She also blogs at Deep Blue Home.

Snowshoe Hares Can't Keep Up With Climate Change

| Tue Apr. 16, 2013 5:05 AM EDT
Growing or shedding a white winter coat at the wrong time is a monster liability for snowshoe hares:

Snowshoe hares live or die by their coat color—turning brown in the growing season and white in the winter. But the timing of the snow is changing faster than some hares can keep up.

The authors of a new paper in PNAS report that natural populations of North American snowshoe hares (Lepus americanusexposed to three years of widely varying snowpack (2009, 2011, 2012) seemed able to adapt to some extent to changes in spring snow melt dates by changing how quickly they molted from white fur to brown, depending on the presence or absence of snow. But they couldn't change the speed of their autumn molt from brown to white. That's because the fall molt appears to be purely a response to the shortening days and unrelated to the appearance of actual snow. 

"On average, it takes about 40 days for a hare to completely change from brown to white," says lead author L. Scott Mills, at the University of Montana College of Forestry and Conservation. "The white-to-brown change takes a few days longer and shows some ability to speed up or slow down according to temperature or snow."

Beyond these findings, the researchers also used an ensemble of climate change projections to predict how changing snow dates might affect hares in the future. Their results suggest that by 2050 there'll be between 29 and 35 fewer days of snow cover, and by 2100 40 to 69 fewer days. That means hares might be hopping on a mismatched background for four to eight times as many days as they do now.

Projections of increasing seasonal color mismatch in the future. The black line for all panels shows average phenology of hare seasonal color molt across the 3 y of the field study. The blue line shows mean modeled snow duration for the recent past (1970–1999). The orange and red lines show the future (mid-century and late-century) mean modeled snow duration for different emissions scenarios. The gray highlighted regions represent coat color mismatch, where white hares (≥60%) would be expected on a snowless background. As the duration with snow on the ground decreases in the future, mismatch will increase by as much as fourfold in the mid-century and eightfold in the late-century.
In the top graph, the gray area shows dates from three recent years where hares' coats didn't match the season. The bottom two charts' gray areas project more and more color mismatch over the coming century. Credit: L. Scot Mills, et el. PNAS (2013). DOI: 10.1073/pnas.1222724110

The future of these hares may boil down to plasticity: the ability of a plant or animal to change its appearance in response to changes in the environment. The authors write:

For example, male rock ptarmigan exhibit behavioral plasticity to reduce conspicuousness by soiling their white plumage after their mates begin egg laying in spring, a phenomenon likely underlain by tradeoffs between sexual selection and predation risk. A more direct avenue for plasticity to reduce mismatch when confronted by reduced snow duration would arise from plasticity in the initiation date or the rate of the seasonal coat color molts. It is not known how much plasticity exists in these traits, nor how much seasonal color mismatch is expected in the future as snow cover lasts a shorter time in the fall and spring. 

Snowshoe hares are the main dinner course for the endangered Canadian lynx, which also inhabits the US. So the hares' ability to adapt or not could fatten lynx in the short term but, as their population declines, leave the cats starving in the future.

Canadian lynx
Canadian lynx: kdee64 at Flickr

At least nine other widely distributed mammals also undergo seasonal color changes: Arctic foxes, collared lemmings, long-tailed weasels, stoats, mountain hares, Arctic hares, white-tailed jackrabbits, and Siberian hamsters. Their ability to match coat color to coming changes in snow cover could determine their fates—and might serve as a lesson for us. As the authors conclude:

The compelling image of a white animal on a brown snowless background can be a poster child for both educational outreach and for profound scientific inquiry into fitness consequences, mechanisms of seasonal coat color change, and the potential for rapid local adaptation. 

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That Sustainable Seafood Label May Be Fishy

| Fri Apr. 12, 2013 5:10 AM EDT
Large swordfish (Xiphias gladius) on deck during long-lining operations:

The Marine Stewardship Council's principles for sustainable fishing are "too lenient and discretionary," according to a new analysis published in Biological Conservation. The MSC's principles "allow for overly generous interpretation by third-party certifiers and adjudicators, which means that the MSC label may be misleading both consumers and conservation funders." This is another black eye for the MSC, which was already failing its own strict standards for awarding the coveted "sustainable" label.

