Posts Tagged research

Jun 27 2015

NOAA Finds West Coast’s Massive Domoic Acid Bloom is Among Most Toxic Ever Recorded

— Posted with permission of SEAFOODNEWS.COM. Please do not republish without their permission. —

Seafood NewsSEAFOODNEWS.COM [Phys Org] by Hannah Hickey and Michelle Ma – June 26, 2015

The bloom that began earlier this year and shut down several shellfish fisheries along the West Coast has grown into the largest and most severe in at least a decade.

UW research analyst Anthony Odell left June 15 from Newport, Oregon, aboard the National Oceanic and Atmospheric Administration’s research vessel Bell M. Shimada. He is part of a NOAA-led team of harmful algae experts who are surveying the extent of the patch and searching for “hot spots”—swirling eddies where previous research from the UW and NOAA shows the algae can grow and become toxic to marine animals and humans.

“The current bloom of Pseudo-nitzschia spp., the diatom responsible for domoic acid and amnesic shellfish poisoning, appears to be the biggest spatially we have ever observed,” Odell said. “It has also lasted for an incredibly long time—months, instead of the usual week or two.”

Odell is the coastal sampling coordinator at the UW’s Olympic Natural Resources Center in Forks, Washington, part of the UW College of the Environment. From his base in Hoquiam, Odell samples shellfish, phytoplankton and water quality, and responds to toxic algae bloom events along Washington’s outer coast.

Now he is doing toxin sampling on the three-week first leg of the NOAA voyage, from San Diego to San Francisco. Three more legs will continue through mid-September, surveying up to the north end of Vancouver Island.

The first samples collected from near San Diego were fairly clean, Odell said, suggesting they were still south of the patch. More recent samples collected this week from near Santa Barbara showed the first signs of the harmful algae. The massive bloom is known to extend at least from central California to Vancouver Island, with reports coming from as far north as Alaska.

As the ship travels north it is making a large back-and-forth grid, sampling the water from very near shore to several miles offshore. NOAA scientists initially scheduled the cruise to survey sardine and hake. Researchers from the UW, NOAA and other partners were invited to join and use the opportunity to conduct a large-scale sampling for marine toxins.

The bloom includes some of the highest toxin levels ever recorded in Monterey Bay, California, and along the central Oregon coast. All of Washington’s razor clamming beaches are currently closed, and the southern coast of Washington has the largest-ever closure of our state’s Dungeness crab fishery.

For the past 12 years, Odell has been a research analyst for the UW-led Olympic Region Harmful Algal Bloom Partnership. The organization provides monitoring data and other information about toxic algae blooms to coastal communities on Washington’s Olympic Peninsula.

The UW’s Washington Sea Grant is involved in a similar monitoring effort for Puget Sound, SoundToxins, which has some 50 volunteers monitor 33 sites weekly throughout the sound.

The massive bloom that emerged this spring comes after a few relatively quiet years. While the phenomenon is natural and cannot be prevented, better knowledge could help to predict and prepare for its effects.

In recent years, UW oceanographers including Barbara Hickey and Ryan McCabe sampled coastal waters to help identify the origin of toxic Pseudo-nitzschia cells on the Washington and Oregon coasts. The studies resulted in the development of computer models that can simulate how the blooms travel.

Researchers pinpoint massive harmful algal bloom

Computer-based forecasts rely on continuous observations from onshore sampling efforts and offshore buoys. A regional ocean-observing data portal led by Jan Newton, an oceanographer at the UW Applied Physics Laboratory, combines water observations from federal, state and other agencies and provides that information and some forecasts to users in real time.

“Such observations are critical to understanding what new elements in the coastal ocean produced such a massive toxic bloom this year, and whether we should expect these conditions to continue,” Hickey said.

The main culprit for the current toxicity is Pseudo-nitzschia, a tiny algae that under certain conditions releases an acid that acts as a neurotoxin. On campus, UW oceanographers are using genetic tools to better understand these microscopic creatures and learn how they respond to changing conditions.

