Data from: Ecological drivers of jellyfish blooms – the complex life history of a 'well-known' medusa (Aurelia aurita)

Jellyfish blooms are conspicuous demographic events with significant
ecological and socio-economic impact. Despite worldwide concern about an
increased frequency and intensity of such mass occurrences, predicting
their booms and busts remains challenging. Forecasting how jellyfish
populations may respond to environmental change requires considering their
complex life histories. Metagenic life cycles, which include a benthic
polyp stage, can boost jellyfish mass occurrences via asexual recruitment
of pelagic medusae. Here we present stage-structured matrix population
models with monthly, individual-based demographic rates of all life stages
of the moon jellyfish Aurelia aurita L. (sensu stricto). We investigate
the life stage-dynamics of these complex populations under low and high
food conditions to illustrate how changes in medusa density depend on
non-medusa stage dynamics. We show that increased food availability can be
an important ecological driver of jellyfish mass occurrences, as it can
temporarily shift the population structure from polyp- to medusa-
dominated. Projecting populations for a winter warming scenario enhanced
the booms and busts of jellyfish blooms. We identify demographic key
variables that control the intensity and frequency of jellyfish blooms in
response to environmental drivers such as habitat eutrophication and
climate change. By contributing to an improved understanding of mass
occurrence phenomena, our findings provide perspective for future
management of ecosystem health.