Epi-benthic megafaunal zonation across an oxygen minimum zone at the Indian continental margin

William R. Hunter, Kazumasa Oguri, Hiroshi Kitazato, Zakir A. Ansari, Ursula Witte

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

The Arabian Sea oxygen minimum zone (OMZ) impinges upon the Indian continental margin at bathyal depths (150-1500m) producing changes in ambient oxygen availability and sediment geochemistry across the seafloor. The influence of these environmental changes upon the epi-benthic megafaunal assemblage was investigated by video survey at six stations spanning the OMZ core (540m), lower boundary (800-1100m) and below the OMZ (2000m), between September and November 2008. Structural changes in the megafaunal assemblage were observed across the six stations, through changes in both megafaunal abundance and lebensspuren (biogenic traces). Most megafauna were absent in the OMZ core (540m), where the assemblage was characterised by low densities of fishes (0.02-0.03m -2). In the lower OMZ boundary, megafaunal abundance peaked at 800m, where higher densities of ophiuroids (0.20-0.44m -2) and decapods (0.11-0.15m -2) were present. Total abundance declined with depth between 800 and 2000m, as the number of taxa increased. Changes in the megafaunal assemblage were predicted by changes in abundance of seven taxonomic groups, correlated to both oxygen availability and sediment organic matter quality. Lebensspuren densities were highest in the OMZ boundary (800-1100m) but traces of large infauna (e.g., echiurans and enteropneusts) were only observed between 1100 and 2000m station, where the influence of the OMZ was reduced. Thus, changes in the megafaunal assemblage across the Indian margin OMZ reflect the responses of specific taxa to food availability and oxygen limitation.
LanguageUndefined
Pages699-710
Number of pages12
JournalDeep-Sea Research Part I: Oceanographic Research Papers
Volume58
Issue number6
Early online date22 Apr 2011
DOIs
Publication statusPublished - 1 Jun 2011

Keywords

  • Arabian sea, Lebensspuren, Megafauna, Oxygen minimum zone, Video survey

Cite this

Hunter, William R. ; Oguri, Kazumasa ; Kitazato, Hiroshi ; Ansari, Zakir A. ; Witte, Ursula. / Epi-benthic megafaunal zonation across an oxygen minimum zone at the Indian continental margin. In: Deep-Sea Research Part I: Oceanographic Research Papers. 2011 ; Vol. 58, No. 6. pp. 699-710.
@article{1d44fd28ccfb4a00add50d4368f92dc4,
title = "Epi-benthic megafaunal zonation across an oxygen minimum zone at the Indian continental margin",
abstract = "The Arabian Sea oxygen minimum zone (OMZ) impinges upon the Indian continental margin at bathyal depths (150-1500m) producing changes in ambient oxygen availability and sediment geochemistry across the seafloor. The influence of these environmental changes upon the epi-benthic megafaunal assemblage was investigated by video survey at six stations spanning the OMZ core (540m), lower boundary (800-1100m) and below the OMZ (2000m), between September and November 2008. Structural changes in the megafaunal assemblage were observed across the six stations, through changes in both megafaunal abundance and lebensspuren (biogenic traces). Most megafauna were absent in the OMZ core (540m), where the assemblage was characterised by low densities of fishes (0.02-0.03m -2). In the lower OMZ boundary, megafaunal abundance peaked at 800m, where higher densities of ophiuroids (0.20-0.44m -2) and decapods (0.11-0.15m -2) were present. Total abundance declined with depth between 800 and 2000m, as the number of taxa increased. Changes in the megafaunal assemblage were predicted by changes in abundance of seven taxonomic groups, correlated to both oxygen availability and sediment organic matter quality. Lebensspuren densities were highest in the OMZ boundary (800-1100m) but traces of large infauna (e.g., echiurans and enteropneusts) were only observed between 1100 and 2000m station, where the influence of the OMZ was reduced. Thus, changes in the megafaunal assemblage across the Indian margin OMZ reflect the responses of specific taxa to food availability and oxygen limitation.",
keywords = "Arabian sea, Lebensspuren, Megafauna, Oxygen minimum zone, Video survey",
author = "Hunter, {William R.} and Kazumasa Oguri and Hiroshi Kitazato and Ansari, {Zakir A.} and Ursula Witte",
year = "2011",
month = "6",
day = "1",
doi = "10.1016/j.dsr.2011.04.004",
language = "Undefined",
volume = "58",
pages = "699--710",
journal = "Deep-Sea Research Part I: Oceanographic Research Papers",
issn = "0967-0637",
publisher = "Elsevier",
number = "6",

}

Epi-benthic megafaunal zonation across an oxygen minimum zone at the Indian continental margin. / Hunter, William R.; Oguri, Kazumasa; Kitazato, Hiroshi; Ansari, Zakir A.; Witte, Ursula.

