Browsing by Author "Duarte, Carlos M."
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- ItemAssessing the capacity of seagrass meadows for carbon burial: Current limitations and future strategies(2013) Duarte, Carlos M.; Kennedy, Hilary; Marba, Nuria; Hendriks, IrisSeagrass meadows support high primary production rates and their canopies are efficient at filtering particles out of their water column as well as in preventing resuspension of the sediments. In addition, decomposition rates in seagrass sediments are slow, because of low nutrient concentration in seagrass detritus and low oxygen concentration in seagrass sediments. These characteristics result in high carbon burial rates in seagrass meadows, which have the capacity to accumulate large stores of carbon in their sediments, raising the seafloor. Carbon fingerprinting techniques allow to calculate both the age of these deposits and, therefore, the rate of carbon burial and identify the contribution of carbon produced by the seagrass. Yet, data on the regional cover and carbon stocks in seagrass meadows is sparse for some regions, particularly the Indo-Pacific, Africa and South America. In addition, our understanding of the factors regulating the variability in carbon sink capacity among seagrass meadows is limited. These gaps limit the capacity to formulate strategies to mitigate climate change based on the carbon sink capacity of seagrass meadows. A research strategy needs be formulated to address these gaps and provide the necessary protocols to ensure the accountability of mitigation actions involving the conservation and restoration of seagrass meadows. (C) 2011 Elsevier Ltd. All rights reserved.
- ItemCompensation irradiance for planktonic community metabolism in the ocean(2010) Regaudie-de-Gioux, Aurore; Duarte, Carlos M.The light compensation irradiance for planktonic metabolic balance, defined as the irradiance where gross planktonic primary production equals community respiration, is an important property describing ecosystem dynamics. Planktonic communities receiving irradiances above the compensation irradiance or compensation depth (i.e., the depth at which the compensation irradiance is received) are autotrophic and act as CO2 sinks, whereas those at lower irradiances or located deeper in the water column act as CO2 sources. However, this property is undefined for heterotrophic communities in which metabolic balance is not set by light availability. The compensation irradiance for planktonic metabolism in the ocean was quantified experimentally and calculated using data available in the literature to assess its variability and possible controls. Gross primary production by the oceanic planktonic communities examined here meet their respiratory requirements at irradiances of about 1.1 +/- 0.4 mol quanta m(-2) d(-1) and tend to be autotrophic above a depth of 36 +/- 9 m, on average. The depth of nitracline is closely correlated with the compensation depth for community metabolism across the studied areas, but the compensation depth tends to be located above the depth of the nitracline. This is expected from the facts that the underlying, net heterotrophic communities should act as sources of inorganic nutrients and that the nitracline cannot develop within the mixed layer where the compensation depth is often located. These results imply that the planktonic communities examined extending from 36 m depth, on average, to the bottom of the euphotic layer tend to be heterotrophic, acting as CO2 and inorganic nutrient sources.
- ItemContrasting sensitivity of marine biota to UV-B radiation between southern and northern nemispheres(2015) Agusti, Susana; Llabres, Moira; Carreja, Beatriz; Fernández, Miriam; Duarte, Carlos M.
- ItemMarine reserves can mitigate and promote adaptation to climate change(2017) Roberts, Callum M.; O’Leary, Bethan C.; McCauley, Douglas J.; Cury, Philippe Maurice; Duarte, Carlos M.; Lubchenco, Jane; Pauly, Daniel; Sáenz-Arroyo, Andrea; Sumaila, Ussif Rashid; Castilla, Juan Carlos; Wilson, Rod W.; Worm, Boris
- ItemQuestioning the Rise of Gelatinous Zooplankton in the World's Oceans(2012) Condon, Robert H.; Graham, William M.; Duarte, Carlos M.; Pitt, Kylie A.; Lucas, Cathy H.; Haddock, Steven H. D.; Sutherland, Kelly R.; Robinson, Kelly L.; Dawson, Michael N.; Decker, Mary Beth; Mills, Claudia E.; Purcell, Jennifer E.; Malej, Alenka; Mianzan, Hermes; Uye, Shin-Ichi; Gelcich, Stefan; Madin, Laurence P.During the past several decades, high numbers of gelatinous zooplankton species have been reported in many estuarine and coastal ecosystems. Coupled with media-driven public perception, a paradigm has evolved in which the global ocean ecosystems are thought to be heading toward being dominated by "nuisance" jellyfish. We question this current paradigm by presenting a broad overview of gelatinous zooplankton in a historical context to develop the hypothesis that population changes reflect the human-mediated alteration of global ocean ecosystems. To this end, we synthesize information related to the evolutionary context of contemporary gelatinous zooplankton blooms, the human frame of reference for changes in gelatinous zooplankton populations, and whether sufficient data are available to have established the paradigm. We conclude that the current paradigm in which it is believed that there has been a global increase in gelatinous zooplankton is unsubstantiated, and we develop a strategy for addressing the critical questions about long-term, human-related changes in the sea as they relate to gelatinous zooplankton blooms.
- ItemTen Thousand Voices on Marine Climate Change in Europe: Different Perceptions among Demographic Groups and Nationalities(2017) Buckley, Paul J.; Pinnegar, John K.; Painting, Suzanne J.; Terry, Geraldine.; Chilvers, Jason.; Lorenzoni, Irene.; Gelcich, Stefan; Duarte, Carlos M.