North Atlantic May Be a New Route for Spread of Avian Flu to North America plus 1 more

[USGS Newsroom <oc_web@xxxxxxxx>]

Title: USGS Newsroom

North Atlantic May Be a New Route for Spread of Avian Flu to North America plus 1 more

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North Atlantic May Be a New Route for Spread of Avian Flu to North America

Posted: 19 Mar 2014 02:10 PM PDT

Summary: The North Atlantic region is a newly discovered important pathway for avian influenza to move between Europe and North America, according to a U.S. Geological Survey report published today

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Contact Information:

Gail Moede Rogall ( Phone: 608-270-2438 ); Marisa Lubeck ( Phone: 303-202-4765 );

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A. Arrows show generalized movements of birds in particular flyways. Red arrows show general movements in the East Atlantic Flyway and yellow arrows show general movement in the North American Atlantic Flyway. Most birds use only portions of the flyways, which are determined mostly by species and by origin of breeding populations.

B. Red dots show the locations of where birds were sampled in the study. Reykjavik is shown for reference. Samples from some locations (Breiðafjörður and Selfoss) were obtained over a larger area than shown because samples were provided by hunters and fishermen within the region. (High resolution image)

The North Atlantic region is a newly discovered important pathway for avian influenza to move between Europe and North America, according to a U.S. Geological Survey report published today.

USGS scientists and Icelandic partners found avian flu viruses from North America and Europe in migratory birds in Iceland, demonstrating that the North Atlantic is as significant as the North Pacific in being a melting pot for birds and avian flu. A great number of wild birds from Europe and North America congregate and mix in Iceland's wetlands during migration, where infected birds could transmit avian flu viruses to healthy birds from either location.

By crossing the Atlantic Ocean this way, avian flu viruses from Europe could eventually be transported to the United States. This commingling could also lead to the evolution of new influenza viruses. These findings are critical for proper surveillance and monitoring of flu viruses, including the H5N1 avian influenza that can infect humans.

"None of the avian flu viruses found in our study are considered harmful to humans," said Robert Dusek, USGS scientist and lead author of the study. "However, the results suggest that Iceland is an important location for the study of avian flu and is worthy of special attention and monitoring."

The study also highlighted the new finding that gulls play an important role in moving avian flu viruses across the North Atlantic.

During the spring and autumn of 2010 and autumn of 2011, the USGS researchers and Icelandic partners collected avian influenza viruses from gulls and waterfowl in southwest and west Iceland (see map). By studying the virus’ genomes — an organism’s hereditary information — the researchers found that some viruses came from Eurasia and some originated in North America. They also found viruses with mixed American-Eurasian lineages.   

"For the first time, avian influenza viruses from both Eurasia and North America were documented at the same location and time," said Jeffrey Hall, USGS co-author and principal investigator on this study. "Viruses are continually evolving, and this mixing of viral strains sets the stage for new types of avian flu to develop."

The partners on the new study include the Southwest Iceland Nature Research Institute, the University of Iceland's Snaefellsnes Research Centre, the University of Minnesota and the J. Craig Venter Institute. This study was funded by the USGS and the National Institute of Health’s Centers of Excellence for Influenza Research and Surveillance.

The report was published today in the journal PLOS ONE and is available online.

For more information on avian influenza research, please visit the USGS National Wildlife Health Center website.

Bighorn Sheep on A Desert Island: Been There, Dung That

Posted: 19 Mar 2014 02:05 PM PDT

Summary: In a finding authors are coining an "unintentional rewilding," scientists identified a cave dung deposit as belonging to bighorn sheep that became extinct on a desert island sometime between the 6th and the 20th century

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Contact Information:

Ethan Alpern ( Phone: 703-648-4406 ); Julio Betancourt ( Phone: 703-648-5840 );

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In a finding authors are coining an "unintentional rewilding," scientists identified a cave dung deposit as belonging to bighorn sheep that became extinct on a desert island sometime between the 6^th and the 20^th century.

The unintentional rewilding occurred when in 1975 wildlife biologists introduced 16 female and 4 male bighorn sheep to Tiburón Island, the largest island in the Gulf of California. Today, the population numbers more than 500 individuals.

A team from the University of California-Riverside, the U.S. Geological Survey, Oregon State University, and East Tennessee State University discuss this non-native rewilding on Tiburón Island, located in the Gulf of California, in this week's PLOS ONE. Ben Wilder, Ph.D. Candidate of UC-Riverside and the lead author of the study, accidentally discovered the 1500-1600 year-old, urine-cemented dung mat on the floor of a small cave in the Sierra Kunkaak, a rugged mountain range of the eastern side of the island.

After comparing the pellets with an extensive collection of dung for both living and extinct herbivores, researchers determined that bighorn sheep formed the dung mat. The ancient sequences exactly matched DNA sequences from modern desert bighorn sheep, and differed substantially from other large herbivores that might have been present.

Until this discovery, there was no knowledge on whether or not bighorn sheep had previously occurred on the island.  

"It's a very clear result," said Clinton Epps, a co-author and a conservation geneticist at Oregon State University. "Furthermore, the sequences are not identical to the modern bighorn populations on Tiburón Island - so we are confident that the sequences do not derive from modern use of the cave by introduced bighorn sheep."

Julio Betancourt, a USGS paleoecologist and co-author of the study, has previously collaborated with geneticists to extract and sequence ancient DNA from cave deposits. Betancourt thinks that, in the future, "molecular caving will become more than an afterthought in arid lands paleoecology."

Michael Hofreiter of the University of Potsdam, a leading authority in ancient DNA research and editor of the paper, notes that, "Given the ongoing progress in paleogenomics and DNA sequencing, it will soon be possible to sequence full genomes from samples like the one recovered from Tiburón island, compare those to genomes from various extant populations and thereby identify the population that is most suitable for reintroduction in a certain area."

The goal of the 1975 re-introduction was use a safe site to foster a large, breeding population that could be used in restocking the mainland, where historic land use decimated native bighorn sheep populations. A controversial aspect of the Tiburón experiment is that it introduced what was then presumed to be a non-native herbivore into a fragile island ecosystem with a unique desert flora.

Wilder said he hopes that these findings will trigger more systematic studies of recent colonization and extinction events throughout these islands and elsewhere to help guide conservation efforts.

The study, "Local extinction and unintentional rewilding of bighorn sheep (Ovis canadensis) on a desert island," was authored by Benjamin T. Wilder, Julio L. Betancourt, Clinton W. Epps; others, and was published this week in PLOS One.