ScienceDaily — Using a combination of theoretical modeling, energy calculations, and field observations, researchers from the California Institute of Technology (Caltech) have for the first time described a mechanism that explains how some of the ocean's tiniest swimming animals can have a huge impact on large-scale ocean mixing.
Their findings are being published in the July 30 issue of the journal Nature.
"We've been studying swimming animals for quite some time," says John Dabiri, a Caltech assistant professor of aeronautics and bioengineering who, along with Caltech graduate student Kakani Katija, discovered the new mechanism. "The perspective we usually take is that of how the ocean—by its currents, temperature, and chemistry—is affecting the animals. But there have been increasing suggestions that the inverse is also important—how the animals themselves, via swimming, might impact the ocean environment."
Specifically, Dabiri says, scientists have increasingly been thinking about how and whether the animals in the ocean might play a role in larger-scale ocean mixing, the process by which various layers of water interact with one another to distribute heat, nutrients, and gasses throughout the oceans.
Dabiri notes that oceanographers have previously dismissed the idea that animals might have a significant effect on ocean mixing, saying that the viscosity of water would damp out any turbulence created, especially by small planktonic animals. "They said that there was no mechanism by which these animals could impact large-scale ocean mixing," he notes.
But Dabiri and Katija thought there might be a mechanism that had been overlooked—a mechanism they call Darwinian mixing, because it was first discovered and described by Charles Darwin. (No, not that Darwin; his grandson.)
"Darwin's grandson discovered a mechanism for mixing similar in principle to the idea of drafting in aerodynamics," Dabiri explains. "In this mechanism, an individual organism literally drags the surrounding water with it as it goes."
Using this idea as their basis, Dabiri and Katija did some mathematical simulations of what might happen if you had many small animals all moving at more or less the same time, in the same direction. After all, each day, billions of tiny krill and copepods migrate hundreds of meters from the depths of the ocean toward the surface. Darwin's mechanism would suggest that they drag some of the colder, heavier bottom water up with them toward the warmer, lighter water at the top. This would create instability, and eventually, the water would flip, mixing itself as it went.
What the Caltech researchers also found was that the water's viscosity enhances Darwin's mechanism and that the effects are magnified when you're dealing with such minuscule creatures as krill and copepods. "It's like a human swimming through honey," Dabiri explains. "What happens is that even more fluid ends up being carried up with a copepod, relatively speaking, than would be carried up by a whale."
"This research is truly reflective of the type of exciting, without-boundaries research at which Caltech engineering professors excel—in this case a deep analysis of the movement of fluid surrounding tiny ocean creatures leading to completely revelatory insights on possible mechanisms of global ocean mixing," says Ares Rosakis, chair of the Division of Engineering and Applied Science at Caltech.
To verify the findings from their simulations, Katija and collaborators Monty Graham (from the Dauphin Island Sea Laboratory), Jack Costello (from Providence College), and Mike Dawson (from the University of California, Merced) traveled to the island of Palau, where they studied this animal-led transport of water--otherwise known as induced drift--among jellyfish, which are the focus of much of Dabiri's work.
"From a fluid mechanics perspective, this study had less to do with the fact that they're jellyfish, and more to do with the fact that they're solid objects moving through water," Dabiri explains.
Katija's jellyfish experiments involved putting fluorescent dye in the water in front of the sea creatures, and then watching what happened to that dye—or, to be more specific, to the water that took up the dye—as the jellyfish swam. And, indeed, rather than being left behind the jellyfish—or being dissipated in turbulent eddies—the dye travelled right along with the swimming creatures, following them for long distances.
These findings verified that, yes, swimming animals are capable of carrying bottom water with them as they migrate upward, and that movement indeed creates an inversion that results in ocean mixing. But what the findings didn't address was just how much of an impact this type of ocean mixing—performed by impossibly tiny sea creatures—could have on a large scale.
After a series of calculations, Dabiri and Katija were able to estimate the impact of this so-called biogenic ocean mixing. And, Dabiri says, it's quite a significant impact.
"There are enough of these animals in the ocean," he notes, "that, on the whole, the global power input from this process is as much as a trillion watts of energy—comparable to that of wind forcing and tidal forcing."
In other words, the amount of power that copepods and krill put into ocean mixing is on the same scale as that of winds and tides, and thus their impact is expected to be on a similar scale as well.
And while these numbers are just estimates, Dabiri says, they are likely to be conservative estimates, having been "based on the fluid transport induced by individual animals swimming in isolation." In the ocean, these individual contributions to fluid transport may actually interact with one another, and amplify how far the ocean waters can be pulled upward.
In addition, says Dabiri, they have yet to consider the effects of such things as fecal pellets and marine snow (falling organic debris), which no doubt pull surface water with them as they drift downward. "This may have an impact on carbon sequestration on the ocean floor," says Dabiri. "It's something we need to look at in the future."
Dabiri says the next major question to answer is how these effects can be incorporated into computer models of the global ocean circulation. Such models are important for simulations of global climate-change scenarios.
The work was supported by grants from the National Science Foundation's Biological Oceanography, Ocean Technology, Fluid Dynamics, and Energy for Sustainability programs, and by the Office of Naval Research, the Department of Defense's National Science and Engineering Graduate Fellowship, and the Charles Lee Powell Foundation.
- Dabiri et al. A viscosity-enhanced mechanism for biogenic ocean mixing. Nature, July 30, 2009
article submitted by Aquatic Army member Michael DiLuzio
TheRecord.com - Getting ordinary plastic bags to rot away like banana peels would be an environmental dream come true.
After all, we produce 500 billion a year worldwide and they take up to 1,000 years to decompose. They take up space in landfills, litter our streets and parks, pollute the oceans and kill the animals that eat them.
Now a Waterloo teenager has found a way to make plastic bags degrade faster -- in three months, he figures.
Daniel Burd's project won the top prize at the Canada-Wide Science Fair in Ottawa. He came back with a long list of awards, including a $10,000 prize, a $20,000 scholarship, and recognition that he has found a practical way to help the environment.
Daniel, a 16-year-old Grade 11 student at Waterloo Collegiate Institute, got the idea for his project from everyday life.
"Almost every week I have to do chores and when I open the closet door, I have this avalanche of plastic bags falling on top of me," he said. "One day, I got tired of it and I wanted to know what other people are doing with these plastic bags."
The answer: not much. So he decided to do something himself.
He knew plastic does eventually degrade, and figured microorganisms must be behind it. His goal was to isolate the microorganisms that can break down plastic -- not an easy task because they don't exist in high numbers in nature.
First, he ground plastic bags into a powder. Next, he used ordinary household chemicals, yeast and tap water to create a solution that would encourage microbe growth. To that, he added the plastic powder and dirt. Then the solution sat in a shaker at 30 degrees.
After three months of upping the concentration of plastic-eating microbes, Burd filtered out the remaining plastic powder and put his bacterial culture into three flasks with strips of plastic cut from grocery bags. As a control, he also added plastic to flasks containing boiled and therefore dead bacterial culture.
Six weeks later, he weighed the strips of plastic. The control strips were the same. But the ones that had been in the live bacterial culture weighed an average of 17 per cent less.
That wasn't good enough for Burd. To identify the bacteria in his culture, he let them grow on agar plates and found he had four types of microbes. He tested those on more plastic strips and found only the second was capable of significant plastic degradation.
Next, Burd tried mixing his most effective strain with the others. He found strains one and two together produced a 32 per cent weight loss in his plastic strips. His theory is strain one helps strain two reproduce.
Tests to identify the strains found strain two was Sphingomonas bacteria and the helper was Pseudomonas.
A researcher in Ireland has found Pseudomonas is capable of degrading polystyrene, but as far as Burd and his teacher Mark Menhennet know -- and they've looked -- Burd's research on polyethelene plastic bags is a first.
