Climate and Jellyfish Outbursts in the Mediterranean Sea: A Synthesis through Metaanalysis

Jellyfish are critical components of marine ecosystems. Whether variations in their population size are driven by human- or climate-mediated processes is a matter for current debate and a challenge in biological oceanography. In this work we gathered pluriannual information of Mediterranean jellyfish to synthesize long term variations of jellyfish outbreaks, their strength and frequency during the last decades in the Mediterranean Sea. Evidence has been found on the interactions between hemisphere-wide climate variability and regional atmospheric changes across the Mediterranean basin. The temporal dynamics of jellyfish outbreaks are consistent with the climate-related environmental changes the Mediterranean Sea undergone during the last decades. We found that jellyfish populations integrate climate related changes in the Mediterranean basin, and the strength of their link with climate variations has increased after the 1980s. The quantitative synthesis performed by meta-analysis provides evidence of an increase in gelatinous carnivore outbursts related to long term changes of sea surface temperature. However, we also found that the jellyfish increase has been indirectly favoured by anthropogenic stress (e.g. overfishing, habitat degradation) which has affected competitors and predators of jellyfish. These results constitute ecological warning indicators of significant changes occurred in the pelagic ecosystem of the Mediterranean Sea after the 1980s.

MOLINERO Juan-Carlos;  BATISTIC Mirna;  DALY-YAHIA Nejib;  YAHIA-KÉFI Ons Daly;  LUCIC Davor;  FERNANDEZ DE PUELLES Maria;  KAMBURSKA Lyudmila;  LICANDRO Priscilla;  MALEJ Alenka;  PRIETO Laura;  SIOKOU-FRANGOU Ioanna;  ZERVOUDAKI Sultana; 

2010-04-19

Global Ocean Ecosystem Dynamics (GLOBEC)

JRC55886

https://publications.jrc.ec.europa.eu/repository/handle/JRC55886,