2013年5月29日星期三

Fast-sinking jellyfish could boost the oceans' uptake of carbon dioxide

Fast-sinking jellyfish could boost the oceans' uptake of carbon dioxide

To assess the efficiency of the biological carbon pump, data on sinking velocities of the different species are necessary. Together with colleagues from Germany, Spain, the United Kingdom and the United States, Dr. Mario Lebrato, Biological Oceanographer in Prof. Andreas Oschlies' group at GEOMAR Helmholtz Centre for Ocean Research Kiel, conducted field and laboratory experiments with gelatinous plankton remains. Their latest article in the international magazine "Limnology and Oceanography" describes for the first time the sinking speed of organic remains from jellyfish and pelagic tunicates. Together with a previous article in the same journal that calculated biomass export efficiency for these organisms for the first time, these new data allow robust estimates of global carbon export associated with gelatinous plankton.

For their experiments, the scientists collected different species of scyphozoans (true jellyfish), ctenophores (comb jellies), and thaliaceans (salps) in the Baltic, the Mediterranean, the Atlantic and the Southern Ocean. The sinking process was observed and filmed in large transparent cylinders filled with seawater at OceanLab Bremen by Dr. Pedro de Jesus Mendes. Later the proportion of organic carbon and nitrogen of the dry biomass and biomass weight were measured. The work was supported by the European Project on Ocean Acidification (EPOCA), the Kiel Cluster of Excellence The Future Ocean, the German project on ocean acidification BIOACID (Biological Impacts of Ocean Acidification), and the US National Science Foundation Office for Polar Programs.

"The sinking speed of jelly remains is much, much higher than what we expected, about 500 to 1600 meters per day," Lebrato sums up. "And, what puzzles researchers working on the biological carbon pump: it is higher than that of non-calcifying phytoplankton and marine snow, the main sinking particles and organic carbon sources to the ocean interior." Fast sinking means that the biomass and its constituents reach the deeper ocean layers without major degradation, where microbial decay releases CO2 that can be stored without direct contact with the atmosphere for millennia. Also, fast sinking provides high quality food resources for benthic organisms, which has already been observed actively feeding on jelly remains. On continental shelves and slope areas, biomass may reach the seabed within a day or less.

Within the studied species, scyphozoans had on average the highest carbon content (26.97 percent), followed by thaliaceans (17.20 percent), and ctenophores (1.40 percent). The jelly carbon content is lower on average than that of phytoplankton or marine snow. But their large populations, occupying at times hundreds of square kilometers in the oceans, combined with a high sinking speed, can deliver large carbon quantities to the seabed.

"Our dataset provides an initial overview and comparison for modelers and experimentalists to use in subsequent studies examining the role of jellies in carbon export and the efficiency of the biological pump," Lebrato says. "We are continuously asked, how much organic carbon and CO2 do gelatinous plankton sink worldwide, whether their export capacities are similar to phytoplankton and marine snow. And if an increase of jellyfish in the future will enhance organic carbon export and CO2 sequestration. Until recently, few people believed that jelly organisms could play any major role in the carbon cycle, thus they have been excluded from large biogeochemical research programs. In consequence, the data available up to now are scarce and we are just starting to comprehend the fundamental properties that will allow us to better understand the role of jellyfish and pelagic tunicates in the global carbon cycle."


Welcome to SUV System Ltd!

SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.

We have built up long term business relationship with about many companies which are stockers and authorized agents. we have a steady and reliable supply to meet customer's demands to the greatest extent .Confidently, we are able to lower your cost and support your business with our years of professional service.

SUV System Ltd is Electronic Components Distributor Supplies,Find Quality Electronic Components Supplies Products IC(Integrated Circuits),Connectors,Capacitor,Resistors,Diodes,Transistors,LED at Suvsystem.com. Sourcing Other Energy, Environment, Excess Inventory Products from Manufacturers and Suppliers at Suvsystem.com

Electronic Components distributor:http://www.suvsystem.com

Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html

IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html

LED Distributor:http://www.suvsystem.com/l/LED-1.html

Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html

Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html

Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html

Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html

SUV System Ltd insists on the managing faith ofsincereness,speciality,foresight, win-win,so we build up stable-relationship customers located all over the world, including the States, Europe, Argentina, UAE, Malaysia, Australia,and India etc

we are focus on the following fields,and hope we can help you.


CRCW120612R7FKTA CRCW120612R7FKEA CRCW120612R4FKTA CRCW120612R4FKEA CRCW120612R1FKTA CRCW120612R1FKEA CRCW120612R0JNTA CRCW120612R0JNEB CRCW120612R0JNEAIF CRCW120612R0JNEA CRCW120612R0FKTA CRCW120612R0FKEB CRCW120612R0FKEA CRCW120612M0JPTA CRCW120612M0JPEAHR CRCW120612M0JPEA CRCW120612K7FKTA CRCW120612K7FKEA CRCW120612K4FKTA CRCW120612K4FKEA CRCW120612K1FKTA CRCW120612K1FKEA CRCW120612K0JNTA CRCW120612K0JNEB CRCW120612K0JNEA CRCW120612K0FKTA CRCW120612K0FKEA CRCW1206127RFKTA CRCW120614K3FKEA CRCW120614K0FKTA CRCW120614K0FKEA CRCW1206147RFKTA CRCW1206147RFKEA CRCW1206147KFKTA CRCW1206147KFKEA CRCW1206143RFKTA CRCW1206143RFKEA CRCW1206143KFKTA CRCW1206143KFKEB CRCW1206143KFKEA
http://www.suvsystem.com/a/1786.aspx