Water quality, seasonality, and trajectory of an aquaculture-wastewater plume in the Red Sea

Abstract

AEI Aquaculture Environment Interactions Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections AEI 10:61-77 (2018) - DOI: https://doi.org/10.3354/aei00254 Water quality, seasonality, and trajectory of an aquaculture-wastewater plume in the Red Sea Aya Hozumi1,*, Pei-Ying Hong2, Stein Kaartvedt3, Anders Røstad1, Burton H. Jones1 1King Abdullah University of Science and Technology (KAUST), Red Sea Research Center (RSRC), Biological and Environmental Sciences & Engineering Division (BESE), Thuwal 23955, Saudi Arabia 2King Abdullah University of Science and Technology (KAUST), Water Desalination and Reuse Center, Biological and Environmental Sciences & Engineering Division (BESE), Thuwal 23955, Saudi Arabia 3Department of Biosciences, University of Oslo, 0316 Oslo, Norway *Corresponding author: aya.hozumi@kaust.edu.sa ABSTRACT: As aquaculture activity increases globally, understanding water mass characteristics of the aquaculture-wastewater plume, its nutrients, and its organic matter load and spatial distribution in the coastal recipient, is critical to develop a more sustainable aquaculture operation and to improve coastal management. We examined wastewater (estimated 42-48 m3 s-1) discharged from the largest aquaculture facility in the Red Sea and surveyed the area around the aquaculture outfall to characterize the biogeochemical properties of the wastewater plume and its spatial distribution. In addition, we assessed its associated microbial community structure. The plume was characterized by elevated levels of salinity, density, and turbidity, and traveled along paths determined by the bathymetry to form a dense, 1-3 m thick layer above the seafloor. The effluent was observed at least 3.8 km from the outfall throughout the year, but up to 8 km in early autumn. The total nitrogen concentration in the plume was more than 4 times higher than in surface waters 1.4 km from the outfall. High-throughput sequencing data revealed that bacterial and cyanobacterial communities significantly differed, and flow cytometry results showed that total cell counts were significantly higher at the outfall. Arcobacter, a genus associated with opportunistic pathogenic species (e.g. A. butzleri), was more abundant, while Prochlorococcus sp. was significantly less abundant at the outfall. This dense, bottom-flowing plume may have a detrimental impact on benthic and demersal communities. KEY WORDS: Anthropogenic effluent · Microbial biomarkers · Nutrification · Coastal management Full text in pdf format PreviousNextCite this article as: Hozumi A, Hong PY, Kaartvedt S, Røstad A, Jones BH (2018) Water quality, seasonality, and trajectory of an aquaculture-wastewater plume in the Red Sea. Aquacult Environ Interact 10:61-77. https://doi.org/10.3354/aei00254 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AEI Vol. 10. Online publication date: February 19, 2018 Print ISSN: 1869-215X; Online ISSN: 1869-7534 Copyright © 2018 Inter-Research.