What caused the current bloom remains a mystery. Nick Bond, a research meteorologist at the UW Joint Institute for the Study of the Atmosphere and Ocean, coined the term “the blob” for the current huge patch of unusually warm water off the West Coast, and has studied its origins. Whether warm water is connected to the algal bloom is unknown.

“Our goal is to try to put this story together once we have data from the cruises,” Vera Trainer, a NOAA scientist and UW affiliate professor of aquatic and fisheries sciences, told the Seattle Times. She manages the Harmful Algal Blooms Program at NOAA’s Northwest Fisheries Science Center and is overseeing the current sampling effort.


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Apr 15 2015

Can squid help make soldiers invisible?

squid

Click to view video(s) — http://www.cnn.com

Atlanta (CNN) — One of the world’s oldest organism groups, cephalopods, like squid, octopus and cuttlefish, have survived in Earth’s oceans for millions of years.

They key to their survival: mastering the art of camouflage.

Now, scientists say, these ancient invertebrates may hold the key to developing a combat technology that will allow soldiers to avoid infrared detection.

Researchers at the University of California, Irvine say they have discovered a way to use proteins in the cells of pencil squid to develop “invisibility stickers” that can be worn by ground troops.

“Soldiers wear uniforms with the familiar green and brown camouflage patterns to blend into foliage during the day, but under low light and at night, they’re still vulnerable to infrared detection,” said Alon Gorodetsky, assistant professor of chemical engineering and material sciences.

“You can draw inspiration from natural systems that have been perfected over millions of years, giving us ideas we might never have been able to come up with otherwise,” he said.

Gorodetsky and his team have focused on specialized squid cells known as iridocytes, which contain a unique light-reflecting protein called reflectin. They were able to engineer E. coli bacteria to synthesize reflectin and coat the protein onto a packing tape-like surface to create the “invisibility stickers.”

Researchers say these reflectin-coated stickers can be changed into virtually any color with a chemical or mechanical stimulus.

“There is a lot of flexibility in how one can deploy this material, essentially, by taking the stickers and putting them all over yourself, you could look one way under optical visualization and another way under active infrared visualization,” Gorodetsky said.

The lab technology is not ready to be used in combat zones as researchers work to develop an adaptive camouflage system, in which multiple stickers are able to work in sync and respond to varying infrared wavelengths.

“We’ve developed stickers for use as a thin, flexible layer of camo with the potential to take on a pattern that will better match the soldiers’ infrared reflectance to their background and hide them from active infrared visualization,” Gorodetsky said.

The researchers’ work was recently presented at the 2015 American Chemical Society national meeting.


Read original story: http://www.cnn.com

Feb 5 2015

Chemical clues in fossil shells may help us understand today’s ocean acidification

By: Brendan Bane

As atmospheric CO2 levels rise, so too do those in the sea, leading to ocean acidification that outpaces that of any other time in tens of millions of years. Some effects of ocean acidification are imminent, like the fact that calcified organisms such as corals and shellfish will have access to less and less of the chemical components they need to build their shells and skeletons. Other outcomes are less clear, and scientists wanting to predict what may come of our quickly acidifying waters are looking to past climatic events that were similar to our own.

One such event, the Paleo-Eocene Thermal Maximum (PETM), which occurred 56 million years ago, is likely our closest analog to modern ocean acidification. Researchers who refer to the PETM as a case study have long suspected that ancient waters acidified then, but until recently, they never had physical evidence of it actually happening. Then just this past year, researchers uncovered the PETM’s chemical chronology encrypted in the shells of fossilized plankton, called foraminifera, and learned that the two timelines aren’t entirely similar; today’s surface ocean is acidifying ten times faster than it did during the PETM. Their findings were published in Paleoceanography in June, 2014.

