Thursday, July 12, 2018

New study finds rat eradication improves fisheries around islands

Rat on palm. Credit Island Conservation, USFWS
If the rat eradication of Lehua Island ends up being successful, it could result in a more productive nearshore fishery.

Which is ironic, in that many of those fighting the eradication program were fishermen.

A new study in the journal Nature says that when rats kill off seabirds on islands, it means those birds are no longer pooping in the nearshore waters, fertilizing reefs. And that means fewer fish on those reefs.

This study was done in the Chagos Archipelago, where some islands have rats and others are rat-free. Researchers looked at both the fertility of the land on those islands and the productivity of their reefs, where erosion from the land would carry nutrients like bird-poop-sourced nitrogen.

The Chagos are atolls and reefs just south of the Equator in the Indian Ocean. Their ownership is disputed between Great Britain and Mauritius. One is Diego Garcia, which houses a U.S military base.

The results of the research were clear, said the authors, who are from Australian, British, Danish and Canadian research institutions.

On islands without rats, seabird density as well as nitrogen deposits were hundreds of times higher. Yes, hundreds: 250 to more than 700 times higher.

Those rat-free islands had reefs that had 48 percent more biomass of "macroalgae, filter-feeding sponges, turf algae and fish."

The researchers looked specifically at damselfish, and found that they both grew faster and had higher total biomass on the rat-free islands.

The theory, then, is that seabirds feed in the open ocean, deliver bird poop to the islands, and that the islands then feed the nearshore waters, which makes the waters more productive and capable of producing more fish.



"Rat eradication on oceanic islands should be a high conservation priority as it is likely to benefit terrestrial ecosystems and enhance coral reef productivity and functioning by restoring seabird-derived nutrient subsidies from large areas of ocean," the authors wrote.
Vampire mouse victim. Credit USFWS

Rats are not the only problems on islands. On Midway Atoll, near the western end of the Hawaiian archipelago, mice began eating seabirds after rats were removed from the islands there. The case of the vampire mice, which chewed into the necks of Laysan albatross, is reviewed here.

On other islands, the mice even seemed to be getting bigger on their diets of eggs and bird flesh. The Washington Post was among the many international publications that picked up the vampire mouse story.

All that said, rodents mainly go after eggs and chicks of nesting seabirds. That was the case at Lehua Island. Here is a description of the situation on the little island north of Ni`ihau before an application of a rodenticide to try to wipe out the rats.

"We found Wedge-tailed Shearwater and Red-tailed Tropicbird eggs broken open, the edges gnawed, the insides consumed. Tiny seabird chick bodies were commonplace–pulled out of burrows and half eaten. This was particularly true for the diminutive Bulwer’s Petrel–the vast majority of Bulwer’s Petrel burrows we found had bits and pieces of chick inside," wrote Andre Raine, Project Manager for the Kauai Endangered Seabird Recovery Project.



A couple of months after the 2017 rat eradication effort at Lehua, Raine said he could clearly see the difference:

"Fat, healthy Wedge-tailed Shearwater chicks shuffled about in their burrows looking like animated fuzzballs. One of our burrow cameras showed a Bulwer’s Petrel chick exercising outside its burrow and actually fledging – a great omen, as this is something we have never recorded on our cameras in previous years," he wrote.

Most, but not all the rats were killed off at Lehua, and wildlife crews were back this year with rat-hunting dogs to try to kill off the survivors and protect the island's nesting seabird population.

And the island's coastal reefs and fisheries.
The removal of rats from islands is a major conservation effort. It has been done successfully at islands in Hawai`i like Mokoli`i off O`ahu and Mokapu off Molokai. When it was accomplished at Palmyra Atoll south of the Hawaiian Islands, it had the unintended effect of killing off the disease-causing Asian tiger mosquito, which had depended on rats for blood meals. 

© Jan TenBruggencate 2018

Sunday, July 8, 2018

Drink coffee, live longer. It seems strange, but the science is compelling.


So what's with the health benefits of coffee?

New studies suggest you will live longer drinking coffee than from taking vitamins, eating good fruits and engaging in the latest "miracle diet" craze.

It's not entirely clear why. Its not the caffeine, because even decaf coffee has the impact of reducing mortality by statistically significant amounts.

One British study released this month followed half a million people over 10 years, and found not only that coffee drinkers live longer, but that the more coffee you drink, the better your chances of a longer life than those who drink less.

