I'm glad you thought about fish getting stuck in your invention Charity. It's a great idea to have clean water flow through the strainer, but an opening also needs to be a good enough size for fish to stay safely in the water. That way, we have nice, clean water along with safe, happy fish! A beeper when the strainer is full of rubbish is a good way to alert us that we need to empty the waste, then we can have a much improved, cleaner sea! Nice one Charity, keep it up!