Organic carbon decomposition, primary and bacterial productivity, and sulphate reduction, in tropical seagrass beds of the Gulf of Carpentaria, Australia
Year: 1991
Type: article
Abstract: The oxidation of organic carbon by bacteria in tropical seagrass communities was studied in austral summer 1986-87.The major seagrass species were Enhalus acoroides, Syringodium isoetifolium, Cymodocea serrulata, Thalassia hemprichii and Cymodocea rotundata.Seagrass gross productivity, determined by a lacuna1 gas technique, ranged from 0.5 to 4.3 g C m-' d-l.In comparison, gross community productivity, measured from diurnal changes in 0 2 concentration in the water column, ranged from 4 to 9 g C m-' 6'.Macroalgae, epibenthic and epiphytic algae made the major contribution to gross primary production in the communities studied, contributing 40 to 90 % of gross primary production.Most of the primary production was utilized by hydrolytic and fermentative bacteria and was ultimately oxidized by sulphate-reducing bacteria.Hydrolytic (aerobic) and fermentative bacterial productivity, determined from rates of incorporation of tritiated thymidine into DNA, ranged from 3 to 13 g C m-' d-l (integrated over a depth of 12 cm in the sediment).The highest rates of sulphate reduction, determined with 35S, coincided with the below-ground distribution of seagrass roots and rhizomes.Between 1.7 and 2.2 g C m-' d-l was oxidized to CO2 by the sulphate-reducing bacteria; this is equivalent to 30 to 80 % of the net community productivity.
Source: Marine Ecology Progress Series
DOI: 10.3354/meps069149
Authors: PC Pollard, DJW Moriarty
Language: English
Subfield: Oceanography
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2010768249