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Jefferson T Turner - One of the best experts on this subject based on the ideXlab platform.
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zooplankton fecal pellets marine snow phytodetritus and the ocean s Biological Pump
Progress in Oceanography, 2015Co-Authors: Jefferson T TurnerAbstract:Abstract The “Biological Pump” is the process by which photosynthetically-produced organic matter in the ocean descends from the surface layer to depth by a combination of sinking particles, advection or vertical mixing of dissolved organic matter, and transport by animals. Particulate organic matter that is exported downward from the euphotic zone is composed of combinations of fecal pellets from zooplankton and fish, organic aggregates known as “marine snow” and phytodetritus from sinking phytoplankton. Previous reviews by Turner and Ferrante (1979) and Turner (2002) focused on publications that appeared through late 2001. Since that time, studies of the Biological Pump have continued, and there have been >300 papers on vertical export flux using sediment traps, large-volume filtration systems and other techniques from throughout the global ocean. This review will focus primarily on recent studies that have appeared since 2001. Major topics covered in this review are (1) an overview of the Biological Pump, and its efficiency and variability, and the role of dissolved organic carbon in the Biological Pump; (2) zooplankton fecal pellets, including the contribution of zooplankton fecal pellets to export flux, epipelagic retention of zooplankton fecal pellets due to zooplankton activities, zooplankton vertical migration and fecal pellet repackaging, microbial ecology of fecal pellets, sinking velocities of fecal pellets and aggregates, ballasting of sinking particles by mineral contents, phytoplankton cysts, intact cells and harmful algae toxins in fecal pellets, importance of fecal pellets from various types of zooplankton, and the role of zooplankton fecal pellets in picoplankton export; (3) marine snow, including the origins, abundance, and distributions of marine snow, particles and organisms associated with marine snow, consumption and fragmentation of marine snow by animals, pathogens associated with marine snow; (4) phytodetritus, including pulsed export of phytodetritus, phytodetritus from Phaeocystis spp., picoplankton in phytodetritus, the summer export pulse (SEP) of phytodetritus in the subtropical North Pacific, benthic community responses to phytodetritus; (5) other components of the Biological Pump, including fish fecal pellets and fish-mediated export, sinking carcasses of animals and macrophytes, feces from marine mammals, transparent exopolymer particles (TEP); (6) the Biological Pump and climate, including origins of the Biological Pump, the Biological Pump and glacial/interglacial cycles, the Biological Pump and contemporary climate variations, and the Biological Pump and anthropogenic climate change. The review concludes with potential future modifications in the Biological Pump due to climate change.
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Zooplankton fecal pellets, marine snow, phytodetritus and the ocean’s Biological Pump
Progress in Oceanography, 2015Co-Authors: Jefferson T TurnerAbstract:Abstract The “Biological Pump” is the process by which photosynthetically-produced organic matter in the ocean descends from the surface layer to depth by a combination of sinking particles, advection or vertical mixing of dissolved organic matter, and transport by animals. Particulate organic matter that is exported downward from the euphotic zone is composed of combinations of fecal pellets from zooplankton and fish, organic aggregates known as “marine snow” and phytodetritus from sinking phytoplankton. Previous reviews by Turner and Ferrante (1979) and Turner (2002) focused on publications that appeared through late 2001. Since that time, studies of the Biological Pump have continued, and there have been >300 papers on vertical export flux using sediment traps, large-volume filtration systems and other techniques from throughout the global ocean. This review will focus primarily on recent studies that have appeared since 2001. Major topics covered in this review are (1) an overview of the Biological Pump, and its efficiency and variability, and the role of dissolved organic carbon in the Biological Pump; (2) zooplankton fecal pellets, including the contribution of zooplankton fecal pellets to export flux, epipelagic retention of zooplankton fecal pellets due to zooplankton activities, zooplankton vertical migration and fecal pellet repackaging, microbial ecology of fecal pellets, sinking velocities of fecal pellets and aggregates, ballasting of sinking particles by mineral contents, phytoplankton cysts, intact cells and harmful algae toxins in fecal pellets, importance of fecal pellets from various types of zooplankton, and the role of zooplankton fecal pellets in picoplankton export; (3) marine snow, including the origins, abundance, and distributions of marine snow, particles and organisms associated with marine snow, consumption and fragmentation of marine snow by animals, pathogens associated with marine snow; (4) phytodetritus, including pulsed export of phytodetritus, phytodetritus from Phaeocystis spp., picoplankton in phytodetritus, the summer export pulse (SEP) of phytodetritus in the subtropical North Pacific, benthic community responses to phytodetritus; (5) other components of the Biological Pump, including fish fecal pellets and fish-mediated export, sinking carcasses of animals and macrophytes, feces from marine mammals, transparent exopolymer particles (TEP); (6) the Biological Pump and climate, including origins of the Biological Pump, the Biological Pump and glacial/interglacial cycles, the Biological Pump and contemporary climate variations, and the Biological Pump and anthropogenic climate change. The review concludes with potential future modifications in the Biological Pump due to climate change.
