Commercial Fishing and Aquaculture Protection Act of 2019 This bill directs the Department of Commerce to provide compensation to commercial fishermen and farm-raised (aquaculture) fish producers for losses due to algae bloom, freshwater intrusion, adverse weather, bird depredation, disease, and other conditions. Commerce must provide payments to eligible fishermen and aquaculture producers based on a formula if their actual total gross revenue for a given year falls below 85% of the average total gross revenue for the previous three years.