Archives for August 2014

Air Race Is Fastest Motorsport on Earth: Photos

Pilots fly up to 230 miles per hour just above motor-speedway courses in the the Red Bull Air Race, which resumes in September.
Discovery News

Walking Fish Reveal How Our Ancestors Evolved Onto Land

This is Polypterus senegalus. (Credit: A. Morin, E.M. Standen, T.Y. Du, H. Larsson)

(Click to enlarge) This is Polypterus senegalus.
(Credit: A. Morin, E.M. Standen, T.Y. Du, H. Larsson)

About 400 million years ago a group of fish began exploring land and evolved into tetrapods — today’s amphibians, reptiles, birds, and mammals. But just how these ancient fish used their fishy bodies and fins in a terrestrial environment and what evolutionary processes were at play remain scientific mysteries.

(From ScienceDaily) – Researchers at McGill University published in the journal Nature, turned to a living fish, called Polypterus, to help show what might have happened when fish first attempted to walk out of the water. Polypterus is an African fish that can breathe air, ‘walk’ on land, and looks much like those ancient fishes that evolved into tetrapods. The team of researchers raised juvenile Polypterus on land for nearly a year, with an aim to revealing how these ‘terrestrialized’ fish looked and moved differently.

“Stressful environmental conditions can often reveal otherwise cryptic anatomical and behavioural variation, a form of developmental plasticity,” says Emily Standen, a former McGill post-doctoral student who led the project, now at the University of Ottawa. “We wanted to use this mechanism to see what new anatomies and behaviours we could trigger in these fish and see if they match what we know of the fossil record.”

Remarkable anatomical changes The fish showed significant anatomical and behavioural changes. The terrestrialized fish walked more effectively by placing their fins closer to their bodies, lifted their heads higher, and kept their fins from slipping as much as fish that were raised in water. “Anatomically, their pectoral skeleton changed to became more elongate with stronger attachments across their chest, possibly to increase support during walking, and a reduced contact with the skull to potentially allow greater head/neck motion,” says Trina Du, a McGill Ph.D. student and study collaborator.

“Because many of the anatomical changes mirror the fossil record, we can hypothesize that the behavioural changes we see also reflect what may have occurred when fossil fish first walked with their fins on land,” says Hans Larsson, Canada Research Chair in Macroevolution at McGill and an Associate Professor at the Redpath Museum.

Unique experiment The terrestrialized Polypterus experiment is unique and provides new ideas for how fossil fishes may have used their fins in a terrestrial environment and what evolutionary processes were at play.

Larsson adds, “This is the first example we know of that demonstrates developmental plasticity may have facilitated a large-scale evolutionary transition, by first accessing new anatomies and behaviours that could later be genetically fixed by natural selection.”

The study was conducted by Emily Standen, University of Ottawa, and Hans Larsson, Trina Du at McGill University.

This study was supported by the Canada Research Chairs Program, Natural Sciences and Engineering Research Council of Canada (NSERC) and Tomlinson Post-doctoral fellowship.

Video: https://www.youtube.com/watch?v=Pu0LMnT9S4k&feature=youtu.be


Consortium for Ocean Leadership

Abandoned landfills are a big problem

Abandoned landfill sites throughout the UK routinely leach polluting chemicals into rivers, say scientists. At Port Meadow alone, on the outskirts of Oxford, they estimate 27.5 tonnes of ammonium a year find their way from landfill into the River Thames. The researchers say it could be happening at thousands of sites around the UK.
ENN: Top Stories

Mars Rover Opportunity to Have Memory Wiped

The time has come — the little Mars rover needs its first memory wipe. Continue reading →
Discovery News

Reducing Water Scarcity

Water scarcity is not a problem just for the developing world. In California, legislators are currently proposing a $ 7.5 billion emergency water plan to their voters; and U.S. federal officials last year warned residents of Arizona and Nevada that they could face cuts in Colorado River water deliveries in 2016. Irrigation techniques, industrial and residential habits combined with climate change lie at the root of the problem. But despite what appears to be an insurmountable problem, according to researchers from McGill and Utrecht University it is possible to turn the situation around and significantly reduce water scarcity in just over 35 years.
ENN: Top Stories

How did humans domesticate wild rabbits?

