Of jellyfish, fish, and humans

This paper follows my journey from childhood in Missouri, where I saw my first jellyfish, to the oceans of the world. Pelagic cnidarians and ctenophores (“jellies”) have been the focus of my career. I think my work has been relevant to the broader scientific community because jellies are predators and potential competitors of fish. In my early research, I quantitatively estimated the predation effects of jellies on zooplankton and ichthyoplankton. I found that most jellies are selective predators, with a few species having diets of only fish larvae or soft-bodied prey. As I learned more about the physical environment that jellies encounter, my early reductionist approach evolved into a more holistic approach. I thought the asexual multiplication from the attached polyp stage would be fundamental in determining jellyfish population size and that the effects of environmental variables could be tested experimentally. It also seemed that humans have changed the natural environment in ways favoring jellies over fish and jelly populations may have increased in developed, eutrophic, hypoxic, overfished, and warming coastal waters. Many opportunities were available that gave me a global perspective. I have persisted despite some difficulties because I love to learn and I am still having fun!