Monthly Succession of Biofouling Communities and Corresponding Inter-Taxa Associations in the North- and South-West of the Arabian Gulf

Liny Jose,Fahad Al Senafi,Thirumahal Muthukrishnan,Christiane Hassenrück,Raeid M M Abed,Dhikra Al Fahdi,Huda Mahmoud

doi:10.3389/fmars.2021.787879

Abstract

Marine biofouling is a complicated process involving changes within micro- and macro-fouling community, species co-occurrence, and inter-taxa association patterns. An investigation of all above-mentioned aspects has rarely been conducted so far. Our study aimed to compare the monthly succession of the biofouling community developed at two locations each in the north- (Kuwait) and south-west (Oman) of the Arabian Gulf (AG) over 6 months, and to explore the association patterns within microfouling and between micro- and macro-fouling communities on a temporal and spatial scale. Spatio-temporal effects on the abundance and composition of micro- and macro-fouling communities were detected based on total biomass, bacterial and phototroph abundances, macrofouling coverage and 16S rRNA gene sequencing. We documented the development of distinct ecological niches within the fouling community resulting in fundamentally different succession patterns depending on location. Network analysis revealed nine clusters of highly interconnected co-occurring fouling bacterial taxa (M1-M9), with strong association (both positive and negative) to microalgae and macrofoulers in both Kuwait and Oman. Early stages of Kuwait biofilm showed M7 (cyanobacterial OTUs) positively and negatively associated with the majority of diatoms and macroalgae (Cladophoraceae), respectively, unlike the later stages where M5 (composed of Vibrio spp.) was positively associated with polychaetes (Hydroides elegans). While the causal relationships behind the observed inter-taxa associations remain unknown, our study provided insights into the underlying dynamics of biofouling processes encountered in the north- and south-west of the AG. Comprehensive future investigations encompassing transcriptomic or metabolomic tools may be required to address the challenge of interpreting such complicated dynamics over time and space in a continuously changing environment.

Highlights

IntroductionMarine biofouling, defined as the undesirable accumulation of benthic organisms on submerged surfaces, is a multistage process that involves surface conditioning, followed by formation of microbial biofilms (e.g., bacteria, diatoms, and algae), and the settlement of sessile (e.g., barnacles, hydroids, mussels, sponges, and bryozoans) and mobile (e.g., crabs, shrimps, and snails) macrofouling organisms (Dang and Lovell, 2016)
Marine biofouling, defined as the undesirable accumulation of benthic organisms on submerged surfaces, is a multistage process that involves surface conditioning, followed by formation of microbial biofilms, and the settlement of sessile and mobile macrofouling organisms (Dang and Lovell, 2016)
Significant differences were observed between Kuwait marinas (i.e., 1–5 and 5–77 NTU in Fintas and Salmiya, respectively) rather than between Oman marinas, which showed comparable average values of 1–2 NTU

Summary

Introduction

Marine biofouling, defined as the undesirable accumulation of benthic organisms on submerged surfaces, is a multistage process that involves surface conditioning, followed by formation of microbial biofilms (e.g., bacteria, diatoms, and algae), and the settlement of sessile (e.g., barnacles, hydroids, mussels, sponges, and bryozoans) and mobile (e.g., crabs, shrimps, and snails) macrofouling organisms (Dang and Lovell, 2016). The structure and speed of development of micro- and macro-fouling communities are influenced by many environmental variables, such as current flow, light availability, nutrient load (Qian et al, 2007; Dang and Lovell, 2016; de Carvalho, 2018), as well as by biological factors, such as the availability, growth rate and metabolic state of fouling species and inter-species interactions (Dang and Lovell, 2016; Pollet et al, 2018; Zhang et al, 2019) Such combination of environmental and biological factors leads to temporal and spatial variations in the composition of fouling communities (Dang and Lovell, 2000, 2016; Oberbeckmann et al, 2016; Navarrete et al, 2020). Despite the extensive literature on temporal and spatial changes in biofouling communities, the concurrent spatio-temporal effects on both micro- and macrofouling communities have been underexplored, except for two studies in the Atlantic Ocean (Dziubinska and Janas, 2007; De Tender et al, 2017)

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