Jeffrey Abell - One of the best experts on this subject based on the ideXlab platform.
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the Biological Pump in the subtropical north pacific ocean nutrient sources redfield ratios and recent changes
Global Biogeochemical Cycles, 2001Co-Authors: Steven Emerson, Sabine Mecking, Jeffrey AbellAbstract:Observations from the Hawaii Ocean Time series indicate that a large fraction of the nitrogen supply to the euphotic zone is presently from nitrogen fixation. There is growing evidence, some presented here, that the main phosphorus flux is from the upper thermocline via eddy-induced mixing processes. These mechanisms of supply create a non-steady state nutrient flux in which the N:P ratio in particulate organic matter exiting the upper ocean (N:P = 23) is greater than the ratio of dissolved nitrogen to phosphorus that is remineralized in the upper thermocline (N:P = 13–14). Carbon to nitrogen ratios in the particulate export flux have remained between 7 and 8 in spite of these N:P changes, suggesting that the Biological carbon export may have increased along with nitrogen fixation even though Redfield Ratio arguments would suggest phosphorus should be limiting. A simple model of the upper ocean circulation and carbon export demonstrates the sensitivity of apparent oxygen utilization (AOU) in the upper thermocline, atmospheric pCO2 and atmospheric pO2 to changes in the carbon Pump. Comparison of AOU distributions from four meridional transects through the northeast subtropical Pacific between 1980 and 1997 suggests there has been an increase of 20–25% over the past two decades. These results cannot be explained without invoking changes in the Biological Pump or upper-ocean ventilation by as much as 30–50%. Estimated atmospheric pCO2 and pO2 responses to this change are <10% and ∼15%, respectively, of the observed trends in the 1990s. Taken together, changes in the organic matter C:N:P ratios and in the AOU within the upper thermocline of the eastern North Pacific indicate that the onset of nitrogen fixation has resulted in an increase in the Biological Pump over that expected from nutrient delivery via ocean circulation. This suggests that at least on decadal timescales, the Biological Pump is not limited by phosphate concentrations in the Redfield ratio (N:P = 15–16).
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The Biological Pump in the subtropical North Pacific Ocean: Nutrient sources, Redfield ratios, and recent changes
Global Biogeochemical Cycles, 2001Co-Authors: Steven Emerson, Sabine Mecking, Jeffrey AbellAbstract:Observations from the Hawaii Ocean Time series indicate that a large fraction of the nitrogen supply to the euphotic zone is presently from nitrogen fixation. There is growing evidence, some presented here, that the main phosphorus flux is from the upper thermocline via eddy-induced mixing processes. These mechanisms of supply create a non-steady state nutrient flux in which the N:P ratio in particulate organic matter exiting the upper ocean (N:P = 23) is greater than the ratio of dissolved nitrogen to phosphorus that is remineralized in the upper thermocline (N:P = 13–14). Carbon to nitrogen ratios in the particulate export flux have remained between 7 and 8 in spite of these N:P changes, suggesting that the Biological carbon export may have increased along with nitrogen fixation even though Redfield Ratio arguments would suggest phosphorus should be limiting. A simple model of the upper ocean circulation and carbon export demonstrates the sensitivity of apparent oxygen utilization (AOU) in the upper thermocline, atmospheric pCO2 and atmospheric pO2 to changes in the carbon Pump. Comparison of AOU distributions from four meridional transects through the northeast subtropical Pacific between 1980 and 1997 suggests there has been an increase of 20–25% over the past two decades. These results cannot be explained without invoking changes in the Biological Pump or upper-ocean ventilation by as much as 30–50%. Estimated atmospheric pCO2 and pO2 responses to this change are
Steven Emerson - One of the best experts on this subject based on the ideXlab platform.
