Macrobenthic community structure and influence on denitrification capacity in soft sediments (Mobile Bay, Alabama)

A1 Journal article (refereed)


Internal Authors/Editors


Publication Details

List of Authors: M. P. Jacquot, K. M. Dorgan, B. Mortazavi, A. A. Kleinhuizen, W. C. Clemo
Publisher: Inter-Research
Place: Mobile Bay, Alabama
Publication year: 2018
Journal: Marine Ecology Progress Series
Journal acronym: MEPS
Volume number: 605
Start page: 17
End page: 35


Abstract

Benthic macrofauna play important roles in coastal ecosystems through
their impact on nutrient cycling and by serving as an mportant trophic
link. This study investigated the influence of environmental stressors
on macrofaunal community abundance, biomass and diversity and evaluated
impacts of those benthic organisms on nutrient fluxes and
denitrification capacity in Mobile Bay, a shallow subtropical estuary in
the northern Gulf of Mexico. Between January and May 2016, 22 stations
in the lower bay were sampled, and the distance from the sea and
sediment characteristics were identified as the principal constraints
for macrofaunal distribution and taxonomic composition. Higher diversity
of macrofauna was found near the mouth of the bay, likely due to
hydrological characteristics of the bay, in addition to distance from
anthropogenic disturbances
near coasts. Sediments comprised of 60−80% sand showed higher
abundances, biomass and diversity compared to muddier or sandier
sediments, potentially because these sediments were more stable.
Although macrofaunal abundance, biomass and diversity differed across
stations in the bay, we did not find a relationship between macrofaunal
abundances or biomass and denitrification capacity. Both abundance and
biomass of infauna were low in Mobile Bay (<4000 ind. m−2 and <5 g
DW m−2 at most sites) compared to those in previous studies which
showed a positive relationship between macrofaunal abundances and
denitrification. The lack of the relation between macrofauna and
denitrification suggests that a threshold of abundance, biomass and/or
burrowing activity is necessary to increase bioturbation or irrigation
to sufficient levels to affect denitrification.


Keywords

Benthic macrofauna, Community diversity, Denitrification, Environmental stressors, Mobile Bay, Nitrogen flux, Sediments

Last updated on 2019-14-10 at 05:13