The separation of fish eggs, live from dead, is a continuing problem for fish hatcheries. Sorting out unfertilized eggs that have not changed from orange to white (blanks) remains an unsolved problem. Traditional mechanical egg sorters insert fish eggs into disks or drums, then compare a small area of the egg to the background using reflective system to differentiate living from dead eggs. Air pressure is used to remove the egg from the sorter. Physical damage to the egg is always a difficulty. If the eggs could be sorted under water in tubes, using both reflective and through-beam density sorting, much physical damage would be eliminated and blanks could possibly be detected and discarded.Applications:The anticipated results of this project are to prove that an underwater sorting system is possible that will enable hatcheries to eliminate dead fish eggs with a minimum of damage to the good eggs. The process would be faster, quieter and safer than current methods. No motors would be involved, thus reducing the danger from electrical current.
