Zhan A.,CAS Research Center for Eco Environmental Sciences |
Briski E.,Helmholtz Center for Ocean Research |
Bock D.G.,University of British Columbia |
Ghabooli S.,University of Windsor |
MacIsaac H.J.,University of Windsor
Marine Biology | Year: 2015
During the past three decades, coastal marine waters have become among the most invaded habitats globally. Ascidians are among the most notorious invaders in these ecosystems. Owing to their rapid spread, frequent population outbreaks, and associated negative ecological and economic impacts, invasive ascidians have become a global problem. Thus, the study of ascidian invasions has become a prominent area of invasion biology. Here, we review current knowledge and conclude that ascidians are good models for studying invasion success in the marine realm. Firstly, we summarize the reconstruction of invasion pathways or colonization histories and associated negative impacts of invasive ascidians, and address the urgent need to clarify ambiguous taxonomy of ascidians. Secondly, we discuss factors that underlie or facilitate invasion success of ascidians, including vectors of introduction and spread, environmental changes, biological traits, and possible genetic issues. Finally, we summarize current science-based policies and management solutions that are in place to prevent and control spread of invasive ascidians. We conclude by highlighting key research questions that remain to be answered, and propose future research to investigate mechanisms of invasion success in the marine realm using ascidians as model systems. © 2015, Springer-Verlag Berlin Heidelberg.
De Boer M.K.,University of Groningen |
Moor H.,University of Stockholm |
Matthiessen B.,Helmholtz Center for Ocean Research |
Hillebrand H.,Carl von Ossietzky University |
Eriksson B.K.,University of Groningen
Oikos | Year: 2014
Landscape connectivity can increase the capacity of communities to maintain their function when environments change by promoting the immigration of species or populations with adapted traits. However, high immigration may also restrict fine tuning of species compositions to local environmental conditions by homogenizing the community. Here we demonstrate that dispersal generates such a tradeoff between maximizing local biomass and the capacity of model periphyton metacommunities to recover after a simulated heat wave. In non-disturbed metacommunities, dispersal decreased the total biomass by preventing differentiation in species composition between the local patches making up the metacommunity. On the contrary, in metacommunities exposed to a realistic summer heat wave, dispersal promoted recovery by increasing the biomass of heat tolerant species in all local patches. Thus, the heat wave reorganized the species composition of the metacommunities and after an initial decrease in total biomass by 38.7%, dispersal fueled a full recovery of biomass in the restructured metacommunities. Although dispersal may decrease equilibrium biomass, our results highlight that connectivity is a key requirement for the response diversity that allows ecological communities to adapt to climate change through species sorting. © 2014 The Authors.
News Article | February 17, 2017
Home to an immense diversity of marine life, the deep ocean also contains valuable minerals with metals such as nickel, copper, cobalt, manganese, zinc, and gold, and rare-earth elements used in electronic technology like smart phones and medical imaging machines. As demand for these resources increases and supplies on land decrease, commercial mining operators are looking to the deep ocean as the next frontier for mining. What are the risks and environmental impacts of deep-sea mining on fragile marine ecosystems? Would seafloor mineral resources be enough to keep up with the evolving demands of modern society? A panel of scholars including Stace Beaulieu, a deep-sea biologist at Woods Hole Oceanographic Institution (WHOI), will discuss these and other questions during the symposium, "Should We Mine the Seafloor?" scheduled on Saturday, February 18, at the AAAS meeting in Boston, MA. A news briefing for science journalists will be held at 4 p.m. on Friday, February 17, in room 103 of the Hynes Convention Center. The speakers will examine the pros and cons of seafloor mining, its engineering feasibility, and its legal and societal implications with the goal of providing the best available, objective, scientific evidence to inform ongoing policy efforts on this important and timely topic. "Our panel is unique in that we bring together knowledge of the demand for critical metals and the potential supply from known and yet-to-be-discovered seafloor mineral resources, and an understanding of deep-sea ecosystems, including a new perspective on ecosystem services that contribute to human well-being," Beaulieu says. Currently, there's no mining occurring in the ocean deeper than the continental shelves, but the industry