Wednesday, May 27, 2015
Hurricanes this year a near slam dunk: Be ready
NOAA’s Central Pacific Hurricane Center is predicting an El
Nino this summer, and that means a much higher chance of hurricanes in our part
of the Pacific.
And we’re due. More on that later.
(Image: This is a satellite image of the eastern Pacific
from today, May 27. The storm system with the red X shows strong signs of
developing into a more powerful storm. Credit: NOAA.)
This year, the NOAA numbers make hurricanes a statistical
slam dunk. Nearly 20-1 odds that we’ll see big storms before December.
That’s not a guarantee, but the odds are looking spookier for
hurricanes than they have in a very long time.
The part of NOAA’s package of statistics that is most
concerning is not so much that we are likely to have a more active hurricane
season. They predict that in any El Nino year.
What’s concerning this year is that there’s only a 5 percent
chance of a less-than active hurricane season. And a 95 percent chance of a
normal to higher season. That’s weighted strongly (70% to 25%) in favor of more
than normal.
Although the average year sees 4 to 5 tropical depressions,
tropical storms and hurricanes in our part of the ocean, there have been years
when there have been virtually none. And we’ve been quiet for what seems like a
very long time.
The last time the state took a direct hit was Hurricane
Iniki in 1992—23 years ago.
Before satellites, it was hard to identify major storms in
the Pacific unless a ship ran into one, or it hit an island. But in terms of storms that have caused damage, there were
Nina in 1957, Dot in 1959, Iwa in 1982, Estelle in 1986, Iniki in 1992.
That’s five big storms in 35 years, or one every seven years
on average.
And the longest time between them was Dot to Iwa, 23 years.
Same as the time from Iniki to 2015.
This may be the year to pay attention. Says NOAA:
“This outlook is based upon the expectation of El Niño continuing
and possibly strengthening as the hurricane season progresses.
“El Niño decreases the vertical wind shear over the tropical central Pacific, favoring the development of more and
stronger tropical cyclones.
“El Niño also favors more westward tracking storms from the
eastern Pacific into the central Pacific.
“This combination typically leads to an above-normal Central
Pacific hurricane season.”
The Central Pacific Hurricane Center is careful to say it can’t guarantee one or
more of those storms will actually hit the Islands, but it does encourage
families to sign up for emailed weather alerts, to sit down and talk about what
they’ll do in the event of a storm, and to put together a hurricane kit.
If you have a phone book, there are instructions in the
front pages. If not find hurricane preparedness tips online.
You can join NOAA’s central Pacific hurricane page on Facebook
.
Oh, and while the hurricane season doesn’t start until June
1, there is already a weather system headed this way. See the image above.
It’s still off Mexico,
but has an 80 percent chance of developing into a tropical depression in the
next two days, and 90 percent in the next five days.
© Jan TenBruggencate 2015
Posted by Jan T at 8:03 AM 0 comments
Labels: Climate Change, Government, Marine Issues, Weather, Wind
Tuesday, May 26, 2015
Superweeds and pesticide resistance in Hawai`i
The diamondback moth, a major pest of Hawaiian watercress, cabbages
and other crucifers, has repeatedly developed resistance to pesticides used to
control it.
There has been a lot of discussion in the Islands about
weeds gaining resistance to pesticides used on genetically modified crops, but
pesticide resistance has been an issue for farmers since long before genetic
modification became prevalent.
(Image: Diamondback moth larvae feeding on cabbage. Credit: Doug Wilson, USDA.)
Almost every pest control method—organic and synthetic pesticides,
and even cultural techniques like crop rotation, have been defeated by
persistent pests.
The message of pesticide resistance is that there’s no magic
bullet. Farmers need to use a range of techniques to control their pests—they can’t
simply count on a single chemical spray to solve all the problems.
In the case of the diamondback moth, Plutella xylostella, it became resistant to pyrethroid pesticides
in Hawai`i in 1992, and when farmers switched to using another natural
pesticide product, Bacillus thuringiensis, the bugs began developing resistance to it in three years.
And not just in Hawai`i—the resistance appears everywhere.
Farmers have switched to other pesticides and have fine
tuned their applications to try to defeat it, but are increasingly depending on
biological controls—other insects that feed on the various life stages of the
moth. Researchers are looking at increasing the effectiveness of viruses that attack the moths, and there's some genetic modification of moths underway in hopes of improving control.
But with respect to pesticide use, there’s still a concern, as consumers insist on food
crops that look nice: “In food crops where damage to vegetables must be
minimal, chemical control has not been eliminated by biological control,” wrote
Ronald F.L. Mau and Jayma L. Martin Kessing of the University of Hawai`i at Mānoa.
