Ocean fish farming puts wild stocks at risk...for lice

The farming of fish in net cages is taking yet another hit for its impact on wild fish.

(Image: Salmon in the wild. U.S. Fish and Wildlife Service image.)

Predictably, keeping living things in crowded circumstances creates issues—whether it's fungal attacks on monoculture crops or recurrent colds among kids in pre-school.

On fish farming, the tight confines of the netted pens promote parasites, which then can infest wild fish, said University of Hawai'i professor L. Neil Frazer, of the Department of Geology and Geophysics, School of Ocean Science and Technology. He wrote an essay in the journal Conservation Biology.

And in some ways, he argues, this form of marine farming creates issues that land-based agriculture doesn't. But he also suggests that there are ways to respond to the problem.

“Farm fish...share water with wild fish, which enables transmission of parasites, such as sea lice, from wild to farm and farm to wild fishes. Sea lice epidemics, together with recently documented population-level declines of wild salmon in areas of sea-cage farming, are a reminder that sea-cage aquaculture is fundamentally different from terrestrial animal culture,” Frazer wrote.

His work was done on Mainland salmon farming, not on any of the local fish farming projects. But Frazer said his work helps explain the phenomenon of declines in wild fish populations around salmon sea cage fish farms.

One issue: In the wild, a sick fish might quickly weaken from inability to feed or be eaten by a passing predator. But in cages, managers use medications and adequate feeding to keep them alive.

“The difference is that sea cages protect farm fish from the usual pathogen-control mechanisms of nature, such as predators, but not from the pathogens themselves. A sea cage thus becomes an unintended pathogen factory,” Frazer wrote.

Sea lice are crab-like creatures that infest fish, eating skin and other tissue and creating injuries that can be opportunities for infection. The prevalence of the parasite can create in increase in the overall number of parasites in the environment, increasing the chance that they will infest wild fish.

Frazer said his work shows that wild fish in the environment around fish farms can be reduced in number and may even disappear.

How to respond? Frazer does not argue that fish farming must be halted. To respond to the issues he raises, he has several recommendations:

“Declines of wild fish can be reduced by short growing cycles for farm fish, medicating farm fish, and keeping farm stocking levels low.

“Declines can be avoided only by ensuring that wild fish do not share water with farmed fish, either by locating sea cages very far from wild fish or through the use of closed-containment aquaculture systems. These principles are likely to govern any aquaculture system where cage-protected farm hosts and sympatric wild hosts have a common parasite with a direct life cycle,” he wrote.

For more information, see http://www3.interscience.wiley.com/journal/120122721/issue.

© 2008 Jan W. TenBruggencate

Ancient secret unveiled: Five extinct Hawaiian birds were originally Americans

Hawai'i changes people, and it changes other living things, too—like several native birds that have been living under deep cover for millions of years.

(Image: Rare shot of the now-extinct Kaua'i 'ō'ō by noted naturalist Rob Shallenberger. Source: US Fish and Wildlife Service.)

New DNA work shows that five species of Hawaiian forest birds—long thought to have evolved from islands of the Western Pacific—are actually originally American birds.

It's just that they evolved in the Hawaiian environment to look like island birds, and they've been fooling scientists for more than 200 years.

Tragically, all five species are now extinct. They include the Big Island kioea, and the Hawaii, Moloka'i, O'ahu and Kaua'i species of the 'ō'ō.

“The Hawaiian 'honeyeaters,' five endemic species of recently extinct, nectar-feeding songbirds in the genera Moho and Chaetoptila, looked and acted like Australasian honeyeaters (Meliphagidae), and no taxonomist since their discovery on James Cook's third voyage has classified them as anything else,” wrote scientists Robert C. Fleischer, Helen F. James and Storrs L. Olson, all of the Smithsonian Institution. Their report was published in “Current Biology.”

These birds looked remarkably like the honeyeaters of the Solomons, New Guinea, Bougainville, Australia, New Zealand, Vanuatu, New Caledonia and other islands of the Western Pacific. So everyone who knew birds was convinced that's where they'd come from.

They were classified among the Australiasian honeyeater family, Meliphagidae, although in their own genera: moho for the 'ō'ō and Chaetoptila for the kioea.

