Spatial patterns in the composition of shallow‐water macroinvertebrate communities of a large New Zealand river

Abstract

Identifying the environmental factors influencing biotic patterns in large rivers will assist with extrapolating biological monitoring results to broader scale conclusions about river condition. In the present study, we collected macroinvertebrates and physico-chemical data at 47 shallow-water (<1-m deep) sites, including nine sites at major tributary junctions, during summer along the lower Waikato River, North Island, New Zealand. Macroinvertebrate communities were dominated by a few relatively abundant and widespread taxa. Upper site samples were characterised by high relative abundances of Diptera, but the significance of this group declined further downstream where Crustacea became more dominant. Overall, more taxa (36) were found at tributary junctions than at mainstem sites within four hydrogeomorphic zones (22-31 taxa per zone). Significant differences among faunal groups identified in a cluster analysis on relative abundance data were detected for the percentage of wood sampled, and for water conductivity which increased downstream at mainstem sites and was high at some junction sites. Non-metric multidimensional scaling of percentage abundance data revealed differences in community composition among zones,

Effects of flow regulation, basin characteristics and land-use on macroinvertebrate communities in a large arid Patagonian river

“…Collier and Lill (2008) observed an increase in diversity at main channel sites with distance down river in a large New Zealand watercourse, most likely as a consequence of interplay between habitat patchiness and successional and hydrogeomorphic processes influencing macroinvertebrate community. In the middle Chubut river basin where turbidity and flood disturbance were high, benthic density was low as found below a tributary of the Colorado River in arid Arizona (Shaver et al 1997, Stevens et al 1997.…”

Estimating vertebrate, benthic macroinvertebrate, and diatom taxa richness in raftable Pacific Northwest rivers for bioassessment purposes

“…Bartsch et al (1998) estimated 18-40 sites were needed for the upper Mississippi River and Raunio and Antilla-Huhtinen (2008) recommended eight sites, but they were studying soft-bottomed systems compared to our typically hard bottomed rivers (Table 1). Collier and Lill (2008) collected 63 macroinvertebrate taxa from the Waikato River, New Zealand, by using a kick net with the same mesh size as ours and by sampling all available habitats, but they only sampled 47 stations (versus our 220 per river) and only counted 200 individuals per sample (versus our 500 per composite sample).…”

Littoral and benthic macroinvertebrate community responses to contrasting stressors in a large New Zealand river

“…3 upper left panel), that supported quite diverse macroinvertebrate communities downstream of Huntly, despite an overall decline in benthic taxa richness below the Waipa confluence. The Waipa River and nearby inflows from the forested Hakarimata Ranges may also contribute novel taxa to the river around tributary junctions (Collier & Lill 2008), although sampling in the present study was not intended to capture local diversity hot spots.…”