is moving forward quickly. Many of the engineering challenges associated with working in the deep sea have already been addressed by the offshore oil and gas industry. Different types of machines for mining have been built and the components for mining systems are currently being tested in deep-sea deployments. About 27 countries have already signed contracts to explore for deep-sea resources with the International Seabed Authority (ISA), the organization that controls mineral exploration and exploitation in the area beyond national jurisdiction. And the first deep-sea mining project --Solwara 1 within the jurisdiction of Papua New Guinea--is scheduled to begin in 2019 by Nautilus Minerals. Beaulieu's talk will address potential environmental impacts from deep-sea mining and highlight new research on the vulnerability and resilience of deep-sea ecosystems. She's also been working with social scientists to address the question of economic impacts from lost and degraded ecosystem services, such as the potential for new medicines from deep-sea, biological resources. The symposium will also feature talks by experts Thomas Graedel, an industrial ecologist at Yale University, and Mark Hannington, a geologist at GEOMAR-Helmholtz Center for Ocean Research. Graedel will examine how the demand for metals might evolve in the next few decades. Hannington's talk will focus on estimates of the abundance of seafloor deposits targeted for mining. The symposium will be moderated by Mindy Todd, a radio producer and journalist at WCAI - The Cape & Islands NPR Station. Should We Mine the Seafloor? The Woods Hole Oceanographic Institution is a private, non-profit organization on Cape Cod, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate a basic understanding of the ocean's role in the changing global environment. For more information, please visit http://www. .
News Article | October 26, 2016
Portable observatories and new marine vehicles: The hinge of historic change in deep sea exploration Five hundred vents newly discovered off the US West Coast, each bubbling methane from Earth's belly, top a long list of revelations about "submerged America" being celebrated by leading marine explorers meeting in New York. "It appears that the entire coast off Washington, Oregon and California is a giant methane seep," says RMS Titanic discoverer Robert Ballard, who found the new-to-science vents on summer expeditions by his ship, Nautilus. The discoveries double to about 1,000 the number of such vents now known to exist along the continental margins of the USA. This fizzing methane (video: http://bit. ) is a powerful greenhouse gas if it escapes into the atmosphere; a clean burning fuel if safely captured. "This is an area ripe for discovery," says Dr. Nicole Raineault, Director of Science Operations with Dr. Ballard's Ocean Exploration Trust. "We do not know how many seeps exist, even in US waters, how long they have been active, how persistent they are, what activated them or how much methane, if any, makes it into the atmosphere." Further research and measuring will help fill important knowledge gaps, including how hydrocarbons behave at depth underwater and within the geological structure of the ocean floor. Expeditions this year include also NOAA's Deepwater Exploration of the Marianas Trench - a 59-day voyage with 22 dives into the planet's deepest known canyons in the Pacific Ocean near Guam. NOAA explorers added three new hydrothermal vents to the world's inventory and a new high-temperature "black smoker" vent field composed of chimneys up to 30 meters tall - the height of a nine-story building. Also revealed: a tiny spot volcano (the first ever discovered in US waters), a new mud volcano, thick gardens of deep-sea corals and sponges, a rare high-density community of basket stars and crinoids (a living fossil), and historic wreckage from World War II. (Photo, video log: http://bit. ) Scores of spectacular, rare and sometimes baffling unknown species encountered on this year's first-ever voyages to new deep ocean areas include several purple animals such as: Beyond being spectacularly photogenic, such animals help scientists better understand the web of life that sustains all species, including humans. As well, understanding how "extremophile" lifeforms survive in such conditions (piezophiles, for example, thrive in high pressure; pyschrophiles, aka cryophiles, live in water as cold as ?20 °C, as in pockets of very salty brine surrounded by sea ice), is usefully relevant to food and pharmaceutical preservation technologies, medical technology, nanotechnology and energy science. Dr. Ballard and about 100 other leading figures in marine science meet Oct. 20-21 to compare thoughts on the future of marine exploration at the 2016 National Ocean Exploration Forum, "Beyond the Ships: 2020-2025," hosted in New York by The Rockefeller University in partnership with Monmouth University. The Forum is also