Crab Meal - Crustacean Shells broken to pieces. (Approximately 4-5-0, approximately 14% Ca). A nutrient-rich byproduct of shrimp, crab and lobster processing facilities. As well as being an excellent source of macronutrients, crustacean shell meal is high in chitin (average 16%). Adding it to your soil puts beneficial chitin-eating bacteria into a feeding frenzy of pathogenic fungi, nematodes and disease-causing bacteria like E. coli and salmonella. A solid body of scientific evidence supports the efficacy of chitinous soil amendments in the control of soil-borne pathogens.