fish stock works great for chowders, seafood pasta recipes, etc. use where any recipe calls for "clam juice". easy to make although a little messy. make a large stock pot full & freeze in plastic cups, remove & store in freezer baggies.
stock preparation:
large stock pot or sauce pan simmer a few black fish racks (no entrails) with a couple onions(leave skins on), a few stalks of celery, bay leaves, peppercorns, pickling spice, garlic cloves,carrots, etc. all or any of the aforementioned to your taste. 3 hours of good simmering should do it. everything should be falling apart. cool & strain. i start with a large collander & work my way down to my fine screen seive or cheese cloth. i freeze in 1 cup portions, some freeze in ice cube trays for smaller portions.

i have used striper racks but i stay with the smaller fish for pollutant concerns.
fish stock really gives any recipe the proper fish flavor....fwiw