Small-scale spatial and temporal variability in coastal benthic O 2 dynamics: Effects of fauna activity

Frank Wenzhöfer*, Ronnie N. Glud

*Kontaktforfatter for dette arbejde

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

Resumé

In situ measurements in a shallow water sediment were performed using three different modules - a microprofiling unit, a transparent benthic chamber, and a planar optode periscope. The combined data set revealed an extremely patchy and variable benthic O2 distribution primarily due to temporal variations in fauna activity and photosynthesis. A distinct diel pattern in the fauna activity, dominated by Hediste diversicolor, resulted in strongly elevated O2 uptake rates of ∼5.3 mmol m-2 h-1 at the onset of darkness. The activity gradually diminished during the night, and the O2 uptake decreased to less than half the maximum rate just before sunrise. The volume of oxic sediment around burrow structures was influenced by changing environmental conditions (benthic photosynthesis and fauna activity) but grossly exceeded that below the primary sediment surface. The volume specific respiration rate around burrows was more than seven times higher than the equivalent value at the sediment surface. A budget of the O 2 consumption revealed that the O2 uptake through the burrow walls just after sunset accounted for the major part of the total O 2 uptake on a diel scale. The study demonstrates that light-driven variations in fauna activity can have great effects on the total benthic O 2 consumption rate with large implications for estimated benthic mineralization rates.

OriginalsprogEngelsk
TidsskriftLimnology and Oceanography
Vol/bind49
Udgave nummer5
Sider (fra-til)1471-1481
Antal sider11
ISSN0024-3590
DOI
StatusUdgivet - 1. sep. 2004
Udgivet eksterntJa

Fingeraftryk

burrows
fauna
uptake mechanisms
sediments
burrow
photosynthesis
sediment
oxic sediment
respiratory rate
temporal variation
mineralization
in situ measurement
respiration
shallow water
environmental factors
environmental conditions
effect
rate
water
consumption

Citer dette

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title = "Small-scale spatial and temporal variability in coastal benthic O 2 dynamics: Effects of fauna activity",
abstract = "In situ measurements in a shallow water sediment were performed using three different modules - a microprofiling unit, a transparent benthic chamber, and a planar optode periscope. The combined data set revealed an extremely patchy and variable benthic O2 distribution primarily due to temporal variations in fauna activity and photosynthesis. A distinct diel pattern in the fauna activity, dominated by Hediste diversicolor, resulted in strongly elevated O2 uptake rates of ∼5.3 mmol m-2 h-1 at the onset of darkness. The activity gradually diminished during the night, and the O2 uptake decreased to less than half the maximum rate just before sunrise. The volume of oxic sediment around burrow structures was influenced by changing environmental conditions (benthic photosynthesis and fauna activity) but grossly exceeded that below the primary sediment surface. The volume specific respiration rate around burrows was more than seven times higher than the equivalent value at the sediment surface. A budget of the O 2 consumption revealed that the O2 uptake through the burrow walls just after sunset accounted for the major part of the total O 2 uptake on a diel scale. The study demonstrates that light-driven variations in fauna activity can have great effects on the total benthic O 2 consumption rate with large implications for estimated benthic mineralization rates.",
author = "Frank Wenzh{\"o}fer and Glud, {Ronnie N.}",
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Small-scale spatial and temporal variability in coastal benthic O 2 dynamics : Effects of fauna activity. / Wenzhöfer, Frank; Glud, Ronnie N.

I: Limnology and Oceanography, Bind 49, Nr. 5, 01.09.2004, s. 1471-1481.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Small-scale spatial and temporal variability in coastal benthic O 2 dynamics

T2 - Effects of fauna activity

AU - Wenzhöfer, Frank

AU - Glud, Ronnie N.

PY - 2004/9/1

Y1 - 2004/9/1

N2 - In situ measurements in a shallow water sediment were performed using three different modules - a microprofiling unit, a transparent benthic chamber, and a planar optode periscope. The combined data set revealed an extremely patchy and variable benthic O2 distribution primarily due to temporal variations in fauna activity and photosynthesis. A distinct diel pattern in the fauna activity, dominated by Hediste diversicolor, resulted in strongly elevated O2 uptake rates of ∼5.3 mmol m-2 h-1 at the onset of darkness. The activity gradually diminished during the night, and the O2 uptake decreased to less than half the maximum rate just before sunrise. The volume of oxic sediment around burrow structures was influenced by changing environmental conditions (benthic photosynthesis and fauna activity) but grossly exceeded that below the primary sediment surface. The volume specific respiration rate around burrows was more than seven times higher than the equivalent value at the sediment surface. A budget of the O 2 consumption revealed that the O2 uptake through the burrow walls just after sunset accounted for the major part of the total O 2 uptake on a diel scale. The study demonstrates that light-driven variations in fauna activity can have great effects on the total benthic O 2 consumption rate with large implications for estimated benthic mineralization rates.

AB - In situ measurements in a shallow water sediment were performed using three different modules - a microprofiling unit, a transparent benthic chamber, and a planar optode periscope. The combined data set revealed an extremely patchy and variable benthic O2 distribution primarily due to temporal variations in fauna activity and photosynthesis. A distinct diel pattern in the fauna activity, dominated by Hediste diversicolor, resulted in strongly elevated O2 uptake rates of ∼5.3 mmol m-2 h-1 at the onset of darkness. The activity gradually diminished during the night, and the O2 uptake decreased to less than half the maximum rate just before sunrise. The volume of oxic sediment around burrow structures was influenced by changing environmental conditions (benthic photosynthesis and fauna activity) but grossly exceeded that below the primary sediment surface. The volume specific respiration rate around burrows was more than seven times higher than the equivalent value at the sediment surface. A budget of the O 2 consumption revealed that the O2 uptake through the burrow walls just after sunset accounted for the major part of the total O 2 uptake on a diel scale. The study demonstrates that light-driven variations in fauna activity can have great effects on the total benthic O 2 consumption rate with large implications for estimated benthic mineralization rates.

U2 - 10.4319/lo.2004.49.5.1471

DO - 10.4319/lo.2004.49.5.1471

M3 - Journal article

AN - SCOPUS:4944258488

VL - 49

SP - 1471

EP - 1481

JO - Limnology and Oceanography

JF - Limnology and Oceanography

SN - 0024-3590

IS - 5

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