Penman (the lead author) offered this image of himself (center), Richard Norris (Scripps) and Pincelli Hull (Yale) inspecting sediment cores from the PETM while aboard a scientific drilling vessel.
Penman (the lead author) offered this image of himself (center), Richard Norris (Scripps) and Pincelli Hull (Yale) inspecting sediment cores from the PETM while aboard a scientific drilling vessel. Photo credit Donald Penman.
“While foraminifera are alive, they incorporate the chemistry of the water into their shells,” said Bärbel Hönisch, associate professor of earth and environmental sciences at Columbia University and coauthor of the study. “When they die, they take that information with them into the sediment.”

Hönisch and several other scientists analyzed the chemical composition of fossilized foraminifera embedded in “nannofossil ooze,” a section of rock particularly rich with tiny fossilized organisms, which they drilled out of sub-ocean sediment near Japan.

Foraminifera, like coral and shellfish, pull carbonate ions from the surrounding seawater to build their shells. In a way, the chemical composition of these shells acts as a snapshot of the chemical composition of the water the foraminifer lived in. When water grows increasingly acidic, foraminifera replace whole carbonate molecules with borate molecules. When the scientists of this study inspected the boron composition of shells from plankton that died during the PETM, they learned not only how acidic the ocean was at the time, but also how quickly its chemistry shifted and how long it stayed that way.

“Acidification during the PETM was relatively rapid,” said oceanographer Richard Zeebe of the University of Hawaii at Manoa, another coauthor of the study, “but it was also sustained. The whole event took a very long time.” A massive surge in atmospheric carbon, its cause still unknown, warmed the globe by four to eight degrees and dropped the ocean’s pH by about 100 percent. Conditions remained that way for approximately 70,000 years. These environmental changes triggered many biological ones. Seafloor-dwelling foraminifera suffered mass extinction while another type of tiny aquatic organism, dinoflagellates, thrived and expanded.

Foraminifera like the one pictured above record their environment’s chemistry in calcium carbonate shells, essentially leaving a trail of chemical breadcrumbs for future investigators. Photo by Howard Spero.
Foraminifera like the one pictured above record their environment’s chemistry in calcium carbonate shells, essentially leaving a trail of chemical breadcrumbs for future investigators. Photo by Howard Spero.
Although the PETM ocean did acidify quickly, it happened ten times slower than what’s happening today. Our ocean’s pH has dropped from 8.2 to 8.1 in the last 150 years, an amount that took a few thousand years in the PETM. Scientists predict the drop will only continue, with the seas reaching a pH of 7.8 to 7.9 by 2100. That change was and continues to be fueled by manmade carbon being pumped into the atmosphere and subsequently absorbed by the ocean.

In understanding how to compare the two events and what outcomes will emerge from modern acidification, rate is key.

“In any aspect of environmental change, particularly global change, rate matters” said lead author Donald Penman of the University of California Santa Cruz. Natural buffers like deep seawater mixing likely mitigated acidification during the PETM. But those same buffers will surely be outpaced by today’s heightened rate. “If you put carbon dioxide into the ocean faster than its natural processes can deal with it,” Penman said, “then they don’t do you any good.”

Marine animals will also be challenged by the speed at which their environment is changing. “We know that organisms and ecosystems can adapt and evolve to slow changes as they have throughout earth’s history,” Penman said. “However, when you invoke the same change over a shorter time, then you can outstrip organisms’ ability to evolve with that change. Species go extinct, and marine ecosystems change dramatically, perhaps irrecoverably.”

The researchers noticed that extinctions occurred during the PETM even at a pH change rate of 0.1 per thousands of years – which may not bode well for today’s foraminifera.

“The fact that some organisms went extinct during the PETM puts our current activities in perspective,” said Hönisch. “If the organisms died then, it is even more likely that some organisms will die now.”

With a clearer picture of the PETM painted, researchers can begin to draw more detailed analogies between the two events, and hopefully catch any drastic environmental changes before they surprise us.

“Now that we have [ocean acidification during PETM] quantified,” Penman said, “we can begin to make calculations of how much and how quickly carbon was emitted during the PETM. This will help us disentangle what sources of carbon and feedbacks were in operation during the PETM, and whether or not they are something we need to worry about in the future.”

