Ecosystem metabolism of benthic and pelagic zones of a shallow productive estuary

Show full item record



Permalink

http://hdl.handle.net/10138/309516

Citation

Staehr , P A , Asmala , E , Carstensen , J , Krause-Jensen , D & Reader , H 2018 , ' Ecosystem metabolism of benthic and pelagic zones of a shallow productive estuary : spatio-temporal variability ' , Marine Ecology. Progress Series , vol. 601 , pp. 15-32 . https://doi.org/10.3354/meps12697

Title: Ecosystem metabolism of benthic and pelagic zones of a shallow productive estuary;
spatio-temporal variability
Author: Staehr, Peter A.; Asmala, Eero; Carstensen, Jacob; Krause-Jensen, Dorte; Reader, Heather
Contributor: University of Helsinki, Ecosystems and Environment Research Programme
Date: 2018-08-09
Number of pages: 18
Belongs to series: Marine Ecology. Progress Series
ISSN: 0171-8630
URI: http://hdl.handle.net/10138/309516
Abstract: Long-term deterioration of water quality is known to reduce the importance of benthic ecosystem metabolism in shallow coastal ecosystems, but drivers of spatial and short-term variability in ecosystem metabolism are poorly understood. We addressed this knowledge gap through detailed seasonal measurements of ecosystem metabolism across depth gradients from shallow (2 to 3 m) eelgrass-dominated to deeper (4 to 5 m) muddy regions of a shallow, productive estuary. Combined measurements of gross primary production (GPP), respiration (R) and, by difference, net ecosystem production (NEP) by the open-water diel oxygen technique and in situ chamber incubations showed high importance of shallow eelgrass habitats for metabolism at the system scale. Seasonal variations in GPP, R and NEP increased with light availability and temperature with highest NEP in all habitats during the warm and sunny mid-summer. The shallow eelgrass-dominated and neighboring habitats were seasonally net autotrophic (NEP = 0.54 and 0.31 mg O2 m-2 d-1, respectively), compared to net heterotrophy (NEP = -0.26 mg O2 m-2 d-1) at the deeper muddy site. Detailed studies along depth gradients further confirmed the role of eelgrass as a key driver of spatial differences in ecosystem metabolism across the estuary. Strong northerly winds (>8 m s-1) caused short-term (<24 h) periods of similar oxygen dynamics and similar apparent productivity in shallow and deeper waters, indicative of efficient lateral mixing, while calm periods (<4 m s-1) enabled formation of ‘pockets’, i.e. water masses with limited connectivity, which exacerbated the metabolic differences between shallow and deep sites.
Subject: 1172 Environmental sciences
Intra-estuarine heterogeneity
Benthic habitat
Pelagic habitat
Temporal variability
Eelgrass
EELGRASS ZOSTERA-MARINA
SEAGRASS ECOSYSTEMS
TEMPORAL DYNAMICS
PLANT-COMMUNITIES
LAKE METABOLISM
COASTAL WATERS
GAS-EXCHANGE
HUDSON RIVER
OXYGEN
SEA
Rights:


Files in this item

Total number of downloads: Loading...

Files Size Format View
Staehr_etal_201 ... RS_ACCEPTED_MANUSCRIPT.pdf 2.124Mb PDF View/Open

This item appears in the following Collection(s)

Show full item record