Yes, it does go bad quickly once it's dead. Seafood is best when you eat it fresh off the boat. If you can't do that, freeze it or can it fresh off the boat. With a good fish market here in New Asgard, it's easy enough to eat by the season and always have what's best in any given time of year - and with making a living so easy, there's no need to live on whatever's cheapest and spend all summer having jellied eels for dinner.