Seas continue to be hit by 'alien invaders'
I quote these parts
"........raising concerns that more damaging non-native creatures like Chinese Mitten crabs or goby frogs might also appear and harm fish"
"......and a type of frog known as the round goby, neogobius melanostomus, which compete with native marine species for food and eat fish eggs, threatening fish stocks"
For one thing I did'nt know frogs eat fish eggs.