The Sun, surprisingly, is as round as it can be: UH researchers

Even the Earth bulges a little as it spins, but the Sun...the Sun is nearly perfectly round.

Rounder than almost anything else--and that's a surprise.

(Image: An photo of the sun, showing sunspots, taken by the Solar Dynamics Observatory. Credit: NASA.)

University of Hawai`i scientists were among those who recently conducted state-of-the-art measurements using a device called the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory satellite.

They found that it is amazingly round. The sun spins, an activity that tends to widen objects at the equator and flatten them between the poles. But not Ol’ Sol. 

The solar research team on this project includes Jeff Kuhn and Isabelle Scholl of the Institute for Astronomy, University of Hawaii at Manoa, Rock Bush  of Stanford University, and Marcelo Emilio, of the Universidade Estadual de Ponta Grossa, Brazil. They reported their findings in the August 16, 2012, Science Express in an article entitled The Precise Solar Shape and Its Variability. The abstract is here.

First, the measurement. They found that if you shrank the Sun to a ball one meter across, then the distance measured through the poles would be only 17 millionths of a meter less than the distance measured at right angles to the poles, through the equator—the equatorial diameter. A sheet of paper is five or six times thicker than that. Most human hair is significantly thicker.

Our Sun spins fully every 28 days and it ought to flatten more than that, according to predictions based on that rotation. With all the sunspots and moving plasma and other stuff, you might also think there would be lots of variance in its shape. 

There isn’t.

"For years we've believed our fluctuating measurements were telling us that the sun varies, but these new results say something different. While just about everything else in the sun changes along with its 11-year sunspot cycle, the shape doesn't,” lead author Kuhn said.

In fact, the sunspot cycle seems to have no role, the authors say. It is “completely unaffected by the solar cycle variability seen on its surface.”

Their best guess: subsurface forces like solar magnetism may be having a much more powerful impact than anyone predicted. The sun's massive gravity, along with other subsurface forces, may counteract the effects of its spin, and keep it in a rounder shape.

This work was supported by NASA grants to Stanford University and the University of Hawaii.

More about the Solar Dynamics Observatory here and here.   

The University of Hawai`i press release on the discovery is here.

© Jan TenBruggencate 2012

Invasive fish ta`ape maintains diversity by fast invasion

It seemed to make so much sense back then—if native species aren't doing well, just bring in stronger competitors rather than figuring out why the locals aren't thriving.

(Image: The introduced snapper, Lutjanus kasmira, commonly known as taʻape. Credit: Keoki Stender)

It happened in forestry, bringing in alien trees to reforest the Islands, rather than figuring out why the native forests were ravaged.

And it happened in fisheries, when the Hawai`i Territorial Division of Fish and Game determined, around the time of statehood, to supplement the islands' existing nearshore marine species with three alien reef fishes, Lutjanus fulvus (blacktail snapper or to‘au), Cephalopholis argus (blue-spotted grouper or roi) and Lutjanus kasmira (bluestriped snapper or ta‘ape).

What's been the result? A couple of them have done so well that organizations sponsor targeted fishing tournaments to try to reduce their impact on the reefs and the native species.

A group of scientists from the Hawai`i Institute of Marine Biology has studied the genetics of the three species to learn what happened to them as they settled in to their new Hawaiian home. The researchers are Michelle Gaither, Robert Toonen, and Brian Bowen.

They were released on O`ahu and Hawai`i Islands, but quickly spread to all the Main Hawaiian Islands, and the ta`ape traveled more than 1,000 miles right up the Northwestern Hawaiian Islands chain to Midway Atoll. Roi thus far has made it to French Frigate Shoals. Only to`au remains in the main islands.

The researchers found that the fast-spreading ta`ape maintained its genetic diversity—a diversity similar to that found in the ta`ape of its source islands in Fresh Polynesia. But the slower-spreading species, particularly the to`au, lost much of their genetic diversity.

It suggests that fast growth itself may play a role in protecting diversity of invasive species, they write.

“We now have a better idea of why some species are more successful invaders than others. The faster a species becomes established in its new environment, the faster it finds food and begins to reproduce, the more likely it is to maintain the genetic diversity that is so important to its long term success as an alien species,” said Gaither, in a press release.

For more information the Hawai`i Institute of Marine Biology work in the Northwestern Hawaiian Islands, see www.hawaii.edu/himb/nwhi/. The abstract from their paper in is here: www.ncbi.nlm.nih.gov/pubmed/22874747. The publication is Proc Biol Sci. 2012 Aug 8.

