Paying Respect to the Elders in Recreational Fisheries Management

Larger and older individuals often produce disproportionally large numbers of future recruits, because of allometry in batch fecundity, offspring size, and spawning frequency.  Unfortunately, the scaling of life history variables is not typically accounted for in evaluating the potential effect of management regulations on stock sustainability.  Furthermore, minimum length regulations that maximize harvest often do so at the expense of maintaining a natural size-structure in the population, with the potential to cause severe size-truncation. We adapted a structured population model to incorporate changes in size-specific life traits and calibrated the model to represent Tautog, a marine fish species with a substantial recreational fishery. We tested the effect of alternate length limits on biological reference points commonly used in fisheries management. We found that yield and availability of trophy sized fish, as well as the spawning potential ratio and measures of reproductive output from larger individuals, were sensitive to the scaling of seasonal fecundity and other life history traits.  Hence, targets for recreational fisheries management and factors important to population sustainability are dependent on the value of elders and the degree to which the harvest of elders is restricted by approaches such as harvested slot limits.