A Mechanized Panel Grading System for the Golden Shiner: Proof of Concept

In 2008, we conducted one swimming perfo rmance and metabolism study and one transportation study on the golden shiner, Notemigonus crysoleucas. During field wo rk fo r these experiments, we consulted baitfish farmers, observed harvests, and participated as workers in actual in-vat grading events. We concluded that the physically demanding in-vat grading process could be imp roved by mechanizat ion, so we developed a prototype system based on existing grading panels. We constructed a gantry system to raise, lo wer, and pull grad ing panels through the length of a rectangular holding vat. Electrical power for the prototype was provided by a 12-volt marine battery. We conducted three successful fish grading events. The grading panel remained in contact with the vat floor and vat walls at all t imes. No fish evaded the panel by swimming under or around the panel, and all unwanted animals such as crawfish and tadpoles were captured. After one of the tests, the farm manager reviewed the graded fish, approved the grade, and immediately loaded the fish for shipment to a customer. A limited benefit-cost analysis indicated that the benefit of mechanization during the first year of operation was approximately US$8,600. The golden shiner Notemigonus crysoleucas is cultured for use as live bait by anglers. Go lden shiners are harvested from ponds containing a mixed-size population, and are placed in rectangular holding vats, where they are sorted into specified weight categories. Workers on Arkansas baitfish farms typically sort golden shiners by physically pulling rectangular panels comp rised of a set of uniformly spaced vertical rods through a vat holding as much as 400 pounds of fish. We developed and tested a device that replaces physical effort with machine power to accomp lish the grading p rocess.