Chinook salmon successful at guarding their redds. Chinook eggs hatch, 90 to 150 days after deposition, depending upon water temperature. Egg deposits are timed to ensure the young salmon fry emerge during an appropriate season for survival and growth. Fry and parr (young fish) usually stay in fresh water 12 to 18 months before traveling downstream to estuaries, where they remain as smolts for several months. Some Chinooks return to the fresh water one or two years earlier than their counterparts, and are referred to as "jack" salmon. "Jack" salmon are typically less than long, but are sexually mature and return at
Salmon louse attached to the abdomen. The salmon louse uses its feet to move around on the host or to swim from one host to another. This parasite is one of the major threats to salmon farmers. Salmon are stocked usually for a 14 - 18 month cycle. Salmon farms are an unusual, but ideal environment for the sea lice to breed. The infestations of sea lice in salmon farms increases the number of lice in the rest of the surrounding water dramatically if the eggs from the gravid louse are allowed to disperse. Sea lice can also affect juvenile salmon while