High‐throughput sequencing reveals neustonic and planktonic microbial eukaryote diversity in coastal waters

Abstract

Neustonic organisms inhabit the sea surface microlayer (SML) and have important roles in marine ecosystem functioning. Here, we use high-throughput 18S rRNA gene sequencing to characterize protist and fungal diversity in the SML at a coastal time-series station and compare with underlying plankton assemblages. Protist diversity was higher in February (pre-bloom) compared to April (spring bloom), and was lower in the neuston than in the plankton. Major protist groups, including Stramenopiles and Alveolata, dominated both neuston and plankton assemblages. Chrysophytes and diatoms were enriched in the neuston in April, with diatoms showing distinct changes in community composition between the sampling periods. Pezizomycetes dominated planktonic fungi assemblages, whereas fungal diversity in the neuston was more varied. This is the first study to utilize a molecular-based approach to characterize neustonic protist and fungal assemblages, and provides the most comprehensive diversity assessment to date of this ecosystem. Variability in the SML microeukaryote assemblage structure has potential implications for biogeochemical and food web processes at the air-sea interface.

Analysis of rbcL sequences reveals the global biodiversity, community structure, and biogeographical pattern of thermoacidophilic red algae (Cyanidiales)

“…, Egge et al. , Taylor and Cunliffe ). The studies using targeted NGS are revealing species diversity never appreciated before.…”

“…This additional culturing step hampers progress in investigating the global species diversity of Cyanidiales. Recently, targeted next-generation sequencing (NGS) has been applied to sample species diversity at an unprecedented resolution (e.g., Cuvelier et al 2010, Egge et al 2013, Taylor and Cunliffe 2014. The studies using targeted NGS are revealing species diversity never appreciated before.…”

Diverse groups of fungi are associated with plastics in the surface waters of the Western South Atlantic and the Antarctic Peninsula

“…Several studies looking at general eukaryotic diversity on plastics have used a general 18S ribosomal RNA (rRNA) marker to profile communities with high‐throughput sequencing, identifying a variety of fungal taxa within their data sets (Debroas, Mone, & Ter Halle, 2017; Kettner et al., 2019; Kirstein, Wichels, Krohne, & Gerdts, 2018; Oberbeckmann et al., 2016). However, the 18S rRNA gene has limited taxonomic resolution for some fungal groups (Richards et al., 2012; Stoeck et al., 2010;Taylor & Cunliffe, 2014) and may give different profiles depending on sequenced region (De Filippis, Laiola, Blaiotta, & Ercolini, 2017). Using fungi‐specific primers, such as those targeting the Internal Transcribed Spacer regions (ITS) of the rRNA operon, ensures a high proportion of sequence reads from fungi and provide good resolution for higher fungi within Ascomycota and Basidiomycota (Andreakis et al., 2015; Rämä et al., 2016).…”

Protein and Carbohydrate Exopolymer Particles in the Sea Surface Microlayer (SML)

“…Aller et al (2005) found that the EF for bacteria and virus abundances were 10 and 7, respectively. Protistan community composition in the SML is different from the underlying waters and is enriched in some taxa (Joux et al, 2006;Cunliffe and Murrell, 2010;Taylor and Cunliffe, 2014). Joux et al (2006) proposed that buoyant particles and bubbles play a role in the enrichment of the SML with specific taxa.…”