The old classifications: Hawai‘i ‘Ō‘ō, Moho nobilis; Moloka‘i ‘Ō‘ō, Moho bishopi; O'ahu ‘Ō‘ō, Moho apicalis; Kaua‘i ‘Ō‘ō, Moho braccatus; Kioea, Chaetoptila angustipluma.

But curious scientists never stop looking, and the team collected DNA samples from museum specimens collected in Hawai'i a century to a century and a half ago, when the birds were still found, thoughthey were rare even then. A book published in 1892 termed Hawai'i “Land of the O-o.”

Author Ash Slivers (a pseudonym), wrote about the birds. A copy of the book is available at Google Books: http://books.google.com/books?id=PsYRAAAAYAAJ&printsec=frontcover&dq=land+of+the+o-o.

“There is a bird called the 'O-o,' that formerly inhabited the islands in considerable humbers. Its plumage is glossy black, except a few feathers under the tail coverts, and a little tuft on each shoulder; these are golden yellow, and from them, in ancient times, royal robes were made. A garment of that kind is now in possession of the Queen, and one is in the Bishop collection. They are valued at incredible sums, as the species is virtually extinct. If you chance to ask a native anything about birds, he is sure to tell you of the 'O-o;' but after that he doesn't know the difference between a bald-headed eagle and a blue-jay,” wrote Slivers, otherwise known as Charles Burnett.

He either knew his birds or had talked to someone who did, since he includes interesting details of the bird's anatomy.

“By a beautiful contrivance of Nature, the O-o carries, at the tip-end of its tongue, a peculiarly equipped, delicate and sensitive brush, by the aid of which it extracts from the calyx of flowers the honey-pools there to be found; and this constitutes largely its main supply of food,” he write, adding that the birds would not turn down a meal of banana or insects.

The DNA evidence studied by Fleischer, James and Olson found that the Hawai'i birds weren't even closely related to those in the Western Pacific. Rather, their nearest relatives were among the waxwings of the Americas, and that their first Hawai'i ancestor had arrived a very long time ago—as much as 14 to 17 million years ago.

While their Mainland ancestors were mainly insect and berry eaters, the Hawai'i birds evolved to take advantage of the nectar in Hawaiian flowers, even evolving specialized split and fringed tongues that assisted in nectar feeding.

Fleischer, James and Olson, with a nod to the traditional scientific terminology, place the Hawaiian birds in their own family, Mohoidae.

Their assessment from genetic data of the time of the birds' ancestor's arrival indicates that it interestingly occurred about the same time as that of the first bird-pollinated plants.

Is there a connection between the arrival of the bird pollinated plants and the nectar sucking birds? Also, why did an American waxwing evolve into something that looked and acted like a Western Pacific honeyeater?

This sort of thing has happened before in nature, and it's something the scientific community calls convergent evolution. That's when very different things evolve to have similar features. Example: Salmon have fins and seals have flippers. One's a fish and one's a mammal, but those swimming devices look quite alike. Another example: wings on bats and birds.

In the words of the scientists who worked on the kioea and the 'ō'ō: “Convergent evolution, the evolution of similar traits in distantly related taxa because of common selective pressures, is illustrated well by nectar-feeding birds, but the morphological, behavioral, and ecological similarity of the mohoids to the Australasian honeyeaters makes them a particularly striking example of the phenomenon.”

(Just to keep things confusing, there's another bird in Hawai'i called the kioea. It's the migratory bristle-thighed curlew. To be clear, that kioea is different from the extinct kioea that's a member of Mohoidae.)

© 2008 Jan W. TenBruggencate

Transpo future gets a new face; X Prize could define it

What's the future of the passenger car?

That's an open question, and it's getting opener.

(Image: A green compressed air car, competing for the Progressive Automotive X Prize. Credit: the X Prize folks.)

Perhaps an electric vehicle with entirely new charging and management scheme, like the one proposed by Better Place, with a private company managing the battery packs while you own the car.

Maybe an electric or hybrid vehicle on the internal combustion model—you own the car, drive to a fill-up station, but simply plug in rather than pumping gas.

