Fishing for supper

Last time we went to this park the girls had to fish using their hands. This time we went prepared with brand new fishing nets. They caught lots of fish and temporarily held them in jam jars. They were very reluctant to throw them back into the river. Why on earth would I want a jar full of stone loaches in the kitchen?
I thought it would be a quiet household without the boys but the girls have been fighting like cat and dog.