It is subject to large population swings, and has been held responsible for the death of farmed salmon in Norway.

[4] Muggiaea atlantica is a neritic species that forms part of the zooplankton, and is found in the upper hundred metres of inshore temperate and subtropical waters worldwide.

[7] Muggiaea atlantica swims in an arc, propelled by pulsations of its bell, and then remains stationary for several minutes.

[9] In the eastern Pacific it is eaten by predatory fish such as the blue rockfish (Sebastes mystinus), and by the floating sea snail Carinaria cristata.

This resulted in a reduction in the grazing pressure on the phytoplankton and an increase in their growth, causing an algal bloom and other cascading ecosystem effects.

[10] The aquaculture industry in Norway suffered a setback in 2007 when more than 100,000 caged salmon were killed by a bloom of M. atlantica, present at a concentration of 2,000 per cubic metre in coastal waters.