For example, the ocean contains an estimated 1.3 × 1028 archaeal cells, 3.1 × 1028 bacterial cells, and 1 × 1030 virus particles.[1][2] The bacterial diversity, a measure of the number of types of bacteria in a community, is estimated to be about 160 for a mL of ocean water, 6,400–38,000 for a g of soil, and 70 for a mL of sewage works.[2] Yet as of 2010[update], it was estimated that the total global environmental DNA sequencing effort had produced less than 1 percent of the total DNA found in a liter of seawater or a gram of soil,[3] and the specific interactions between microbes are largely unknown.