U:\2021\BM210482_IBo_Waihi_North_Project\Documents\WNP_Freshwater_Report_May_2022\FINAL_Freshwater_Report_FOR DELIVERY_June 2022\FINAL DELIVERED 17 JUNE 2022\WAI-985-000-REP-LC-0007_Rev0_Freshwater_20220621_FINAL.docx Mean chlorophyll-a concentrations were below the threshold of 50 mg/m2 for the protection of benthic biodiversity (Biggs, 2000) at all sites. Mean Ash Free Dry Weight (AFDW) was below the threshold of <35 g/m2 for the protection of aesthetics / recreation and trout habitat and angling (Biggs, 2000) at all sites. 7.3.4 Macroinvertebrate Assemblages Macroinvertebrate communities were diverse across all sites and representative of high-quality stream habitats, with high abundance of EPT taxa present across all sites (Table 6). All communities were dominated by sensitive EPT taxa (ephemeroptera, trichoptera and plecoptera), comprising at least 67% of all individuals present. Individuals from taxa groups gastropod (snails), diptera (true flies) and coleoptera (beetles) were also recorded with a range of other groups present in much lower-abundances including midges, amongst others. Table 6: Macroinvertebrate metrics. Means (n=6) are presented, January and February 2019. Metric (mean) T-Stream West T-Stream East WKP-3 WKP-2 Total abundance 220 276 176 810 No. of taxa 18.0 20.7 16.2 26.0 No. of EPT taxa 12.3 13.5 11.0 16.7 Percent EPT taxa 69.3 64.1 69.3 64.1 MCI score 135.8 135.3 129.8 113.8 QMCI score 7.8 8.0 7.3 6.2 7.3.5 Fish Communities Fish communities were diverse for the sampling sites with a total of six different species present across the four survey sites. The Wharekirauponga Waterfall, of approximately 4 m in height, is located on the Wharekirauponga Stream between the WKP- and T-Stream sites. The presence of this waterfall creates a significant barrier for fish passage and its presence has a substantial impact on fish communities upstream and downstream, as outlined below. No introduced fish species were observed at any survey site. 7.3.5.1 Sites T-Stream West and T-Stream East Sites T-Stream West and T-Stream East were both located upstream of the Wharekirauponga Waterfall. Longfin eel and kōaro were present at both T-Stream West and T-stream East, while shortjaw kokopu was found at site T-Stream East. Juvenile eels, or elvers, were also present at both sites and unidentified juvenile galaxiids were recorded at site T-Stream West. Elver species may be from the species shortfin eel or longfin eel. Fish abundances were similar with 27 and 20 individuals recorded at T-Stream West and T-Stream East, respectively. 7.3.5.2 Sites WKP-3 and WKP-2 Sites WKP-3 and WKP-2 are both located downstream of the Wharekirauponga Waterfall and both have a more diverse fish community than the sites upstream. This diversity is in no doubt owning to their comparatively easy accessibility from the sea. In addition to longfin eel (Anguilla dieffenbachii) and kōaro (Galaxias brevipinnis), torrentfish (Cheimarrichthys fosteri), redfin bully (Gobiomorphus huttoni) and common smelt (Retropinna retropinna) were also present at both
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