increases in estimated fishing effort in all states except Florida.

Standardization of vessels in Florida leads to a downward adjustment in

measured fishing effort for all years since 1962. Thus, it can be seen

that the failure to adjust nominal effort (vessels) by the fishing power

indices can result in serious overestimations of stock assessment mea-

sures such as catch per unit of effort.

 The similarity of the fishing power function to the traditional

economic production function facilitates an analysis of the substituta-

bility of average crew and vessel size in "producing" fishing power.

The importance of such substitution relates primarily to questions

involving appropriate management levels of effort. Consider, for

example, a situation where a specified number of vessels with a given

average fishing power per vessel are determined to constitute of appro-

priate amount of effort by management authorities. Any change in average

fishing power per vessel will create a change in effective fishing

effort, even though the actual number of vessels may remain constant.

The implication here is that changes in fishing power determinants

(average crew and vessel size) must be managed such that changes in

these factors do not change average fishing power, or the number of

vessels must be adjusted to reflect these changes.

 Constant levels of fishing power may be analyzed with iso-fishing

power contours calculated from the fishing power function in equation

(75). The expression for these contours for a given level of fishing

power, Ep is given by


 X E1.0417 i-0.4792 (77)
 li Po 2i