Fate and possible effects of excessive sperm released during spawning

Abstract

A great number of marine animals rely on communal spawning for procreation. Male gonad material released during spawning represents a significant proportion of the total biomass of the population. Only insignificant proport~ons of this material are functional in fertilization, the remainder represents a nutritional input to phagotrophic and osmotrophic microbial food webs, allowing increased productivity a t this level of the ecosystem. Degradation of male gonad material also results in increased nutrient availability for eventual phytoplankton productivity The extent to which this might influence survival of f~sh larvae is discussed A great number of marine animals rely on sexual mechanisms involving external fertilization, spawning , for procreation. Spawning entails the release into the water of massive amounts of male gonad material, only a minimal fraction of which is directly involved in fertilization. Male gonads comprise from some 20 % (herring and mackerel) to about 10 % (codfish and haddock) of live spawn-ripe individual fish weight. Accordingly, material corresponding to some 5 % to 10