0106_brendan_1Penman (the lead author) offered this image of himself (center), Richard Norris (Scripps) and Pincelli Hull (Yale) inspecting sediment cores from the PETM while aboard a scientific drilling vessel. Photo credit Donald Penman.

0106_brendan_3_360Foraminifera like the one pictured above record their environment’s chemistry in calcium carbonate shells, essentially leaving a trail of chemical breadcrumbs for future investigators. Photo by Howard Spero.

Citations:
Penman, D. E., Hönisch, B., Zeebe, R. E., Thomas, E., & Zachos, J. C. (2014). Rapid and sustained surface ocean acidification during the Paleocene‐Eocene Thermal Maximum. Paleoceanography.
Hönisch, B., Ridgwell, A., Schmidt, D. N., Thomas, E., Gibbs, S. J., Sluijs, A., … & Williams, B. (2012). The geological record of ocean acidification. science, 335(6072), 1058-1063.


Read the original post Mongabay.com.

Jan 26 2015

Stanford Researchers Strap ‘Crittercam’ Onto Squid

Stanford Researchers Strap ‘Crittercam’ Onto Squid, Discover How They Speak, Hide Themselves

squid_camera_012315Camera strapped onto a Humboldt squid. (Stanford University)

 

STANFORD (CBS SF) – Researchers at Stanford University strapped cameras on squid off the coast of Mexico and found the sea creatures likely use visual patterns to communicate and to hide themselves from predators, according to a study released this week.

Their study, published in the Journal of Experimental Biology, found Humboldt squid rapidly change their body colors from red to white to red again, in what researchers called “flashing.” They believe the behavior could be a way the squid speak with each other.

“The frequency and phase relationships [synchronization] between squid during flashing can be changed and this suggests that there is some information being conveyed that makes minute control over these details important to the squid,” Stanford researcher Hannah Rosen told the journal.

The researchers made their findings with the help of so-called “Crittercams” from National Geographic that were strapped onto the squid using Lycra-like “sweaters.”

Another behavior found by researchers is called “flickering,” where the squid produce waves of red and white across their bodies, likely to camouflage themselves from predators near the surface. They also observed what could be mating behavior of the squid.

Researchers plan to outfit more squid with cameras.


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Dec 18 2014

Unusual Species Highlight West Coast Cetacean and Ecosystem Survey

dolphins

The research ship Ocean Starr returned to San Diego Wednesday, completing NOAA Fisheries’ first comprehensive survey of whales, dolphins and porpoises and the marine ecosystem off the West Coast in six years. Highlights of the four-month survey included unusual marine mammals and birds drawn by warm ocean conditions, and the first offshore tests of an innovative new system for remotely counting marine mammals through sound.

“You don’t know what you will find until you are out on the ship, which is what makes it so important,” said Jay Barlow, chief scientist of the California Current Cetacean and Ecosystem Assessment Survey that stretched from California north to Washington. “This has been a very interesting and surprising survey because we’ve seen species we wouldn’t expect, which gives us information about their distribution as well as about current ocean conditions.”

The Survey led by the Southwest Fisheries Science Center identifies and counts cetaceans, seabirds and marine turtles using high-powered binoculars and towed listening arrays. The team also uses a series of specialized nets and oceanographic sampling gear to survey microorganisms that provide important clues about ocean conditions as well to monitor the physical environment through which the ship is traveling. In some cases researchers take tiny biopsies from whales and dolphins for genetic studies of population structure, foraging habits and health.

Scientists use the survey results to assess numbers of whales and dolphins and trends in their abundance, which helps determine the degree of protection the species may need.

Unusual species sighted included pygmy killer whales seen for the first time off California and warm-water seabirds such as band-rumped storm petrels seen for the first time in the Northeast Pacific. The survey also sighted sei, blue, fin, humpback, killer and short-finned pilot whales. In one instance the crew could hear a particularly loud chorus of singing humpback whales in the open air on deck.

The abundance of sei whales was a surprise, with more sightings of this species than the last five surveys combined from 1991 to 2008.

