Maerozooplankton of a deep sea hydrothermal vent: In situ rates of oxygen consumption1

Abstract

Oxygen consumption rates of mixed macrozooplankton from the vicinity of a deep sea hydrothermal vent system were measured with a three-chambered slurp-gun respirometer manipulated by the submersible Alvin at one vent station, clam acres (2,615-m depth), on the axis of the East Pacific Rise at 2 1"N. Diffuse warm-water effluents (125°C) along crevices between pillow lava formations were densely populated with epibenthic megafauna. In sharp contrast, the surrounding nonvent area had similar physical features but few visible fauna. Four plankton collections were made in the vent area and two in the nonvent area on two separate dives. Vent and nonvent plankton were dominated, numerically and gravimetrically, by a Calanoid copepod, Isaacsicalanus paucisetus. Abundance and biomass of the mixed plankton were highest over the vent area and decreased by as much as two orders of magnitude over the nonvent area. Although weight-specific oxygen consumption rates of plankton from the vent and nonvent areas, measured at the same ambient temperature (1.6"C) were of similar magnitude (1.68-4.26 ~1 O2 mg-l dry wt d-l), both were one to two orders of magnitude lower than published rates for surface-water mixed plankton. Oxygen consumption rates per cubic meter ranged from 564.5 ~1 0, m-3 d-l at one vent site to 4.3 over the nonvent area. Vent and nonvent rates of oxygen consumption per cubic meter fall within the range of values previously measured for mixed macrozooplankton from surface waters to bathypelagic depths.

Acoustic Doppler current profiler observations of a mid‐ocean ridge hydrothermal plume

“…In particular, we might expect zooplankton to sample the chemosynthetic bacteria production within the plume, thereby increasing the zooplankton abundance within or at the boundaries of the plume. This argument is supported by Smith [1985], who finds a hundredfold increase in zooplankton abundance above the vents. Plankton tows by J.…”

Mesozooplankton carbon requirement in the Tyrrhenian Sea: its vertical distribution, diel variability and relation to particle flux

“…The ETS method can therefore be useful for obtaining data on carbon requirements in bathypelagic environments below 1000 m water depth, an oceanic region very poorly investigated to date in this respect (Koppelmann & Weikert 1999, Koppelmann et al 2000. Table 5 lists some in situ (Smith 1982, 1985, Smith et al 1986) and ETS-estimated (Koppelmann et al 2000, Halsband-Lenk et al 2003) respiration measurements, for the Pacific Ocean and for the Levantine and Arabian Seas, respectively.…”

Assessing the apparent imbalance between geochemical and biochemical indicators of meso- and bathypelagic biological activity: What the @$♯! is wrong with present calculations of carbon budgets?

“…Many animals do not survive the sampling and decompression when caught at deep-water temperatures and transported through the warm epipelagic zone, especially in non-polar regions. Some direct respiration measurements, made with manned submersibles, exist from mesopelagic depths in the Atlantic Ocean (Bailey et al, 1994), from benthopelagic depths in the Pacific Ocean (Smith, 1982(Smith, , 1985Smith et al, 1986), and from the meso-and bathypelagic zones for certain taxa such as copepods (Thuesen et al, 1998;Ikeda et al, 2006) and medusae (Thuesen and Childress, 1994). Measured in situ weight-and carbon specific respiration rates for mesopelagic gelatinous animals were 2-5 times higher than shipboard measurements of the same species (Bailey et al, 1994).…”