What is the problem the community is having with salt and fish?

Randy and the community discover how important salt and fish are to survival. Salt is necessary beyond seasoning food. Workers in the hot Florida sun sweat out body salt and, unless it is replaced, they get weak, ill and listless. Salt is not available for trade and salt starvation causes absolute craving. There is no way to make salt. Fish are a staple and if they don't bite there is no way to get them and even shrimp nets don't work.