Drifting along with the ocean currents, they range from less than a millimetre to almost 2 metres in size and include representatives from many different lineages in the animal tree of life. However, all gelatinous zooplankton have one thing in common; a transparent, soft body without an exoskeleton and a high water content. Frequent reports of "invasions", "swarms", and serious stings from some gelatinous zooplankton groups have captured the public's attention but scientific interest has long been lagging behind. This is partly due to the fact that gelatinous organisms are not regarded as commercially important which leads to difficulty in acquiring funding for projects. Lately however, it appears that the scientific community has come to the realization that gelatinous organisms could be important players in the future ocean, benefitting from ongoing changes. This rising scientific interest has been exemplified by the success of the gelatinous zooplankton session, which took place at the 2014 ICES Annual Science Conference. Gelatinous zooplankton on a global perspective: interactions with fisheries and consequences for socio-economics was co-sponsored by the North Pacific Marine Science Organization (PICES) and attracted 45 contributions from 18 different countries.
The theme session conveners, Ric Brodeur (USA, PICES), José Acuña (Spain, ICES) and Cornelia Jaspers (Denmark, ICES), were delighted with the positive response from the "jelly" community and the large interest in sharing the latest results, as well as discussing future directions. During the two day session, researchers from around the world presented a suite of different ecosystems and approaches, ranging from field to modelling studies, showing that gelatinous organisms are far from a dead end in the food chain. "It is very promising to see the community becoming so well connected, that a lot of young enthusiastic researchers are involved, and that research teams are collaborating on a global scale", commented Cornelia Jaspers who initiated this special theme session.
To emphasize Jaspers point on enthusiastic young researchers, both Early Career Scientist Best Presentation awards were presented to researchers from the gelatinous zooplankton theme session: Raquel Marques, University of Algarve, Portugal and Jessica Y. Luo, Miami University, USA. Marques discussed her team's research on the pelagic population dynamics of Aurelia sp. in French Mediterranean lagoons , which suggests that jellyfish populations might be controlled by fish predation. , Luo presented her team's results from an imaging system which allowed unique, fine scale observations of circa 50 taxa and close to one million gelatinous zooplankton organisms in connection to different water masses and frontal systems of the northern Gulf of Mexico.
The current issue of Journal of Plankton Research features ten selected papers from the 2014 ICES ASC session, which are collected together with a general introduction on interactions of gelatinous zooplankton within marine food webs.
The current issue of the Journal of Plankton research featuring a photo of different gelatinous zooplankton organisms covering tropical to Arctic oceans. Photo: R.R. Hopcroft and Cornelia Jaspers.