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A Scripps Institution of Oceanography at the University of California San Diego-led research team discovered for the first time that a common marine sponge hosts bacteria that specialize in the production of toxic compounds nearly identical to man-made fire retardants. The new findings put the research team one step closer to unraveling the mystery of this powerful group of chemical compounds, known as polybrominated diphenyl ethers (PBDEs), in the marine environment. PBDEs are a subgroup of brominated flame retardants that are combined into foam, textiles, and electronics to raise the temperature at which the products will burn. These man-made industrial chemicals are powerful endocrine disruptors that mimic the activity of the human body's most active thyroid hormone. Vinayak Agarwal, a postdoctoral researcher at Scripps, picked up a cold case first started nearly 50 years ago by Scripps chemist John Faulkner, an early pioneer in the study of natural products from the sea, to continue the investigation into the source of these toxic compounds that are found in large quantities in the world’s oceans. “For the first time we were able to conclusively show that genes and enzymes produced in bacteria from sponges are responsible for the production of these compounds toxic to humans,” said Agarwal, co-first author of the paper along with Scripps PhD student Jessica Blanton. The study was part of the National Science Foundation (NSF)/ National Institute of Environmental Health Sciences (NIEHS)-funded Center for Oceans and Human Health research being conducted at Scripps. In 2014, Agarwal and colleagues at Scripps Oceanography were the first to discover that unrelated free-living marine bacteria produce these fire retardant compounds naturally, albeit in very small quantities. In this new study, the researchers employed two modern-day techniques—genome “mining” pioneered by Scripps marine chemist Brad Moore and an environmental DNA sequencing approach pioneered by Scripps biologist Eric Allen—to take the investigation a step further and identify the specific genes and enzymes involved in the overproduction of the toxic molecules in sponges. Marine sponges obtain food and oxygen by filtering seawater through the pores and channels in their bodies. This constant water flow means that these immobile animals host many bacteria, viruses, and fungi in their complex microbiomes. The research team collected 18 sponge samples for the study during two research expeditions to Guam. They then isolated the various components of this complex mixture of organisms from the sponge’s tissues to identify the specific genes and enzymes that code for the production of PBDEs. “For many years scientists were finding clues that suggested nature was making these compounds,” said Bradley Moore, a professor at the Scripps Center of Marine Biotechnology and Biomedicine and the Skaggs School of Pharmacy and Pharmaceutical Sciences at UC San Diego, and a senior author of the study. “Now that we understand how they are produced in the marine environment, we are exploring why they exist, and the human health concerns associated with them.” Moore’s genome "mining" approach along with Allen’s metagenomic sequencing gives scientists a way to connect the natural chemicals produced by organisms back to the enzymes that construct them. The study, which appears on the cover of the May issue of the journal Nature Chemical Biology, was a unique collaboration among chemists and biologists at UC San Diego and elsewhere. “This study is a powerful combination of chemical, biological and environmental research,” said Henrietta Edmonds of the NSF’s Division of Ocean Sciences, which supported the research. “It has the potential to help us understand the production, fate and health consequences of natural and pollutant compounds in the marine environment.” “We care about naturally produced PBDEs because they end up in the food chain,” said Frederick Tyson, Ph.D., of the NIEHS, which helped to fund the research. “Preliminary data from this research team suggest that some naturally occurring PDBEs may be even more toxic than those that are man-made, so we need to develop a better understanding of these compounds.” These ocean-dwelling microbes have been found in habitats as diverse as sea grasses, corals and whales. The next step of the investigation for the researchers is to mine the genes and enzymes in other marine hosts to find out what other organisms are making similar toxic compounds and why. Co-authors from Scripps Oceanography include Sheila Podell, Michelle Schorn, Julia Busch, and Paul Jensen. Researchers Arnaud Taton and James Golden from UC San Diego’s Division of Biological Sciences, Jason Biggs from University of Guam’s Marine Laboratory, Zhenjian Lin and Eric Schmidt from the University of Utah, and Valerie Paul from the Smithsonian Marine Station also contributed to the study. Funding for the research was provided through: National Science Foundation grants OCE-1313747, DGE-1144086, IOS-1120113, MCB-1149552; National Institutes of Health grants P01-ES021921, K99-ES026620, R01-GM107557, R01-CA172310, S10-OD010640; the U.S. Department of Energy grant DE-EE0003373; and a Helen Hay Whitney Foundation postdoctoral fellowship.