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the Biological Pump in the subtropical north pacific ocean nutrient sources redfield ratios and recent changes
Global Biogeochemical Cycles, 2001Co-Authors: Steven Emerson, Sabine Mecking, Jeffrey AbellAbstract:Observations from the Hawaii Ocean Time series indicate that a large fraction of the nitrogen supply to the euphotic zone is presently from nitrogen fixation. There is growing evidence, some presented here, that the main phosphorus flux is from the upper thermocline via eddy-induced mixing processes. These mechanisms of supply create a non-steady state nutrient flux in which the N:P ratio in particulate organic matter exiting the upper ocean (N:P = 23) is greater than the ratio of dissolved nitrogen to phosphorus that is remineralized in the upper thermocline (N:P = 13–14). Carbon to nitrogen ratios in the particulate export flux have remained between 7 and 8 in spite of these N:P changes, suggesting that the Biological carbon export may have increased along with nitrogen fixation even though Redfield Ratio arguments would suggest phosphorus should be limiting. A simple model of the upper ocean circulation and carbon export demonstrates the sensitivity of apparent oxygen utilization (AOU) in the upper thermocline, atmospheric pCO2 and atmospheric pO2 to changes in the carbon Pump. Comparison of AOU distributions from four meridional transects through the northeast subtropical Pacific between 1980 and 1997 suggests there has been an increase of 20–25% over the past two decades. These results cannot be explained without invoking changes in the Biological Pump or upper-ocean ventilation by as much as 30–50%. Estimated atmospheric pCO2 and pO2 responses to this change are <10% and ∼15%, respectively, of the observed trends in the 1990s. Taken together, changes in the organic matter C:N:P ratios and in the AOU within the upper thermocline of the eastern North Pacific indicate that the onset of nitrogen fixation has resulted in an increase in the Biological Pump over that expected from nutrient delivery via ocean circulation. This suggests that at least on decadal timescales, the Biological Pump is not limited by phosphate concentrations in the Redfield ratio (N:P = 15–16).
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The Biological Pump in the subtropical North Pacific Ocean: Nutrient sources, Redfield ratios, and recent changes
Global Biogeochemical Cycles, 2001Co-Authors: Steven Emerson, Sabine Mecking, Jeffrey AbellAbstract:Observations from the Hawaii Ocean Time series indicate that a large fraction of the nitrogen supply to the euphotic zone is presently from nitrogen fixation. There is growing evidence, some presented here, that the main phosphorus flux is from the upper thermocline via eddy-induced mixing processes. These mechanisms of supply create a non-steady state nutrient flux in which the N:P ratio in particulate organic matter exiting the upper ocean (N:P = 23) is greater than the ratio of dissolved nitrogen to phosphorus that is remineralized in the upper thermocline (N:P = 13–14). Carbon to nitrogen ratios in the particulate export flux have remained between 7 and 8 in spite of these N:P changes, suggesting that the Biological carbon export may have increased along with nitrogen fixation even though Redfield Ratio arguments would suggest phosphorus should be limiting. A simple model of the upper ocean circulation and carbon export demonstrates the sensitivity of apparent oxygen utilization (AOU) in the upper thermocline, atmospheric pCO2 and atmospheric pO2 to changes in the carbon Pump. Comparison of AOU distributions from four meridional transects through the northeast subtropical Pacific between 1980 and 1997 suggests there has been an increase of 20–25% over the past two decades. These results cannot be explained without invoking changes in the Biological Pump or upper-ocean ventilation by as much as 30–50%. Estimated atmospheric pCO2 and pO2 responses to this change are
Timothy M. Lenton - One of the best experts on this subject based on the ideXlab platform.
