Crab breeding is a lucrative business, I was told. Now, it doesn’t take a math nerd to tell you that this is a venture worth looking into. It’s increasingly rare that the crabs you eat come from the wild. Brown crabs in particular are sensitive to changes in water salinity. Storms that wash in too much freshwater or sea water will affect the population. If mangrove swamps go the way scientists say they will, brown crabs may one day have to be 100% farm-raised.