The study is entitled "Association of Coffee Drinking with Mortality by Genetic Variation in Caffeine Metabolism." It was published in the journal JAMA Internal Medicine, a publication of the American Medical Association, by authors are Erikka Loftfield, Marilyn Cornelis, Neil Caporaso, Kai Yu, Rashmi Sinha and Neal Freedman.

The study was designed to look into whether drinking a lot of coffee is a problem for people with genetic issues with caffeine metabolism, but it found that everyone—including those whose caffeine metabolism was faster or slower—had reduced mortality if they drank coffee.

This isn’t entirely new. There have been previous studies linking coffee to better longevity and to reduced rates of various diseases. That helped lead to the recommendation that up to 40 ounces of coffee (five 8-ounce cups) can be part of a healthy diet, from the 2015 report of the U.S. Dietary Guidelines Advisory Committee.

This new study is a massive study using the more than 9 million members of the UK Biobank. This study targeted 503,000 volunteers—excluding those who were pregnant, or whose coffee or nicotine intake information was incomplete. It looked at those who drink ground coffee, instant coffee and decaffeinated coffee. The average age going into the study was 57, and there were slightly more women than men. The researchers followed them for 10 years, during which time more than 14,000 of them died

People lived longer, even if they drank decaf—so it's something in the coffee or the coffee drinking, and not just the caffeine. "These findings suggest the importance of noncaffeine constituents in the coffee-mortality association and provide further reassurance that coffee drinking can be a part of a healthy diet," the study's authors write.

The authors looked at details of participants' smoking, as well as sex, weight, exercise, race, education and how much they also drank tea (it is a British survey, after all). A fifth were non-coffee-drinkers.

Ground coffee was a little healthier than instant and decaf, but they were all better than none. The study found that sex, age, weight and previous health issues did not make much difference in the outcome.

The study 's conclusion ends with this key message: "Our results provide further evidence that coffee drinking can be part of a healthy diet and may provide reassurance to those who rink coffee and enjoy it."

An earlier study of 400,000 people was published in 2012, in an edition of the New England Journal of Medicine. It had similar results. The study was entitled "Association of Coffee Drinking with Total and Cause-Specific Mortality," and was by Neal D. Freedman, Yikyung Park, Christian C. Abnet, Albert R. Hollenbeck, and Rashmi Sinha. Freedman and Sinha were authors of both papers that we discuss here.

They followed 230,000 men and 170,000 women aged 50 to 71 over 13 years, during which period about 50,000 of them died. The study found that people who drink several cups of coffee daily have lower mortality—they don't die as early as ones who don't drink coffee or who drink less coffee.

This is particularly noteworthy—and strange—because coffee drinkers tend to make bad lifestyle choices:

"As compared with persons who did not drink coffee, coffee drinkers were more likely to smoke cigarettes and consume more than three alcoholic drinks per day, and they consumed more red meat. Coffee drinkers also tended to have a lower level of education; were less likely to engage in vigorous physical activity; and reported lower levels of consumption of fruits, vegetables, and white meat. However, coffee drinkers, especially women who drank coffee, were less likely to report having diabetes. About two thirds of coffee drinkers reported drinking predominantly caffeinated coffee.

Still, according to both studies, if you drink three to five cups of coffee a day, even decaffeinated coffee, you're roughly 10 percent less likely to die in a given period.

What the heck is going on? Everybody knows about the caffeine, but if the decaf drinkers get the same protective effect (which may mean that caffeinated soft drinks don't do the same thing, incidentally) what's causing the reduce mortality?

Well, it turns out there are about 1,000 other compounds in coffee. So it might be one or more of those things.

The authors point out that they can't prove the coffee causes the health effect. It might be that something else about coffee drinkers is making them less likely to die as soon.

If it is not caffeine having an effect, maybe it's antioxidants, the authors of the 2012 paper suggest.

"Coffee contains more than 1000 compounds that might affect the risk of death. The most well-studied compound is caffeine, although similar associations for caffeinated and decaffeinated coffee in the current study and a previous study suggest that, if the relationship between coffee consumption and mortality were causal, other compounds in coffee (e.g., antioxidants, including polyphenols) might be important.

There's also a 2017 study in the Annals of Internal Medicine of coffee drinkers in 10 European countries. It had similar results: " Coffee drinking was associated with reduced risk for death from various causes. This relationship did not vary by country." 