supported by the Monmouth-Rockefeller Marine Science and Policy Initiative, NOAA, the Schmidt Ocean Institute, and James A. Austin, Jr. Ocean exploration has arrived at a historic hinge, Forum organizers say, with profound transformation underway thanks to new technologies, led by increasingly affordable "roboats" - autonomous or remotely controlled vehicles that dive into the ocean or ply the surface laden with sensors collecting information from instruments suspended beneath them. ROV SuBastian, for example, is a new eco-friendly 3,100 kg (6,500 pound) deep-sea research platform for the Schmidt Ocean Institute's R/V Falkor, equipped with ultra high-resolution 4K cameras, mechanical arms that move seven ways and can sample to depths of 4,500 meters (2.8 miles), with a lighting system equivalent to the lamps of 150 car high-beams. (SuBastian sea trials video: http://bit. High-res photos, b-roll: http://bit. ). Says Wendy Schmidt, co-founder of Schmidt Ocean Institute: "With ROV SuBastian we will help make life on the ocean floor real to people who will never visit the sea, so they, too, can begin to appreciate the importance of ocean health and make the connection between life in the deep sea and life on land." "You don't have to be a scientist at sea to recognize the importance of the marine environment, and we are only at the beginning of our understanding. We never anticipated discovering the world's deepest living fish, the ghostfish (video: http://bit. ), back in 2014, and are excited about the life we will discover next." ROV SuBastian will have that opportunity this December during its first science cruise, in the Mariana Back-Arc in the western Pacific. (Cruise details: http://bit. . All dives will be live-streamed on Schmidt Ocean Institute's YouTube page: http://bit. ). Contributing as well to the transformation: Modern communications and sampling techniques, including eDNA, big data analysis and other high-tech advances that automate and vastly accelerate the work, opening the way for experts and the public to reach, see, chart, sample and monitor formerly secret depths of the seas. Innovations include portable observatories for underwater monitoring and a "curious exploration robot," programmed to focus on everything unfamiliar to its data bank brain (photo: http://bit. , video: http://bit. , credit WHOI). According to innovator Yogesh Girdhar of the Woods Hole Oceanographic Institution, in a recent test off the Panama coast, a similar swimming robot discovered a startlingly enormous population of crabs. Other engineers, meanwhile, are developing "game changing" unmanned undersea and surface vehicles tricked out with an array of sophisticated sensors to perform a suite of underwater tasks, enabled to run for months by recent improvements in battery technology. (See video, for example, of Boeing's 51-foot Echo Voyager: http://bit. ). Such "roboats" can be programmed to conduct deep sea exploration or searches using a lawn mower pattern, surfacing regularly to report data back to shore via satellite, or to patrol a coastal area, returning to port after one or two months to recharge and redeploy. These technologies will enable today's generation to "explore more of Planet Earth than all previous generations combined," predicts Dr. Ballard, whose celebrated career will be recognized at the Forum with the Monmouth University Urban Coast Institute's Champion of the Ocean award. The technologies will not only help discover and monitor new mineral and living resources, they could help secure interests vital to the world's economy or identify the best paths for communications cables that span the ocean floor - the veins of the Internet. Until recently, ocean exploration has involved ships operated like fishing vessels, dipping sensors and hauling up data. Forum participants such as John Kreider of Oceaneering International envision such ships in future serving as hives from which flotillas and squadrons of autonomous underwater, surface and aerial vehicles are launched - robots guided by experts on board or remotely, such as from a distant university campus via "telepresence," returning with images and data orders of magnitude larger than ever before. Thanks to modern communication technologies, schoolchildren, their teachers and indeed any interested members of the public can, and do, now follow expeditions online in real time. Among the many compelling interests and pursuits of marine scientists and historians in the public, private and military sectors: Says scientist James (Jamie) A. Austin, Jr. of the University of Texas, "the slow, time consuming and expensive way we've done ocean exploration forever - one ship doing one task at a time - is giving way to autonomous systems that net massive hauls of data, with advances in big data analysis enabling scientists to make sense of it rapidly." Dr. Austin envisions installations on the seafloor - measuring tremors or helping scientists