Data from: Marine environmental DNA biomonitoring reveals seasonal patterns in biodiversity and identifies ecosystem responses to anomalous climatic events

Marine ecosystems are changing rapidly as the oceans warm and become more
acidic. The physical factors and the changes to ocean chemistry that they
drive can all be measured with great precision. Changes in the biological
composition of communities in different ocean regions are far more
challenging to measure because most biological monitoring methods focus on
a limited taxonomic or size range. Environmental DNA (eDNA) analysis has
the potential to solve this problem in biological oceanography, as it is
capable of identifying a huge phylogenetic range of organisms to species
level. Here we develop and apply a novel multi-gene molecular toolkit to
eDNA isolated from bulk plankton samples collected over a five-year period
from a single site. This temporal scale and level of detail is
unprecedented in eDNA studies. We identified consistent seasonal
assemblages of zooplankton species, which demonstrates the ability of our
toolkit to audit community composition. We were also able to detect clear
departures from the regular seasonal patterns that occurred during an
extreme marine heatwave. The integration of eDNA analyses with existing
biotic and abiotic surveys delivers a powerful new long-term approach to
monitoring the health of our world’s oceans in the context of a rapidly
changing climate.