Design of an automated fish marking machine

Marking of juvenile fish in hatcheries, before releasing into lakes and rivers, is an activity that is very valuable in fishery management. Samples of grown fish could be subsequently harvested and examined to collect data, that would be useful for many purposes such as predicting fish stocks, determining migration patterns of fish, and ascertaining the survival ratio of hatchery fish. A simple presence/absence type mark can be applied fast and may provide a straightforward identification means for hatchery fish. This paper presents the design development process of an automated machine for spray marking of fish. The machine consists of three main modules: the feeding unit; the conveying unit; the spray marking unit; and the pigment recirculation unit. The paper will present the development and integration of these modules