Vibrio anguillarum: Prevalence in three carbohydrate loaded marine recipients and a control

Abstract

A bacteriological study of prevalences of Vibrio anguillarum like organisms (VLO) in three marine recipients, polluted with effluents from sugar and cellulose factories, showed some characteristic features. In the winter period very low counts of VLO were recorded. During temperature rise in spring the VLO values rise to a characteristic level persisting from June to September. A decline occurs at this time, except in sites polluted from sugar plants, where there is a delay of appr. one month. In the relatively stable period the prevalence of VLO in the recipients is appr. 10–100 per ml water and 1.000–10.000 per gram sediment while the corresponding values for the control are 1–10 per ml and 100–1000 per gram, respectively. Thus fish living in these recipients are exposed to a ten times higher risk from VLO, which is reflected in a higher prevalence of an ulcus disease in cod. The complicated nature of pollution induced diseases makes it impossible directly to correlate VLO and disease prevalence. Prevalence studies of VLO in marine recipients give valuable information on growth conditions (“organic pollution”) for marine vibrios and the risk to fish, wild living and cultured. Therefore this group of bacteria should to be added to the list of marine indicator organisms, where the indication is based on the environmental risk.