News Article | May 11, 2017
Site: www.eurekalert.org

A Scripps Institution of Oceanography at the University of California San Diego-led research team discovered for the first time that a common marine sponge hosts bacteria that specialize in the production of toxic compounds nearly identical to man-made fire retardants. The new findings put the research team one step closer to unraveling the mystery of this powerful group of chemical compounds, known as polybrominated diphenyl ethers (PBDEs), in the marine environment. PBDEs are a subgroup of brominated flame retardants that are combined into foam, textiles, and electronics to raise the temperature at which the products will burn. These man-made industrial chemicals are powerful endocrine disruptors that mimic the activity of the human body's most active thyroid hormone. Vinayak Agarwal, a postdoctoral researcher at Scripps, picked up a cold case first started nearly 50 years ago by Scripps chemist John Faulkner, an early pioneer in the study of natural products from the sea, to continue the investigation into the source of these toxic compounds that are found in large quantities in the world's oceans. "For the first time we were able to conclusively show that genes and enzymes produced in bacteria from sponges are responsible for the production of these compounds toxic to humans," said Agarwal, co-first author of the paper along with Scripps PhD student Jessica Blanton. The study was part of the National Science Foundation (NSF)/ National Institute of Environmental Health Sciences (NIEHS)-funded Center for Oceans and Human Health research being conducted at Scripps. In 2014, Agarwal and colleagues at Scripps Oceanography were the first to discover that unrelated free-living marine bacteria produce these fire retardant compounds naturally, albeit in very small quantities. In this new study, the researchers employed two modern-day techniques--genome "mining" pioneered by Scripps marine chemist Brad Moore and an environmental DNA sequencing approach pioneered by Scripps biologist Eric Allen--to take the investigation a step further and identify the specific genes and enzymes involved in the overproduction of the toxic molecules in sponges. Marine sponges obtain food and oxygen by filtering seawater through the pores and channels in their bodies. This constant water flow means that these immobile animals host many bacteria, viruses, and fungi in their complex microbiomes. The research team collected 18 sponge samples for the study during two research expeditions to Guam. They then isolated the various components of this complex mixture of organisms from the sponge's tissues to identify the specific genes and enzymes that code for the production of PBDEs. "For many years scientists were finding clues that suggested nature was making these compounds," said Bradley Moore, a professor at the Scripps Center of Marine Biotechnology and Biomedicine and the Skaggs School of Pharmacy and Pharmaceutical Sciences at UC San Diego, and a senior author of the study. "Now that we understand how they are produced in the marine environment, we are exploring why they exist, and the human health concerns associated with them." Moore's genome "mining" approach along with Allen's metagenomic sequencing gives scientists a way to connect the natural chemicals produced by organisms back to the enzymes that construct them. The study, which appears on the cover of the May issue of the journal Nature Chemical Biology, was a unique collaboration among chemists and biologists at UC San Diego and elsewhere. "This study is a powerful combination of chemical, biological and environmental research," said Henrietta Edmonds of the NSF's Division of Ocean Sciences, which supported the research. "It has the potential to help us understand the production, fate and health consequences of natural and pollutant compounds in the marine environment." "We care about naturally produced PBDEs because they end up in the food chain," said Frederick Tyson, Ph.D., of the NIEHS, which helped to fund the research. "Preliminary data from this research team suggest that some naturally occurring PDBEs may be even more toxic than those that are man-made, so we need to develop a better understanding of these compounds." These ocean-dwelling microbes have been found in habitats as diverse as sea grasses, corals and whales. The next step of the investigation for the researchers is to mine the genes and enzymes in other marine hosts to find out what other organisms are making similar toxic compounds and why. Co-authors from Scripps Oceanography include Sheila Podell, Michelle Schorn, Julia Busch, and Paul Jensen. Researchers Arnaud Taton and James Golden from UC San Diego's Division of Biological Sciences, Jason Biggs from University of Guam's Marine Laboratory, Zhenjian Lin and Eric Schmidt from the University of Utah, and Valerie Paul from the Smithsonian Marine Station also contributed to the study. Funding for the research was provided through: National Science Foundation grants OCE-1313747, DGE-1144086, IOS-1120113, MCB-1149552; National Institutes of Health grants P01-ES021921, K99-ES026620, R01-GM107557, R01-CA172310, S10-OD010640; the U.S. Department of Energy grant DE-EE0003373; and a Helen Hay Whitney Foundation postdoctoral fellowship. Scripps Institution of Oceanography at the University of California, San Diego, is one of the oldest, largest, and most important centers for global science research and education in the world. Now in its second century of discovery, the scientific scope of the institution has grown to include biological, physical, chemical, geological, geophysical, and atmospheric studies of the earth as a system. Hundreds of research programs covering a wide range of scientific areas are under way today on every continent and in every ocean. The institution has a staff of more than 1,400 and annual expenditures of approximately $195 million from federal, state, and private sources. Scripps operates oceanographic research vessels recognized worldwide for their outstanding capabilities. Equipped with innovative instruments for ocean exploration, these ships constitute mobile laboratories and observatories that serve students and researchers from institutions throughout the world. Birch Aquarium at Scripps serves as the interpretive center of the institution and showcases Scripps research and a diverse array of marine life through exhibits and programming for more than 430,000 visitors each year. Learn more at scripps.ucsd.edu and follow us at: Facebook | Twitter | Instagram. At the University of California San Diego, we constantly push boundaries and challenge expectations. Established in 1960, UC San Diego has been shaped by exceptional scholars who aren't afraid to take risks and redefine conventional wisdom. Today, as one of the top 15 research universities in the world, we are driving innovation and change to advance society, propel economic growth, and make our world a better place. Learn more at http://www. .