Next, Burd tested his strains' effectiveness at different temperatures, concentrations and with the addition of sodium acetate as a ready source of carbon to help bacteria grow.
At 37 degrees and optimal bacterial concentration, with a bit of sodium acetate thrown in, Burd achieved 43 per cent degradation within six weeks.
The plastic he fished out then was visibly clearer and more brittle, and Burd guesses after six more weeks, it would be gone. He hasn't tried that yet.
To see if his process would work on a larger scale, he tried it with five or six whole bags in a bucket with the bacterial culture. That worked too.
Industrial application should be easy, said Burd. "All you need is a fermenter . . . your growth medium, your microbes and your plastic bags."
The inputs are cheap, maintaining the required temperature takes little energy because microbes produce heat as they work, and the only outputs are water and tiny levels of carbon dioxide -- each microbe produces only 0.01 per cent of its own infinitesimal weight in carbon dioxide, said Burd.
"This is a huge, huge step forward . . . We're using nature to solve a man-made problem."
Burd would like to take his project further and see it be used. He plans to study science at university, but in the meantime he's busy with things such as student council, sports and music.
"Dan is definitely a talented student all around and is poised to be a leading scientist in our community," said Menhennet, who led the school's science fair team but says he only helped Burd with paperwork.
Other local students also did well at the national science fair.
Devin Howard of St. John's Kilmarnock School won a gold medal in life science and several scholarships.
Mackenzie Carter of St. John's Kilmarnock won bronze medals in the automotive and engineering categories.
Engineers Without Borders awarded Jeff Graansma of Forest Heights Collegiate a free trip to their national conference in January.
Zach Elgood of Courtland Avenue Public School got honourable mention in earth and environmental science.
Krill convert microscopic phytoplankton into a food source for numerous other species and are a principal food source for many species of fish, seabirds and marine mammals. (Credit: Photo by Jamie Hall / NOAA's Sanctuaries Collection)
ScienceDaily — The National Oceanic and Atmospheric Administration (NOAA) has published a final rule in the Federal Register prohibiting the harvesting of krill in the Exclusive Economic Zone (EEZ) off the coasts of California, Oregon, and Washington. The rule goes into effect on August 12, 2009. Krill are a small shrimp-like crustacean and a key source of nutrition in the marine food web.
"Krill are the foundation for a healthy marine ecosystem," said Mark Helvey, NOAA's Fisheries Service Southwest Assistant Regional Administrator for Sustainable Fisheries. "Protecting this vital food resource will help protect and maintain marine resources and put federal regulations in line with West-Coast states."
While the States of California, Oregon and Washington currently have regulations prohibiting the harvesting of krill within three miles of their coastlines, there was no similar federal restriction within the three to 200-mile confines of the EEZ.
The krill prohibition was adopted as Amendment 12 to the Coastal Pelagic Species Fishery Management Plan (FMP), which was developed by the Pacific Fishery Management Council (PFMC) under the Magnuson-Stevens Fishery Conservation and Management Act. The krill harvest prohibition was originally proposed to the PFMC and NOAA Fisheries Service by NOAA's Office of National Marine Sanctuaries. Today's rule implements Amendment 12 to the FMP and is intended to preserve key nutritional relationships in the California Current ecosystem, which includes five National Marine Sanctuaries.
"This is a great success for protecting the entire California Current ecosystem", said William Douros, West Coast Regional Director for NOAA's Office of National Marine Sanctuaries. "This decision reflects strong teamwork within NOAA and a commitment to addressing the issues raised by the Pacific Fishery Management Council and Sanctuary Advisory Councils."
Amendment 12 adds all species of krill under a new category, "prohibited harvest species." This new group may not be caught or taken by any fishery or gear type within the EEZ.
Krill are important because they convert microscopic phytoplankton into a food source for numerous other species and are a principal food source for many species of fish, seabirds and marine mammals. Some of the species that depend on krill as prey are listed as threatened or endangered under the Endangered Species Act, and many others are important as target species for commercial and recreational fisheries on the west coast.
ScienceDaily - NOAA-supported scientists, led by Nancy Rabalais, Ph.D., from the Louisiana Universities Marine Consortium (LUMCON), found the size of this year's Gulf of Mexico dead zone to be smaller than forecasted, measuring 3,000 square miles. However the dead zone, which is usually limited to water just above the sea floor, was severe where it did occur, extending closer to the water surface then in most years.
Earlier this summer, NOAA-sponsored forecast models developed by R. Eugene Turner, Ph. D. of Louisiana State University and Donald Scavia, Ph.D. of the University of Michigan, predicted a larger than normal dead zone area of between 7,450 – 8,456 square miles. The forecast was driven primarily by the high nitrate loads and high freshwater flows from the Mississippi and Atchafalaya rivers in spring 2009 as measured by the U.S. Geological Survey.
Rabalais believes the smaller than expected dead zone is due to unusual weather patterns that re-oxygenated the waters, among other factors.
"The winds and waves were high in the area to the west of the Atchafalaya River delta and likely mixed oxygen into these shallower waters prior to the cruise, thus reducing the area of the zone in that region," said Rabalais. "The variability we see within each summer highlights the continuing need for multiple surveys to measure the size of the dead zone in a more systematic fashion."
"The results of the 2009 cruise at first glance are hopeful, but the smaller than expected area of hypoxia appears to be related to short-term weather patterns before measurements were taken, not a reduction in the underlying cause, excessive nutrient runoff." said Robert Magnien, PhD., director of NOAA's Center for Sponsored Coastal Ocean Research. "The smaller area measured by this one cruise, therefore, does not represent a trend and in no way diminishes the need for a harder look at efforts to reduce nutrient runoff."
The average size of the dead zone over the past five years, including this cruise, is now 6,000 square miles. The interagency Gulf of Mexico/Mississippi River Watershed Nutrient Task Force has a goal to reduce or make significant progress toward reducing this dead zone average to 2,000 square miles or less by 2015. The Task Force uses a five year average due to relatively high interannual variability.
The dead zone is fueled by nutrient runoff, principally from agricultural activity, which stimulates an overgrowth of algae that sinks, decomposes, and consumes most of the life-giving oxygen supply in the water. The Gulf of Mexico dead zone is of particular concern because it threatens valuable commercial and recreational Gulf fisheries that generate about $2.8 billion annually.
The models used to forecast the area of the dead zone are constructed for understanding the important underlying causes to inform long-term management decisions, but they do not include short-term variability due to weather patterns.
Prior to the LUMCON cruise, NOAA's Southeast Monitoring and Assessment Program (SEAMAP) found a similar sized dead zone during its annual five-week summer fish survey.
ScienceDaily — The argument that increasing whale populations are behind declining fish stocks is completely without scientific foundation, leading researchers and conservation organizations said in June as the International Whaling Commission opened its 60th meeting in Santiago, Chile.
The Humane Society International, WWF and the Lenfest Ocean Program today presented three new reports debunking the science behind the ‘whales-eat-fish’ claims emanating from whaling nations Japan, Norway and Iceland. The argument has been used to bolster support for whaling, particularly from developing nations.
“It is not the whales, it is over-fishing and excess fishing capacity that are responsible for diminishing supplies of fish in developing countries,” said fisheries biologist Dr. Daniel Pauly, director of the University of British Columbia Fisheries Centre.
“Making whales into scapegoats serves only to benefit wealthy whaling nations while harming developing nations by distracting any debate on the real causes of the declines of their fisheries.”
Who’s eating all the fish? The food security rationale for culling cetaceans, the report co-authored by Dr Pauly for the Humane Society International contrasts “the widely different impacts of fisheries and marine mammals” with fisheries targeting larger fish where available and marine mammals consuming mainly smaller fish and organisms.
