I was on a fishing trip on a friend-of-the-family's yacht once. He'd just bought it, used, and there wasn't room anywhere for the beer we brought (we generally ration one case of beer per person per day, and occasionally run out; there were about eight of us on this trip).
The ice maker dumps into the two fish holds, which are pretty big-- maybe 3' x 5' x 3'. So we said, hell, let's just put the beer in there and fill it up with ice.
Midway through the trip, we got hot. Dorado practically jumping into our boat, yellowtail that we ate raw so we'd have room to put more of it on ice, one of those trips. Soon, we realized that the fish and the beer would have to share the hold, until we could find room in the bilge freezers for one or the other.
The lesson which we all learned that trip was, if you have beer and fresh fish sharing a cooler, make real, real sure that you rinse the can off before you take a swig. More than one of us grabbed a can of beer, gave it a quick, cursory rinse, and took a swig only to end with a big mouthful of fish slime the consistency of loogies. That'll send anyone to the gunwhale, puking their last three beers into the deep blue of the Pacific.
It does seem to make pretty good chum if you're not trolling too fast, though.