Human-induced stresses of overfishing, eutrophication,
climate change, translocation and habitat modification
appear to be promoting jellyfish (pelagic cnidarian and
ctenophore) blooms to the detriment of other marine
organisms. Mounting evidence suggests that the structure
of pelagic ecosystems can change rapidly from one
that is dominated by fish (that keep jellyfish in check
through competition or predation) to a less desirable
gelatinous state, with lasting ecological, economic and
social. Management actions needed to
stop such changes require tactical coping strategies
and longer-term preventative responses based on fundamental
and targeted research on this understudied
group.