A Scripps Institution of Oceanography at the University of California San Diego-led research team discovered for the first time that a common marine sponge hosts bacteria that specialize in the production of toxic compounds nearly identical to man-made fire retardants. The new findings put the research team one step closer to unraveling the mystery of this powerful group of chemical compounds, known as polybrominated diphenyl ethers (PBDEs), in the marine environment. PBDEs are a subgroup of brominated flame retardants that are combined into foam, textiles, and electronics to raise the temperature at which the products will burn. These man-made industrial chemicals are powerful endocrine disruptors that mimic the activity of the human body's most active thyroid hormone. Vinayak Agarwal, a postdoctoral researcher at Scripps, picked up a cold case first started nearly 50 years ago by Scripps chemist John Faulkner, an early pioneer in the study of natural products from the sea, to continue the investigation into the source of these toxic compounds that are found in large quantities in the world’s oceans. “For the first time we were able to conclusively show that genes and enzymes produced in bacteria from sponges are responsible for the production of these compounds toxic to humans,” said Agarwal, co-first author of the paper along with Scripps PhD student Jessica Blanton. The study was part of the National Science Foundation (NSF)/ National Institute of Environmental Health Sciences (NIEHS)-funded Center for Oceans and Human Health research being conducted at Scripps. In 2014, Agarwal and colleagues at Scripps Oceanography were the first to discover that unrelated free-living marine bacteria produce these fire retardant compounds naturally, albeit in very small quantities. In this new study, the researchers employed two modern-day techniques—genome “mining” pioneered by Scripps marine chemist Brad Moore and an environmental DNA sequencing approach pioneered by Scripps biologist Eric Allen—to take the investigation a step further and identify the specific genes and enzymes involved in the overproduction of the toxic molecules in sponges. Marine sponges obtain food and oxygen by filtering seawater through the pores and channels in their bodies. This constant water flow means that these immobile animals host many bacteria, viruses, and fungi in their complex microbiomes. The research team collected 18 sponge samples for the study during two research expeditions to Guam. They then isolated the various components of this complex mixture of organisms from the sponge’s tissues to identify the specific genes and enzymes that code for the production of PBDEs. “For many years scientists were finding clues that suggested nature was making these compounds,” said Bradley Moore, a professor at the Scripps Center of Marine Biotechnology and Biomedicine and the Skaggs School of Pharmacy and Pharmaceutical Sciences at UC San Diego, and a senior author of the study. “Now that we understand how they are produced in the marine environment, we are exploring why they exist, and the human health concerns associated with them.” Moore’s genome "mining" approach along with Allen’s metagenomic sequencing gives scientists a way to connect the natural chemicals produced by organisms back to the enzymes that construct them. The study, which appears on the cover of the May issue of the journal Nature Chemical Biology, was a unique collaboration among chemists and biologists at UC San Diego and elsewhere. “This study is a powerful combination of chemical, biological and environmental research,” said Henrietta Edmonds of the NSF’s Division of Ocean Sciences, which supported the research. “It has the potential to help us understand the production, fate and health consequences of natural and pollutant compounds in the marine environment.” “We care about naturally produced PBDEs because they end up in the food chain,” said Frederick Tyson, Ph.D., of the NIEHS, which helped to fund the research. “Preliminary data from this research team suggest that some naturally occurring PDBEs may be even more toxic than those that are man-made, so we need to develop a better understanding of these compounds.” These ocean-dwelling microbes have been found in habitats as diverse as sea grasses, corals and whales. The next step of the investigation for the researchers is to mine the genes and enzymes in other marine hosts to find out what other organisms are making similar toxic compounds and why. Co-authors from Scripps Oceanography include Sheila Podell, Michelle Schorn, Julia Busch, and Paul Jensen. Researchers Arnaud Taton and James Golden from UC San Diego’s Division of Biological Sciences, Jason Biggs from University of Guam’s Marine Laboratory, Zhenjian Lin and Eric Schmidt from the University of Utah, and Valerie Paul from the Smithsonian Marine Station also contributed to the study. Funding for the research was provided through: National Science Foundation grants OCE-1313747, DGE-1144086, IOS-1120113, MCB-1149552; National Institutes of Health grants P01-ES021921, K99-ES026620, R01-GM107557, R01-CA172310, S10-OD010640; the U.S. Department of Energy grant DE-EE0003373; and a Helen Hay Whitney Foundation postdoctoral fellowship.


