How did the fish get to the Atlantic? While the exact cause is unknown, it's likely that humans provided a helping hand. Experts speculate that people have been dumping unwanted lionfish from home aquariums into the Atlantic Ocean for up to 25 years. Marine invaders are nearly impossible to eradicate once established. That is why it is highly illegal to release non-native species into the wild, the results are most often disastrous to the native ecosystem.