Data from: Metabarcoding reveals environmental factors influencing spatio-temporal variation in pelagic micro-eukaryotes

Marine environments harbour a vast diversity of micro-eukaryotic organisms
(protists and other small eukaryotes) that play important roles in
structuring marine ecosystems. However, micro-eukaryote diversity is not
well understood. Likewise, knowledge is limited regarding micro-eukaryote
spatial and seasonal distribution, especially over long temporal scales.
Given the importance of this group for mobilizing energy from lower
trophic levels near the base of the food chain to larger organisms,
assessing community stability, diversity and resilience is important to
understand ecosystem health. Herein, we use a metabarcoding approach to
examine pelagic micro-eukaryote communities over a 2.5-year time series.
Bimonthly surface sampling (July 2009 to December 2011) was conducted at
four locations within Mobile Bay (Bay) and along the Alabama continental
shelf (Shelf). Alpha-diversity only showed significant differences in
Shelf sites, with the greatest differences observed between summer and
winter. Beta-diversity showed significant differences in community
composition in relation to season and the Bay was dominated by diatoms,
while the Shelf was characterized by dinoflagellates and copepods. The
northern Gulf of Mexico is heavily influenced by the Mobile River Basin,
which brings low-salinity nutrient-rich water mostly during winter and
spring. Community composition was correlated with salinity, temperature
and dissolved silicate. However, species interactions (e.g. predation and
parasitism) may also contribute to the observed variation, especially on
the Shelf, which warrants further exploration. Metabarcoding revealed
clear patterns in surface pelagic micro-eukaryote communities that were
consistent over multiple years, demonstrating how these techniques could
be greatly beneficial to ecological monitoring and management over
temporal scales.