In: Deep-Sea Research Part I: Oceanographic Research Papers, Vol. 58, No. 6, 01.06.2011, p. 699-710.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Epi-benthic megafaunal zonation across an oxygen minimum zone at the Indian continental margin

AU - Hunter, William R.

AU - Oguri, Kazumasa

AU - Kitazato, Hiroshi

AU - Ansari, Zakir A.

AU - Witte, Ursula

PY - 2011/6/1

Y1 - 2011/6/1

N2 - The Arabian Sea oxygen minimum zone (OMZ) impinges upon the Indian continental margin at bathyal depths (150-1500m) producing changes in ambient oxygen availability and sediment geochemistry across the seafloor. The influence of these environmental changes upon the epi-benthic megafaunal assemblage was investigated by video survey at six stations spanning the OMZ core (540m), lower boundary (800-1100m) and below the OMZ (2000m), between September and November 2008. Structural changes in the megafaunal assemblage were observed across the six stations, through changes in both megafaunal abundance and lebensspuren (biogenic traces). Most megafauna were absent in the OMZ core (540m), where the assemblage was characterised by low densities of fishes (0.02-0.03m -2). In the lower OMZ boundary, megafaunal abundance peaked at 800m, where higher densities of ophiuroids (0.20-0.44m -2) and decapods (0.11-0.15m -2) were present. Total abundance declined with depth between 800 and 2000m, as the number of taxa increased. Changes in the megafaunal assemblage were predicted by changes in abundance of seven taxonomic groups, correlated to both oxygen availability and sediment organic matter quality. Lebensspuren densities were highest in the OMZ boundary (800-1100m) but traces of large infauna (e.g., echiurans and enteropneusts) were only observed between 1100 and 2000m station, where the influence of the OMZ was reduced. Thus, changes in the megafaunal assemblage across the Indian margin OMZ reflect the responses of specific taxa to food availability and oxygen limitation.

AB - The Arabian Sea oxygen minimum zone (OMZ) impinges upon the Indian continental margin at bathyal depths (150-1500m) producing changes in ambient oxygen availability and sediment geochemistry across the seafloor. The influence of these environmental changes upon the epi-benthic megafaunal assemblage was investigated by video survey at six stations spanning the OMZ core (540m), lower boundary (800-1100m) and below the OMZ (2000m), between September and November 2008. Structural changes in the megafaunal assemblage were observed across the six stations, through changes in both megafaunal abundance and lebensspuren (biogenic traces). Most megafauna were absent in the OMZ core (540m), where the assemblage was characterised by low densities of fishes (0.02-0.03m -2). In the lower OMZ boundary, megafaunal abundance peaked at 800m, where higher densities of ophiuroids (0.20-0.44m -2) and decapods (0.11-0.15m -2) were present. Total abundance declined with depth between 800 and 2000m, as the number of taxa increased. Changes in the megafaunal assemblage were predicted by changes in abundance of seven taxonomic groups, correlated to both oxygen availability and sediment organic matter quality. Lebensspuren densities were highest in the OMZ boundary (800-1100m) but traces of large infauna (e.g., echiurans and enteropneusts) were only observed between 1100 and 2000m station, where the influence of the OMZ was reduced. Thus, changes in the megafaunal assemblage across the Indian margin OMZ reflect the responses of specific taxa to food availability and oxygen limitation.

KW - Arabian sea, Lebensspuren, Megafauna, Oxygen minimum zone, Video survey

U2 - 10.1016/j.dsr.2011.04.004

DO - 10.1016/j.dsr.2011.04.004

M3 - Article

VL - 58

SP - 699

EP - 710

JO - Deep-Sea Research Part I: Oceanographic Research Papers

T2 - Deep-Sea Research Part I: Oceanographic Research Papers

JF - Deep-Sea Research Part I: Oceanographic Research Papers

SN - 0967-0637

IS - 6

ER -