For the 20,000 swordfish 'sustainably' hooked in Canadian waters yearly, longliners also catch 100,000 sharks, 1,200 endangered loggerhead turtles, and 170 leatherback turtles.

The World Wildlife Fund, one of the world's biggest environmental groups, and Unilever, one of the world's biggest seafood processors, founded the MSC in 1997 to provide "the best environmental choice in seafood." But as I've reported herehere, here, and here—and as MoJo's Tom Philpott reported recently here—the prestige of the MSC sustainable blue label has been eroded, challenged, and at times undermined by scientific assessment of the fisheries and genetic analysis of the fish going to market.

The authors of this latest study write:

Despite high costs and difficult procedures, conservation organizations and other groups have filed and paid for 19 formal objections to MSC fisheries certifications. Only one objection has been upheld such that the fishery was not certified. Here, we collate and summarize these objections and the major concerns as they relate to the MSC's three main principles: sustainability of the target fish stock, low impacts on the ecosystem, and effective, responsive management.

Here are some of the lowlights of the MSC report card:

  • Over the past decade, there have been 19 formal objections to Marine Stewardship Council (MSC) fisheries certifications 
  • Adjudicators have upheld only one objection: the Faroese Northeast Atlantic mackerel
  • 12 percent of MSC fisheries have received formal objections
  • By weight, these fisheries represent 35 percent of MSC-certified seafood
  • Loopholes and loose wording in MSC standards allow for controversial fisheries to be certified


School of sardines
Sardines: TANAKA Juuyoh (田中十洋) at Wikimedia Commons.

I wrote about one of these contested fisheries—the Gulf of California sardine—in my portrait of Mexican ecologist Enriqueta Velarde. She's one of the the authors of this Biological Conservation paper who noted that the Gulf of California sardine is only one of several forage fish and other species at or near the bottom of the food chain that have been labeled sustainable, but whose populations are of great concern to scientists. From the paper

The MSC has certified these small pelagic fisheries all over the world, including Antarctic krill (Euphausia superba), Norway spring spawning herring (Clupea harengus), Gulf of California sardine (Sardinops sagax) and Argentine anchovy (Engraulis anchoita). These forage species are important in the diets of seabirds, marine mammals and larger finfish and therefore the overfishing of forage fish can lead to declines in their predators. When sardines are available in the Gulf of California, they comprise up to 97% of the diet of some seabird species. Despite the importance of these small pelagic fish in supporting healthy ecosystems, few forage fisheries are managed in an appropriately precautionary fashion. A recent report recommended cutting catches of forage fish in half in many ecosystems, thereby doubling the minimum biomass of forage fish that must be left in the water. ​

The authors also found great fault with the sustainable label awarded to Canada's longline swordfishery because of its extraordinarily high bycatch of other species. For the 20,000 swordfish "sustainably" hooked in Canadian waters yearly, longliners also catch 100,000 sharks, 1,200 endangered loggerhead turtles, and 170 leatherback turtles. As Yale Environment 360 reported: "When the MSC labels a swordfish fishery that catches more sharks than swordfish 'sustainable,' it's time to re-evaluate its standards," says lead author Claire Christian, director of the Secretariat of the Antarctic and Southern Ocean Coalition.

The Worst Wildlife Disease Outbreak Ever in North America Just Got Way Worse

| Tue Apr. 9, 2013 5:02 AM EDT
Cluster of hibernating gray bats (Myotis grisescens):

The US Fish and Wildlife Service confirms white-nose syndrome (WNS) is present at Fern Cave National Wildlife Refuge in Alabama. This cave provides winter hibernation space for several bat species, including the largest documented wintering colony of endangered gray bats. More than a million individuals of this federally listed and IUCN listed species nest at Fern Cave. 