“The decline of the mean trophic levels of fisheries catch over the past 50 years is a signature of fishing down marine food webs and leaves marine mammals exonerated,” the report said.
The report also probes the culling whales increases food security for the poor argument by examining the final destination of catches of coastal fisheries in the South Pacific, Caribbean and West Africa. With less than half the catch going to domestic markets and the majority “gravitating toward the markets of affluent developed countries, one can speak of fish migrating from the more needy to the less needy”.
Also presented to the IWC Scientific Committee was the preliminary results into analysis of the interaction between whales and commercial fisheries in north west Africa. The modeling, funded by the Lenfest Ocean Program, shows no real competition between local or foreign fisheries and great whales.
The whales spend only a few months in the area during their vast seasonal migrations, eat relatively little while breeding and tend to consume fundamentally different types of food resources than the marine species targeted by both local and foreign fisheries. Inserting modelling assumptions to presume that whales are not breeding in the area and eat species important to the fishing industry still fails to show whales are a significant source of competition to fishing.
Also released today is review of the scientific literature originating from Japan and Norway - the two countries most strongly promoting the idea that whales pose problems for fisheries. The review, funded by WWF, found significant flaws in much of the science and concluded that “where good data are available, there is no evidence to support the contention that marine mammal predation presents an ecological issue for fisheries.”
Dr. Susan Lieberman of WWF said “These three reports provide yet more conclusive evidence that whales are not responsible for the degraded state of the world’s fisheries. It is now time for governments to focus on the real reason for fisheries decline – unsustainable fishing operations.”
ScienceDaily — The new research study led by scientists at Scripps Institution of Oceanography at UC San Diego suggests that by improving overall ocean health, corals are better able to recover from bleaching events, which occur when rising sea temperatures force corals to expel their symbiotic algae, known as zooxanthellae. Coral bleaching is a phenomenon that is expected to increase in frequency as global climate change increases ocean temperatures worldwide.
The new findings, published in the July 22 issue of the journal PLoS One, show that following a major bleaching event Mountainous star coral (Montastraea faveolata) on various reefs in Honduras and Belize was able to recover and grow normally within two to three years when the surrounding waters and reef were relatively healthy. In comparison, those corals living with excessive local impacts, such as pollution, were not able to fully recover after eight years.
"You can imagine that when you are recovering from a sickness, it will take a lot longer if you don't eat well or get enough rest," said Jessica Carilli, Scripps graduate student and lead author on the study. "Similarly, a coral organism that must be constantly trying to clean itself from excess sediment particles will have a more difficult time recovering after a stressful condition like bleaching."
Carilli and colleagues analyzed 92 coral cores collected from four reef sites off the coast of Honduras and Belize. The cores were collected from reefs with different degrees of local stress from pollution, overfishing and sediment and nutrient run off from land. By using x-rays, the researchers were able to examine the coral's annual growth rate records since 1950, including the time before and after a major bleaching event in 1998.
"It is clear that Mesoamerican corals really fell off a cliff in 1998 -- nearly everybody suffered mass bleaching," said Dick Norris, Scripps professor of paleooceanography and co-author of the study. "There are no pristine reefs in the region, but the ones in the best shape clearly are more resilient than those that are long-suffering. It shows that a little improvement in growing conditions goes a long way in recovering coral health."
Corals are widely considered to be barometers for global warming and are important for biodiversity in the world's oceans. Coral reefs thrive in warm tropical oceans under just the right conditions that include moderate temperatures and low nutrient and sediment input from land-based sources. Protecting reef health from local sources of stress, such as runoff, can improve resilience to global warming stress.
Coral bleaching occurs when the tiny zooxanthellae, living with the tissues of coral polyps, which are responsible for their vibrant colors, are lost and the coral turns white in color.
The fast-recovering were corals collected from Turneffe Atoll, which is farther offshore than the main Belize Barrier Reef and Cayos Cochinos, a marine biological reserve off the northern coast of Honduras. Those that took longer to recover to pre-1998 conditions were from the Sapodilla Cayes in southern Belize and Utila in Honduras. The Sapodilla Cayes are a marine protected area, but experience significant runoff impacts; meanwhile Utila is quite heavily populated and local impacts probably result from development, sewage and other sources.
ScienceDaily — Scientists from NOAA’s Coral Reef Watch Program say conditions are favorable for significant coral bleaching and infectious coral disease outbreaks in the Caribbean, especially in the Lesser Antilles. The forecast is based on the July NOAA Coral Reef Watch outlook, which expects continued high water temperatures through October 2009.
Scientists are concerned that bleaching may reach the same levels or exceed those recorded in 2005, the worst coral bleaching and disease year in Caribbean history. In parts of the eastern Caribbean, as much as 90 percent of corals bleached and over half of those died during that event."
“Just like any climate forecast, local conditions and weather events can influence actual temperatures. However, we are quite concerned that high temperatures may threaten the health of coral reefs in the Caribbean this year,” said C. Mark Eakin, Ph.D., coordinator of NOAA’s Coral Reef Watch.
Prolonged coral bleaching of more than a week can lead to coral death and the subsequent loss of coral reef habitats for a range of marine life. It also affects local economies and tourism.
“By providing local officials with advance warning that a bleaching event is about to occur, some steps can be taken to protect the corals,” said Eakin. “Possible responses include mobilizing monitoring resources to measure extent and impact of bleaching, and establishing temporary restrictions on other reef uses like diving, boating and recreational fishing, to keep these activities from adding to the stress of higher sea temperatures already affecting the coral reefs.”
There is also potential for similar conditions in the central Gulf of Mexico and a region stretching from the Lesser Antilles to Puerto Rico, across to the southern coast of Hispaniola and the Caribbean coast of Nicaragua. Other areas of concern are the central Pacific region including the equatorial Line Islands and Kiribati. Some heat induced stress may also develop between the Northern Mariana Islands and Japan.
Coral bleaching is associated with a variety of factors, especially increased ocean temperatures. This causes the coral to expel symbiotic micro-algae living in their tissues – algae that provide sustenance for coral. The loss of algae leaves coral tissue devoid of color, making it appear bleached.
The bleaching risk may in fact be higher in certain regions than in this initial forecast as the model used for the outlook does not account for El Niño, something NOAA’s operational Climate Forecast System indicates is likely over the next year. If El Niño continues to strengthen, this could increase the bleaching risk in the central to eastern Pacific and Caribbean. NOAA’s National Climatic Data Center also reported that in June the world’s ocean surface temperature was the warmest on record.
(Thresher Shark Supervalu and Affiliates continue to kill with no regard for their customers wishes or the plight of the species or the aquatic environment.)
ScienceDaily — Sharks are disappearing from the world's oceans. The numbers of many large shark species have declined by more than half due to increased demand for shark fins and meat, recreational shark fisheries, as well as tuna and swordfish fisheries, where millions of sharks are taken as bycatch each year.
Now, the global status of large sharks has been assessed by the World Conservation Union (IUCN), which is widely recognized as a highly comprehensive, scientific-based information source on the threat status of plants and animals.
"As a result of high and mostly unrestricted fishing pressure, many sharks are now considered to be at risk of extinction," explained Julia Baum, a member of the IUCN's Shark Specialist Group who will be speaking at the American Association for the Advancement of Science Annual Conference in Boston on February 17.
"Of particular concern is the scalloped hammerhead shark, an iconic coastal species, which will be listed on the 2008 IUCN Red List as globally 'endangered' due to overfishing and high demand for its valuable fins in the shark fin trade," added Baum, who is an NSERC Postdoctoral Fellow at Scripps Institution of Oceanography.
Baum pointed out that fishing for sharks in international waters is unrestricted, and she supports a recently adopted United Nations resolution calling for immediate shark catch limits as well as a meaningful ban on shark finning (the practice of removing only a shark's fins and dumping the still live but now helpless shark into the ocean to die).
