Wild 5 part 1 - Leah goes fishing
2 March 2012 Last updated at 18:37 GMT
For two months Leah has been travelling all over the UK to bring you the biggest stories from around our coastline.
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 can be caught.
Watch Leah's report to find out what 'sustainable fishing' is.