For two months Leah has been travelling all over the UK to bring you the biggest stories from around our coastline.
She's been finding out about the threats to life in Britain's seas, and what's being done to help.
In the first of her reports she heads out to sea to catch fish.
For many years fishermen caught as much as they wanted. But now fish like cod are under threat, so many countries set limits on how much could be caught.
Watch Leah's report to find out what sustainable fishing is.