We know that V. cholerae goes into a dormant, spore-like state when environmental conditions do not favour reproduction. At this stage, it is "viable but non-culturable" (lines 40 to 49).
Therefore, we can infer that when V. cholerae is not dormant, it is culturable.
No one knows exactly what conditions awaken it from dormancy, but microbiologist Rita Colwell has noted that cholera cases near the Bay of Bengal correlate closely with seasonal peaks in sea-surface temperatures (lines 51 to 54).
The final sentence does tell us that it is possible that salinity enables V. cholerae to spread; however, it is more strongly supported that it is sea-surface temperature due to Colwell's observations.
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