Research at Dalhousie University over the past five years, conducted by Baum and the late Ransom Myers, demonstrated the magnitude of shark declines in the northwest Atlantic Ocean. All species the team looked at had declined by over 50 per cent since the early 1970s. For many large coastal shark species, the declines were much greater: tiger, scalloped hammerhead, bull and dusky shark populations have all plummeted by more than 95 per cent.
ScienceDaily — Recent news reports about scuba divers off San Diego being menaced by large numbers of Humboldt's or jumbo squid have raised the ire of University of Rhode Island biologist Brad Seibel. As a leading expert on the species who has dived with them several times, he calls the reports "alarmist" and says the squid's man-eating reputation is seriously overblown.
For years Seibel has heard stories claiming that Humboldt squid will devour a dog in minutes and could kill or maim unsuspecting divers.
"Private dive companies in Mexico play up this myth by insisting that their customers wear body armor or dive in cages while diving in waters where the squid are found. Many also encourage the squid's aggressive behavior by chumming the waters. I didn't believe the hype, but there was still some doubt in my mind, so I was a little nervous getting into the water with them for the first time," Seibel said.
Scuba diving at night in the surface waters of the Gulf of California in 2007, Seibel scanned the depths with his flashlight and saw the shadows of Humboldt squid far in the distance. After he got up his nerve, he turned off the light. When he turned it back on again 30 seconds later, he was surrounded by what seemed like hundreds of the squid, many just five or six feet away from him. Most were in the 3-4 foot size range, while larger ones were sometimes visible in deeper waters. But the light appeared to frighten them, and they immediately dashed off to the periphery.
The URI researcher's dive was more than just a personal test. It was part of a scientific examination of the species some call "red devil" to learn more about their physiology, feeding behavior and swimming abilities.
Humboldt squid feed in surface waters at night, then retreat to great depths during daylight hours. "They spend the day 300 meters deep where oxygen levels are very low," Seibel said. "We wanted to know how they deal with so little oxygen."
Seibel said that while the squid are strong swimmers with a parrot-like beak that could inflict injury, man-eaters they are not. Unlike some large sharks that feed on large fish and marine mammals, jumbo squid use their numerous small, toothed suckers on their arms and tentacles to feed on small fish and plankton that are no more than a few centimeters in length.
The highlight of Seibel's research cruise with colleagues from the Monterey Bay Aquarium Research Institute was diving with the impressive animals. Other divers participating were Lloyd Trueblood of URI, Steve Haddock of MBARI, and Alison Sweeney of the University of California, Santa Barbara.
Seibel was surprised by the large number of squid he encountered, which made it easy to imagine how they could be potentially dangerous to anything swimming with them. Their large numbers also made Seibel somewhat pleased that they appeared frightened of his dive light. Yet he said the animals were also curious about other lights, like reflections off his metal equipment or a glow-in-the-dark tool that one squid briefly attacked.
"Based on the stories I had heard, I was expecting them to be very aggressive, so I was surprised at how timid they were. As soon as we turned on the lights, they were gone," he said. "I didn't get the sense that they saw the entire diver as a food item, but they were definitely going after pieces of our equipment."
According to Seibel, there have been many active discussions among biologists and the dive community about the safety of diving with Humboldt squid. As a result of his experience, the URI scientist is preparing a formal report with his recommendations for safely diving with the squid, including suggestions to always carry a back-up dive light and to be tethered to a boat. Any time humans enter the habitat of a large animal, there is potential for dangerous interactions, he said, so divers should use caution.
"However, I want to spread the word that they aren't the aggressive man-eaters as they have been portrayed," Seibel said.
ScienceDaily - A reduction of as little as five per cent in fisheries catch could result in as much as 30 per cent of the British Columbia coastal ecosystems being protected from overfishing, according to a new study from the UBC Fisheries Centre in Canada.
The study, by Natalie Ban and Amanda Vincent of Project Seahorse, proposes modest reductions in areas where fisheries take place, rather than the current system of marine protected areas which only safeguard several commercially significant species, such as rockfish, shrimp, crab, or sea cucumber. The article is published July 21 in PLoS One.
Using B.C.'s coastal waters as a test case, the study affirms that small cuts in fishing – if they happen in the right places – could result in very large unfished areas. For example, a two per cent cut could result in unfished areas covering 20 per cent of the B.C. coast, offered real conservation gains.
"The threat of over-fishing to our marine ecosystems is well-documented," says Ban, who recently completed her PhD at the UBC Fisheries Centre. "Our study suggests a different approach could reduce the impacts on fishers as well as helping us move towards achieving conservation goals."
Part of the reason for the research was to open a debate on how to meet conservation goals set during the 2002 World Summit on Sustainable Development, which included establishing a network of marine protected areas by 2012.
"With the current rates of progress, there is no chance of meeting our 2012 targets," says Ban. "Given that fishers recognize the problem of overfishing but often regard marine protected areas as serving only to constrain them, another approach must be found. That's why we undertook this study."
The research looked at spatial catch data from Fisheries and Ocean Canada for 13 commercial fisheries on Canada's west coast to show that large areas representing diverse ecoregions and habitats might be protected at a small cost to fisheries.
"Given the dismal state of many fisheries, we urgently need to identify alternative approaches to sustaining marine life while respecting the needs of fishers and fishing communities," says Amanda Vincent, Canada Research Chair in Marine Conservation at UBC and Project Seahorse director. "We have little to lose – and much to gain – in trying a new approach in areas where marine conservation remains inadequate. Our research is globally relevant."
SARASOTA, Florida -- An endangered Kemp's ridley sea turtle (Lepidochelys kempii) has been brought to Mote Marine Laboratory's Sea Turtle Hospital after it swallowed a balloon - an episode that we hope will remind residents and visitors to stow their trash carefully.
The 3.3-pound young turtle with a carapace 8.7 inches long washed up on a sandbar near the south end of Lido Key on Tuesday, July 14, with what appeared to be fishing line hanging from its mouth. Concerned swimmers called Mote biologists, who brought the Kemp's ridley to Mote's Sea Turtle Hospital.
Before removing the pink line, which had scraped skin from the turtle's face, Mote staff used radiographs to verify that the turtle had not swallowed a fishing hook. Instead, they found remnants of a black balloon.
"Balloons can look like jellyfish or squid - things sea turtles like to eat," said Senior Biologist Kristen Mazzarella of Mote's Sea Turtle Conservation and Research Program. "It's extremely common to find sea turtles that have swallowed balloons, fishing hooks, monofilament lines and other dangerous objects."
Swallowing trash can injure or kill sea turtles, all of which are considered endangered or threatened under federal law. Kemp's ridleys, among the smallest and the rarest of the world's seven sea turtle species, have visited Sarasota County only a handful of times to nest, but Mote's Sea turtle hospital has rehabilitated dozens because of illness, disorientation and other problems.
Mote's new Kemp's ridley patient, nicknamed Anakin, is receiving fluids, antibiotics
and food at the Sea Turtle Hospital. The turtle, which arrived anemic and dehydrated, is being closely monitored for any additional health problems. It will be released into wild if appropriate.
Anakin is Mote's first turtle with a bellyful of balloon, but perhaps not the last.
"We pick up a lot of balloons wrapped in seaweed from local beaches," said Mazzarella of Mote's Sea Turtle Patrol - a team of staff, interns and volunteers who monitor sea turtle nesting every day on 35 miles of Sarasota county beaches during nesting season, May through October.
"To protect sea turtles and other wildlife, we recommend that people dispose of trash in the appropriate containers and recycle it when possible," Mazzarella said. "If you see trash washing up on the beach, pick it up before the tide takes it back out to sea."
NOTTINGHAM, U.K. -- Drifting across the world's oceans are a group of unicellular marine microorganisms that are not only a crucial source of food for other marine life — but their fossils, which are found in abundance, provide scientists with an extraordinary record of climatic change and other major events in the history of the earth.