estimate the rate at which Earth swallows carbon into its mantle through plate tectonics, for example - with data delivered by a device periodically flying up and down to the surface. Simply mapping the ocean floor is an important goal. While satellites have fully charted the seafloor in low resolution, only 10% is mapped in detail. At an estimated cost of $2.9 billion - or about $9 per square kilometer ($23 per square mile) - a "Gurgle Earth" map of the deep oceans could be completed at high resolution using swath like, multi-beam sonar. The hazard of uncharted oceanic mountains, trenches, volcanoes and other features was dramatically underscored in 2005 when a nuclear attack submarine, the USS San Francisco, struck a seamount in the Pacific at high speed, killing one crew member and injuring 97. Over 50% of US territory lies beneath the ocean surface and such mapping could also expand American territorial and resource claims. With documentation of the continental shelf, America's Exclusive Economic Zone, 11.3 million square km in size today, could extend a further 2.2 million square km - a 20% enlargement, representing an underwater area larger than Alaska. (See http://bit. ). Other recent finds of ancient shipwrecks and even ancient human remains, he adds, reveal that early mariners didn't simply hug the coastline but sailed courageously great distances from shore, and make it possible to determine who they were. While these and countless biological discoveries represent things discovered underwater, the intent of future exploration campaigns include measuring more, sampling more, and better understanding physical, geological and living processes - knowledge of vital importance for security, responsible ocean use and sustainable resource management. Asked what he thought might yet be discovered underwater, Dr. Ballard compares that to asking Lewis or Clark what they thought they'd find on their historic traverse of America. The reply, he says, would have been "I don't know. I'm getting into a canoe and I'm going to paddle." In one of several papers written for the Forum, meanwhile, U.S. Ambassador Cameron Hume adds that, beyond exploring and the initial characterization of an ocean area, humanity also needs to pursue subsequent research and long-term observing. In his paper, Dr. Jerry Schubel of the Aquarium of the Pacific, lamenting the relatively low level of public attention accorded to ocean exploration, points to new opportunities for awareness raising created by social media. "Understanding life on other planets," he says, "may help us understand the origins of life in the universe, but it can't match the relevance and importance of ocean exploration to the future of life on this planet." Says organizer Prof. Jesse Ausubel, faculty member at The Rockefeller University: "SuBastian and the Roboats sounds like a rock band, but it is the future of ocean exploration. One million marine species and one million shipwrecks may remain to be discovered. Let's use new approaches to multiply exploration." Says Forum organizer Vice Admiral Paul Gaffney, former President of Monmouth University and Urban Coast Institute Ocean Policy Fellow: "America is the greatest maritime nation in the history of the world, yet we scarcely know submerged America and only about 10% of the global oceans. At this Forum, we are encouraging ocean technology leaders to join the discussion and support more comprehensive exploration campaigns indispensable for sustainable use of the oceans and inspiring ocean stewardship." The ultimate aim: to formulate compelling, feasible campaigns to be carried out by the participants in the 2020-2025 timeframe. At the Forum, Dr. Jyotika Virmani will share the roster of teams for the $7 million Shell Ocean Discovery XPRIZE, a global competition to promote unmanned ocean exploration. In a letter to the Forum (in full: http://bit. ), the President of the US National Academy of Sciences, famed ocean explorer Marcia McNutt, says "a number of events have underscored how essential our mission is to vastly improve knowledge of the marine environment." Inadequate knowledge of ocean terrain and currents hampered the search for flight MH 370 in 2014, for example. CubeSats, she notes, have "'democratized' space, providing access for pennies on the dollar. Similarly, new commercial tools, although still in their infancy, hold the promise of ushering in the citizen science era of ocean exploration." "The task we face is simply too large to continue to use 20th century tools if we hope to make a dent in the problem." Oct. 20-21Venue: The Rockefeller University, 1230 York Ave, New York, NY.Website, including Forum programme and speaker biographies: http://phe. Supporters: the Monmouth-Rockefeller Marine Science and Policy Initiative , NOAA, the Schmidt Ocean Institute, and James A. Austin, Jr. Positioning Ocean Exploration In a Chaotic Sea of Changing Media Jerry R. Schubel (Aquarium of the