Respective contribution of urban wastewater and mangroves on nutrient dynamics in a tropical estuary during the monsoon season

TitleRespective contribution of urban wastewater and mangroves on nutrient dynamics in a tropical estuary during the monsoon season
Publication TypeJournal Article
Year of Publication2020
AuthorsTaillardat, P, Marchand, C, Friess, DA, Widory, D, David, F, Ohte, N, Nakamura, T, Van Vinh, T, Thanh-Nho, N, Ziegler, AD
JournalMarine Pollution Bulletin
Volume160
Pagination111652
ISSN0025326X
Abstract

Estuaries of Southeast Asia are increasingly impacted by land-cover changes and pollution. Here, our research objectives were to (1) determine the origins of nutrient loads along the Can Gio estuary (Vietnam) and (2) identify the processes that affect the nutrient pools during the monsoon. We constructed four 24-h time-series along the salinity gradient measuring nutrient concentrations and stable isotopes values. In the upper estuary, urban effluents from Ho Chi Minh City were the main input of nutrients, leading to dissolved oxygen satura­ tion < 20%. In the lower estuary, ammonium and nitrite concentration peaks were explained by mangrove export. No contribution from aquaculture was detected, as it represents < 0.01% of the total river discharge. Along the salinity gradient, nutrient inputs were rapidly consumed, potentially by phytoplankton while nitrate dual-stable isotopes indicated that nitrification occurred. Thus, even in a large and productive estuary, urban wastewater can affect nutrient dynamics with potentially important ecological risks.

URLhttps://linkinghub.elsevier.com/retrieve/pii/S0025326X20307700
DOI10.1016/j.marpolbul.2020.111652
Catégorie HCERES
ACL - Peer-reviewed articles
Publication coopération et recherche SUD
Non