The Survey included the first offshore tests of the Drifting Acoustic Spar Buoy Recorder (DASBR), a pioneering system developed at the Southwest Fisheries Science Center to record the calls and other sounds of marine mammals while drifting the open ocean. Crews recover the DASBRs by following a GPS beacon and later acoustic analysis can distinguish the number and density of different species of marine mammals in surrounding waters.

The successful launch and recovery of several DASBRs over the course of the survey helps pave the way for longer-term deployment of the devices that cost less than $5,000 each. DASBRs drift in the open ocean and avoid the engine noise of similar arrays towed behind ships. That allows them to collect more data at a lower cost, supplementing traditional surveys that require expensive ship operations.

More information can be found on the Southwest Fisheries Science Center and  California Current Cetacean and Ecosystem Assessment Survey web sites.

View San Diego ABC Channel 10 News The previous link is a link to Non-Federal government web site. Click to review NOAA Fisheries Disclaimer and CBS Channel 8 News The previous link is a link to Non-Federal government web site. Click to review NOAA Fisheries Disclaimer  reports on the California Current Cetacean and Ecosystem Assessment Survey.

A selection of photographs The previous link is a link to Non-Federal government web site. Click to review NOAA Fisheries Disclaimer from the four-month West Coast cetacean and ecosystem survey can be viewed on flickr.com.

 


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Dec 18 2014

Climate change projected to drive marine species northward

New study predicts eastern Pacific species shifting poleward by 30 km per decade

Contributed by Michael Milstein December 10, 2014

Anticipated changes in climate will push West Coast marine species from sharks to salmon northward an average of 30 kilometers per decade, shaking up fish communities and shifting fishing grounds, according to a new study published in Progress in Oceanography.

The study suggests that shifting species will likely move into the habitats of other marine life to the north, especially in the Gulf of Alaska and Bering Sea. Some will simultaneously disappear from areas at the southern end of their ranges, especially off Oregon and California.

“As the climate warms, the species will follow the conditions they’re adapted to,” said Richard Brodeur, a NOAA Fisheries senior scientist at the Northwest Fisheries Science Center’s Newport Research Station and coauthor of the study. “We’re going to see more interactions between species and there will be winners and losers that we cannot foresee.”
Climate models used to project species shifts

The study, led by William Cheung of the University of British Columbia, estimated changes in the distribution of 28 near-surface fish species commonly collected by research surveys in the northeast Pacific Ocean. The researchers used established global climate models to project how the distribution of the fish would shift by 2050 as greenhouse gases warm the atmosphere and, in turn, the ocean surface.

Brodeur cautioned that like any models, climate models carry uncertainty. While they provide a glimpse of the most likely changes in global climate, they may be less accurate when estimating more fine-scale, local changes.

“Nothing is certain,” he said, “but we think we have a picture of the most likely changes.”

Some species shifts are already being documented as West Coast waters are warming: predatory Humboldt squid from Central and South America have invaded the West Coast of North America in recent years, albacore have shifted to more northerly waters and eulachon have disappeared from warming waters at the southern end of their range.
Effects on the marine ecosystem

“Thinking more broadly, this re-shuffling of marine species across the whole biological community may lead to declines in the beneficial functions of marine and coastal ecosystems,” said Tom Okey, a Pew Fellow in Marine Conservation at the University of Victoria and a coauthor of the study. “These declines may occur much more rapidly and in more surprising ways than our expected changes in species alone.”

The study anticipates warm-water species such as thresher sharks and chub mackerel becoming more prominent in the Gulf of Alaska and off British Columbia. Some predators such as sea lions and seabirds, which rear their young in fixed rookeries or colonies, may find the fish they usually prey on moving beyond predators’ usual foraging ranges.

“If their prey moves farther north, they either have to travel farther and expend more energy to get to them, or find something else to eat,” Brodeur said. “It’s the same thing for fishermen. If it gets warmer, the fish they depend on are going to move up north and that means more travel time and more fuel will be needed to follow them, or else they may need to switch to different target species. It may not happen right away but we are likely to see that kind of a trend.”