News Article | November 17, 2016
Site: www.eurekalert.org

For the first time, Smithsonian researchers and collaborators have designed a marine reserve network to protect species threatened by overfishing while boosting fishing yields on nearby fishing grounds, resolving a long-standing global "conserve or catch" conflict in marine conservation efforts. A team led by scientists from the Smithsonian's Marine Conservation Program report in the journal Conservation Letters Nov. 17 that they have designed a model network of marine reserves off the Caribbean coast of Honduras, which can support the long-term preservation of spiny lobsters within the country's waters while also increasing fishing yields of the species in fishing areas outside the reserves' borders. "Placing marine reserves across existing fishing grounds can often be very contentious," said Stephen Box, senior author on the study and lead marine biologist of the Marine Conservation Program at the Smithsonian Marine Station in Fort Pierce, Fla., a marine biodiversity and ecosystem research center of the Smithsonian's National Museum of Natural History. "Fishers may oppose plans they see as taking away a large proportion of their fishing area, which could threaten their income without clear benefits being apparent. Our design approach resolves this point of tension showing that it is possible to design reserve networks that provide measurable benefits to fishers, improving catches while sustaining the target population. This really is important as it can help align fisheries stakeholders and conservation practitioners behind a joint plan, removing a key obstacle to reaching sustainable conservation successes with economically important marine species." Fully protected marine reserves are an important tool for managing the ocean's resources. By protecting the plants and animals that live within them, reserves protect a portion of exploited populations to recover and persist for future generations. But increasingly, researchers and conservationists are recognizing that for these reserves to succeed, they must balance their long-term conservation goals with the more immediate needs of local communities. Economic and sustainability objectives are often seen as being in conflict with one another, but according to the authors of the new study, both can and should be considered during the initial planning of a new reserve network and can be balanced effectively. "We want to protect [the ocean's resources] so they will be available in the future, but we also want to let people keep using them," said Iliana Chollett, the lead author of the study and a postdoctoral fellow in the Marine Conservation Program and at the University of California, Davis. Designing a reserve that will benefit local fisheries requires deep knowledge of the ecosystem and the species the reserve is designed to protect. With reliable data about animal behavior and ocean currents, computer models can calculate how a reserve will affect the abundance of a particular species in fishing areas outside its boundaries, as well as the reserve's impact on long-term sustainability. Such models have been used to assess existing or proposed reserves, but because they require massive amounts of data and intense computer processing, they have been considered impractical for use in the design phase to identify the best locations to place a new reserve network. Chollett, whose research aims to find alternatives to dangerous and unsustainable fishing practices that are currently used in Latin America and the Caribbean, knew it would take a lot of time and effort to use this approach to design a new reserve--but she believed it could be done. She and her colleagues set out to design a network of reserves to restore and preserve populations of spiny lobsters in the waters off the northeastern coast of Honduras. The spiny lobster is the most economically valuable marine resource in the Caribbean and a key component of the commercial fishery in Honduras, but its numbers are believed to be threatened due to overfishing. Researchers from the Smithsonian Marine Station, Florida Atlantic University, the Florida Fish and Wildlife Conservation Commission, the University of California, Davis and the University of Queensland worked together to collect and analyze the relevant biological and oceanographic data. Their analysis incorporated marine biologists' findings about how spiny lobsters grow, reproduce and die and how adult lobsters move across the ocean floor. Data about ocean currents, which can carry and distribute tiny lobster larvae far from the places where they hatch, and habitat maps of the seafloor were also essential. The team used these data to determine where in the ocean lobster populations would increase if particular patches were protected by reserves and how these areas would seed and spill over into fished areas. They ran the model repeatedly, using the Smithsonian's high-performance computer to predict the effect of numerous reserve networks in order to optimize the design. They found that by protecting 20 percent of the fishing grounds, they could ensure the long-term survival of the lobster population while also increasing the numbers of lobsters expected to inhabit local fishing areas available to the local fishers. A crucial finding was that the network enabled a sustainable fishery only if current levels of fishing effort remain stable into the future. Chollett says the reserve network that the team has designed could be an important component in a larger effort to introduce models and strategies to improve Honduran fishing practices and make them more sustainable. She also hopes the approach will be broadly applied to the design of marine reserves around the world.


