Gas bubbles in the sea: a review and model proposals

Abstract

The literature pertaining to both free bubbles (pt 1) and bubbles associated with fish anotomy (pt 2) is reviewed with particular emphasis on their distributions in the sea and influencing factors. An attempt is made to compact the results to date into simple, mostly empirically-based models. Some of the models proposed contras t with those previously used. For example, depth dependence of free-bubble concentrations is pr~P9sed to be simply influenced by pressure, which causes a (depth) 2 / ~ relationship for Medwin IS 1970 data (radius> 60 micrometres) for depths greater than 10 metres, while at shallower depths the dependence is less. In refitting data of fish-bladder volume to be proportional to (length)N, N was strongly dependent on the type of fish, and in all cases, N was larger than previously accepted. Finally, a free-bubble concentration-function model is proposed which is a linear sum of functions of a single generating mechanism (waves, rain, photosynthesis, etc.). Although this laststep may be premature from the standpoint of our present knowledge of the subject, it supplies a basic structure and aids in clarifying where knowledge is lacking.