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BPOP-v1 model: exploring the impact of changes in the Biological Pump on the shelf sea and ocean nutrient and redox state
Geoscientific Model Development, 2020Co-Authors: Elisa Lovecchio, Timothy M. LentonAbstract:Abstract. The Biological Pump of the ocean has changed over Earth's history, from one dominated by prokaryotes to one involving a mixture of prokaryotes and eukaryotes with trophic structure. Changes in the Biological Pump are in turn hypothesized to have caused important changes in the nutrient and redox properties of the ocean. To explore these hypotheses, we present here a new box model including oxygen (O), phosphorus (P) and a dynamical Biological Pump. Our Biological Pump, Oxygen and Phosphorus (BPOP) model accounts for two – small and large – organic matter species generated by production and coagulation, respectively. Export and burial of these particles are regulated by a remineralization length ( zrem ) scheme. We independently vary zrem of small and large particles in order to study how changes in sinking speeds and remineralization rates affect the major biogeochemical fluxes and O and P ocean concentrations. Modeled O and P budgets and fluxes lie reasonably close to present estimates for zrem in the range of currently measured values. Our results highlight that relatively small changes in zrem of the large particles can have important impacts on the O and P ocean availability and support the idea that an early ocean dominated by small particles was nutrient rich due to the inefficient removal of P to sediments. The results also suggest that extremely low oxygen concentrations in the shelf can coexist with an oxygenated deep open ocean for realistic values of zrem , especially for large values of the small-particle zrem . This could challenge conventional interpretations that the Proterozoic deep ocean was anoxic, which are derived from shelf and slope sediment redox data. This simple and computationally inexpensive model is a promising tool to investigate the impact of changes in the organic matter sinking and remineralization rates as well as changes in physical processes coupled with the Biological Pump in a variety of case studies.
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BPOP-v1 model: exploring the impact of changes in the Biological Pump on the shelf sea and ocean nutrient and redox state
2019Co-Authors: Elisa Lovecchio, Timothy M. LentonAbstract:Abstract. The ocean’s Biological Pump has changed over Earth history from one dominated by prokaryotes, to one involving a mixture of prokaryotes and eukaryotes with trophic structure. Changes in the Biological Pump are in turn hypothesised to have caused important changes in the ocean’s nutrient and redox properties. To explore these hypotheses, we present here a new box model including oxygen (O), phosphorus (P) and a dynamical Biological Pump. Our Biological Pump, Oxygen and Phosphorus (BPOP) model accounts for two – small and large – organic matter species generated by production and coagulation, respectively. Export and burial of these particles are regulated by a remineralization length (zrem) scheme. We independently vary zrem of small and large particles in order to study how changes in sinking speeds and remineralization rates affect the major biogeochemical fluxes, and O and P ocean concentrations. Modelled O and P budgets and fluxes lay close to present estimates for zrem in the range of currently measured values. Our results highlight that relatively small changes in zrem of the large particles can have important impacts on the O and P ocean availability and support the idea that an early ocean dominated by small particles was nutrient rich due to inefficient removal to sediments. The results also highlight that shelf ocean anoxia can coexist with an oxygenated deep open ocean for realistic values of zrem, especially for large values of the small particle zrem. This could challenge conventional interpretations that the Proterozoic deep ocean was anoxic, which are derived from shelf and slope sediment redox data. This simple and computationally inexpensive model is a promising tool to investigate the impact of changes in the organic matter sinking and remineralization rates as well as changes in physical processes coupled to the Biological Pump in a variety of case studies.
Makio C. Honda - One of the best experts on this subject based on the ideXlab platform.
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Enhanced role of eddies in the Arctic marine Biological Pump
Nature communications, 2014Co-Authors: Eiji Watanabe, Makio C. Honda, Shigeto Nishino, Takashi Kikuchi, Jonaotaro Onodera, Naomi Harada, Katsunori Kimoto, Kohei Matsuno, Atsushi Yamaguchi, Akio IshidaAbstract:The future conditions of Arctic sea ice and marine ecosystems are of interest not only to climate scientists, but also to economic and governmental bodies. However, the lack of widespread, year-long biogeochemical observations remains an obstacle to understanding the complicated variability of the Arctic marine Biological Pump. Here we show an early winter maximum of sinking biogenic flux in the western Arctic Ocean and illustrate the importance of shelf-break eddies to Biological Pumping from wide shelves to adjacent deep basins using a combination of year-long mooring observations and three-dimensional numerical modelling. The sinking flux trapped in the present study included considerable fresh organic material with soft tissues and was an order of magnitude larger than previous estimates. We predict that further reductions in sea ice will promote the entry of Pacific-origin Biological species into the Arctic basin and accelerate biogeochemical cycles connecting the Arctic and subarctic oceans.