El Nino years, when tropical influences temporarily warm the eastern Pacific, offer a preview of what to expect as the climate warms.

Shifts in marine communities may be most pronounced in high-latitude regions such as the Gulf of Alaska and Bering Sea, which the study identifies as “hotspots” of change. Cold-water species such as salmon and capelin have narrower temperature preferences than warmer water species, making them more sensitive to ocean warming and likely to respond more quickly.

An intrusion of warm-water species into cooler areas could lead to significant changes in marine communities and ecosystems. The diversity of northern fish communities, now often dominated by a few very prolific species such as walleye pollock, may increase as southern species enter the region, leading to new food web and species interactions.

alabacore_NOAAFishWatchAlbacore tuna have shifted to more northerly waters.

eulachon_NOAA_AFSCEulachon have disappeared from warming waters at the southern end of their range.

humboldtsquid_noaa_oceanexploreHumboldt squid from Central and South America have invaded the West Coast of North America in recent years.

ThresherShark.SWFSCAccording to the study, thresher sharks may become more prominent in the Gulf of Alaska and off British Columbia.


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Nov 18 2014

UC Santa Cruz researchers say densovirus may be responsible for wiping out West Coast starfish

Posted with permission from SEAFOODNEWS.COM

[San Francisco Chronicle] by Peter Fimrite – November 18, 2014

Seafood News

Scientists have identified a virus that they believe is the mysterious killer that is wiping out starfish along the Pacific coast, but they can’t figure out why it suddenly became so deadly or whether it will continue its reign of destruction.

The pathogen believed responsible for causing millions of sea stars along the coast of California to wither and die was identified as a densovirus, a type of parvovirus, researchers at UC Santa Cruz and Cornell University said Monday.The disease was found not only in the tissues of its victims, but in brittle stars, which are closely related, and sea urchins.

It was also in seawater and sediments collected from affected areas, including Santa Cruz and Monterey, according to a paper published Monday in the Proceedings of the National Academy of Sciences.  Strangely, the virus was also detected in museum specimens dating back to 1942, meaning the disease has been lurking for decades but only recently turned deadly, said co-author Peter Raimondi, chairman of the ecology and evolutionary biology department at UC Santa Cruz. The virus wiped out starfish along huge swaths of the coast from Mexico to Alaska starting last year and has recently gone on a rampage through the Olympic Coast, in Washington state.

“What is unresolved is why it is so virulent,” said Raimondi, who leads the Pacific Rocky Intertidal Monitoring Program, which has been documenting the spread of the disease along the West Coast. “This virus has been around for at least 70 years, which brings up the question of why now?”

Another conundrum, said Raimondi, is the fact that the virus is present in other species, like sea urchins, which have not been dying nearly as much as starfish.

“Even if they don’t get infected, they carry it,” Raimondi said of the sea urchins. “That could be very problematic with respect to recovery.”

The mysterious pathogen, dubbed sea star wasting disease, was first detected in the summer of 2013 in Southern California. It was then found in tide pool areas along the coast of Monterey and has since spread through Oregon, Washington, British Columbia and southern Alaska. The telltale sign of the syndrome was that it caused starfish to become mushy and deteriorate until body parts began falling off.  Dead and dying starfish have been found close to shore and deeper underwater.

The disease even found its way last year into the filtration system of the Monterey Bay Aquarium, which uses seawater in its tanks. The virus has ravaged 20 varieties of starfish, going through a kind of progression, usually starting with the Ochre star, the purple or orange starfish most commonly seen in intertidal regions, Raimondi said. The pathogen has also ravaged the population of sunflower stars, the largest sea stars in the world. Short-spined sea stars and giant sea stars have also been hit hard. Raimondi said starfish feed on a variety of invertebrates, including mussels, sea urchins, clams and snails, which could be a source of the spreading disease.

