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Marine and Freshwater Research Marine and Freshwater Research Society
Advances in the aquatic sciences
RESEARCH ARTICLE

DNA metabarcoding reveals multiple co-occurring species in Stephanodiscus spring diatom blooms in a temperate freshwater river

Buhari Lawan Muhammad A , Yongsik Sin B and Jang-Seu Ki https://orcid.org/0000-0002-6007-9262 A C
+ Author Affiliations
- Author Affiliations

A Department of Biotechnology, Sangmyung University, Hongjimoon-2gil 20, Jongno-gu, Seoul 03016, South Korea.

B Department of Environmental Engineering & Biotechnology, Mokpo National Maritime University, Haeyangdaehak-ro 91, Mokpo 58628, Jeollanam-do, South Korea.

C Corresponding author. Email: kijs@smu.ac.kr

Marine and Freshwater Research 72(9) 1353-1364 https://doi.org/10.1071/MF20254
Submitted: 19 August 2020  Accepted: 29 January 2021   Published: 6 April 2021

Abstract

Spring diatom blooms dominate the annual cycle of phytoplankton abundance in temperate freshwater systems. Many researchers have questioned whether severe blooms are attributable to a single species and warrant the identification of similar, concurrently occurring organisms. Here, we investigated spring diatom blooms in a temperate freshwater system (Yeongsan River, South Korea) that is thought to predominantly include the diatom Stephanodiscus hantzschii. Water samples were collected from four different sites during the blooms that occurred in March 2015. We analysed physicochemical and biological parameters and examined the species composition of the spring blooms using DNA metabarcoding via pyrosequencing. Our results revealed that several diatom species co-occurred during the blooms: Cyclotella sp. was the most frequently detected, followed by Cyclostephanos dubius and Discostella sp., whereas Stephanodiscus was only detected at two stations with low occurrence. These results suggest the coexistence of many diatoms during spring blooms in the Yeongsan River; however, Cyclotella sp. was responsible for the spring bloom attributed to S. hantzschii. DNA metabarcoding can be a useful tool for resolving species identities in spring diatom blooms in temperate freshwater systems. In addition, the co-occurrence of similar species should be considered when implementing efforts to monitor and control spring blooms.

Keywords: biomonitoring, Cyclotella sp., phytoplankton, spring bloom.


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