Pacific) http://bit. Exploring the Ocean through Sound Jennifer L. Miksis-Olds (University of New Hampshire) and Bruce Martin (Dalhousie) http://bit. Discussion Paper on Marine Minerals Mark Hannington, University of Ottawa, and Sven Petersen, GEOMAR Helmholtz Center for Ocean Research http://bit. Emerging Technologies for Biological Sampling in the Ocean Shirley Pomponi, Cooperative Institute for Ocean Exploration, Research, & Technology [CIOERT], Harbor Branch Oceanographic Institute, Florida Atlantic University http://bit. The Forum is the latest in a series mandated by Congress (Title XII of Public Law 111-11) in March 2009 when it officially established the NOAA ocean exploration program. This law requires NOAA to consult with the other federal agencies involved in ocean exploration, as well as external stakeholders, to establish a "coordinated national ocean exploration program" that promotes data management and sharing, public understanding, and technology development and transfer. The law also requires NOAA to organize an "ocean exploration Forum to encourage partnerships and promote collaboration among experts and other stakeholders to enhance the scientific and technical expertise and relevance of the national program." The 2016 Forum convenes approximately 100 experts from academia, government, and the private sector to discuss adaptation and integration of technologies that can be employed in ocean exploration campaigns in the 2020-2025 timeframe. The Forum will look to a future of expanded exploration activities by making more platforms capable of measuring, sampling, or imaging yet-to-be-explored areas - employing a suite of technologies that have been dubbed "flyaway systems." Expanding spatial coverage and reducing cost of data collection are key ocean exploration priorities over a ~10 year time horizon. These priorities can be realized by creatively adapting and assembling existing technologies, and deploying them onboard autonomous devices, buoys, various so-called ships-of-opportunity, and other platforms, in addition to the existing fleet of dedicated ocean exploration vessels. The Forum will help federal funding agencies and foundations define and prioritize exploration technology investment options for 2020-2030, and stimulate a vision among leading explorers of what it might be like to conduct expeditions in this time frame. James A. (Jamie) Austin Jr., University of Texas Robert Ballard, Ocean Exploration Trust and University of Rhode Island Frank Herr, Office of Naval Research, US Navy John Kreider, Oceaneering International Alan Leonardi, NOAA Ocean Exploration and Research Shirley Pomponi, Florida Atlantic University Rick Rikoski, Hadal Inc. Jerry Schubel, Aquarium of the Pacific Lance Towers, The Boeing Company Victoria Tschinkel, 1000 Friends of Florida Invitees represent the academic, government, non-profit, and for-profit communities, with expertise in both the engineering aspects of creating relevant equipment, and in exploratory and scientific applications of such equipment. Beyond the Ships: 2020-2025 is the first of four annual Marine Science & Policy Series conferences that will be organized by Rockefeller and Monmouth, with events taking place on alternating campuses in New York City and West Long Branch, New Jersey.
News Article | November 15, 2016
Fish catches in overfished European waters — stretching from the Arctic to the Black Sea — could increase by 57 percent if stocks were managed sustainably, a marine conservation group said Tuesday. The Oceana environmental group says scientists believe catches of haddock, cod, herring and sardine in the Atlantic could increase by at least 300 percent. Group spokeswoman Maria Cornax said Tuesday there was "no excuse" not to start fishing sustainably. "This is actually meant to help the fishery industry," she said. "They can get increased profits." The European Commission, executive arm of the EU, has proposed maintaining or increasing the fishing quotas for 42 species which are rated in good health, and reduce catches for 28 stocks which are faring poorly. It said it based its suggestion on advisory bodies including the Copenhagen-based International Council for the Exploration of the Sea. Oceana's research, which it billed as "the most comprehensive overview so far," was based on 397 stocks compared to around 150 monitored by the Commission. Oceana published its findings before next month's EU meeting to set the 2017 fishing limits in the North Sea. Oceana said 85 percent of stocks were now "in an unhealthy state." The study was led by a Germany-based GEOMAR Helmholtz Center for Ocean Research. Last month, the EU agreed to set tougher cod catch quotas in the western part of the Baltic Sea, but stayed well above targets sought by scientists who pushed for a cut of about 90 percent, and environmentalists who called for a temporary stop. EU fisheries ministers agreed on a 56 percent quota cut for the cod.
