Succession pattern and phylotype analysis of microphytobenthic communities in a simulated oil spill seagrass mesocosm experiment

Microphytobenthic communities play a significant role in nutrient modulation, sediment stabilization, and primary production seagrass beds, which provide various ecosystem services. We hypothesized that microphytobenthic sediments of chronically oil-exposed beds will exhibit increased resiliency to stressors associated with oil exposure as opposed never exposed spills. prepared 14-liter seawater mesocosms, each containing submersed macrophyte Ruppia maritima collected from the Chandeleur Islands, Louisiana, Estero Bay, Florida. Mesocosms were initially 50% water-accommodated fractions (WAF) subsequently diluted by daily artificial exchanges over 8 days simulate tidal dilution. High-throughput amplicon sequencing based on 23S rRNA gene targeting cyanobacteria chloroplasts eukaryotic microphytobenthos was conducted assess impact oiling additional assessment via microscopy. combination traditional microscopic analysis provided robust examination both methods roughly complemented other. Distinct succession patterns detected benthic algal (Louisiana) versus unexposed (Florida) bed sediments. The across all samples showed diatoms dominated sample percentages ranging 42 97%, followed (2 50%). It is noteworthy drastic changes community structure terms larger taxonomic level not observed, rather change occurred at phylotype level. These results also confirmed Similarity (SIMPER) identified seven phylotypes (Cyanobacteria, Bacillariophyceae, Mediophyceae) Louisiana one (Bacillariophyceae) Florida relative sequence abundance after exposure. detailed identifying sentinel indicators provides base for future research microalgae response disturbance.