The pathogen can also spread in the water almost like the common cold among the dense, often interwoven, populations of starfish, he said.The disappearance of starfish could have serious consequences by shifting the ecological balance of the sea. Mussels and other starfish prey could begin to overpopulate areas where their numbers were once controlled, Raimondi said. As a result, he said, fish, invertebrates, crabs and other species that feed on algae, plants and other sea life that thrive when starfish are in control will be marginalized and forced to look elsewhere for food.

Signs of hope

There is a light, however, amid the darkness. Huge numbers of baby sea stars have appeared in previously devastated sites in the Monterey Bay region, according to surveys conducted this year. In one study site, on a reef called Terrace Point, off Santa Cruz, researchers found more juvenile sea stars than have seen in 15 years of monitoring.

“There were just immense numbers of babies,” said Raimondi, who believes the diseased and dying sea stars went into reproductive mode, shooting out sperm and eggs as an evolutionary response to stress. “If they live, it’s going to mean we are going to have a recovery here in the next few years.”

Problem persists

Raimondi said the discovery of the suspected killer does not resolve the problem, but it helps in the quest to figure out what is going on in the ocean and, perhaps, prepare for change.

“One question is whether this virus evolved and became much more lethal,” Raimondi said. “The other possibility is that there is an environmental stress that is causing sea stars to become more susceptible, for instance warmer water or ocean acidification. It could be both. We don’t know. Our research will be looking at whether this is an isolated example or whether these things could become more common in the future. One question is whether this virus evolved and became much more lethal.”


View the original post: SeafoodNews.com

Nov 18 2014

Why isn’t anyone talking about Ocean Acidification?

acidification

Climate change is not the only outcome of increased greenhouse gas concentrations. The oceans have absorbed a lot of the excess carbon in the atmosphere, reducing the impacts of climate change to date, but at a cost. Higher concentrations of carbon dioxide (CO2) in the atmosphere have led to an increase in acidity of ocean water, a process known as ocean acidification. The process of acidification is laid out by Cheryl Logan in a user-friendly 2010 summary in the journal Bioscience.

Ocean acidification occurs when CO2 dissolves in ocean water, undergoing a chemical reaction that produces carbonic acid. The rate of this reaction is completely predictable and as a result the progression of acidification as CO2 levels increase is completely predictable. Unlike climate change, ocean acidification is not controversial at all—basically nobody disputes that it is happening—and happening rapidly.

As Logan explains, acidity is measured through the concentration of hydrogen ions—called the pH scale, for power of hydrogen—more hydrogen equals greater acidity. Since the late 19th century, the concentration of hydrogen ions in the ocean has increased by 30%, and that will increase another 150% by 2100, according to common emissions projections.

That is a massive change to ocean chemistry in a short amount of time, and many of the ocean’s inhabitants are struggling to adapt. The shells of many marine organisms are made of calcium carbonate, which is highly susceptible to acid. Logan explains how some organisms are starting to have trouble forming new shells, and in extreme cases, existing shells are getting thinner.

Just in case the plight of a few snails seems like a relatively minor concern, the issue goes well beyond snails. Corals, sea urchins, many species of plankton- organisms crucial to marine habitats and food webs- all rely on calcium carbonate as part of their structure. Some research even suggests that acidification can disrupt the ability of plants to perform photosynthesis. As marine organisms are responsible for much of the Earth’s oxygen production, this might one day threaten our very survival.

Acidification has the potential to completely disrupt the ocean’s—and perhaps even the planet’s—ecosystem before climate change has a chance to do so. Despite the urgency Logan describes, the American public is largely unaware of the issue. Public awareness notwithstanding, the solution to ocean acidification is straightforward: burn less carbon. Efforts to curb the climate change will address acidification as well, but progress is slow. It is astounding that such a key issue, one that might genuinely threaten our survival as a species, is still so little-known.