Now, planktonic foraminifera — single-celled shell building members of the marine microplankton community — have given up a secret of their very own.
A team of experts, including scientists from The University of Nottingham, have presented remarkable evidence that planktonic foraminifera may have survived mass extinction by taking refuge on the sea floor.
Dr Chris Wade from the Institute of Genetics, said: "Using genetic data we have been able to prove that the planktonic species Streptochilus globigerus and the benthic — sediment living — foraminiferan Bolivina variabilis are one and the same biological species. Moreover, geochemical evidence shows that this species actively grows within the open-ocean surface waters, thus occupying both planktonic and benthic domains. Such ecologically-flexible species are eminently suited to the recolonisation of the extinction-susceptible planktonic domain following mass extinctions events, such as the end-Cretaceous event."
It had been thought that all modern planktic foraminifers were descended from the few lucky survivors of the meteor impact that wiped out the dinosaurs and 65 to 70 per cent of life on earth 65 million years ago. However, this might not be the case.
Dr Wade together with PhD student Heidi Seears have shown that live specimens of the planktonic species Streptochilus globigerus, collected 600 miles offshore in the middle of the Arabian Sea, are genetically identical to the benthic species Bolivina variabilis, found off the coast of Kenya.
Their surprising discovery suggests that planktonic foraminifera may have survived the end Cretaceous mass-extinction by abandoning the poisonous oceans for a refuge in the relative safety of the sea-floor. When the oceans returned to normal, the survivors were able to recolonise the ocean surface once more.
The research, carried out in collaboration with the University of Edinburgh, has been published in the Journal Proceedings of the National Academy of Sciences (PNAS).
Dr Kate Darling, from the University of Edinburgh, said: "If some species can switch between free-swimming and bottom-dwelling lifestyles, then it's possible that most planktic foraminifers may have survived the late Cretaceous extinction in the sediment, not in the plankton. It seems likely that the foraminifer species which had the ability to occupy both habitats survived on the sea-floor, avoiding the meteor impact catastrophe in the oceans above.
After weeks of silence from Supervalu and its affiliates Oceanic Defense along with Care2.com have launched an official petition to request the immediate removal of all shark meat and shark products from all stores.
We are now also calling for a full boycott of all locations (see listing below) as to such a time when the company announces their environmental wrongdoing as removes shark indefinitely.
To sign the petition please go to the following link:
Stores to Boycott:
ScienceDaily — Sharks, barracuda and other large predatory fishes disappear on Caribbean coral reefs as human populations rise, endangering the region's marine food web and ultimately its reefs and fisheries, according to a sweeping study by researcher Chris Stallings of The Florida State University Coastal and Marine Laboratory.
While other scientists working in the Caribbean have observed the declines of large predators for decades, the comprehensive work by Stallings documents the ominous patterns in far more detail at a much greater geographic scale than any other research to date.
"Seeing evidence of this ecological and economic travesty played out across the entire Caribbean is truly sobering," said Associate Professor John Bruno of the University of North Carolina at Chapel Hill, who served as the PLoS One academic editor for Stallings' new paper.
"I examined 20 species of predators, including sharks, groupers, snappers, jacks, trumpetfish and barracuda, from 22 Caribbean nations," said Stallings, a postdoctoral associate at the FSU Coastal and Marine Laboratory. "I found that nations with more people have reefs with far fewer large fish because as the number of people increases, so does demand for seafood. Fishermen typically go after the biggest fish first, but shift to smaller species once the bigger ones become depleted. In some areas with large human populations, my study revealed that only a few small predatory fish remain."
Stallings said that although several factors -- including loss of coral reef habitats -- contributed to the general patterns, careful examination of the data suggests overfishing as the most likely reason for the disappearance of large predatory fishes across the region. He pointed to the Nassau grouper as a prime example. Once abundant throughout the Caribbean, Nassau grouper have virtually disappeared from many Caribbean nearshore areas and are endangered throughout their range.
"Large predatory fish such as groupers and sharks are vitally important in marine food webs," Stallings said. "However, predicting the consequence of their loss is difficult because of the complexity of predator-prey interactions. You can't replace a 10-foot shark with a one-foot grouper and expect there to be no effect on reef communities. Shifts in abundance to smaller predators could therefore have surprising and unanticipated effects. One such effect may be the ability of non-native species to invade Caribbean reefs."
A case in point, said Stallings, is the ongoing invasion by Pacific lionfish, which were introduced by aquarium releases.
"Lionfish are minor players on their native Pacific reefs, yet they are undergoing a population explosion and overeating small fishes in the greater Caribbean region," said Professor Mark Hixon of Oregon State University, Stallings' doctoral advisor at OSU. "Preliminary evidence suggests that lionfish are less invasive where large predatory native fishes are abundant, such as in marine reserves," Hixon said.
The study also demonstrates the power of volunteer and community research efforts by non-scientists. Stallings used data from the Reef Environmental Education Foundation's (REEF) online database, which contains fish sightings documented by trained volunteer SCUBA divers, including more than 38,000 surveys spanning a 15-year period.
"Chris was completely undaunted by the lack of fisheries data and essentially adopted the 'Audubon Christmas Bird Count' approach in a marine system to find strong evidence for a native fisheries effect," said Felicia Coleman, director of the FSU Coastal and Marine Laboratory and Stallings' postdoctoral advisor.
Given that about half the world's populations live near coastlines and that the world population is growing, demands for ocean-derived protein will continue to increase, Stallings warned. He said meeting such demands while retaining healthy coral reefs may require multiple strategies, including implementation of marine reserves, finding alternative sources of protein, and increased efforts to implement family-planning strategies in densely populated areas.
- Stallings et al. Fishery-Independent Data Reveal Negative Effect of Human Population Density on Caribbean Predatory Fish Communities. PLoS ONE, 2009; 4 (5): e5333 DOI: 10.1371/journal.pone.0005333
ScienceDaily — Despite broad "dolphin safe" practices, fishing activities have continued to restrict the growth of at least one Pacific Ocean dolphin population, a new report led by a researcher at Scripps Institution of Oceanography at UC San Diego has concluded.
Populations of dolphins in the Eastern Pacific were expected to increase in abundance after successful regulations and agreements were enacted to reduce dolphin deaths as a result of fishing "bycatch," cases in which animals are caught unintentionally along with intended targets.
But the new study, published in the October issue of Marine Ecology Progress Series, reveals that negative impacts from fishing activities remain. Instead of reducing numbers through direct mortalities, the study by Katie Cramer of Scripps Institution of Oceanography and Wayne Perryman and Tim Gerrodette of the National Oceanic and Atmospheric Administration's (NOAA's) Southwest Fisheries Science Center shows that fishing activities have disrupted the reproductive output of the northeastern pantropical spotted dolphin. The researchers note that reproductive output of the eastern spinner dolphin also declined, but a direct link to fishing effort was inconclusive.
"The results of this study clearly show that depleted dolphin populations have failed to recover in part due to a decline in reproductive output, and that fishing has had an effect on reproduction," said Cramer, a graduate student researcher in the Scripps Center for Marine Biodiversity and Conservation. "This shows that the fisheries indeed are still having an impact."
The new conclusions are based on broad surveys conducted by NOAA Fisheries Service between 1987 and 2003 designed to assess the size and health of dolphin populations in the eastern Pacific Ocean. The surveys included military reconnaissance camera images of more than 20,000 animals.
Cramer, who participated in helicopter surveys between 1998 and 2003, and her colleagues used the image database to analyze entire dolphin schools, focusing in particular on mother-calf pairs.
