Researchers analyzed bacteria in Laizhou Bay using a method called PCR-RFLP. They looked at DNA from water and sediment samples and found different types of bacteria. In sediment, Proteobacteria and Bacteroidetes were common, with Proteobacteria being the most dominant. In water, they found nine types of bacteria, with Proteobacteria being the most common again. Different subgroups of Proteobacteria were also identified in both sediment and water samples.