Mass occurrence of medusae („jellyfish blooms“)

Mass occurrence of medusae („jellyfish blooms“)

Medusae (jellyfish) often occur in masses („jellyfish blooms“) that show negative affects on economy and tourism. The gelatinous bodies can clog fishing nets or cooling systems of coastal industries. 

Medusa species with painful stings scare away bathers from the beaches. Jellies are greedy zooplankton predators and food competitors for many fish species. Therefore they are an additional thread for overfished species. Mass occurrences of jellyfish can also have negative affects on aquacultures. In autumn 2007 a mass occurrence of the “Purple Jellyfish” or “Mauve Stinger” (Pelagia noctiluca) in a salmon farm in Northern Ireland killed more than 100.000 fishes.

Since the increase of “jellyfish blooms” was noticed in the last few decades, several studies were accomplished to investigate the causes and correlations with changing environmental factors, e.g. in the European project EUROGEL (EUROpean GELatinous Zooplakton: Mechanisms behind jellyfish blooms and their ecological an socio-economic effects), from 2002-2005. The „First International Jellyfish Blooms Symposium“ took place in Alabama (USA) in January 2000 (Hydrobiologia, Volume 451, 2001), followed by another four Jellyfish Symposia in 2007, Coolangata, Australia (Hydrobiologia, Volume 616, 2009), 2010 in Mar del Plata, Argentina in (Hydrobiologia Volume 690, 2012), 2013 in Hiroshima, Japan (Marine Ecology Progress Series Volume 510), and 2013 in Barcelona, Spain (Marine Ecology Progress Series, Volume 591).

The “6th International Jellyfish Blooms Symposium” will take place in Cape Town, South Africa in November 2019.

 

Jellyfish Blooms englisch