Aim:  To evaluate the electropositive, alumina nanofibre (NanoCeram) cartridge filter as a primary concentration method for recovering adenovirus, norovirus and male‐specific coliphages from natural seawater. Methods and Results:  Viruses were concentrated from 40 l of natural seawater using a NanoCeram cartridge filter and eluted from the filter either by soaking the filter in eluent or by recirculating the eluent continuously through the filter using a peristaltic pump. The elution solution consisted of 3% beef extract and 0·1 mol l−1 of glycine. The method using a peristaltic pump was more effective in removing the viruses from the filter. High recoveries of norovirus and male‐specific coliphages (>96%) but not adenovirus (<3%) were observed from seawater. High adsorption to the filter was observed for adenovirus and male‐specific coliphages (>98%). The adsorption and recovery of adenovirus and male‐specific coliphages were also determined for fresh finished water and source water. Conclusion:  The NanoCeram cartridge filter was an effective primary concentration method for the concentration of norovirus and male‐specific coliphages from natural seawater, but not for adenovirus, in spite of the high adsorption of adenovirus to the filter. Significance and Impact of the Study:  This study demonstrates that NanoCeram cartridge filter is an effective primary method for concentrating noroviruses and male‐specific coliphages from seawater, thereby simplifying collection and processing of water samples for virus recovery.