Benthic diatom samples were collected in December 2002 and March 2003 from all sites
and stored at -20 °C in the dark before processing at the NIWA Christchurch laboratory.
In addition to periphyton grown on polyethylene slides, epipelon and epiphyton samples
were collected if available. Primarily, macrophytes that were common in either wetland
type were sampled to ensure sufficient replication across sites. Wherever possible, plant
fragments of a variety of macrophyte forms such as rushes, aquatic bryophytes, and other
hydrophytes were gathered to assess potential morphological impacts on epiphyton
communities. Taxa such as Juncus spp. and Carex spp. were summarized in the family
Cyperaceae. A list of substrates taken at the studied wetlands is given in table 3.1 (for a
more detailed chart see Appendix, Part B); sampled plant specimens were also catalogued