A team led by scientists from the Smithsonian's Marine Conservation Program report in the journal Conservation Letters Nov. 17 that they have designed a model network of marine reserves off the Caribbean coast of Honduras, which can support the long-term preservation of spiny lobsters within the country's waters while also increasing fishing yields of the species in fishing areas outside the reserves' borders. "Placing marine reserves across existing fishing grounds can often be very contentious," said Stephen Box, senior author on the study and lead marine biologist of the Marine Conservation Program at the Smithsonian Marine Station in Fort Pierce, Fla., a marine biodiversity and ecosystem research center of the Smithsonian's National Museum of Natural History. "Fishers may oppose plans they see as taking away a large proportion of their fishing area, which could threaten their income without clear benefits being apparent. Our design approach resolves this point of tension showing that it is possible to design reserve networks that provide measurable benefits to fishers, improving catches while sustaining the target population. This really is important as it can help align fisheries stakeholders and conservation practitioners behind a joint plan, removing a key obstacle to reaching sustainable conservation successes with economically important marine species." Fully protected marine reserves are an important tool for managing the ocean's resources. By protecting the plants and animals that live within them, reserves protect a portion of exploited populations to recover and persist for future generations. But increasingly, researchers and conservationists are recognizing that for these reserves to succeed, they must balance their long-term conservation goals with the more immediate needs of local communities. Economic and sustainability objectives are often seen as being in conflict with one another, but according to the authors of the new study, both can and should be considered during the initial planning of a new reserve network and can be balanced effectively. "We want to protect [the ocean's resources] so they will be available in the future, but we also want to let people keep using them," said Iliana Chollett, the lead author of the study and a postdoctoral fellow in the Marine Conservation Program and at the University of California, Davis. Designing a reserve that will benefit local fisheries requires deep knowledge of the ecosystem and the species the reserve is designed to protect. With reliable data about animal behavior and ocean currents, computer models can calculate how a reserve will affect the abundance of a particular species in fishing areas outside its boundaries, as well as the reserve's impact on long-term sustainability. Such models have been used to assess existing or proposed reserves, but because they require massive amounts of data and intense computer processing, they have been considered impractical for use in the design phase to identify the best locations to place a new reserve network. Chollett, whose research aims to find alternatives to dangerous and unsustainable fishing practices that are currently used in Latin America and the Caribbean, knew it would take a lot of time and effort to use this approach to design a new reserve—but she believed it could be done. She and her colleagues set out to design a network of reserves to restore and preserve populations of spiny lobsters in the waters off the northeastern coast of Honduras. The spiny lobster is the most economically valuable marine resource in the Caribbean and a key component of the commercial fishery in Honduras, but its numbers are believed to be threatened due to overfishing. Researchers from the Smithsonian Marine Station, Florida Atlantic University, the Florida Fish and Wildlife Conservation Commission, the University of California, Davis and the University of Queensland worked together to collect and analyze the relevant biological and oceanographic data. Their analysis incorporated marine biologists' findings about how spiny lobsters grow, reproduce and die and how adult lobsters move across the ocean floor. Data about ocean currents, which can carry and distribute tiny lobster larvae far from the places where they hatch, and habitat maps of the seafloor were also essential. The team used these data to determine where in the ocean lobster populations would increase if particular patches were protected by reserves and how these areas would seed and spill over into fished areas. They ran the model repeatedly, using the Smithsonian's high-performance computer to predict the effect of numerous reserve networks in order to optimize the design. They found that by protecting 20 percent of the fishing grounds, they could ensure the long-term survival of the lobster population while also increasing the numbers of lobsters expected to inhabit local fishing areas available to the local fishers. A crucial finding was that the network enabled a sustainable fishery only if current levels of fishing effort remain stable into the future. Chollett says the reserve network that the team has designed could be an important component in a larger effort to introduce models and strategies to improve Honduran fishing practices and make them more sustainable. She also hopes the approach will be broadly applied to the design of marine reserves around the world. Explore further: AP Analysis: How well will Antarctic marine reserve work? More information: Iliana Chollett et al, A Genuine Win-Win: Resolving the "Conserve or Catch" Conflict in Marine Reserve Network Design, Conservation Letters (2016). DOI: 10.1111/conl.12318