Still, this research isn't entirely straightforward. This article from the Mayo Clinic suggests that while there may be health benefits from coffee, there are also risks for some folks. 
Oh, and taking vitamins and supplements? One study says "the results from controlled trials are dismal."
Another, on antioxidant vitamins in heart health says: "After an initial enthusiasm for antioxidants in the secondary prevention of cardiovascular disease, recent reports from of several large randomized trials have failed to show any beneficial effects." 
The takeaway seems to be that it's healthier to eat a good diet with lots of fruits and vegetables than to take supplements to make up for a bad diet. But also, that there might be some benefit to having a couple of cups of coffee with those leafy meals.
© Jan TenBruggencate 2018

Friday, July 6, 2018

Kīlauea: Dramatic, long-term changes continue. Catastrophic event possible but unlikely.


It is tough to grasp the enormous changes going on at Kīlauea volcano, including the impact on the prized national park as well as the catastrophic impacts on downslope residents.

(The view at right is from Volcano House. If you've looked over Kīlauea from this site, you'll recognize how completely different it looks now. The image is from an automated National Park Service camera.)
In the day-to-day news cycle, we tend to use a tight focus on what has been destroyed lately--the hundreds upon hundreds of lost homes, the thousands of acres of forest gone, the loss of transportation systems and the destruction of the Jaggar Museum--but scientists at the Hawaiian Volcano Observatory recently took a wider look, and the future doesn't look bright.

The U.S. Geological Survey report is entitled Volcanic Hazard at the Summit of Kīlauea, June 29, 2018 Update.
The Kīlauea caldera is collapsing at two to three inches daily, dramatically changing the look of the landscape. The lava lake has dropped 1,000 feet from its high. The parking lot at Halema`uma`u has been torn up like a sheet of paper, and it is covered by ash and rocks that have been ejected from the firepit.

If you remember the Halema`uma`u overlook, remember it well. It has now been closed since 2008, and if you ever see it again, it will look very different. The crater, for example, is four times as big as it was.

For the next few months, we can anticipate more earthquakes, ground cracking, ash plumes, vog and large scale deformation as Halema`uma`u engulfs more and more of Kīlauea Crater. It may eventually take up all of what we now know as the crater.

A sudden, massive, severely damaging collapse is considered possible, although unlikely. New lava fountains hundreds of feet high are possible. So is an earthquake much bigger than the ones felt recently.

"Strong earthquakes can occur at any time, and the risk of these events is larger now due to ongoing stress changes in and around the caldera. These earthquakes will not necessarily occur during swarm seismicity or in association with (collapse-explosion) events, may be large, and may happen outside of the caldera," the report says.

The only good news in this scenario is that if a massive, destructive collapse of the caldera occurs, there ought to be some notice of it:

"…Large-scale hazardous caldera collapse is a possible future outcome, although it is considered to be very unlikely and should be preceded by detectable warning signals. HVO should recognize these warning signs by direct observation and instrumental monitoring and, should they be detected, will alert authorities and the public."
That said:.

"The most likely course of activity for the immediate future at the summit of Kīlauea Volcano is continued subsidence of the caldera floor, episodic slumping into Halema`uma`u, felt moderate-sized earthquakes, and small ash plumes. The duration of this activity may be related to the duration of the (Lower East Rift Zone) eruption but cannot be confidently predicted," the USGS says.

In short, the most likely scenario is that we keep seeing what we’ve been seeing for the past couple of months. The less likely scenario is that it gets worse.

You can keep track of the technical details of the eruption at the USGS Hawaiian Volcano Observatory website

Another great resource is the lyrical narratives of retired Hawai`i Volcanoes National Park ranger Bobby Camara, Dispatches from Volcano

© Jan TenBruggencate 2018

Thursday, June 28, 2018

New book on Breadfruit: Make it part of your agroforest


It's no surprise that the British sailed around the world, twice, to collect breadfruit.

The ulu is that important a crop. Rich in nutrients, versatile, drought-resistant and darned easy to farm. You just plant them once, and then harvest fruit for the rest of your life.

That work of food production in the tropics and subtropics is going to get easier still with the guidance from Craig Elevitch and Diane Ragone's new volume, Breadfruit Agroforestry Guide: Planning and Implementation of Regenerative Organic Methods. Elevitch is Director of Agroforestry Net and Ragone is director of the Breadfruit Institute at the National Tropical Botanical Garden.

Their new book is available as an ebook from the National Tropical Botanical Garden website or in print for $19.95 at Amazon. 