The scientists compared the data with the number of fishing events in which a dolphin school is chased by speedboats and encircled in a large "purse-seine" net in order to capture the large yellowfin tuna that often swim with dolphin schools. While such fishing led to high dolphin mortalities after purse-seine fishing was launched in the eastern tropical Pacific in the 1950s, bycatch deaths declined by the end of the 1990s due to new fishing techniques that ensured that dolphins are eventually released from the nets alive.
Yet despite mortality reductions, dolphin populations have not recovered at a rate expected since bycatch was reduced.
Using the aerial photographic database, Cramer and her colleagues found a strong link between the amount of fishing and reproductive output in a given year for the dolphin population most heavily targeted by the fishery, the northeastern pantropical spotted dolphin. Both the proportion of adult animals in the photographs with a calf, and the length at which calves disassociated from their mothers (a measure of the length at which the calves stop nursing), declined with increasing fishing effort.
Together, the results showed that fishing had a negative impact on calf survival rates and/or birth rates. This could be caused when fishing operations separate mothers from their suckling calves, interfere with the conception or gestation of calves or a combination of the two.
"The link between fishing activity and ... reproductive output indicates that the fishery has population-level effects beyond reported direct kill," the authors write in their report.
What remains unknown is the exact mechanism leading to reduced reproductive output. This question is currently being investigated by researchers at NOAA Fisheries' Southwest Fisheries Science Center in La Jolla.
Adapted from materials provided by University of California - San Diego.
ScienceDaily — The potential for a huge Pacific Ocean tsunami on the West Coast of America may be greater than previously thought, according to a new study of geological evidence along the Gulf of Alaska coast.
The new research suggests that future tsunamis could reach a scale far beyond that suffered in the tsunami generated by the great 1964 Alaskan earthquake. Official figures put the number of deaths caused by the earthquake at around 130: 114 in Alaska and 16 in Oregon and California. The tsunami killed 35 people directly and caused extensive damage in Alaska, British Columbia, and the US Pacific region*.
The 1964 Alaskan earthquake – the second biggest recorded in history with a magnitude of 9.2 – triggered a series of massive waves with run up heights of as much as 12.7 metres in the Alaskan Gulf region and 52 metres in the Shoup Bay submarine slide in Valdez Arm.
The study suggests that rupture of an even larger area than the 1964 rupture zone could create an even bigger tsunami. Warning systems are in place on the west coast of North America but the findings suggest a need for a review of evacuation plans in the region.
The research team from Durham University in the UK, the University of Utah and Plafker Geohazard Consultants, gauged the extent of earthquakes over the last 2,000 years by studying subsoil samples and sediment sequences at sites along the Alaskan coast. The team radiocarbon-dated peat layers and sediments, and analysed the distribution of mud, sand and peat within them. The results suggest that earthquakes in the region may rupture even larger segments of the coast and sea floor than was previously thought.
The study published in the academic journal Quaternary Science Reviews and funded by the National Science Foundation, NASA, and the US Geological Survey shows that the potential impact in terms of tsunami generation, could be significantly greater if both the 800-km-long 1964 segment and the 250-km-long adjacent Yakataga segment to the east were to rupture simultaneously.
Lead author, Professor Ian Shennan, from Durham University’s Geography Department said: “Our radiocarbon-dated samples suggest that previous earthquakes were fifteen per cent bigger in terms of the area affected than the 1964 event. This historical evidence of widespread, simultaneous plate rupturing within the Alaskan region has significant implications for the tsunami potential of the Gulf of Alaska and the Pacific region as a whole.
“Peat layers provide a clear picture of what’s happened to the Earth. Our data indicate that two major earthquakes have struck Alaska in the last 1,500 years and our findings show that a bigger earthquake and a more destructive tsunami than the 1964 event are possible in the future. The region has been hit by large single event earthquakes and tsunamis before, and our evidence indicates that multiple and more extensive ruptures can happen.”
Tsunamis can be created by the rapid displacement of water when the sea floor lifts and/or falls due to crustal movements that accompany very large earthquakes. The shallow nature of the sea floor off the coast of Alaska could increase the destructive potential of a tsunami wave in the Pacific.
Earthquake behaviour is difficult to predict in this region which is a transition zone between two of the world's most active plate boundary faults; the Fairweather fault, and the Aleutian subduction zone. In 1899 and 1979, large earthquakes occurred in the region but did not trigger a Tsunami because the rupturing was localized beneath the land instead of the sea floor.
Prof Ron Bruhn from the University of Utah said: “If the larger earthquake that is suggested by our work hits the region, the size of the potential tsunami could be signficantly larger than in 1964 because a multi-rupture quake would displace the shallow continental shelf of the Yakutat microplate.
“In the case of a multi-rupture event, the energy imparted to the tsunami will be larger but spread out over a longer strike distance. Except for the small communities at the tsunami source in Alaska, the longer length will have more of an effect on areas farther from the source such as southeastern Alaska, British Columbia, and the US west coast from Washington to California.”
Warning systems have been in place on the US western seaboard and Hawaii since the 1946 Aleutian Islands tsunami. Improvements were made following the 2004 earthquake under the Indian Ocean that triggered the most deadly tsunami in recorded history, killing more than 230,000 people.
Prof Shennan said: “Earthquakes can hit at any time of the day or night, and that’s a big challenge for emergency planners. A tsunami in this region could cause damage and threaten life from Alaska to California and beyond; in 1964 the effects of the tsunami waves were felt as far away as southern California and were recorded on tide gages throughout the Pacific Ocean.”
Dr George Plafker from Plafker Geohazard Consultants said: “A large scale earthquake will not necessarily create a large wave. Tsunami height is a function of bathymetry, and the amount of slip and dip of the faults that take up the displacement, and all these factors can vary greatly along the strike. “Tsunamis will occur in the future. There are issues in warning and evacuating large numbers of people in coastal communities quickly and safely. The US has excellent warning systems in place but awareness is vital.”
Adapted from materials provided by Durham University, via AlphaGalileo.
Coral reef with Anthias fish colony. (Credit: iStockphoto/Pawel Borowka)
ScienceDaily — Coral reef survival is balancing on a knife edge as the combined effects of ocean acidification and ocean warming events threaten to push reefs to the brink of extinction this century, warned a meeting of leading scientists.
Organised by ZSL, the International Programme on the State of the Ocean (IPSO) and the Royal Society, the meeting identified the level of atmospheric CO2 predicted to result in the demise of coral reefs.
At anticipated rates of emission increase, it is expected that 450 ppm CO2 will be reached before 2050. At that point, corals may be on a path to extinction within a matter of decades.
By 2050, the remaining coral reefs could fall victim to ocean acidification. Such a catastrophe would not be confined to reefs, but could start of a domino-like sequence of the fall of other marine ecosystems.
Sir David Attenborough who co-chaired the meeting said “We must do all that is necessary to protect the key components of the life of our planet as the consequences of decisions made now will likely be forever as far as humanity is concerned”.
Scientific evidence shows that we have long passed the point at which the marine environment offers reefs a guaranteed future.
“The kitchen is on fire and it’s spreading round the house. If we act quickly and decisively we may be able to put it out before the damage becomes irreversible. That is where corals are now.” said Dr Alex Rogers of ZSL and IPSO.
The meeting was held to identify tipping points for corals and to expose the issues raised by the plight of coral reefs. A statement detailing these concerns will be submitted to the UN FCCC process currently underway.
Until now, world leaders negotiating emissions reductions have not taken the ocean into serious account, but with so much at risk, the oceans can no longer be ignored.
Now, there is every reason to believe that the oceans may in fact be the most vulnerable sector of our planet to climate change – with dire consequences for us all.
Adapted from materials provided by Zoological Society of London (ZSL).