News Article | January 4, 2016
Site: www.sciencenews.org

One whale spotted in the wrong ocean seemed merely odd. But a second misplaced whale looked more like a sign of an ecological shake-up: Pacific Ocean fauna moving into the Atlantic Ocean and vice versa. As the Arctic’s icy barriers melt, new waterways may soon allow many formerly separated animals to move and mix. “We do believe we’re seeing a faunal exchange,” says Seabird McKeon of the Smithsonian Marine Station in Fort Pierce, Fla. Species moving from one ocean might disrupt life in the other — competing with some longtime residents, preying on others — or maybe change hardly anything. “We just do not know what’s going to happen,” McKeon says. He and seven other scientists compiled from various sources several years’ worth of wrong-ocean sightings of whales and birds suspected to have crossed the Arctic or mingled with counterparts from the opposite ocean. The compilation, published online November 30 in Global Change Biology, isn’t big. But for long-lived creatures such as whales and some seabirds, a trickle of animals could establish a new population. Unusual sightings of birds and mammals (a selection below) suggest that once-blocked populations of animals might already be moving now that enough Arctic ice is melting to allow it.  Expansion of an Arctic population into Hudson Bay as ice blockades melt allows the whales to prey on beluga whales, narwhals and at least four seal species. An Atlantic subspecies was spotted in California in 2011; Pacific subspecies were found in Newfoundland and Norway in 2014. The Northern Pacific seabird was seen in England in 2009. The North Atlantic seabird may now be breeding in the Pacific. “Even if the strays are few, even if it’s a very slow process, there is a chance of establishment,” McKeon says. “That’s why we’re excited for people to really start watching this process.” Birders, whale watchers and other citizen scientists offer the best hope for catching early signs of any species moving across the Arctic. “If an individual bird ends up in an alternative ocean basin, that is not something that is likely to be picked up by standard scientific programs,” McKeon says. In the past, thick permanent sea ice in the Arctic plus potentially lethal water temperatures, scarce food, unusual salinity and other menaces have acted as a barrier between oceans, largely blocking animal journeys for the last 3 million years. But climate change is opening up a path. The 10 skimpiest minimums for summertime ice observed since the satellite era began have all occurred in the last 11 years, NASA analyses show. Summer ice has dwindled enough on occasion, such as in 2012, to raise commercial hopes of workable waterway passages for shipping. Feasible paths are opening in successive years through the archipelago of islands in eastern Canada, and other routes may form, too, so trade ships in coming decades may be able to shortcut through the summertime Arctic. Human commerce and the politics of climate change get more widespread attention than the chance that animals will venture along the new routes. But rearranging species’ ranges could have sweeping consequences, too. A notorious example of the unintended troubles that range changes can cause comes from the Suez Canal in Egypt. The canal “has been singularly successful as an invasion corridor,” says Bella Galil of the National Institute of Oceanography in Haifa, Israel. Of nearly 700 alien species now found in the Mediterranean Sea, half have arrived through the canal since it opened in 1869, Galil reported in the April Biological Invasions. In summer, swarms of nomad jellyfish (Rhopilema nomadica), originally from the Red Sea, clog fishing nets and block intake pipes at desalinization and power plants in Israel. Another newcomer, the poisonous Lagocephalus sceleratus puffer fish, puts several people in the hospital each year. And introductions such as the goldband goatfish and a kind of spiny oyster have wiped out their native counterparts. In contrast, the Panama Canal shepherds traffic through locks filled with freshwater, which reduces the risk of saltwater Pacific species sloshing through to the Caribbean Sea and vice versa. And thank goodness. McKeon says he has heard discussions about whether a saltwater canal in Panama would have let the venomous sea snakes from the Pacific wriggle their way into the Caribbean. In the rapidly changing Arctic, at least one Pacific species has already established populations on the North Atlantic side for the first time in about 800,000 years. Microscopic strings of silica-encased Neodenticula seminae diatoms turned up in the late 1990s in the Labrador Sea, an international research team reported in 2007. The researchers argue against the notion that the diatoms merely hitchhiked in some ship’s ballast water. Instead, the diatoms’ presence could be a sign that ocean circulation patterns are changing in the Arctic, swirling water and its living residents across the pole. What the diatoms will do Atlanticside isn’t clear, but they have now spread to northern Nordic waters, a paper published in 2013 reports, where there’s no sign