How pesticide resistance develops is pretty simple to explain. In
every population, there are a few individuals that will be tolerant of a new pesticide—will
survive it. The few
who survive will be the only ones to reproduce—and their offspring are far more
likely to be tolerant. Soon, if you keep using the pesticide, most of the
population will be resistant to it and your bug spray will no longer be effective.
Resistance is found for fungicides, insecticides and herbicides as well as for some cultural techniques. There is a bug that responded to farmers switching to
a different crop every other year, by going dormant for the intervening year so they’d be ready when the
original crop was again available.
But while pests are resilient, so are farmers. There are
numerous techniques to overcome pesticide resistance.
“Growers can help delay the development of resistance by
applying pesticides only when they are needed, by rotating between different
chemical classes, and by using rates of pesticides within the labeled range.
Integrating non-chemical approaches such as pheromone mating disruption and
cultural controls can also help delay resistance,” wrote the authors of Fruit Crop Ecology and Management, a publication of Michigan State University.
So, some of the techniques to combat resistance:
Use pesticides that biodegrade rapidly, so subsequent
generations of pests aren’t exposed and don’t further increase resistance.
Use combinations of pesticides—some may be resistant to one
or the other, but few to both.
Plant “sacrificial” crops—either in nearby fields or even
every other row—so there are always non-resistant bugs for resistant bugs to
mate with, reducing the overall resistance. Alternatively, leave some areas
untreated.
Learn more about the pests and use a tighter target—in the
case of a bug, attack only a specific life stage rather than trying to kill the
larvae, the adults and the rest all at once.
Experiment with non-pesticide techniques to reduce bug
numbers—remove plants they require to complete their life cycle, rotate crops
to reduce buildup of crop-specific pests, use baits and attractants to draw
pests away from the crops.
And there are other techniques.
One that doesn’t work well is a homeowner’s solution of
simply using more pesticide in hopes of getting ALL the pests.
“Deceptively reasonable on first inspection, this approach
rarely works in practice. The reason is that pesticide residues are usually
deposited very unevenly in most field situations, even when very high rates are
used. Uneven deposition of pesticides allows resistant pests to survive in
greater proportions than susceptible pests, thereby increasing resistance,” says
Washington State University’s online pamphlet on pesticide resistance.
The popular press likes to write about Roundup-resistant "superweeds." But they are, of course, not super in any way other than Roundup resistance. They're still susceptible to mulching, to other herbicides, to hoes and mowers, and to techniques that restore their Roundup sensitivity.
Pesticide resistance is not the end of the world—but its
management is a significant and normal part of modern farming.
The Washington
State paper says integrated pest management, including moderate, targeted pesticide
use, has been shown to work. Key missions for the farmer, Washington State says:
They must monitor pests regularly, carefully manage (not
overuse) their treatments, and “make full use of nonpesticidal methods, such as
biological and cultural control, sanitation and host plant resistance.”
The whole issue of resistance is complex—stacks of scientific
papers and many very dense books have been written about it. Included above are
just a few insights into the issue.
Missouri farmer Blake Hurst was quoted in the New York Times:
"The war between man and weed goes on. No different than it has since the beginning of time,"
© Jan TenBruggencate 2015
Posted by Jan T at 8:33 AM 4 comments
Labels: Agriculture, Botany, Conservation, Genetic engineering, Government, Pesticides, Pollution, Sustainability, technology, Zoology
Tuesday, May 19, 2015
Native Hawaiian ducks repopulating the island chain
Laysan ducks, the most geographically isolated duck species
in the world, has now leapfrogged across the Hawaiian archipelago, from its
Laysan home to Midway in 2004 and last year to Kure Atoll.
(Image: Laysan duck and her clutch. Credit: DLNR.)
Laysan ducks, Anas laysanensis, which are sometimes called Laysan teals, were once found throughout
the Hawaiian Islands, up and down the chain from the high islands to the tiny
atolls to the northwest.
But under pressure from humans, other predators like rats, habitat
loss and other issues, they finally were only present on Laysan. Laysan is a
sandy island with a central marsh that’s located about halfway up the
archipelago from Kauai to Kure.
The species is currently the rarest species of duck in the northern hemisphere, with the smallest range of any
In 1911, under pressure from introduced predatory rats and
from rabbits that ate much of the island’s vegetation, the population at Laysan
was down to 20 birds. But with rabbit and rat removal, the population began expanding.
Eventually, with numbers on Laysan at several hundred birds,
wildlife officials felt the population was healthy enough to try to develop new
populations. The risk of the entire population being on one small island was
too great.
The first move was to take a bunch of the birds and shift
them to Midway, where wildlife officials are stationed and could keep an eye on
them.
And here at RaisingIslands, we take some small credit for the
survival of these birdies. We were aboard the voyaging canoe Hokule`a in 2004, before
Laysan ducks were transplanted from Laysan to Midway.