The 72-page volume will be useful to home growers, but it's designed for agricultural professionals and extension agents, and it's an unabashed paean to the tropical and subtropical tree in complex food production systems.

The mission of the authors is not only to point up the value of breadfruit as a species, but to celebrate its role in a food forest—as part of an agroforest. Traditional Pacific societies grew breadfruit as part of a forest garden that might include taro, sugar cane, ti, banana, kava, noni and many other crops.

They argue that such a system doesn't require external fertilizers and buffers the impacts of fluctuation in markets for single crops. Multi-story agroforestry captures carbon in the soil, protects plants from the wind and reduces moisture loss.

The National Tropical Botanical Garden has a research agroforestry breadfruit garden at its McBryde Garden on Kaua`i. And it has a collection of about 150  breadfruit varieties at Kahanu Garden on Maui and at McBryde.


There are many varieties of breadfruit. The traditional Hawaiian seedless variety is just one. Others fruit at different times, produce crops that taste different, and some have seeds that can be eaten like chestnuts. 

Trees product a hundred to several hundred fruit annually, often in two seasons. The fruit is edible at any stage. Unripe fruit can be cooked and eaten as a vegetable; soft ripe fruit are eaten as a starch, and they can be baked, fried or used in any number of dishes. 

I visited an island in the Solomons where ripe breadfruit was dried for use in the season when they weren't available fresh. Other Pacific cultures preserve them underground. But they'll last a while on your kitchen shelf, and refrigeration works, too.

The book was funded by Patagonia Provisions, the Hawai`i Department of Agriculture, Kauai Office of Economic Development, and Western Sustainable Agricultural Research and Education. Its publishers are the Breadfruit Institute and Permanent Agriculture Resources.

The same authors in 2013 produced what works as a companion volume: Breadfruit Production Guide: Recommended practices for growing, harvesting, and handling. You can download that one free here

But actually buying the books--search for them at Amazon--helps support the programs Ragone and Elevitch run.

Here's what the authors had to say, from the press release on the new book:
Ragone: “Breadfruit has been grown sustainably since humans began cultivating it thousands of years ago. It’s vital that we revive centuries of indigenous knowledge and traditional methods into a modern context. Doing so will help breadfruit thrive and support communities for many generations.”

Elevitch: “This is a crucial time for the future of breadfruit and island agriculture in general. Given that the single-crop plantation model with high chemical inputs leads to declining soil fertility and plant health, growers are now developing models for breadfruit production rooted in traditional methods.”

© Jan TenBruggencate 2018

Monday, June 11, 2018

Hawai`i data shows CO2 at record levels in atmosphere: and growing faster than ever


Annual CO2 growth rate. Source: NOAA, Scripps
Carbon dioxide levels in the atmosphere continue to grow at a record rate, promising that climate change will continue long beyond our lifetimes.

That's from data collected in Hawai`i—at the Mauna Loa Observatory, which has been collecting atmospheric CO2 data for 60 years. 

The Scripps release on the milestone is here.

In May, those levels reached a record high of 411.31 parts per million.

The latest tally was released last week by scientists from Scripps Institution of Oceanography at the University of California San Diego and NOAA.

And despite international efforts to control emissions, they appear to not be effectively under control. The level of emissions is not only continuing to grow, but it's growing faster. It was growing at 1.5-1.6 parts per million in the 1980s through 1990s, but during the past 10 years has been growing at 2.2 parts per million.

“Many of us had hoped to see the rise of CO2 slowing by now, but sadly that isn't the case. It could still happen in the next decade or so if renewables replace enough fossil fuels,” said Scripps CO2 program director Ralph Keeling, whose father Charles Keeling started the Mauna Loa CO2 program in 1958.

But while it's possible to reverse the growth trend in CO2, for species of all kinds, including humans, the future isn’t bright.

“Today's emissions will still be trapping heat in the atmosphere thousands of years from now.” Pieter Tans, lead scientist of NOAA’s Global Greenhouse Gas Reference Network.

With Kilauea volcano erupting continually for so long, many ask if that has a significant impact on atmospheric carbon dioxide. Researchers say it's clear that most of the CO2 change is from fossil fuel use, not the volcano.

And the proximity of Kilauea to Mauna Loa is also not a big factor. The high rate of growth in atmospheric CO2 is not only being observed at Mauna Loa but also at other sites in NOAA’s Global Greenhouse Gas Reference Network.

© Jan TenBruggencate 2018