Coastal hypoxia and anoxia: a multi-tiered, holistic approach
Coastal hypoxia and anoxia: a multi-tiered, holistic approach
Editor(s): J. Bernhard, H. Rumohr, C. Heip, and J. Middelburg
The worldwide increase in coastal hypoxia and anoxia over the past decades is an alarming signal that underlines profound changes in and collapses of (“dead zone”) ecosystem processes in shallow shelf seas. This special issue is largely based on experimentally induced small-scale anoxia in a benthic soft-bottom community at 24m depth (northern Adriatic, Mediterranean). The approach combines Plexiglas chambers with time-lapse photography, microsensors, core sampling and the DET technique (diffusive equilibrium in thin films). This yielded detailed data on
  • macrofauna behavioral responses and tolerances,
  • meiofauna (harpacticoid copepods and foraminiferans) responses,
  • sediment geochemistry processes, and
  • post-anoxia scavenging and recovery.
  • Macrofauna behaviour links physiological functions and ecological processes and therefore depicts multi-level effects of oxygen deficiency. A detailed series of behavioral responses reveals more tolerant and more sensitive species and emphasizes the broad range of possible responses in a community setting. Among the meiofauna, the focus is on harpacticoid copepod and foraminiferan abundance and diversity. A fluorescent staining technique (cell tracker green: CTG) is applied for the first time to copepods, improving the distinction between living and dead components. An accompanying pulse-chase lab experiment with pre-labeled diatoms reveals functional responses of primary consumers (copepods) to anoxia. The in situ sediment geochemistry processes (key pore water and solid phase parameters in response to migration of redox layers, mobility of trace elements) are documented (millimeter-scale resolution). Finally, post-anoxia time-lapse films examine the sequence of scavenger/predator arrivals and (the lack of) macroepifauna recolonization even after 2 years.

    Combined, these perspectives yield a more comprehensive picture of events during and after anoxia, improving on the information available from laboratory experiments and fragmentary in situ documentations. This is a step forward in interpreting post-hypoxia/anoxia community composition and recovery potential in the past and present.

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22 Apr 2014
Artificially induced migration of redox layers in a coastal sediment from the Northern Adriatic
E. Metzger, D. Langlet, E. Viollier, N. Koron, B. Riedel, M. Stachowitsch, J. Faganeli, M. Tharaud, E. Geslin, and F. Jorissen
Biogeosciences, 11, 2211–2224,,, 2014
04 Apr 2014
Foraminiferal species responses to in situ, experimentally induced anoxia in the Adriatic Sea
D. Langlet, C. Baal, E. Geslin, E. Metzger, M. Zuschin, B. Riedel, N. Risgaard-Petersen, M. Stachowitsch, and F. J. Jorissen
Biogeosciences, 11, 1775–1797,,, 2014
21 Mar 2014
Effect of hypoxia and anoxia on invertebrate behaviour: ecological perspectives from species to community level
B. Riedel, T. Pados, K. Pretterebner, L. Schiemer, A. Steckbauer, A. Haselmair, M. Zuschin, and M. Stachowitsch
Biogeosciences, 11, 1491–1518,,, 2014
22 Jan 2014
Meiofauna winners and losers of coastal hypoxia: case study harpacticoid copepods
M. Grego, B. Riedel, M. Stachowitsch, and M. De Troch
Biogeosciences, 11, 281–292,,, 2014
26 Nov 2013
Short-term post-mortality scavenging and longer term recovery after anoxia in the northern Adriatic Sea
M. Blasnig, B. Riedel, L. Schiemer, M. Zuschin, and M. Stachowitsch
Biogeosciences, 10, 7647–7659,,, 2013
21 Nov 2013
Foraminiferal survival after long-term in situ experimentally induced anoxia
D. Langlet, E. Geslin, C. Baal, E. Metzger, F. Lejzerowicz, B. Riedel, M. Zuschin, J. Pawlowski, M. Stachowitsch, and F. J. Jorissen
Biogeosciences, 10, 7463–7480,,, 2013
09 Jul 2013
CellTracker Green labelling vs. rose bengal staining: CTG wins by points in distinguishing living from dead anoxia-impacted copepods and nematodes
M. Grego, M. Stachowitsch, M. De Troch, and B. Riedel
Biogeosciences, 10, 4565–4575,,, 2013
26 Jun 2013
Structural and functional responses of harpacticoid copepods to anoxia in the Northern Adriatic: an experimental approach
M. De Troch, M. Roelofs, B. Riedel, and M. Grego
Biogeosciences, 10, 4259–4272,,, 2013
08 Nov 2012
Variation in stable carbon and oxygen isotopes of individual benthic foraminifera: tracers for quantifying the magnitude of isotopic disequilibrium
T. Ishimura, U. Tsunogai, S. Hasegawa, F. Nakagawa, T. Oi, H. Kitazato, H. Suga, and T. Toyofuku
Biogeosciences, 9, 4353–4367,,, 2012
23 Apr 2014
Preface "Coastal hypoxia and anoxia: a multi-tiered holistic approach"
M. Stachowitsch
Biogeosciences, 11, 2281–2285,,, 2014
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