The crew of the canoe dug up plants of the native sedge,
makaloa, which ducks particularly like. We transported the plants aboard the
canoe as it sailed up the Hawaiian archipelago, and we delivered them to
Midway, where they were planted alongside ponds dredged for the benefit of the
ducks.
That original transplanting of ducks to Midway had its
problems, from disease to tsunami, but 11 years later, the Midway flock of
Laysan ducks is doing well. Here is a 2007 RaisingIslands post on the duck
boom.
In 2008, a botulism outbreak killed many of the Northwestern Hawaiian Islands ducks, including a quarter of the Midway population.
Today, the population of Laysan ducks on Midway is in the
neighborhood of 400 birds. They’re doing so well that 28 of the Midway birds were
transplanted last year to Kure Atoll, the westernmost island in the Hawaiian archipelago.
As occurred with Midway, the transfer followed the removal of rats, the digging
of ponds and the transplanting of native plants to the island, to provide the ducks
with the best habitat possible.
The translocation was a joint project of the state Department of Land and Natural Resources' Division of Forestry and Wildlife, the
U.S. Fish and Wildlife Service's National Wildlife Refuge System, the U.S.
Geological Survey, Hawaii Wildlife Center, Kure Atoll Conservancy and
Papahānaumokuākea Marine National Monument,. (The Monument is managed by the NOAA, USFWS, and the
State of Hawai’i._
And the ducks have done well on Kure.
“We documented that all 28 founder birds translocated to
Kure in the fall of 2014 had survived six months after their translocation and
release,” said Cynthia Vanderlip, Kure Atoll state wildlife sanctuary manager.
In the spring season of 2015 on Kure, the 28 birds produced 19 ducklings,
bringing the population to more than 40—an auspicious beginning.
“Everyone working on this project to help save an endangered
species is thrilled that this reintroduction may reduce extinction risk of this
rare Hawaiian endemic duck. We all feel like proud parents,” Vanderlip said.
You can see a video of the ducks here.
Here is the state Department of Land and Natural Resources’
press release on the ducks and ducklings.
© Jan TenBruggencate 2015
Posted by Jan T at 2:24 PM 0 comments
Labels: Birds, Botany, Conservation, Government, Marine Issues, Voyaging, Zoology
Sunday, May 17, 2015
Comet's clues critical in solar system origin probe.
But this weird?
(Image: Three rocks [left] and fine-grained dust [right]
from Wild 2. Credit: R. Ogliore & Z. Gainsforth.)
Geophysicist Ryan Ogliore, of the University of Hawai`i Institute
of Geophysics and Planetology, looked into the comet Wild 2, and found a bizarre assemblage of materials.
“The comet's nucleus today is made up of small rocks and
ice, separated by fractions of an inch, that originally formed billions of
miles apart. Some rocks have seen temperatures above 2500 degrees Fahrenheit,
but adjacent ice has been kept close to absolute zero for billions of years.
Every tiny grain we look at has its own fascinating story to tell.”
Here is the University of Hawai`i press release on their findings.
Ogliore and his team studied samples from the comet that
were collected by the NASA Stardust mission. Wild 2 is a comet that used to
travel outside Neptune’s orbit, but was diverted to nearer Earth’s orbit in
1974, when it got too close to Jupiter’s gravitational zone.
The team’s findings were printed in the journal Geochimica
et Cosmochimica Acta. The citation: Ogliore, R.C., Nagashima, K., Huss, G.R.,
Westphal, A.J., Gainsforth, Z., Butterworth, A.L., Oxygen Isotopic Composition
of coarse- and fine-grained material from Comet 81P/Wild 2, Geochimica et
Cosmochimica Acta (2015), doi: http://dx.doi.org/10.1016/j.gca.2015.04.028
They found both tiny dust particles and larger rock bits,
but the evidence suggest that different particles were formed in vastly
different places in the solar system. Some, as Ogliore said above, had at some
point gotten very hot. Others have been beyond icy cold for immensely long
periods of time.
Some of the larger rocks appear similar to rocks found in
primitive meteorites. But the tiny dust particles, strangely for something
orbiting out in Jupiter’s zone, looks like the dust that you’d expect from the
inner solar system.
What could be going on?
“Does the fine-grained dust from comet Wild 2 represent a
diverse sampling of many inner-solar-system objects that were transported to
the outer solar system, or in fact, the raw starting materials of the solar
system?” said Ogliore.
They’ll be looking into that. It may provide clues to how
the Solar System developed. Wild 2 has some interesting clues for us.
“The comet, in an orbit beyond Neptune since its formation,
retains an intact a record of early-Solar-System processes,” Ogliore and his
team wrote.
It may be, they write, “A window into the birth of the solar
system."
© Jan TenBruggencate 2015.
Posted by Jan T at 5:25 PM 0 comments
Labels: Astronomy, Geology, Physics, technology
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