they have ever been before. Of perhaps more popular interest than transplanted diatoms are potentially Arctic-crossing whales. Gray whales persist in the Pacific but went extinct in the Atlantic more than two centuries ago. In 2010, a marine-mammal monitoring program photographed a gray whale off the coast of Israel. “It was really a huge surprise to everybody,” says Elizabeth Alter of York College CUNY in Jamaica, N.Y., a coauthor with McKeon on the new paper. “There was discussion at first of whether the photos might have been photoshopped.” (They were not, it turned out.) In 2013, a monitoring group sighted another gray whale along the coast of Namibia. It seems improbable that gray whales from the northern Pacific had looped down to the Southern Hemisphere to swim around continents and then into the Atlantic, Alter says. She suspects the whales were feeding along the Arctic coastline as they normally do, and without much ice to block their progress, inadvertently hugged the coast all the way to the Atlantic side. Should gray whales eventually re­colonize the Atlantic, McKeon expects that their new neighbors would notice. Unlike similar whales with baleen plates in their mouths, grays gulp whale-sized mouthfuls of soft sea-bottom gunk to savor its hidden crustaceans. In the course of dining, the whales stir up sediment, scattering clouds of invertebrates that other species eat and leaving behind whale-gouges as habitat. It’s impossible to know the impacts, but McKeon speculates on what could happen to the blue crabs that bury themselves in the mud at the mouth of the Chesapeake Bay in winter: “I can’t imagine anything much better as a snack for a wintering gray whale than sleepy blue crabs.” Melting may also bring new opportunities to another whale species, the bowheads, which live in the Arctic full time. “They can break ice that’s 2 feet thick with their heads,” Alter says. The Atlantic and Pacific bowhead populations have shared genes over the last several thousand years, Alter’s DNA studies show. And in 2010, biologists tracking both populations by satellite found a whale from each population feeding near each other. After about a week, the whales retreated in opposite directions, but left clear evidence that the melting Arctic permits populations from separate oceans to mix. Also on McKeon’s list of possible vanguards of Arctic crossovers is a northern gannet, a plunge-diving, fish-eating seabird that soars over the Atlantic with a wingspan of about 2 meters. “What every gull dreams of being,” he says. In 2011, one of these gannets showed up off the coast of Alaska. Possibly the same bird reached the Farallon Islands along northern California. The most plausible explanation, McKeon says, is that the bird had worked its way through some avian northwest passage with open water for fishing along its flight path. Open water in the Arctic could also move animals indirectly. As summer sea ice shrinks more and more, shipping could boom along Arctic routes. These ships take on ballast water in one place and release the ballast in another, letting animals (smaller than whales) catch a lift, says Jacqueline Grebmeier of the University of Maryland Center for Environmental Science. The prevailing wisdom has been that stowaways wouldn’t survive the harsh Arctic, but as the Arctic climate changes, Grebmeier can imagine circumstances now in which ballast creatures might. Whales and charismatic seabirds may be easier to spot when they switch oceans, but ballast stowaways may turn out to be more common. And as important.


Sharp K.H.,Smithsonian Marine Station | Distel D.,Ocean Genome Legacy | Paul V.J.,Smithsonian Marine Station
ISME Journal | Year: 2012

In this study, we examine microbial communities of early developmental stages of the coral Porites astreoides by sequence analysis of cloned 16S rRNA genes, terminal restriction fragment length polymorphism (TRFLP), and fluorescence in situ hybridization (FISH) imaging. Bacteria are associated with the ectoderm layer in newly released planula larvae, in 4-day-old planulae, and on the newly forming mesenteries surrounding developing septa in juvenile polyps after settlement. Roseobacter clade-associated (RCA) bacteria and Marinobacter sp. are consistently detected in specimens of P. astreoides spanning three early developmental stages, two locations in the Caribbean and 3 years of collection. Multi-response permutation procedures analysis on the TRFLP results do not support significant variation in the bacterial communities associated with P. astreoides larvae across collection location, collection year or developmental stage. The results are the first evidence of vertical transmission (from parent to offspring) of bacteria in corals. The results also show that at least two groups of bacterial taxa, the RCA bacteria and Marinobacter, are consistently associated with juvenile P. astreoides against a complex background of microbial associations, indicating that some components of the microbial community are long-term associates of the corals and may impact host health and survival. © 2012 International Society for Microbial Ecology All rights reserved.


