A recent algal bloom occurred in the Baltimore Inner Harbor resulted in thousands of dead menhaden. It has been speculated that the oxygen depletion caused by bacterial respiration resulted in the massive fish kill. However, little is known about how the bacterial populations change during the bloom period. This study is set up to investigate: 1) the change of viral and bacterial abundance during the bloom’ 2) type of culturable bacteria associated the algal bloom. Two litter water samples were collected every other day over a two week span. Small amounts of the raw water sample was plated and an additional sample of raw water was fixed for counting. Different types of bacteria were isolated based on their various morphology and characterized based on their 16S rRNA gene sequences.

Results/Conclusions:

The study illustrated a huge increase of bacterial abundance directly after the algae bloom and a rapid recession of bacterial cells and viral particles. One bacterial strain (BIH2), identified as Vibrio sp., appeared to be the most abundant type during the fish kill. The bacterium BIH2 was most closely related to the Vibrio species found in zebrafish guts.