The photo-physiological costs associated with acute sediment stress events in three near-shore turbid water corals

Many coral reef communities thriving in inshore coastal waters characterised by chronically high natural turbidity (>5 mg l-1) have adapted to low light (<200 µmol photons m-2 s-1) and high sedimentation rates (>10 mg cm-2 d-1). Yet, short (hours) acute sediment stress events driven by wind...

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Main Authors: Browne, Nicola, Precht, E., Last, K., Todd, P.
Format: Journal Article
Published: Inter-Research 2014
Subjects:
Online Access:http://hdl.handle.net/20.500.11937/11508
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author Browne, Nicola
Precht, E.
Last, K.
Todd, P.
author_facet Browne, Nicola
Precht, E.
Last, K.
Todd, P.
author_sort Browne, Nicola
building Curtin Institutional Repository
collection Online Access
description Many coral reef communities thriving in inshore coastal waters characterised by chronically high natural turbidity (>5 mg l-1) have adapted to low light (<200 µmol photons m-2 s-1) and high sedimentation rates (>10 mg cm-2 d-1). Yet, short (hours) acute sediment stress events driven by wind waves, dredging operations involving suction or screening, or shipping activities with vessel wake or propeller disturbance, can result in a rise in turbidity above the natural background level. Although these may not be lethal to corals given the time frame, there could be a considerable impact on photo-trophic energy production. A novel sediment delivery system was used to quantify the effects of 3 acute sediment resuspension stress events (turbidity = 100, 170, 240 mg l-1; sedimentation rates = 4, 9, 13 mg cm-2 h-1) on 3 inshore turbid water corals common in the Indo-Pacific (Merulina ampliata, Pachyseris speciosa and Platygyra sinensis). Coral photo-physiology response (respiration, net photosynthesis, and maximum quantum yield) was measured immediately after 2 h of exposure. The respiration rate increased (from 0.72-1.44 to 0.78-1.76 µmol O2 cm-2 h-1) as the severity of the acute sediment resuspension event increased, whereas the photosynthetic rate declined (from 0.25-0.41 to -0.19-0.25 µmol O2 cm-2 h-1). Merulina was the least tolerant to acute sediment resuspension, with a photosynthesis and respiration ratio (P/R ratio) of <1.0 when turbidity levels reached >170 mg l-1, while Platygyra was most tolerant (P/R > 1.0). Fluorescence yield data suggest that the rapid photo-acclimation ability of Platygyra enabled it to maintain a positive carbon budget during the experiments, illustrating species-specific responses to acute sediment stress events.
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spelling curtin-20.500.11937-115082017-09-13T14:55:43Z The photo-physiological costs associated with acute sediment stress events in three near-shore turbid water corals Browne, Nicola Precht, E. Last, K. Todd, P. Mesocosm experiments Singapore Coral photosynthesis Sedimentation Sediment resuspension Turbidity Many coral reef communities thriving in inshore coastal waters characterised by chronically high natural turbidity (>5 mg l-1) have adapted to low light (<200 µmol photons m-2 s-1) and high sedimentation rates (>10 mg cm-2 d-1). Yet, short (hours) acute sediment stress events driven by wind waves, dredging operations involving suction or screening, or shipping activities with vessel wake or propeller disturbance, can result in a rise in turbidity above the natural background level. Although these may not be lethal to corals given the time frame, there could be a considerable impact on photo-trophic energy production. A novel sediment delivery system was used to quantify the effects of 3 acute sediment resuspension stress events (turbidity = 100, 170, 240 mg l-1; sedimentation rates = 4, 9, 13 mg cm-2 h-1) on 3 inshore turbid water corals common in the Indo-Pacific (Merulina ampliata, Pachyseris speciosa and Platygyra sinensis). Coral photo-physiology response (respiration, net photosynthesis, and maximum quantum yield) was measured immediately after 2 h of exposure. The respiration rate increased (from 0.72-1.44 to 0.78-1.76 µmol O2 cm-2 h-1) as the severity of the acute sediment resuspension event increased, whereas the photosynthetic rate declined (from 0.25-0.41 to -0.19-0.25 µmol O2 cm-2 h-1). Merulina was the least tolerant to acute sediment resuspension, with a photosynthesis and respiration ratio (P/R ratio) of <1.0 when turbidity levels reached >170 mg l-1, while Platygyra was most tolerant (P/R > 1.0). Fluorescence yield data suggest that the rapid photo-acclimation ability of Platygyra enabled it to maintain a positive carbon budget during the experiments, illustrating species-specific responses to acute sediment stress events. 2014 Journal Article http://hdl.handle.net/20.500.11937/11508 10.3354/meps10714 Inter-Research fulltext
spellingShingle Mesocosm experiments
Singapore
Coral photosynthesis
Sedimentation
Sediment resuspension
Turbidity
Browne, Nicola
Precht, E.
Last, K.
Todd, P.
The photo-physiological costs associated with acute sediment stress events in three near-shore turbid water corals
title The photo-physiological costs associated with acute sediment stress events in three near-shore turbid water corals
title_full The photo-physiological costs associated with acute sediment stress events in three near-shore turbid water corals
title_fullStr The photo-physiological costs associated with acute sediment stress events in three near-shore turbid water corals
title_full_unstemmed The photo-physiological costs associated with acute sediment stress events in three near-shore turbid water corals
title_short The photo-physiological costs associated with acute sediment stress events in three near-shore turbid water corals
title_sort photo-physiological costs associated with acute sediment stress events in three near-shore turbid water corals
topic Mesocosm experiments
Singapore
Coral photosynthesis
Sedimentation
Sediment resuspension
Turbidity
url http://hdl.handle.net/20.500.11937/11508