An analysis of sinking rates of natural copepod and euphausiid fecal pellets1

Komar, Paul D.; Morse, A. P.; Small, Lawrence F.; Fowler, Scott W.

doi:10.4319/lo.1981.26.1.0172

Cited by 185 publications

(93 citation statements)

References 12 publications

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“…8, the May elutriator results fell between the MarchMay and May-June SV-IRS results. Comparison with other sinking rate calculations-We know of no other settling rate measurements of the sort we describe here, but estimates have been made from observations in the laboratory of phytoplankton and fecal pellet settling, in the field by SCUBA or submersible observation (Komar et al 1981;Shanks and Trent 1980;Asper 1987;Alldredge and Gotschalk 1989;Pilskaln et al 1998), and using marker events in trap fluxes measured at different depths (Honjo and Manganini 1993;Honjo et al 1999;Berelson 2002). Most of these measurements or estimates suggest that particles settle at rates of 70 to 330 m d -1 in the upper 500 m. There is some evidence that particle sinking velocities vary with depth (Honjo and Manganini 1993;Honjo et al 1999), and a recent analysis by Berelson (2002) synthesizing US JGOFS equatorial Pacific and Arabian Sea particle trap data further suggests higher settling rates in deeper (>1000 m) waters.…”

Section: Assessment and Discussionmentioning

confidence: 99%

Novel techniques for collection of sinking particles in the ocean and determining their settling rates

Peterson

Wakeham

Lee

et al. 2005

Limnology & Ocean Methods

120

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Sinking particulate organic matter (POM) is the major vehicle for exporting carbon from the sea surface to the ocean interior. Collection of sinking material in a manner that enables identification of the underlying mechanistic controls on settling and decomposition is fundamental for quantifying the vertical flux and changing composition of particles. Observations made during the Joint Global Ocean Flux Study (JGOFS) indicate that 50% to 80% of the vertical flux of carbon occurs due to gravitational sinking (e.g., Gardner 2000; Baliño et al. 2001;Fasham et al. 2001). During its transit toward the sea floor, most (usually >90%) particulate organic carbon (POC) is returned to inorganic form and redistributed in the water column. This redistribution determines the depth profile of dissolved CO 2 , including its concentration in the surface mixed layer, and hence the rate at which the ocean can absorb CO 2 from the atmosphere and sequester it in the deep ocean. A quantitative and mechanistic understanding of water column POC remineralization is critical to predicting the response of the global carbon cycle to environmental change.Sediment traps are widely used to quantify vertical fluxes of material and to collect sinking POM for chemical analyses. They have provided proof of spatial, episodic, seasonal and interannual fluxes of POM through the water column, have linked variability in surface water processes to fluxes in the interior of the ocean and to the sea floor, and have shown the intense remineralization and alteration that affects POM in the water column (see papers in Ittekkot et al. 1996; JGOFS Deep-Sea Research volumes, see http://usjgofs.whoi.edu/ publications/deepsearesearch.html). Trap designs have been highly variable, ranging from small cylinders (e.g., Vertex MultiPits, Knauer et al. 1979) to large cones (Parflux traps, Honjo and Doherty 1988); both free-drifting/surface-tethered and bottom-moored traps have been used.Considerable effort has focused on quantifying the material collected in traps. Questions about trap accuracy are related to trap geometry, hydrodynamic biases, trapping efficiencies and flux calibration, use of poisons/preservatives, and zooplankton "swimmers." Accuracy of traps is especially questionable in surface waters and regimens where current-driven shear is high or where swimmers are abundant (e.g., Lee et al. 1988;Ittekkot et al. 1996;Gardner 2000 AbstractThree new approaches for collecting and processing sinking particles for biogeochemical studies are presented. They include (1) a modification of our existing indented rotating sphere carousel (IRSC) sediment trap design from its conventional time-series function to one that collects particles based on discrete particle settling-velocity ranges; (2) development of a large, free-floating NetTrap based on the design of a closing plankton net capable of collecting large amounts (~1 g) of very fresh sinking particulate material in short time periods (24-36 h) to facilitate microbial decomposition experiments; and (3) an elut...