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Enhanced role of eddies in the Arctic marine Biological Pump
Nature Communications, 2014Co-Authors: Eiji Watanabe, Makio C. Honda, Shigeto Nishino, Takashi Kikuchi, Jonaotaro Onodera, Naomi Harada, Katsunori Kimoto, Kohei Matsuno, Atsushi Yamaguchi, Akio IshidaAbstract:Arctic sea ice has been in rapid decline in recent decades, yet the impact on biogeochemical cycling is unknown due to insufficient sampling. Watanabe et al. combine year-long mooring observations with numerical models to show that an eddy-induced Biological Pump would be enhanced by sea ice retreat. The future conditions of Arctic sea ice and marine ecosystems are of interest not only to climate scientists, but also to economic and governmental bodies. However, the lack of widespread, year-long biogeochemical observations remains an obstacle to understanding the complicated variability of the Arctic marine Biological Pump. Here we show an early winter maximum of sinking biogenic flux in the western Arctic Ocean and illustrate the importance of shelf-break eddies to Biological Pumping from wide shelves to adjacent deep basins using a combination of year-long mooring observations and three-dimensional numerical modelling. The sinking flux trapped in the present study included considerable fresh organic material with soft tissues and was an order of magnitude larger than previous estimates. We predict that further reductions in sea ice will promote the entry of Pacific-origin Biological species into the Arctic basin and accelerate biogeochemical cycles connecting the Arctic and subarctic oceans.
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Biological Pump in Northwestern North Pacific
Journal of Oceanography, 2003Co-Authors: Makio C. HondaAbstract:The northwestern North Pacific is considered to be one of the most productive areas in the global ocean. Although the marginal zones along the Japanese and Kuril islands, Kamchatka Peninsula, and Aleutian Islands are certainly productive, recent studies do not always show high primary production values in the western subarctic gyre (WSG). In addition, a recent analysis of the Biological Pump in the WSG showed that, in contrast to what was previously reported, the vertical change of the particulate organic carbon flux with depth is large. Nevertheless, the Biological Pump in the northwestern North Pacific may function to draw down the partial pressure of CO2 in the surface water because the ratio of the organic carbon flux to inorganic carbon flux (Corg/Cinorg), the export flux, and the export ratio from the surface water are higher than those in other oceans. This article also introduces recent research on changes to the Biological Pump that might have been caused by global warming.
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the Biological Pump in the northwestern north pacific based on fluxes and major components of particulate matter obtained by sediment trap experiments 1997 2000
Deep-sea Research Part Ii-topical Studies in Oceanography, 2002Co-Authors: Makio C. Honda, Keiri Imai, Yukihiro Nojiri, Fumiko Hoshi, Toshikatsu Sugawara, Masashi KusakabeAbstract:Abstract To characterize the export flux of biogenic and lithogenic materials to the ocean interior and evaluate the ability of the Biological Pump to take up atmospheric CO2 in the northwestern North Pacific, sediment trap experiments were conducted at three stations (station KNOT: 44°N, 155°E; 50N: 50°N, 165°E; station 40N: 40°N, 165°E). The export fluxes showed seasonal variability with a high flux period in summer at station KNOT and in spring and autumn at stations 50N and 40N. The settling particles were mostly biogenic opal, comprising 50% of the total mass flux. The annual average export flux in 1998 was smaller than that in 1999 at the three stations, perhaps a result of the calm 1997/1998 winter associated with an El Nino event. Station KNOT had the largest total mass, organic carbon, and opal fluxes and the largest mole ratios of opal to carbonate (opal/CaCO3(mole)) and organic carbon to inorganic carbon (Co/Ci) compared with those at other two stations. These fluxes and ratios in the western, central and eastern parts of the northern North Pacific tended to decrease eastward. It is likely that the intensity of winter mixing or the supply of macro- and micronutrients influences the biogeochemistry of the northern North Pacific. Compared to the export flux of biogenic materials previously observed in the world ocean, the northwestern North Pacific, including the Bering Sea, has high opal/CaCO3(mole) and Co/Ci ratios. Moreover, at station KNOT, the ratio of the organic carbon flux in the deep sea to surface primary productivity (transfer efficiency: TE) was estimated to be approximately 5%, 3%, and 2% at 1000, 3000, and 5000 m, respectively. These values were significantly higher than TE values reported previously in the other oceanic regions. The high Co/Ci ratio and TE lead us to conclude that the Biological Pump in the northwestern North Pacific works more efficiently to decrease pCO2 in the surface seawater and, consequently, to enhance the uptake of atmospheric CO2 by the ocean.