Winter Egg Development
January - March
Winter at Craig Brook National Fish Hatchery is a time of waiting. The eggs that were spawned the previous November are slowly developing in the incubation trays. The water temperature can dip to just a few degrees above freezing, so the eggs develop very slowly. In mid-January, eggs reach the 'eyed-egg' stage; hatchery staff begin the task of processing the eggs from their individual trays into large groups. During this process, dead eggs are removed; the eggs are measured and counted before being laid down in a uniform amount of eggs per tray.
Following egg processing (or batching) the arduous task of egg picking begins. The hatchery staff devotes numerous hours in removing dead and unfertilized eggs from the egg trays, one at a time, with small pipettes (similar to small turkey basters). This is done on a continuous basis, to ensure that the trays remain clean and the eggs are kept healthy.
Starting in late-February and continuing until early spring, the eggs begin to hatch into sac fry, sometimes called alevin. The process of removing dead fry and egg shells is paramount to the health of the population.
In addition to caring for eggs and fry during the winter, the hatchery staff spends time writing reports based on data collected throughout the year; and they begin preparations for the upcoming fry stocking season.