Growout 2 Systems
The Growout 2 building (GO2) is a 26,400 ft² building currently under construction. It consists of 16 fiberglass tanks that are 25’ wide and have an operating capacity of almost 19,000 gallons or 71,923 liters each (shown above). Juveniles from the greenhouse will be transferred to this building for further on-growing.  We are using two styles of biofiltration in this building in an effort to determine which is most cost effective. One bay will house individual drop filters for each tank, which are similar to conventional bead filters.  These filters contain a media that is used not only for biofiltration, but mechanical filtration as well.  The other bay will house moving bed biofilters for biofiltration and drum filters for mechanical filtration, and this concept is similar to that for the hatchery and nursery systems.

When the fish reach approximately 4 kg (2.5 years) in weight, they will be sampled to determine their sex.  The males and females are identified using a biopsy procedure because there are no external characteristics.  During the biopsy procedure, the fish is anesthetized. A small incision is made in the abdomen and the gonads are visually inspected. Female fish are then sutured closed (shown above), and the fish is returned to the tank to recover.  The female sturgeon may be kept for many years until the ovaries produce caviar.  If the male sturgeon are of marketable size, they are harvested after the biopsy.  Only a small number of males will be retained each year to serve as future broodstock.