• Baker, E. T., H. B. Milburn, and D. A. Tennant, 1988: Field assessment of sediment trap efficiency under varying flow conditions. J. Mar. Res.,46, 573–592.

    • Crossref
    • Export Citation
  • Buesseler, K. O., 1991: Do upper ocean sediment traps provide an accurate record of particle flux? Nature,353, 420–423.

    • Crossref
    • Export Citation
  • ——, A. F. Michaels, D. A. Siegel, and A. H. Knap, 1994: A three-dimensional time-dependent approach to calibrating sediment trap fluxes. Global Biogeochem. Cycles,8, 179–193.

  • ——, D. A. Siegel, A. F. Michaels, J. R. Valdes, and J. F. Price, 1999:A comparison of quantity and composition of material caught in a neutrally buoyant sediment trap versus a surface-tethered trap. Deep-Sea Res., in press.

  • Butman, C. A., 1986: Sediment trap biases in turbulent flows: Results from a laboratory flume study. J. Mar. Res.,44, 645–693.

    • Crossref
    • Export Citation
  • ——, W. D. Grant, and K. D. Stolzenbach, 1986: Predictions of sediment trap biases in turbulent flows: A theoretical analysis based on observations in the literature. Results from a laboratory flume study. J. Mar. Res.,44, 601–644.

    • Crossref
    • Export Citation
  • Carlson, C. A., H. W. Ducklow, and A. F. Michaels, 1994: Annual flux of dissolved inorganic carbon from the euphotic zone in the northwestern Sargasso Sea. Nature,371, 405–408.

    • Crossref
    • Export Citation
  • Coale, K. H., 1990: Labyrinth of doom: A device to minimize the“swimmer” component on sediment trap collections. Limnol. Oceanogr.,35, 1376–1380.

    • Crossref
    • Export Citation
  • Davis, R. E., D. C. Webb, L. A. Regier, and J. Dufour, 1992: The Autonomous Lagrangian Circulation Explorer (ALACE). J. Atmos. Oceanic Technol.,9, 264–285.

    • Crossref
    • Export Citation
  • Deuser, W. G., 1986: Seasonal and interannual variations in deep-water particle fluxes in the Sargasso Sea. Deep-Sea Res.,33, 225–247.

    • Crossref
    • Export Citation
  • ——, and E. H. Ross, 1980: Seasonal changes in the flux of organic carbon to the deep Sargasso Sea. Nature,283, 364–365.

    • Crossref
    • Export Citation
  • Diercks, A., and V. Asper, 1994: Neutrally buoyant sediment traps: The first designs. Eos, Trans. Amer. Geophys. Union,75, 22.

  • Duda, T. F., and D. C. Webb, 1997: The drifting, rotating deep ocean shearmeter. Oceans ’97 MTS/IEEE Proc., Washington, DC, MTS, 796–801.

  • ——, C. S. Cox, and T. K. Deaton, 1988: The Cartesian diver: A self-profiling Lagrangian velocity recorder. J. Atmos. Oceanic Technol.,5, 16–33.

    • Crossref
    • Export Citation
  • Gardner, W. D., 1985: The effect of tilt on sediment trap efficiency. Deep-Sea Res.,32, 349–361.

    • Crossref
    • Export Citation
  • ——, 1999: Sediment trap technology and sampling in surface waters. First Int. JGOFS Symp., Villefrance sur Mer, France. [Available online at http://www-ocean.tamu.edu/JGOFS/contents.html.].

  • ——, and Y. Zhang, 1997: The effect of brine on the collection efficiency of cylindrical sediment traps. J. Mar. Res.,55, 1029–1048.

    • Crossref
    • Export Citation
  • ——, P. E. Biscaye, and M. J. Richardson, 1997: A sediment trap experiment in the Vema Channel to evaluate the effect of horizontal particle fluxes on measured vertical fluxes. J. Mar. Res.,55, 995–1028.

    • Crossref
    • Export Citation
  • Gust, G., R. H. Byrne, R. E. Bernstein, P. R. Petzer, and W. Bowles, 1992: Particle fluxes and moving fluids: Experience of synchronous trap collections in the Sargasso Sea. Deep-Sea Res.,39, 1071–1083.

    • Crossref
    • Export Citation
  • ——, A. F. Michaels, R. Johnson, W. G. Deuser, and W. Bowles, 1994: Mooring line motions and sediment trap hydrodynamics:In situ intercomparison of three common deployment designs. Deep-Sea Res.,41, 831–857.

    • Crossref
    • Export Citation
  • Honjo, S., J. Dymond, R. Collier, and S. J. Manganini, 1995: Export production of particles to the equatorial Pacific Ocean during the 1992 EqPac experiment. Deep-Sea Res.,42, 841–870.

    • Crossref
    • Export Citation
  • Karl, D. M., and G. A. Knauer, 1989: Swimmers: A recapitulation of the problem and a potential solution. Oceanography,2, 32–35.