A MBARI-designed robotic instrument called the Environmental Sample Processor. (Credit: Credit: MBARI)
ScienceDaily (July 15, 2009) — Scientists at NOAA's National Centers for Coastal Ocean Science and the Monterey Bay Aquarium Research Institute (MBARI) have successfully conducted the first remote detection of a harmful algal species and its toxin below the ocean's surface. The achievement was recently reported in the June issue of Oceanography.
This achievement represents a significant milestone in NOAA's effort to monitor the type and toxicity of harmful algal blooms (HABs). HABs are considered to be increasing not only in their global distribution, but also in the frequency, duration, and severity of their effects. HABs damage coastal ecosystem health and pose threats to humans as well as marine life. Climate change is expected to exacerbate this trend, since many critical processes that govern HABs dynamics, such as water temperature and ocean circulation, are influenced by climate.
A MBARI-designed robotic instrument called the Environmental Sample Processor, or 'ESP,' designed as a fully-functional analytical laboratory in the sea, lets researchers collect the algal cells and extract the genetic information required for organism identification as well as the toxin needed to assess the risk to humans and wildlife. The ESP then conducts specialized, molecular-based measurements of species and toxin abundance, and transmits results to the laboratory via radio signals.
"This represents the first autonomous detection of both a HAB species and its toxin by an underwater sensor," notes Greg Doucette, Ph.D., a research oceanographer at NOAA's Center for Coastal Environmental Health and Biomolecular Research laboratory in Charleston, S.C. "It allows us to determine not only the organism causing a bloom, but also the toxicity of the event, which ultimately dictates whether it is a threat to the public and the ecosystem."
For the first demonstration of the ESP's ability to detect HABs and their toxins, Doucette and his MBARI colleague, Chris Scholin, Ph.D., targeted certain members of the algal genus Pseudo-nitzschia and their neurotoxin, domoic acid in Monterey Bay, Calif.
Pseudo-nitzschia and domoic acid have been a concern in the Monterey Bay area for well over a decade. In 1991, the first U.S. outbreak of domoic acid poisoning was documented in Monterey Bay. This outbreak resulted in the unusual deaths of numerous pelicans and cormorants that ingested sardines and anchovies, which had accumulated the domoic acid by feeding on a bloom of the toxic algae.
In the spring of 1998, a mass mortality of sea lions in and around the Monterey Bay area was attributed to the sea lions' feeding on domoic acid contaminated anchovies. Since that time, Pseudo-nitzschia and domoic acid have appeared on virtually an annual basis in California coastal waters and are the objects of an intensive statewide monitoring program run by the California Dept. of Public Health. Humans also can be affected by the toxin through consumption of contaminated seafood such as shellfish.
"Our public health monitoring program is one of the many groups that can benefit directly from the ESP technology and ability to provide an early warning of impending bloom activity and toxicity," said Gregg Langlois, director of the state of California's Marine Biotoxin Monitoring Program. "This is critical information for coastal managers and public health officials in mitigating impacts on the coastal ecosystem, since the toxicity of these algae can vary widely from little or no toxicity to highly toxic."
Beyond improving forecasting of HABs, this research will contribute to the rapidly emerging U.S. Integrated Ocean Observing System (IOOS) by adding a new way to make coastal ocean observations.
Adapted from materials provided by National Oceanic and Atmospheric Administration.
Fossil diatom algae of Cretaceous age from the Alpha Ridge of the Arctic Ocean. (Credit: Image courtesy of National Oceanography Centre, Southampton (UK)
ScienceDaily — New evidence for ice-free summers with intermittent winter sea ice in the Arctic Ocean during the Late Cretaceous – a period of greenhouse conditions - gives a glimpse of how the Arctic is likely to respond to future global warming.
Records of past environmental change in the Arctic should help predict its future behaviour. The Late Cretaceous, the period between 100 and 65 million years ago leading up to the extinction of the dinosaurs, is crucial in this regard because levels of carbon dioxide (CO2) were high, driving greenhouse conditions. But scientists have disagreed about the climate at this time, with some arguing for low Arctic late Cretaceous winter temperatures (when sunlight is absent during the Polar night) as against more recent suggestions of a somewhat milder 15°C mean annual temperature.
Writing in Nature, Dr Andrew Davies and Professor Alan Kemp of the University of Southampton's School of Ocean and Earth Science based at the National Oceanography Centre, Southampton, along with Dr Jennifer Pike of Cardiff University take this debate a step forward by presenting the first seasonally resolved Cretaceous sedimentary record from the Alpha Ridge of the Arctic Ocean.
The scientists analysed the remains of diatoms – tiny free-floating plant-like organisms - preserved in late Cretaceous marine sediments. In modern oceans, diatoms play a dominant role in the 'biological carbon pump' by which carbon dioxide is drawn down from the atmosphere through photosynthesis and a proportion of it exported to the deep ocean. Unfortunately, the role of diatoms in the Cretaceous oceans has until now been unclear, in part because they are often poorly preserved in sediments.
But the researchers struck lucky. "With remarkable serendipity," they explain, " successive US and Canadian expeditions that occupied floating ice islands above the Alpha Ridge of the Arctic Ocean, recovered cores containing shallow buried upper Cretaceous diatom ooze with superbly preserved diatoms." This has allowed them to conduct a detailed study of the diatom fossils using sophisticated electron microscopy techniques. In the modern ocean, scientists use floating sediment traps to collect and study settling material. These electron microscope techniques that have been pioneered by Professor Kemp's group at Southampton have unlocked a 'palaeo-sediment trap' to reveal information about Late Cretaceous environmental conditions.
They find that the most informative sediment core samples display a regular alternation of microscopically thin layers composed of two distinctly different diatom assemblages, reflecting seasonal changes. Their analysis clearly demonstrates that seasonal blooming of diatoms was not related to the upwelling of nutrients, as has been previously suggested. Rather, production occurred within a stratified water column, indicative of ice-free summers. These summer blooms comprised specially adapted species resembling those of the modern North Pacific Subtropical Gyre, or preserved in relatively recent organically rich Mediterranean sediments called 'sapropels'.
The sheer number of diatoms found in the Late Cretaceous sediment cores indicates exceptional abundances equalling modern values for the most productive areas of the Southern Ocean. "This Cretaceous production, dominated by diatoms adapted to stratified conditions of the polar summer may also be a pointer to future trends in the modern ocean," say the researchers: "With increasing CO2 levels and global warming giving rise to increased ocean stratification, this style of (marine biological) production may become of increasing importance."
However, thin accumulations of earthborn sediment within the diatom ooze are consistent with the presence of intermittent sea ice in the winter, a finding that supports "a wide body of evidence for low Arctic late Cretaceous winter temperatures rather than recent suggestions of a 15C mean annual temperature at this time." The size distribution of clay and sand grains in the sediment points to the formation of sea ice in shallow coastal seas during autumn storms but suggests the absence of larger drop-stones suggests that the winters, although cold, were not cold enough to support thick glacial ice or large areas of anchored ice.
Commenting on the findings, Professor Kemp said: "Although seasonally-resolved records are rarely preserved, our research shows that they can provide a unique window into past Earth system behaviour on timescales immediately comparable and relevant to those of modern concern."
Davies, A., Kemp, A. S. & Pike, J. Late Cretaceous seasonal ocean variability from the Arctic. Nature 460, 254-258 (9 July 2009).
The research was supported by the Natural Environment Research Council.Source: http://www.sciencedaily.com/releases/2009/07/090709095422.htm
- Davies, A., Kemp, A. S. & Pike, J. Late Cretaceous seasonal ocean variability from the Arctic. Nature, 460, 254-258 (9 July 2009) DOI: 10.1038/nature08141
Costa Mesa California -- After weeks of campaigning, urging Supervalu/Albertson's to stand up and embrace their environmental stewardship hype from their own website we find out that head office has not communicated anything to their stores.
Yesterday, Oceanic Defense performed spot checks on multiple locations in Orange County California. In the 3 cities we canvased we found shark in 2 of the 3.