But both of those can use cars on the existing vehicular platform. You can't tell them from gas and diesel cars.

Sure, maybe the future looks just like the past.

But then there's the X Prize. The Progressive Automotive X Prize is offering a $10 million prize for the best car capable of going 100 miles on a single gallon of gas or the equivalent (like the amount of electricity equivalent to a gallon of gas—or diesel, or something else), while still being able to carry four individuals and being a vehicle folks would actually use.

We've been covering the X Prize in this website (check out our last post on the topic at http://raisingislands.blogspot.com/2008/07/making-cars-sexy-efficient.html.)

Recently, when we asked for an update, the organization's Carrie Fox wrote: “We’ve recently opened the Registration Period, and now have 22 Registered Contenders, out of the 120+ that signed Letters of Intent to compete. Registration remains open until February 2009 and we expect that many more teams will join this first 22 in the Registered Contender status.”

There's a fair chance that this competition will show us a new face of electric vehicles.

The spider-looking Aptera producer (www.aptera.com) is among the initial contenders. So is Zap (www.zapworld.com), which makes all sorts of electric vehicles, including scooters and bikes, and has a sexy-looking three-wheeler in mind, with the single wheel in back. TTW Italia (www.ttwvehicles.com) has a futuristic three-wheeler with the single wheel in front.

Avion (www.100mpgplus.com) is entering a pure diesel that it figures can beat 100 miles to the gallon. The Physics Lab of Lake Havasu (www.physicslablh.com) is entering its Green Giant, an electric drive train in a full size SUV “exploiting hydraulics, PV, heat-steam, diesel/natural gas, and hydrogen.”

MDI/SPM from France (www.zeropollutionmotors.com) is entering with its compressed air car.

And there are plenty of other innovative ideas.

To look at some of them, check out the X Prize site, http://www.progressiveautoxprize.org/.

Many of them are traditional-looking sedans in which dreamers and engineers are sticking really hot technology, but some are, well, pretty different looking.

And maybe that's the future.

© 2008 Jan W. TenBruggencate

Oceans acidifying 10 times faster than thought

Our island state and the world are even more severely threatened by the acidification of the ocean than previously known.

(Image: Washington State waters, where researchers measured dramatic increases in acidification.)


Scientists are already measuring declines in populations of creatures as a result of acidification—and notably the replacement of certain shellfish by acid-tolerant seaweeds.

Ocean acidification is perhaps the most under-reported feature of the steady advance of the amount of carbon dioxide in the atmosphere.

“For a potential environmental problem that is receiving increasing attention, there is surprisingly little published data in the scientific literature on how pH in the ocean is actually changing over time, and none that we know of outside of the tropics,” said Tim Wootton, of the Department of Ecology and Evolution at the University of Chicago.

Some of the seminal research on sea acidification was performed in Hawaiian waters just within the past couple of years. But new research is adding breadth and depth to that data—and it is finding that the oceans are growing acid alarmingly faster than anyone thought.

Wootton's team, including colleagues Catherine Pfister and James Forester, conducted a multi-year study of ocean acidity off Washington State. One of their findings was that there is considerable variability in the pH level of the ocean, based largely in changes in ocean biology. But the other finding was that acidity is rising very fast.

Their paper, “Dynamic patterns and ecological impacts of declining ocean pH in a high-resolution multi-year dataset,” was published in the Proceedings of the National Academy of Sciences.

The fundamental process is this: As carbon dioxide increases in the air, it mixes with the water, forming carbonic acid. The result is that the pH of the ocean—the measure of water acidity or alkalinity—is decreasing. That means the ocean is growing more acid.

“An alarming surprise is how rapidly pH has declined over the study period at our site--about 10 times faster than expected,” Wootton said in an email to RaisingIslands.

He said his studies showed that acidity of the oceans varies with changes in biological activity in the ocean, but that the overall direction is toward greater acidity.

Some of the creatures that most obviously are affected by the pH changes are ones that develop shells made of calcium carbonate or have skeletons that are weakened in a less alkaline environment.