    • Crossref
    • Export Citation
  • Knauer, G. A., J. H. Martin, and K. W. Bruland, 1979: Fluxes of particulate carbon, nitrogen, and phosphorus in the upper water column of the northeast Pacific. Deep-Sea Res.,26A, 97–108.

    • Crossref
    • Export Citation
  • Lee, C., S. G. Wakeham, and J. I. Hedges, 1988: The measurement of oceanic particle flux—Are “swimmers” a problem? Oceanography,1, 34–36.

    • Crossref
    • Export Citation
  • Michaels, A. F., M. W. Silver, M. M. Gowing, and G. A. Knauer, 1990: Cryptic zooplankton “swimmers” in upper ocean sediment traps. Deep-Sea Res.,37, 1285–1296.

    • Crossref
    • Export Citation
  • ——, N. R. Bates, K. O. Buesseler, C. A. Carlson, and A. H. Knap, 1994: Carbon-cycle imbalances in the Sargasso Sea. Nature,372, 537–540.

    • Crossref
    • Export Citation
  • Murray, J. W., R. Le Borgne, and Y. Dandonneau, 1997: JGOFS studies in the equatorial Pacific. Deep-Sea Res.,44, 1759–1764.

    • Crossref
    • Export Citation
  • Quay, P., 1997: Was a carbon balance measured in the equatorial Pacific during JGOFS? Deep-Sea Res.,44, 1765–1781.

    • Crossref
    • Export Citation
  • Rodier, M., and R. Le Borgne, 1997: Export flux of particles at the equator in the western and central Pacific ocean. Deep-Sea Res.,44, 2085–2113.

    • Crossref
    • Export Citation
  • Rossby, T., J. Fontaine, and E. C. Carter Jr., 1994: The f/h float—Measuring stretching vorticity directly. Deep-Sea Res.,41, 975–992.

    • Crossref
    • Export Citation
  • Simonetti, P., 1998: Low-cost endurance ocean profiler. Sea Technol.,39, 17–21.

  • U.S. GOFS, 1989: Sediment trap technology and sampling. GOFS Planning Rep. 10, 14 pp. [Available from U.S. GOFS Planning Office, Woods Hole, MA 02543.].

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A Neutrally Buoyant, Upper Ocean Sediment Trap

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  • 1 Physical Oceanography Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts
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Abstract

The authors have designed and deployed a neutrally buoyant sediment trap (NBST) intended for use in the upper ocean. The aim was to minimize hydrodynamic flow interference by making a sediment trap that drifted freely with the ambient current. The principal design problem was to make the NBST descend to and stay near a prescribed depth. For a variety of reasons, the most success has been with NBSTs that were autoballasted by means of a microprocessor-controlled volume changer. Autoballasting NBSTs has demonstrated an ability to hold a prescribed depth to within 10 m.

There have been two successful, concurrent deployments of NBSTs and conventional surface-tethered sediment traps (STSTs) at the Bermuda Atlantic Times Series site. During both periods the observed flow past the STSTs was low, about 0.05 m s−1, so that hydrodynamic effects on the STSTs would have been minimized. Comparisons of the trap results (described in a companion paper by Buesseler et al.) indicate that the total mass of collected material was generally similar in the two traps. Other variables, including the composition of the material and the fraction contributed by swimmers, were markedly different (swimmers are small animals that enter a trap intact and presumably alive). These are intriguing results but could not be conclusive since there is no absolute standard for such measurements. Future field work that includes comprehensive geochemical sampling will be required to learn which sediment trapping method yields the more useful observations.

Corresponding author address: Dr. James F. Price, Woods Hole Oceanographic Institution, Physical Oceanography Dept., Clark 209A, MS #29, Woods Hole, MA 02543.

Email: jprice@whoi.edu

Abstract

The authors have designed and deployed a neutrally buoyant sediment trap (NBST) intended for use in the upper ocean. The aim was to minimize hydrodynamic flow interference by making a sediment trap that drifted freely with the ambient current. The principal design problem was to make the NBST descend to and stay near a prescribed depth. For a variety of reasons, the most success has been with NBSTs that were autoballasted by means of a microprocessor-controlled volume changer. Autoballasting NBSTs has demonstrated an ability to hold a prescribed depth to within 10 m.

There have been two successful, concurrent deployments of NBSTs and conventional surface-tethered sediment traps (STSTs) at the Bermuda Atlantic Times Series site. During both periods the observed flow past the STSTs was low, about 0.05 m s−1, so that hydrodynamic effects on the STSTs would have been minimized. Comparisons of the trap results (described in a companion paper by Buesseler et al.) indicate that the total mass of collected material was generally similar in the two traps. Other variables, including the composition of the material and the fraction contributed by swimmers, were markedly different (swimmers are small animals that enter a trap intact and presumably alive). These are intriguing results but could not be conclusive since there is no absolute standard for such measurements. Future field work that includes comprehensive geochemical sampling will be required to learn which sediment trapping method yields the more useful observations.

Corresponding author address: Dr. James F. Price, Woods Hole Oceanographic Institution, Physical Oceanography Dept., Clark 209A, MS #29, Woods Hole, MA 02543.

Email: jprice@whoi.edu

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