ROSKILDE FJORD

Moon Jellyfish

(Aurelia aurita).

In recent years there has been a rapid increase in the jellyfish population in the fjord. They live independently of one another, but they often gather in dense shoals. They live on zooplankton and fry but are not themselves eaten by other species and are therefore at the top of the food chain. Not much is known about the effect of jelly fish on the ecosystem and water quality of the fjord, but they may well limit the populations of some fish whose young they eat.


Large numbers of jellyfish can be seen in late summer.