© Jan TenBruggencate 2012

Nihoa millerbirds repopulate Laysan Island, redux

Researchers leave today (Aug. 10, 2012) for Nihoa Island to collect native Nihoa millerbirds, to help repopulate the species on Laysan Island.

(Image: It’s not easy working on remote islands. Here, a team transfers captured millerbirds from Nihoa to a waiting small boat during the first Laysan repopulation effort. Credit: USFWS Pacific.)

Millerbirds became extinct on Laysan, in the Northwestern Hawaiian Islands, after introduced rabbits destroyed the island’s vegetation a century ago. The rabbits have long since been removed, and Fish and Wildlife Service teams have been working for two decades to restore some of the native vegetation there.

Meanwhile, the endangered millerbird has been vulnerable, since its only population in the world has been on that single, tiny, volcanic island from which it gets its name. 

Nihoa lies 150 miles to the west of Kaua`i, and is the easternmost island of the 1,000-mile long Papahānaumokuākea Marine National Monument , which encompasses the Northwestern Hawaiian Islands.

Researchers last year made the first transfer of the birds from rocky Nihoa Island, where they still thrive, to sandy Laysan, which lies 650 miles to the west. Those birds have done well. Twenty-four were moved onto Laysan Sept. 10, 2011, and they have already produced 17 young.

This translocation is a project of the U.S. Fish and Wildlife Service (FWS), American Bird Conservancy (ABC), and other organizations. It takes place entirely within the Hawaiian Islands National Wildlife Refuge and Papahānaumokuākea Marine National Monument and World Heritage site.

Much of what is known about Nihoa millerbirds was discovered by pioneering zoologist Sheila Conant, a University of Hawai`i professor who studied them extensively starting in the 1980s. She continues to be involved.

(Image: Nihoa millerbird, which will help create a new population of millerbirds on Laysan. Credit: Robby Kohley via U.S. Fish and Wildlife Service.) 

“The reproductive success of the first group of birds moved to Laysan is very encouraging and demonstrates that Laysan is quite a hospitable island for millerbirds from Nihoa,” she said. “This second translocation will provide this tiny, new population with the best chance of flourishing. The reestablishment of millerbirds on Laysan is an extraordinary and long-needed step in the species’ recovery.”

The project hopes to capture another 26 birds to bring the total number of transferred millerbirds to 50. A biologist will overwinter on Laysan to monitor the birds.

Habitat restoration and restoring species to their former habitats is a rare conservation event, but it has shown considerable success with birds like the Hawaiian goose or nene, once not present but which is now thriving on Kaua`i. In another example, during the past decade, Laysan ducks have been restored to Midway Atoll, and they appear to be responding well to the new habitat.

“This type of restoration work is sorely needed for other Hawaiian birds,” Conant said.

There’s more about the Millerbird project at www.fws.gov/pacificislands/ and www.abcbirds.org/abcprograms/oceansandislands/hawaii.html.

© Jan TenBruggencate 2012

If you're 100, better odds you were born in the fall

In what seems like a bizarre bit of trivia, new research indicates that people born from September to November have the best chance of living to 100 or older.

At least that’s the case for people who are now very old. It may not be as much the case for folks born more recently than the mid-1950s or so. 

And it may not be a useful predictor very long after birth. A lot of the mortality that leads to the preference for fall-born kids may occur among the very young—perhaps within the first few months of life.

It may be useful to look at the numbers backward: Kids born in early summer—May, June and July, are far less likely than average to be represented among centenarians.

This data comes from researchers who have previously done Hawai`i work, although this particular research is not Hawai`i-specific. They are Leonid A. Gavrilov and Natalia S. Gavrilova, of the University of Chicago’s Center on Economics and Demography of Aging. 

The Gavrilovs conclude that “earlylife environmental conditions may have long-lasting effects on human aging and longevity.”

Their paper, Season of Birth and Exceptional Longevity: Comparative Study of American Centenarians, Their Siblings, and Spouses, was published in the Journal of Aging Research. They looked not only at U.S. data, but found similar patterns in Europe, where the required birth and life data are available. The paper is available here. 

Aging is of interest to Hawai`i in part because Hawai`i folks live longer than most:  Island residents can expect to live to 81.5 years, more than in any other state. Our previous post on the Gavrilov’s research is here. 

The new research suggests a number of reasons for the seeming anomaly favoring fall-born elders. 

