FIG. 4.

Relative abundance of merA phylotypes within the four clone libraries. A threshold of 97% nucleotide identity was used to define each merA phylotype. SI, sea ice; LG, lagoon. Different shading patterns indicate different phylotypes, and sections with similar patterns in each bar denote similar phylotypes that were present in more than one library. Phylotype numbers, provided for those phylotypes that represent at least 10% of a library, correspond to those used as phylotype designations shown in Fig. 2.