“Although we have some idea about the chemical processes affecting pH in seawater, know that pH affects integrity of the calcium carbonate shells and skeletons that many marine animals have, and can demonstrate that plants and animals respond to reduced pH in the lab, we also know that we cannot easily extrapolate laboratory studies to ecosystem in nature,” Wootton said.

His team's work out in the real world shows that the laboratory results do reflect what happens in nature, but not necessarily entirely accurately.

“Our analyses reveal generally reduced performance of calcifying organisms, as expected, but this does not uniformly hold true. Because of the extensive experimental studies we have carried out at our site, we know that these exceptions are readily explained by the web of interactions among species,” he said.

Among those species most significantly affected, according to the study, were large calcifying mussels and goose barnacles. Since these animals are in the food chain for other species, it suggests a larger impact that is not yet readily apparent.

In the paper, the authors write about the challenge:

“The results of our analysis of ecological dynamics follow the general prediction that declining pH will negatively affect calcareous species, but the web of species interactions complicates the response,”
For instance, while the mussels and gooseneck barnacles did more poorly, acorn barnacles and certain fleshy seaweeds actually did better.

The essence: things are changing, changing fast, and we don't know exactly where they'll end up.

This blog has covered acidification aggressively in several previous posts:
http://raisingislands.blogspot.com/2008/07/ocean-acidification-requires-action.html.
http://raisingislands.blogspot.com/2008/01/ocean-acidification-carbon-dioxide.html.
http://raisingislands.blogspot.com/2007/10/ocean-acidity-rising-faster-than-feared.html.
http://raisingislands.blogspot.com/2007/09/ocean-acidity-from-co2-could-violate.html.
http://raisingislands.blogspot.com/2007/09/ocean-acidity-next-big-climate-thing_01.html.

© 2007 Jan W. TenBruggencate

Slimy snails, slippery slugs--more here than you ever thought

Something nipping at your seedlings and chewing at your leaves?

Could be a snail or a slug, and it could be because there are more of them here than anyone guessed.

(Image: Giant African snails, from the U.S. Department of Agriculture website, http://www.aphis.usda.gov/newsroom/hot_issues/ga_snail/giant_snail.shtml.)

A new survey found 38 non-native snails and slugs in nurseries in Hawai'i, five of them entirely new. They found two more species, but those were the native ones.

The surprising finding lands on top of the rejection of a Christmas tree shipments this year due to slug infestations. And it points to another way for alien pests to enter the Hawaiian environment. They can ride the winds and waves, hitchhike on planes and ships, but a lot of them arrive on plants.

If they arrive on aircraft, then they have a convenience denied to many human passengers these days: inflight meals.

The new study was published in the international Journal of Pest Management under the title, “The horticultural industry as a vector of alien snails and slugs: widespread invasions in Hawaii.” The authors are Robert H. Cowie, Kenneth A. Hayes, Chuong T. Tran and Wallace M. Meyer III, are from the University of Hawai'i's Center for Conservation Research and Training.

The infestation of nursery stock is a problem for various reasons. It can cost the nursery companies money when their shipments are rejected at the port. And they cause problems with production within the nurseries as they feed. Furthermore, they can cause problems outside the nurseries.

“When they are transported to and become established in new areas they may cause agricultural, horticultural and environmental problems,” the authors wrote.

The tiny coqui frog is an example. Unlike the snails and slugs, this denizen of nursery products makes its presence heard with a piercing evening call by its males.

The slug and snail study looked at 40 nurseries on six islands. Every nursery on every island was infested with multiple species.

“The rate of introduction of new species of snails and slugs shows no sign of declining,” the authors wrote.

They urge awareness on the part of nursery operators and quarantine officials. Nurseries, both to protect their own investments and to protect the gardens of their customers, are encouraged to maintain hygienic facilities.

In part, the issues is that with many of the smaller and hard-to-find species, it's not yet clear what their impacts will be on the local environment. Do they carry disease, do they eat some garden species in preference to others, do they compete with and push out native species?

“While some ... consequences, notably of the larger, more obvious species, are clear and dramatic, little is known about the impacts of the smaller and less noticeable species, yet these may also be important,” the authors wrote.

©2008 Jan TenBruggencate