Salmon run plankton. At this point the baby salmon are called "fry". At the end of the summer the fry develop into juvenile fish called "parr". Parr feed on small invertebrates and are camouflaged with a pattern of spots and vertical bars. They remain in this stage for up to three years. As they approach the time when they are ready to migrate out to the sea the parr lose their camouflage bars and undergo a process of physiological changes which allows them to survive the shift from freshwater to saltwater. At this point salmon are called "smolt". Smolt spend time in
Healthy Life Years asked concerning the longstanding activity limitation is: "For the last six months, to what extent have you been limited because of a health problem in activities that people usually do?" Some available answers are "severely limited", "limited but not severely", or "not limited at all". The indicators used to calculate a person's healthy life years are self-reported to a certain extent and therefore would be considered limited. The collected data is affected by the respondent's subjective perception as well as by their social and cultural background. That is because people from different social backgrounds like different cultures, race and ethnicity,