We spoke to employees and sea food managers at multiple locations in Newport Beach, Costa Mesa and Huntington Beach California. Not one employee was aware of any type of environmental wrong doing. We informed employees that what they were selling was an endangered species and that their stores should stop selling it immediately. Most were shocked. They said: "Wow, I had no idea? I wasn't told anything by head office." Others said: "I don't really stock it, its not a good seller. The only time I bring it in is when I am told to by management when it appears in the flyer."
Oceanic Defense is truly disappointed with the handling of this global issue by one of the largest grocery chains in the USA. Stephanie Martin, director of communications refuses to acknowledge the wanton disregard both she and her entire organization has towards the aquatic environment. She continues to ignore our requests and shelters the rest of the "environmental stewards" from any sort of ethical realization. Until now...
Thanks to Supervalu insiders we now have top level email addresses for you.
This evening we are releasing the names and email addresses of the Supervalu board members. Earlier today we sent each member an email asking them to reconsider the company's decision to sell this endangered species. Unfortunately, we did not receive a single reply. (see email below)
Please feel free to contact them and voice your own dissatisfaction. As always please send an email to our friend Stephanie Martin: Stephanie.Martin@supervalu.com
Introducing the Supervalu Board of Directors
Craig Herkert - Craig.Herkert@supervalu.com SUPERVALU CEO
Jeff Noddle - Jeff.Noddle@supervalu.com Executive Chairman
Mike Jackson - Mike.Jackson@supervalu.com President and Chief Operating Officer
David Boehnen - David.Boehnen@supervalu.com Executive Vice President
Janel Haugarth - Janel.Haugarth@supervalu.com Executive Vice President; President and Chief Operating Officer, Supply Chain Services
Pamela Knous Executive Vice President; Chief Financial Officer
Duncan Mac Naughton - Duncan.MacNaughton@supervalu.com Executive Vice President, Merchandising and Marketing
Dave Pylipow - Dave.Pylipow@supervalu.com Executive Vice President, Human Resources
Kevin Tripp - Kevin.Tripp@supervalu.com Executive Vice President; President, Retail Midwest
Pete Van Helden - Pete.VanHelden@supervalu.com Executive Vice President; President, Retail West
A copy or our email to each board member follows:
It is with great disappointment that I must contact you. Recently it came to our organization’s attention that Supervalu was involved in the destruction of a globally identified endangered species by selling Thresher shark at some of your affiliate locations.
Communications were made and returned with form letters from Stephanie Martin, director of communications. She did not address the issues we introduced nor seemed to understand the implications this has on a global species. As more and more people received the same letter from Supervalu it became clear that a campaign was needed to illustrated the devastating affects Supervalu continues to make on the aquatic ecosystem.
Our blog summarizes the struggle we have had with Ms. Martin & Supervalu. You will find documented evidence from both the IUCN and the EDF proving that what Supervalu sells is considered a globally endangered species. In this day and age we can no longer think locally. We are all part of a global community and economy. We must think globally.
Any type of large pelagic animal is dangerous to consume but sharks rank highest in the amount of methyl mercury they contain. The FDA states that shark meat has 60 times more mercury that should be ingested in a daily diet. They go on to say that women and children should NEVER consume the meat. Why would you sell it?
Regardless of the above fact the most pressing issue is the global depletion of the shark population. Sharks are close to 90% extinct due to overfishing and the shark fin trade. By selling shark meat you are directly or indirectly contributing to the eradication of a species.
Your website makes claims of “environmental stewardship” and “global awareness” but ignoring such facts completely unravels any sort of environmental leadership.
We have continued to contact Ms. Martin, she ignores our emails and lacks the environmental understanding of just what Supervalu is doing to our environment. Oceanic Defense canvassed many locations around the country yesterday. We spoke to the people working behind the sea food counters and informed them of the devastating affects the selling of shark has on the global community. They were shocked to say the least and were not aware of such issues. This shows that Ms. Martin has not communicated any of these real issues to the people at the store level. Many people have vowed to boycott Supervalu and its affiliates until sharks are removed from your sea food counters.
We urge you to stop selling a proven globally endangered species and really shine as the environmental stewards your websites claims to be.
We are here to assist you in the transition to a shark free shopping experience.
About Oceanic Defense
Oceanic Defense is a world wide organization with membership in over 60 countries, spanning 6 continents with 1 mission: Healthy aquatic ecosystems free of human abuse and neglect. Our mission is to illustrate the fact that what we do as consumers has a direct impact on our ocean’s health.
Jeff Shaw - Founder
Activation Through Education
ERIE, Pennsylvania -- Where the first Americans came from, when they arrived and how they got here is as lively a debate as ever, only most of the research to date has focused on dry land excavations. But, last summer’s pivotal underwater exploration in the Gulf of Mexico led by Mercyhurst College archaeologist Dr. James Adovasio yielded evidence of inundated terrestrial sites that may well have supported human occupation more than 12,000 years ago, and paved the way for another expedition this July.
As part of their 2008 findings, the researchers located and mapped buried stream and river channels and identified in-filled sinkholes that could potentially help document the late Pleistocene landscape and contain artifacts and associated animal remains from early human occupations. Continued exploration, Adovasio said, will be geared toward assessing a human presence on the now submerged beaches and intersecting river channels.
“There’s no doubt that early North American occupations are underwater, but it’s like looking for a needle in a haystack,” he said. “We have found the haystack; now we’ve got to find the needles.”
That happens July 23-Aug. 7 when Adovasio leads a team of scientists representing leading institutions from government and higher education to St. Petersburg, Fla., where they’ll resume their search for evidence of early Americans in an area 100-to-200 miles off Florida’s west coast, now about 300 feet under water. For the second year, Adovasio will be assisted by co-principal investigator Dr. C. Andrew Hemmings of Mercyhurst College and the Gault School of Archaeological Research in Austin, Texas. This year as last, the primary funding source is the National Oceanic and Atmospheric Administration (NOAA).
The decision to take their expedition underwater in the first place, Adovasio said, stems from the premise that early Americans probably hugged the American coastline, congregating around freshwater rivers, before heading inland. At that time, much of the world’s water was confined to glaciers, causing ocean levels to be lower and exposing more of the continental shelf. As the earth warmed and water levels rose, evidence of past settlements became submerged.
Dredging and storms have turned up artifacts on the Gulf Coast as well as the Atlantic and Pacific coastlines, but Adovasio said this is the first time a group of scientists has staked out a submerged piece of real estate suspected of containing preserved Ice Age beaches and systematically gone in search of early human occupations.
From the University of South Florida’s research boat, the team will use remotely operated vehicles and remote sensing tools to explore the submerged sites. In shallower depths, divers will inspect sites to collect artifacts and animal fossils and recover sediments for geological analysis and possible radiocarbon testing.
“Proof of past human habitation here would reinforce the disintegration of the once prevalent hypothesis about who the first Americans were, how they got here and when they arrived,” said Adovasio, who rose to fame 30 years ago while excavating the Meadowcroft Rockshelter near Pittsburgh, Pa. Radiocarbon dating at Meadowcroft revealed the presence of human campsites as many as 16,000 years ago, which went a long way toward dashing the Clovis-first paradigm, holding that the first humans arrived in the Americas about 12,000 years ago, as revealed by a site near Clovis, New Mexico.
The inaugural expedition confirmed many of the scientists’ original hypotheses and earned second-year funding from NOAA in the amount of $120,000, Adovasio said. Besides NOAA, additional supporters, providing everything from in-kind services to personnel, include the Mercyhurst Archaeological Institute, the Gault School of Archaeological Research, the Florida Bureau of Archaeological Research, the Florida Geological Survey, the University of South Florida, the University of Michigan and the University of Illinois at Chicago Circle, among others, Adovasio noted.