Shifts in species dominance related to spatial assemblages and variation in environmental parameters in a tropical mangrove estuary

Aniefiok Ini Inyang; Mei-Lin Wu; Ekpo Eyo Antai; Ita Ewa-Oboho; Ogooluwa Samuel Adeagbo

doi:10.1016/j.marenvres.2023.106173

Shifts in species dominance related to spatial assemblages and variation in environmental parameters in a tropical mangrove estuary

Mar Environ Res. 2023 Oct:191:106173. doi: 10.1016/j.marenvres.2023.106173. Epub 2023 Sep 12.

Authors

Aniefiok Ini Inyang¹, Mei-Lin Wu², Ekpo Eyo Antai³, Ita Ewa-Oboho¹, Ogooluwa Samuel Adeagbo⁴

Affiliations

¹ Department of Marine Biology, Akwa Ibom State University, Ikot Akpaden, Nigeria.
² State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China; Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, China. Electronic address: mlwu@scsio.ac.cn.
³ Department of Marine Biology, Akwa Ibom State University, Ikot Akpaden, Nigeria; Department of Biological Oceanography, Faculty of Oceanography, University of Calabar, Calabar, Nigeria.
⁴ Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA.

PMID: 37713780
DOI: 10.1016/j.marenvres.2023.106173

Abstract

A shift in species dominance in the mangrove microalgae community in Cross River Estuary System (CRES), Nigeria, was carried out during the wet season to highlight the microalgae structure, identify potential indicators, and evaluate the water quality variation. Plankton samples were collected at sixteen selected sampling sites along the river. Diatoms showed the highest number of species (240 species), contributing more than 70% of the total microalgae abundance. Cluster analysis of the microalgae community delimits the CRES into three sections; upper (UCRS), middle (MCRS), and lower (LCRS) communities. The spatial shift in the microalgae community showed that the green algae (Eudorina elegans and Hylotheca dissiliens) dominated the UCRS communities, while diatoms dominated the MCRS (Polymyxus coronalis and Actinocyclus normanii) and LCRS (A. normanii and A. octonarius). The principal component analysis showed that the UCRS was influenced by turbidity and nitrate, while the MCRS and LCRS were characterized by phosphate, electrical conductivity, and salinity/total dissolved solids. The similarity percentage (SIMPER) analysis showed that Surirella tenera and Hylotheca dissiliens contributed >3.5% inter site dissimilarity between the UCRS and LCRS microalgae community. The redundancy analysis revealed that some microalgae species such as Odontella mobiliensis, Coscinodiscopsis jonesiana, A. normanii, and A. octonarius responded positively to salinity change and ammonia concentration in the estuary, while S. tenera, P. coronalis, Bacillaria paxilifer, Navicula transitans, Cyclotella meneghiniana, Humidophila contenta, Melosira granulata, Aulacoseira herzogii, Eudorina elegans, H. dissiliens, Mougeotia sp., and Dinobryon sertularia responded positively to turbidity, nitrate, and phosphate concentration. This study illustrates that CRES inhabit rich biodiversity of microalgae which some taxa could be used as indicators of the environmental changes in marine waters.

Keywords: Changing environment; Estuarine-mangrove forest; Microalgae communities; Water quality.

MeSH terms

Biodiversity
Diatoms*
Environmental Monitoring
Estuaries
Microalgae*
Nitrates
Phosphates
Seasons

Substances

Nitrates
Phosphates