White-nose syndrome—a fungal disease possibly imported from Europe on the boots of spelunkers (cave explorers)—hits bats at their winter hibernation roosts. It was first identified in North America in New York in 2006/2007 and has since spread to 22 states (more on that here) and five Canadian provinces. WNS has decimated bat populations with mortality rates reaching 100 percent at some sites. In the northeastern United States, bat numbers have plummeted by at least 80 percent, says the USGS, with ~6.7 million bats killed continent wide. The Center for Biological Diversity reports that biologists consider this the worst wildlife disease outbreak ever in North America.

Scanning electron micrograph of a bat hair colonized by Geomyces destructans
Scanning electron micrograph of a bat hair colonized by Geomyces destructans: Gudrun Wibbelt, Andreas Kurth, David Hellmann, Manfred Weishaar, Alex Barlow, Michael Veith, Julia Prüger, Tamás Görföl, Lena Grosche, Fabio Bontadina, Ulrich Zöphel, Hans-Peter Seidl, Paul M. Cryan, and David S. Blehert via Wikimedia Commons
The disease is caused by the fungus Geomyces destructans, which infects the muzzle, ears, and wings of afflicted hibernating bats. Bats with WNS get all messed up during the cold winter months—flying outside during the day and clustering near the entrances of caves and mines where they would normally be hibernating. 
"The documentation of the disease from Fern Cave is extremely alarming and could be catastrophic."

"With over a million hibernating gray bats, Fern Cave is undoubtedly the single most significant hibernaculum for the species," says Paul McKenzie, Endangered Species Coordinator for USFWS. "Although mass mortality of gray bats has not yet been confirmed from any WNS infected caves in which the species hibernates, the documentation of the disease from Fern Cave is extremely alarming and could be catastrophic."

Strong words for a government agency. But the Center for Biological Diversity (CBD) is even more pissed off. "With white-nose syndrome wiping out bats across the eastern United States, it should be all hands on deck," says Mollie Matteson, a CBD bat specialist. "But tragically the response to this crisis continues to be lackluster. [Bats are] supremely important for farming, for our food security. They eat thousands of tons of insects, including crop pests, every year."

The CBD says researchers estimate the economic value of bug-eating bats to American agriculture at $22 billion, maybe as much as $53 billion a year. Yet federal funding for WNS research and disease response coordination has been scarce the past several years and is likely to become even scarcer in the 2013 and 2014 federal budgets.

Watch: Crack-Up of Sea Ice in the Arctic Ocean

| Fri Apr. 5, 2013 5:15 AM EDT
Gigantic area of sea ice caught in the process of fracturing in the Arctic Ocean off northern Alaska beginning in late January 2013:

As I reported last week, sea ice in the Arctic Ocean reached its maximum growth for the winter on about 13 March and is now losing more ice than it's gaining. The National Snow and Ice Data Center initially reported that 2013 was the sixth lowest sea ice extent on record. NASA has revised that to an even more dismal fifth-lowest sea ice extent on record.

In the image above—and even more so in the video time-lapse below—you can see the tremendous dynamism at work in this frozen ocean. Jostled by monster winds and ocean currents, sea ice sheets constantly shift, crack, and grind against one another. 

And that's what's happening on the left side of the video (above) in late January, according to NASA's Earth Observatory. A high-pressure weather system parked over the region produced warmer temperatures and winds flowing in a southwesterly direction. Those winds drove the Beaufort Gyre clockwise. And that gyre pulled pieces of sea ice west past Point Barrow, Alaska's northwestern-most point. 

The crack-up began in late-January and spread west toward Banks Island throughout February and March 2013. A series of February storms passing over central Alaska exacerbated the fracturing. By the end of February large pieces of ice had borken all the way to the western coast of Banks Island, a distance of ~600 miles (1,000 kilometers).

It's fascinating for me to see this area of the Arctic Ocean—particularly the Beaufort Sea part of the Arctic Ocean—which I sailed through in its entirety last October (more on that here) and saw not one speck of sea ice then. So all of the ice cap breaking up here is likely young, first-year ice.