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Section: Assessment and Discussionmentioning

confidence: 99%

Novel techniques for collection of sinking particles in the ocean and determining their settling rates

Peterson

Wakeham

Lee

et al. 2005

Limnology & Ocean Methods

120

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“…The sinking rates of these different particles can range over several orders of magnitude. For whole phytoplankton, Smayda (1970) has shown that growing cells sink more slowly than senescent cells and that cells with diameters from 1 to 1000 pm respectively sink from 0.01 to 100 m d-l. Representative fecal pellets from copepods and euphausiids sink at sizedependent rates from 10 to 1000 m d-' (Komar et al 1981). These various sinking rates interact with vertical water motion (Titman & Kilham 1976) to determine the residence time of detrital biogenlc silica in the euphotic zone.…”

Section: Latitude Latitudementioning

confidence: 99%

Nitrate and silicic acid in the world ocean: patterns and processes

Kamykowski¹,

Zentara²

1985

Mar. Ecol. Prog. Ser.

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Two world ocean data sets, GEOSECS and NODC, were analyzed for patterns in the nitrate versus silicic acid regression relation. Significant regional nitrate or silicic acid excesses (i.e. amount of one of these plant nutrients remaining in the water after the other is no longer measurable) tend to occur in some areas of upwelling, shallow sills, deep convection or high rainfall/river outflow. The Southern Ocean is unique in the intensity and complexity of projected (regression intercepts on the nitrate [y] or silicic acid [X] axis) excesses. These global nutrient depletion patterns pertain to regional comparisons of phytoplankton succession and thus to the overall character of plankton community structure. Intercept patterns in different areas are affected by the processes that determine absolute nutrient concentrations at the beginning, and their relative decline during, the growth season. The region south of the southern Polar Front is unlque because winter nutrient concentrations are unusually high around Antarctica due to water mass characteristics and because nutrients generally remain unusually abundant over the growth season partly in response to the cycle of incident solar radiation. The patterns in the regression intercepts in this region largely result from variations in the regression slopes which respond to different weightings of the chemical and biological pathways that determine nitrate and silicic acid concentrations in the upper water column. The nitrate and silicic acid profiles in the Southern Ocean contain information on the temporal average of primary production and of nitrogen recycling up to the tlme of sample collection within the growth season. The interpretation of this information depends on the detail to which the processes that determine the water column concentrations of nitrate and silicic acid are known.

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“…A solid matter density of s ϭ 1.23 g cm Ϫ3 represents the wet density of euphausiid fecal pellets (Komar et al 1981), and s ϭ 2.5 g cm Ϫ3 is equal to the density of quartz. When the density of solid particles enclosed in an aggregate is high, the volume ratio ␣/␤ must be larger for aggregates to be neutrally buoyant.…”

Section: Model-based Evaluation Of the Effect Of Tep On The Vertical mentioning

confidence: 99%

Ascending marine particles: Significance of transparent exopolymer particles (TEP) in the upper ocean

Azetsu-Scott¹,

Passow²

2004

Limnology & Oceanography

223

146

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The high abundance of transparent exopolymer particles (TEP) in marine and freshwater greatly affects particle dynamics. TEP act as glue for colliding particles and form the matrix in aggregates, thereby altering aggregation dynamics. We studied the sinking behavior of freshly produced, particle-free TEP and of aggregates composed of TEP and latex spheres in a laboratory using water collected from Santa Barbara Channel, California. Particle-free TEP ascend and accumulate in the surface layer of a settling column at an average velocity of 1.6 ϫ 10 Ϫ4 cm s Ϫ1 . The estimated density of TEP ranges from 0.70 to 0.84 g cm Ϫ3 . TEP also transported latex spheres of 45.6 and 1.82 m in diameter and a density of 1.05 g cm Ϫ3 to the surface layer. We describe a simple model illustrating the role of TEP for the vertical transport of solid particles. The densities and relative proportions of TEP, solid particles, and interstitial water within an aggregate determine its sinking or ascending velocity. High ratios of TEP to solid particles retard the sinking of aggregates, prolonging their residence time in the surface ocean. Our results demonstrate that TEP can provide a vehicle for the upward flux of biological and chemical components in the marine environment, including bacteria, phytoplankton, carbon, and reactive trace elements.

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An analysis of sinking rates of natural copepod and euphausiid fecal pellets1

Cited by 185 publications

References 12 publications

Novel techniques for collection of sinking particles in the ocean and determining their settling rates

Novel techniques for collection of sinking particles in the ocean and determining their settling rates

Nitrate and silicic acid in the world ocean: patterns and processes

Ascending marine particles: Significance of transparent exopolymer particles (TEP) in the upper ocean

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