PROBLEM TO BE SOLVED: To improve rearing efficiency of shellfish by supplying sufficient oxygen and accommodating to mass rearing and production by automating the feeding.SOLUTION: A shellfish aquaculture system includes: a rearing water tank 10 that stores a plurality of multi-stage rearing containers 1 in which shellfish are placed and reared, and in which rearing water W is put； a rearing water supply device 20 for supplying the rearing water tank 10 with the rearing water W； and a feeder 40 for feeding food for the shellfish to the rearing water tank 10. The rearing water supply device 20 has an oxygen dissolver 21 that causes the oxygen supplied from an oxygen cylinder to the rearing water W to exist in solution. The feeder 40 has an alga breeding device 41 for breeding algae as the food of the shellfish.
