The Activity and Catchability of the Lobster (Homarus americanus) in Relation to Temperature

Abstract

The activity (walking rate) of lobsters acclimated to various temperatures increased from 2 to 10 °C. and from 20 to 25 °C. but was constant between 10 and 20 °C. Lobsters acclimated to low temperatures were most active above the acclimation temperature. Those acclimated to intermediate and high temperatures were most active at the acclimation temperatures. Experimental fishing of a relatively constant stock showed that the catch per 100 standard trap hauls (index of catchability) was linearly related to temperature. Slope of line is, however, dependent on stock density. Catchability is shown to be proportional to activity minus a constant. This relationship permits use of catch per unit effort and accumulated catch data to estimate lobster populations.