r

symbol

1) Product-moment (Pearson's) correlation coefficient, expressing the degree of association between two (linearly) related variables.
3) availability (the part of a fish population which lives in areas where it is susceptible to fishing during a given fishing season. This part receives recruits from or becomes mingled with the non-available part of the stock at other seasons, or in other years (Ricker, 1975). Fish become available through migration, movement in the water column, or growth)
3) intrinsic growth rate (how much a population can grow between successive time periods when not slowed down by competition. Often estimated with production models and plays an important role in evaluating the sustainability of different harvest levels and the capacity to recover after depletion).