Scales were the preferred structure to study age of fish
With increasing age the connection between the length and age of fish
Currently we assume the age of fish
at first capture is about 1 year and Fcurrent was 0.
macrocephalus in Wilson Inlet essentially doubled between 1988-89 and 2006-08, the differences between the predicted lengths at age of fish
at each of the dominant integer ages in the two periods were <2% and thus considered not to be of biological significance.
4B), and to the lengths at age of fish
that could not be sexed by using gonads but could be assigned a sex on the basis of the combination of its length and color (see Results).
Age of fish
was estimated by examining whole otoliths for fish less than 80 cm FL and thin sections were prepared for aging larger fish (DeVries and Grimes, 1997).
With the exception of the oldest age of fish
at recapture, the fishing mortality rates also tend to be estimated with good precision (CVs of less than 0.
Otolith increments from known-age fish were enumerated to validate that growth increments were deposited daily and to validate the age of fish
at first ring formation.
14]C time series is not entirely necessary for validating the age of fish
, and perhaps of any other organism.
However, because we could estimate the age of fish
at time of recapture, we were able to manipulate the von Bertalanffy equation to obtain the following equation:
Miller and Geibel (1973) and MacGregor (1983) both used scales to age blue rockfish (which also can underestimate the age of fish
[Beamish and MacFarlane, 1987]), and, yet, their growth models more closely approximated the model produced by our study.
Hook size may have had a limited effect on size differences because the mean lengths at age of fish
we sampled that were caught with commercial or recreational gear were not significantly different, and Nelson (1988) reported that the hook sizes did not seem to affect the size distributions of several fish species captured in his study.