Lisa-ann Gershwin : They can grow 10 % of their body length per hour and go through two generations in a day . Jellyfish taking over vulnerable seas , displacing other creatures . She says jellyfish can kill off fish-sustaining krill that 's harvested for omega-3 supplements . Comment: Jellyfish thrive as oceans get warmer ; they eat the eggs and larvae of fish . Gershwin : We need to make industry stop polluting water and prevent global warming .
Lisa-ann Gershwin : Jellyfish taking over vulnerable seas , displacing other creatures . She says jellyfish can kill off fish-sustaining krill that 's harvested for omega-3 supplements . Comment: Jellyfish thrive as oceans get warmer ; they eat the eggs and larvae of fish . Gershwin : We need to make industry stop polluting water and prevent global warming .