Aims This experimental study focuses on survival and consistence ofVibrio parahaemolyticusin cold-water sediments and how increasing temperature and nutritional availability can affect growth. Methods and Results A pathogenic strain ofV. parahaemolyticuswas inoculated in seawater microcosms containing bottom sediment. Gradually, during 14 days, the temperature was upregulated from 8 to 21 degrees C. CulturableV. parahaemolyticuswas only found in the sediment but declined over time and did not recover even after another 2 days at 37 degrees C. Numbers of culturable bacteria matched the amount found by q-PCR indicating that they did not enter a dormant state, contrary to those in the water layer. After adding decaying phytoplankton as fertilizer to the microcosms of 8 and 21 degrees C for 7 and 14 days, the culturability of the bacteria increased significantly in the sediments at both temperatures and durations of exposure. Conclusion The study showed thatV. parahaemolyticuscan stay viable in cold-water sediment and growth was stimulated by fertilizers rather than by temperature. Significance and Impact of the Study Vibrio parahaemolyticusis a common cause of seafood-borne gastroenteritis and is today recognized in connection to increasing ocean temperature. The results indicate that this pathogen should be considered a risk in well-fertilized environments, such as aquacultures, even during cold periods.