Until recently, little has been known about what genetic changes transform wild animals into domesticated ones. An international team of scientists, one of whom is a University of Montana assistant professor, has made a breakthrough by showing that genes controlling the development of the brain and the nervous system were particularly important for rabbit domestication. The study was published Aug. 28 in Science and gives answers to many genetic questions.
ENN: Top Stories

Fish and Coral Smell a Bad Neighborhood: Marine Protected Areas Might Not be Enough to Help Overfished Reefs Recover

Testing fish in a choice chamber A new study in Science showed that young fish have an overwhelming preference for water from healthy reefs. The researchers put water from healthy and degraded habitats into a flume that allowed fish to choose to swim in one stream of water or the other. The researchers tested the preferences of 20 fish each from 15 different species and found that regardless of species, family or trophic group, each of the 15 species showed up to an eight times greater preference for water from healthy areas. (Credit: Danielle Dixson)

(Click to enlarge) Testing fish in a choice chamber A new study in Science showed that young fish have an overwhelming preference for water from healthy reefs. The researchers put water from healthy and degraded habitats into a flume that allowed fish to choose to swim in one stream of water or the other. The researchers tested the preferences of 20 fish each from 15 different species and found that regardless of species, family or trophic group, each of the 15 species showed up to an eight times greater preference for water from healthy areas.
(Credit: Danielle Dixson)

Pacific corals and fish can both smell a bad neighborhood, and use that ability to avoid settling in damaged reefs.

(From ScienceDaily) – Damaged coral reefs emit chemical cues that repulse young coral and fish, discouraging them from settling in the degraded habitat, according to new research. The study shows for the first time that coral larvae can smell the difference between healthy and damaged reefs when they decide where to settle.

Coral reefs are declining around the world. Overfishing is one cause of coral collapse, depleting the herbivorous fish that remove the seaweed that sprouts in damaged reefs. Once seaweed takes hold of a reef, a tipping point can occur where coral growth is choked and new corals rarely settle.

The new study shows how chemical signals from seaweed repel young coral from settling in a seaweed-dominated area. Young fish were also not attracted to the smell of water from damaged reefs. The findings suggest that designating overfished coral reefs as marine protected areas may not be enough to help these reefs recover because chemical signals continue to drive away new fish and coral long after overfishing has stopped.

“If you’re setting up a marine protected area to seed recruitment into a degraded habitat, that recruitment may not happen if young fish and coral are not recognizing the degraded area as habitat,” said Danielle Dixson, an assistant professor in the School of Biology at the Georgia Institute of Technology in Atlanta, and the study’s first author.

The study will be published August 22 in the journal Science. The research was sponsored by the National Science Foundation (NSF), the National Institutes of Health (NIH), and the Teasley Endowment to Georgia Tech.

The new study examined three marine areas in Fiji that had adjacent fished areas. The country has established no-fishing areas to protect its healthy habitats and also to allow damaged reefs to recover over time.

Juveniles of both corals and fishes were repelled by chemical cues from overfished, seaweed-dominated reefs but attracted to cues from coral-dominated areas where fishing is prohibited. Both coral and fish larvae preferred certain chemical cues from species of coral that are indicators of a healthy habitat, and they both avoided certain seaweeds that are indicators of a degraded habitat.

The study for the first time tested coral larvae in a method that has been used previously to test fish, and found that young coral have strong preferences for odors from healthy reefs.

“Not only are coral smelling good areas versus bad areas, but they’re nuanced about it,” said Mark Hay, a professor in the School of Biology at Georgia Tech and the study’s senior author. “They’re making careful decisions and can say, ‘settle or don’t settle.’”

The study showed that young fish have an overwhelming preference for water from healthy reefs. The researchers put water from healthy and degraded habitats into a flume that allowed fish to choose to swim in one stream of water or the other. The researchers tested the preferences of 20 fish each from 15 different species and found that regardless of species, family or trophic group, each of the 15 species showed up to an eight times greater preference for water from healthy areas.

The researchers then tested coral larvae from three different species and found that they preferred water from the healthy habitat five-to-one over water from the degraded habitat.