Campbell J.E.,Smithsonian Marine Station | Fourqurean J.W.,Florida International University
Journal of Ecology | Year: 2014

Developing a framework for assessing interactions between multiple anthropogenic stressors remains an important goal in environmental research. In coastal ecosystems, the relative effects of aspects of global climate change (e.g. CO2 concentrations) and localized stressors (e.g. eutrophication), in combination, have received limited attention. Using a long-term (11 month) field experiment, we examine how epiphyte assemblages in a tropical seagrass meadow respond to factorial manipulations of dissolved carbon dioxide (CO2(aq)) and nutrient enrichment. In situ CO2(aq) manipulations were conducted using clear, open-top chambers, which replicated carbonate parameter forecasts for the year 2100. Nutrient enrichment consisted of monthly additions of slow-release fertilizer, nitrogen (N) and phosphorus (P), to the sediments at rates equivalent to theoretical maximum rates of anthropogenic loading within the region (1.54 g N m-2 d-1 and 0.24 g P m-2 d-1). Epiphyte community structure was assessed on a seasonal basis and revealed declines in the abundance of coralline algae, along with increases in filamentous algae under elevated CO2(aq). Surprisingly, nutrient enrichment had no effect on epiphyte community structure or overall epiphyte loading. Interactions between CO2(aq) and nutrient enrichment were not detected. Furthermore, CO2(aq)-mediated responses in the epiphyte community displayed strong seasonality, suggesting that climate change studies in variable environments should be conducted over extended time-scales. Synthesis. The observed responses indicate that for certain locations, global stressors such as ocean acidification may take precedence over local eutrophication in altering the community structure of seagrass epiphyte assemblages. Given that nutrient-driven algal overgrowth is commonly cited as a widespread cause of seagrass decline, our findings highlight that alternate climate change forces may exert proximate control over epiphyte community structure. Developing a framework for assessing interactions between multiple anthropogenic stressors remains an important goal in environmental research. In coastal ecosystems, the relative effects of global climate change (e.g. CO2 concentrations) and localized stressors (e.g. eutrophication), in combination, have received limited attention. Our in situ experiment reveals that global stressors such as ocean acidification (OA) may take precedence over local eutrophication in altering the community structure of seagrass epiphytes. Given that nutrient-driven algal overgrowth is commonly cited as a widespread cause of seagrass decline, our findings highlight that alternate climate change forces, such as OA, may exert proximate control over epiphyte community structure. © 2014 British Ecological Society.


Paerl H.W.,University of North Carolina at Chapel Hill | Paul V.J.,Smithsonian Marine Station
Water Research | Year: 2012

Cyanobacteria are the Earth's oldest (~3.5bya) oxygen evolving organisms, and they have had major impacts on shaping our modern-day biosphere. Conversely, biospheric environmental perturbations, including nutrient enrichment and climatic changes (e.g. global warming, hydrologic changes, increased frequencies and intensities of tropical cyclones, more intense and persistent droughts), strongly affect cyanobacterial growth and bloom potentials in freshwater and marine ecosystems. We examined human and climatic controls on harmful (toxic, hypoxia-generating, food web disrupting) bloom-forming cyanobacteria (CyanoHABs) along the freshwater to marine continuum. These changes may act synergistically to promote cyanobacterial dominance and persistence. This synergy is a formidable challenge to water quality, water supply and fisheries managers, because bloom potentials and controls may be altered in response to contemporaneous changes in thermal and hydrologic regimes. In inland waters, hydrologic modifications, including enhanced vertical mixing and, if water supplies permit, increased flushing (reducing residence time) will likely be needed in systems where nutrient input reductions are neither feasible nor possible. Successful control of CyanoHABs by grazers is unlikely except in specific cases. Overall, stricter nutrient management will likely be the most feasible and practical approach to long-term CyanoHAB control in a warmer, stormier and more extreme world. © 2011 Elsevier Ltd.

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