The authors suggest it could be associated with maternal nutrition (summer-born kids were in utero during the harsh winter deprivations.) Temperature (avoiding extremely high summer temperatures or extremely low deep winter temperatures  in the first month of life.)  The “deadline hypothesis” (fall-born kids were older and therefore more advanced at the start of school, gaining an education advantage on their peers that rolls into better lifelong nutrition and opportunity and a healthier life.)

And it may also be that certain infectious diseases affecting the very young are more likely to hit summer-born kids. A powerful data point is that kids born in the fall don’t die of infections disease at as high a rate as their siblings.

“According to the USA statistics, mortality below age one month in 1940 was the lowest in September–November suggesting lower infectious load during this period of the year, because most infant deaths in the past were caused by infections,” the authors wrote.

© Jan TenBruggencate 2012

Plastics killing seabirds all over Pacific

Laysan albatross on their Hawaiian nesting islands are the signature species for the devastating impacts of plastics in the marine environment, but increasingly, the dead albatross are not alone.

 

The haunting image of the problem is dead albatross chicks, their burst bellies jammed full of plastic lighters, bottle caps, discarded toothbrushes and other multicolored debris.

(Image: A northern fulmar, this one photographed in 2008 in Scotland. Credit: Dick Daniels, http://carolinabirds.org/)

But new studies on a Pacific seabird that comes ashore in the Pacific Northwest is also showing dramatically high plastic contents. Some northern fulmars have as much as 5 percent of their body weight in plastic in their bellies. 

These birds, known to science as Fulmarus glacialis, don’t feed exactly the same way albatross do, but there’s plenty of plastic to go around. In fulmars, researchers found twine, candy wrappers and styrofoam.

Let’s digress a little about the scope of the problem.

The albatross chicks die so full of plastic that they can’t take in nutrition, but it’s not just mechanical fullness that kills sealife. Also entanglement—turtles and seals trapped by abandoned nets and coils of rope—and the chemicals released by the plastics they eat.

“Microplastics are both abundant and widespread within the marine environment, found in their highest concentrations along coastlines and within mid-ocean gyres. Ingestion of microplastics has been demonstrated in a range of marine organisms, a process which may facilitate the transfer of chemical additives or hydrophobic waterborne pollutants to biota,” says a report in Marine Pollution Bulletin, by  Matthew Cole and Pennie Lindequeof Plymouth Marine Laboratory, Claudia Halsband of the High North Research Centre for Climate and the Environment in Norway, and Tamara Galloway of the University of Exeter in the United Kingdom. 

If the plastic is big enough it can trap and snare them, if it’s smaller it can choke them, and even when it’s microscopic, it’s not gone.

“Unlike inorganic fines present in sea water, microplastics concentrate persistent organic pollutants (POPs) by partition. The relevant distribution coefficients for common POPs are several orders of magnitude in favour of the plastic medium,” writes Anthony Andrady in the August 2011 issue of thesame journal. 

Back to the northern fulmars, also called Arctic fulmars. We don’t see them in Hawai`i since they cling to higher latitudes and colder climates. But they are in the same family as the Hawaiian shearwaters and petrels: 

Researchers in the North Sea have used stomach contents of fulmars to document high levels of plastics in that environment. We have long known that the Pacific is also a dumping ground—even before last year’s Japan tsunami scoured island coastlines and dumped their debris into the sea. Now research on northern fulmars in the Pacific is confirming what we already knew from albatross chicks—the plastic problem is massive.

Here is an article on the subject in e! Science News.   Science Daily has an article here. 

“We quantified the stomach contents of 67 fulmars from beaches in the eastern North Pacific in 2009–2010 and found that 92.5% of fulmars had ingested an average of 36.8 pieces, or 0.385 g of plastic. Plastic ingestion in these fulmars is among the highest recorded globally,” says the paper's abstract.

"Despite the close proximity of the 'Great Pacific Garbage Patch,' an area of concentrated plastic pollution in the middle of the North Pacific gyre, plastic pollution has not been considered an issue of concern off our coast. But we've found similar amounts and incident rates of plastic in beached northern fulmars here as those in the North Sea,” says author Stephanie Avery-Gomm , a zoologist at the University of British Columbia.

Oh, the euphemism "beached?" It generally means "washed up dead."

Here’s the journal reference for that article: Stephanie Avery-Gomm, Patrick D. O’Hara, Lydia Kleine, Victoria Bowes, Laurie K. Wilson, Karen L. Barry. Northern fulmars as biological monitors of trends of plastic pollution in the eastern North Pacific. Marine Pollution Bulletin, 2012; DOI: 10.1016/j.marpolbul.2012.04.017

© Jan TenBruggencate 2012