Chemical cues from corals also swayed the fishes’ preferences, the study found. The researchers soaked different corals in water and studied the behavior of fish in that water, which had picked up chemical cues from the corals. Cues of the common coral Acropora nasuta enhanced attraction to water from the degraded habitat by up to three times more for all 15 fishes tested. A similar preference was found among coral larvae.

Acropora corals easily bleach, are strongly affected by algal competition, and are prone to other stresses. The data demonstrate that chemical cues from these corals are attractive to fish and corals because they are found primarily in healthy habitats. Chemical cues from hardy corals, which can grow even in overfished habitats, were less attractive to juvenile fishes or corals.

The researchers also soaked seaweed in water and tested fish and coral preferences in that water. Cues from the common seaweed Sargassum polycystum, which can bloom and take over a coral reef, reduced the attractiveness of water to fish by up to 86 percent compared to water without the seaweed chemical cues. Chemical cues from the seaweed decreased coral larval attraction by 81 percent.

“Corals avoided that smell more than even algae that’s chemically toxic to coral but doesn’t bloom,” Dixson said.

Future work will involve removing plots of seaweed from damaged reefs and studying how that impacts reef recovery.

A minimum amount of intervention at the right time and the right place could jump start the recovery of overfished reefs, Hay said. That could bring fish back to the area so they settle and eat the seaweed around the corals. The corals would then get bigger because the seaweed is not overgrown. Bigger corals would then be more attractive to more fish.

“What this means is we probably need to manage these reefs in ways that help remove the most negative seaweeds and then help promote the most positive corals,” Hay said.

This research is supported by the National Science Foundation (NSF), under award number OCE-0929119, and the National Institutes of Health, under award number U01-TW007401. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the sponsoring agency.

Video: https://www.youtube.com/watch?v=eo6rHkL7Fck#t=61


Consortium for Ocean Leadership

Bob Gagosian – From the President’s Office: 8-28-2014

Bob Gagosian (Photo by Will Ramos / Ocean Leadership)

Congress is poised to return to Washington September 8th after a month long summer recess.  Unfortunately though, it is unlikely that they will accomplish much legislative work in the few weeks they will be in session before they adjourn again, this time to campaign for the November elections.  That means a Continuing Resolution for the beginning of the fiscal year 2015 (October 1st). In other words, we essentially start the federal fiscal year with the same budget as FY 2014. In addition, the Congressional Budget Office update on the federal budget and economic outlook for 2014 -2024 is essentially flat to negative for discretionary funding, which is where scientific research is supported.

So, with that good news, what can you do personally?  It is essential that you reach out to your elected officials while they are back in your districts. If you didn’t get a chance during this past month, please make the effort during campaign season.  I hope that you will convey how your community relies on science, both in economic and social terms.  All politics is truly local, and if you don’t have the ear of your representatives, then someone else with a very different agenda may have undue influence.  It is important to invite your congressional delegation members to your institution so they can see first-hand your enthusiasm and the importance of your science and science in general, for the good of their district, their state, and our nation.  We need to be passionate about translating our science into terms that policy makers can understand and act upon.  And, we need to convey, embrace and engage what we don’t fully understand, because that is where science will make the difference between generating good decisions versus poor ones.  At the end of the day, we elect these people to represent us and to make informed decisions on our behalf.  I feel strongly that it is our responsibility as citizens of this country to make sure that they have the best information available.

I hope you enjoy this Labor Day weekend and summer’s finale.

Bob


Consortium for Ocean Leadership

Fracked off – natural gas victims flee Colorado’s toxic air

Natural gas is widely touted as a ‘green fuel’. But as Paul Thacker found in Colorado, fracking’s national ‘ground zero’, it’s anything but. Lives and health are being ruined by pollution from taxpayer-subsidized gas wells, flaring and refining plants, while property values collapse. Now a mass of environmental refugees are fleeing the ravaged state.
Environment news & analysis, climate change reports –
The Ecologist

Choking the Oceans With Plastic

The Great Pacific Garbage Patch is growing — and there is really only one way to make it shrink.
NYT > Oceans