Here's NASA's two-minute explainer on the Arctic winter of 2013, amid the mega-changes underway so far this century. Chilling.

Invasive Crab Restoring Cape Cod's Dwindling Salt Marshes

| Wed Apr. 3, 2013 9:51 AM EDT
European green crab, at juvenile stage where it appears green:

The European green crab—an invasive species in North America and one of the "worst 100" invaders on the Global Invasive Species Database—may not be the utter evil we once thought. A couple of new papers (here and here) from a team at Brown University detail how they're actually helping the dwindling salt marshes of Cape Cod recover. It's a fascinating detective story—from the frontlines of an emerging field known as historical ecology—and it's rife with plot twists and red herrings, which begins like this: 

  1. People built mosquito ditches into Cape Cod's salt marshes in the 1930s to drain flooded mosquito breeding habitat 
  2. Which resulted in the appearance of corridors of low marsh cordgrass in areas formerly dominated by high marsh plants 
  3. Coastal development ramped up big-time after World War II, with the permanent human population on the Cape doubling every 20 years from 1939-2005
Purple marsh crab
Purple marsh crab: Photo courtesy of Mark Bertness

Enter a mysterious die-off of Cape Cod low marsh cordgrasses that began decades ago. Researchers eventually traced the culprit to the native purple marsh crab, photo above, which was eating through the cordgrasses at alarming speed.

But why had this good crab suddenly gone bad? The researchers kept researching. Turns out that predators of those crabs—blue crabs and striped bass—were being overfished by recreational fishers. In the course of 337,000 fishing trips to Cape Cod annually, these fishers had triggered a trophic cascade.

That's when the removal of predators messes up the ecosystem two or more trophic links removed. In other words, a system-wide meltdown of a  functioning ecosystem. And one unlikely to recover its former state.

Turns out the mosquito ditches, which had seemed more or less harmless since their installation decades earlier, were accomplices in this trophic cascade. That's because the ditches had facilitated corridors of low marsh cordgrasses. As striped bass and blue crabs were being overfished, purple crabs were experiencing a fourfold increase in population. Suddenly these corridors of low marsh cordgrasses became superhighways for hungry purple crabs to eat themselves into a novel state of hyperabundance.

At developed sites with increased accessibility and fishing pressure (a), the purple marsh crab (S reticulatum, [c]) is released from predatory control (eg blue crab [Callinectes sapidus] and striped bass [Morone saxatilis], [b]) and consumes cordgrass (S alterniflora, [d]) along creek and ditch banks
At developed sites with increased accessibility and fishing pressure (a), the purple marsh crab, [c]) is released from predatory control (eg blue crab and striped bass, [b]) and consumes cordgrass , [d]) along creek and ditch banks: TC Coverdale, et al. Frontiers in Ecology and Evolution. DOI:10.1890/120130

But wait. The story's not over. Enter the introduction of an invasive species, the European green crab with a reputation for biological badassness. According to the findings of the researchers, just published in Ecology, these unwanted invaders (they probably got to Cape Cod as stowaways on ships) discovered the banquets of incredibly yummy (okay, I surmised that part) purple crabs that almost no one else was eating. Nature being what it is, the badass crab struck hard.

Hard enough to begin to reverse the decades'-long decline of Cape Cod's salt marshes. Which, BTW, keep the Cape from eroding off into the Atlantic Ocean. The authors write:

Our results show that, despite previous evidence of negative impacts on native species throughout its introduced range, [the European green crab] is well suited to accelerate the recovery of heavily degraded salt marsh ecosystems in New England.

The effect of the invasive crab doesn't even have to involve actually eating all that many native purple crabs, lead author Mark Bertness tells me. "Fear of being eaten can be a stronger ecosystem effect than being eaten, because predation happens one event at a time whereas a single predator can scare away dozens of prey yielding much larger ecological effects." Though he adds this caution: "Marsh recovery driven by fear of green crabs is superficial and doesn't replace the centuries of accretion and carbon sequestration taken to build Cape Cod marshes."

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