JSTOR Citations:

A Review of Ocean Acidification and America’s Response
Cheryl A. Logan
BioScience
Vol. 60, No. 10 (November 2010), pp. 819-828
Published by: Oxford University Press

Marine and Coastal Science: Will Ocean Acidification Erode the Base of the Food Web?
Carol Potera
Environmental Health Perspectives
Vol. 118, No. 4 (APRIL 2010), p. A157
Published by: The National Institute of Environmental Health Sciences (NIEHS)


View original post: JSTOR|Daily

Oct 22 2014

The joy of sex began 385 million years ago with armored fish, scientists say

fish-fossilsProfessor John Long has discovered that the earliest example of sex was invented by Scottish amoured fish called placoderms.

An ancient fish with evolutionary ties to humans could have originated intercourse as we know it, which scientists say is ‘nothing short of remarkable.’

Scientists studying fossils have discovered that the intimate act of sexual intercourse used by humans was pioneered by ancient armored fishes, called placoderms, about 385 million years ago in Scotland.

In an important discovery in the evolutionary history of sexual reproduction, the scientists found that male fossils of the Microbrachius dicki, which belong to a placoderm group, developed bony L-shaped genital limbs called claspers to transfer sperm to females.

Females, for their part, developed small paired bones to lock the male organs in place for mating.

Placoderms are the earliest vertebrate ancestors of humans.

“Placoderms were once thought to be a dead-end group with no live relatives, but recent studies show that our own evolution is deeply rooted in placoderms and that many of the features we have — such as jaws, teeth and paired limbs — first originated with this group of fishes,” said John Long, a paleontologist at Flinders University in South Australia who led the research.

This new finding, he added, shows that “they gave us the intimate act of sexual intercourse as well”.

Matt Friedman, a paleobiologist from Britain’s Oxford University who was not involved in the research, described its findings as “nothing short of remarkable” and said they suggested much more could be learned from the fossil fishes.

Long, whose study was published in the journal Nature on Sunday, discovered the ancient fishes’ mating abilities when he stumbled across a single fossil bone in the collections of the University of Technology in Tallinn, Estonia, last year.

The research then involved scientists from Australia, Estonia, Britain, Sweden and China, who analyzed fossil specimens from museum collections across the world.

These demonstrate the first use of internal fertilization and copulation as a reproductive strategy known in the fossil record.

Measuring about 8 centimeters (3 inches) in length, Microbrachius lived in ancient lake habitats in Scotland, as well as parts of Estonia and China.

Long explained that “Microbrachius” means little arms, but said scientists have been baffled for centuries by what these bony paired arms were actually there for.

“We’ve solved this great mystery,” he said. “They were there for mating, so that the male could position his claspers into the female genital area.”

In one of the more bizarre findings of the study, Long said the fishes probably copulated from a sideways position with their bony jointed arms locked together — making them look more as if they were square dancing than having sex.

“This enabled the males to maneuver their genital organs into the right position for mating,” he said.

youtubeWatch video


View the original article: NYDailyNews.com | REUTERS Monday, October 20, 2014

Oct 16 2014

Ecosystem-Based Fisheries Management

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NOAA strives to adopt an ecosystem-based approach throughout its broad ocean and coastal stewardship, science, and service programs. The goal of ecosystem-based management is to maintain ecosystems in a healthy, productive, and resilient condition so they can provide the services humans want and need. NOAA Fisheries refers to the ecosystem-based approach to management that is focused on the fisheries sector as ecosystem-based fisheries management (EBFM). While EBFM is directed towards fisheries management, a similar approach, accounting for ecosystem interactions and considerations, can be applied in the management of protected and other trust marine species.

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EBFM is a new way of looking at the management of living marine resources. The traditional management strategy for fisheries and other living marine resources is to focus on one species in isolation. For example, if a particular species’ population was declining, fishery managers might decide to reduce the annual catch limit the following year in an attempt to reduce overexploitation. However, fishing is only one variable that affects a species’ population. Additional elements come in to play, such as interactions with other species, the effects of environmental changes, or pollution and other stresses on habitat and water quality. To more effectively assess the health of any given fishery and to determine the best way to maintain it, fishery managers should take ecosystem considerations into account.

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Videos:

Fisheries in the California Current Ecosystem

Fisheries in the Northwest Atlantic Large Marine Ecosystem


 

 

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