Kirillov S.A.,Arctic and Antarctic Research Institute |
Dmitrenko I.A.,University of Manitoba |
Holemann J.A.,Alfred Wegener Institute for Polar and Marine Research |
Kassens H.,Helmholtz Center for Ocean Research |
Bloshkina E.,Arctic and Antarctic Research Institute
Continental Shelf Research | Year: 2013
The large recurrent areas of open water and/or thin ice (polynyas) producing cold brine-enriched waters off the fast-ice edge are evident in the Laptev Sea in winter time. A number of abrupt positively correlated transitions in temperature and salinity were recorded in the bottom and intermediate layers at a mooring station in the West New Siberian (WNS) polynya in February-March 2008. Being in the range of ~0.5. °C and ~1.6. psu these changes are induced by horizontal motions across the polynya and correspond to temperature and salinity horizontal gradients in the range of 0.3-1.0. °C/10. km and 1.4-3.5. psu/10. km, respectively. The events of distinct freshening and temperature decrease coincide with a northward current off the fast-ice edge, while southward currents brought saltier and warmer waters at intermediate depths. We suggest that the observed transitions are connected to altering pycnocline depths across the polynya. The source of relatively fresher waters at the intermediate depths in polynya is supposed to originate from penetrative mixing of surface low salinity waters to intermediate water depth. Several forcing processes that could be responsible for a penetrative mixing through the density interface in polynya are discussed. These are penetrative convection and shear-driven mixing that originates from two-layer water dynamics and/or baroclinic tidal motions. The heavily ridged seaward fast-ice edge could produce an additional source of turbulent mixing even through a shear-free density interface due to the increased roughness at the ice-water interface. © 2013 Elsevier Ltd.
Sawall Y.,Leibniz Center for Tropical Marine Ecology |
Sawall Y.,Helmholtz Center for Ocean Research |
Jompa J.,Hasanuddin University |
Litaay M.,Hasanuddin University |
And 2 more authors.
Marine Pollution Bulletin | Year: 2013
Coral recruitment was assessed in highly diverse and economically important Spermonde Archipelago, a reef system subjected to land-based sources of siltation/pollution and destructive fishing, over a period of 2years. Recruitment on settlement tiles reached up to 705spatm-2yr-1 and was strongest in the dry season (July-October), except off-shore, where larvae settled earlier. Pocilloporidae dominated near-shore, while a more diverse community of Acroporidae, Poritidae and others settled in the less polluted mid-shelf and off-shore reefs. Non-coral fouling community appeared to hardly influence initial coral settlement on the tiles, although, this does not necessarily infer low coral post-settlement mortality, which may be enhanced at the near- and off-shore reefs as indicated by increased abundances of potential space competitors on natural substrate. Blast fishing showed no local reduction in coral recruitment and live hard coral cover increased in oligotrophic reefs, indicating potential for coral recovery, if managed effectively. © 2013 Elsevier Ltd.
Costello M.J.,University of Auckland |
Appeltans W.,Flanders Marine Institute VLIZ |
Appeltans W.,Intergovernmental Oceanographic Commission of UNESCO |
Bailly N.,Aquatic Informatics |
And 10 more authors.
Biological Conservation | Year: 2014
Scientists should ensure that high quality research information is readily available on the Internet so society is not dependant on less authoritative sources. Many scientific projects and initiatives publish information on species and biodiversity on the World Wide Web without users needing to pay for it. However, these resources often stagnate when project funding expired. Based on a large pool of experiences worldwide, this article discusses what measures will help such data resources develop beyond the project lifetime. Biodiversity data, just as data in many other disciplines, are often not generated automatically by machines or sensors. Data on for example species are based on human observations and interpretation. This requires continuous data curation to keep these up to date. Creators of online biodiversity databases should consider whether they have the resources to make their database of such value that other scientists and/or institutions would continue to finance its existence. To that end, it may be prudent to engage such partners in the development of the resource from an early stage. Managers of existing biodiversity databases should reflect on the factors being important for sustainability. These include the extent, scope, quality and uniqueness of database content; track record of development; support from scientists; support from institutions, and clarity of Intellectual Property Rights. Science funders should give special attention to the development of scholarly databases with expert-validated content. The science community has to appreciate the efforts of scientists in contributing to open-access databases, including by citing these resources in the Reference lists of publications that use them. Science culture must thus adapt its practices to support online databases as scholarly publications. To sustain such databases, we recommend they should (a) become integrated into larger collaborative databases or information systems with a consequently larger user community and pool of funding opportunities, and (b) be owned and curated by a science organisation, society, or institution with a suitable mandate. Good governance and proactive communication with contributors is important to maintain the team enthusiasm that launched the resource. Experience shows that 'bigger is better' in terms of database size because the resource will have more content, more potential and known uses and users of its content, more contributors, be more prestigious to contribute to, and have more funding options. Furthermore, most successful biodiversity databases are managed by a partnership of individuals and organisations. © 2013 Elsevier Ltd.
