Technical Memorandum Report No. 57
L. Stephen Lau, Philip C. Loh, and Roger S. Fujioka
Human enteric viruses were recovered from 0.19 to 0.76 m3 samples obtained from various natural marine water sites using the portable virus concentrator (Aquella). The concentration and frequency of viruses and coliform bacteria were highest within the sewage plume over the ocean discharge pipe and proportionately decreased as the sample distance from the plume was increased. Viruses were recovered at a maximum distance of 3 218 m from the plume but never from a station 6 436 m from the plume. However, since the same type of sewage-borne viruses were also recovered from boat marinas and from a stream entering the ocean, the sewage ocean outfall may not be the only source of viruses entering the ocean. Significantly, viruses were occasionally recovered from samples which were negative for coliform bacteria. The expected stability of human enteric viruses in the marine waters was determined to be approximately 48 hours using type 1 poliovirus as the model virus. All marine waters obtained from various sites off the coast of Hawaii were determined to be virucidal and evidence was obtained that marine microorganisms are the natural virucidal agents in these waters.