Because the shell is a natural productivity. We need to give it time to grow certain types of shellfish, which takes a long time to even get the size according to the needs of the market.
The shell is a natural product. We have to give it time to grow. The shells of some species take up to several years to scale to meet the needs of the market.
Because the shell is a natural product We need to give it in growth. The shells of some kind lasted several years to the size according to the needs of the market.