News Article | January 7, 2016
Phytoplankton that harvest sunlight in the world’s oceans make more heat than food, a new study finds. The microscopic marine organisms, which serve as an important food source in the ocean, use photosynthesis to turn sunlight into cellular fuel. But nearly twice as much of the sunlight energy captured by phytoplankton in the ocean is released as heat than is used to make food, researchers report January 7 in Science. The finding suggests that phytoplankton don’t photosynthesize as efficiently as researchers had thought. “The photosynthetic efficiency of global phytoplankton is very low, surprisingly low,” says study coauthor Paul Falkowski, an oceanographic biophysicist at Rutgers University in New Brunswick, N.J. “It was a complete shock to us.” When phytoplankton harness sunlight, one by-product is fluorescence. Satellites tuned to detecting fluorescent red light have gathered data on the ocean’s photosynthesizing phytoplankton. But satellites can’t see through clouds, and some of the red light they pick up comes from particles in Earth’s atmosphere. So Falkowski and his team developed an instrument highly sensitive to the red fluorescence of phytoplankton that could be deployed on oceangoing research vessels. The scientists gathered more than 150,000 phytoplankton fluorescent measurements during cruises in the Atlantic, Pacific, Arctic and Southern oceans from 2008 to 2014. From the data, the team calculated how much sunlight was directed toward making cellular fuel compared with how much was lost as heat or fluorescence. While 35 percent of the absorbed light was used for making food to fuel the phytoplankton’s growth, nearly 60 percent of the light was converted to heat. “That’s a large amount of light absorbed by phytoplankton in the ocean that’s just being reemitted as heat,” says Thomas Browning, a marine biogeochemist at the GEOMAR Helmholtz Center for Ocean Research in Kiel, Germany, who was not involved on the study. He called it “a novel finding.” In laboratory studies with nutrient conditions encouraging phytoplankton growth, the team observed the opposite result: Around 65 percent of absorbed light was used to make cellular fuel, while less than 35 percent was lost as heat. The team blames phytoplankton’s inefficient photosynthesis in the ocean on nutrient-poor waters, which cover 30 percent of the world’s oceans. Without sufficient nutrients, the photosynthesis structures in phytoplankton don’t work properly and struggle to efficiently convert sunlight into usable energy. The study illustrates the need for instruments that monitor phytoplankton changes in the future, Browning says. “We want to know how their activity and distribution are changing over time.”
Effect of algal species and concentration on development and fatty acid composition of two harpacticoid copepods, Tisbe sp. and Tachidius discipes, and a discussion about their suitability for marine fish larvae
Arndt C.,Helmholtz Center for Ocean Research |
Sommer U.,Helmholtz Center for Ocean Research
Aquaculture Nutrition | Year: 2014
We compared the development and fatty acid content of the harpacticoid copepods Tachidius discipes and Tisbe sp. fed with different microalgal species (Dunaliella tertiolecta, Rhodomonas sp., Phaeodactylum tricornutum, Isochrysis galbana and a concentrate of Pavlova sp.), which differed in cell size and fatty acid composition. Tisbe could develop in 11 days with every alga to the same average stage, whereas Tachidius developed poorly when fed with Isochrysis and Dunaliella. Feeding with Phaeodactylum resulted in a fast development of both copepods at low algal concentrations. However, reproduction was higher with Rhodomonas as food than with the other algae. Fatty acid compositions of copepods were influenced by their food source, but both were able to convert docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) from precursors. Tachidius fed with Rhodomonas or Phaeodactylum was closest to the DHA/EPA/arachidonic acid (ARA) ratio of 10 : 5 : 1 considered optimal for some marine fish larvae. Tachidius showed similar development and reproduction capacity as Tisbe, but requested higher absolute fatty acid contents in the diet. Tisbe was superior in the utilization of bacteria as additional food source and the bioconversion of precursor fatty acids. Phaeodactylum and Rhodomonas are recommendable food sources for both copepod species, but Phaeodactylum is more easily cultured. © 2014 John Wiley & Sons Ltd.