The ecological condition of Waikato wadeable streams based on the Regional Ecological Monitoring of Streams (REMS) Programme

The Waikato Regional Council has been carrying out summer assessments of invertebrate community composition and habitat in streams and rivers annually since 1994 for the Regional Ecological Monitoring of Streams (REMS) programme. The aim of this work is to document the state and trend of ecological health in the region‘s streams as part of State of the Environment monitoring. The current sampling network comprises (i) ‗long-term sites‘ that have been sampled for 10 years or more using consistent protocols for assessment of trends over time (40 sites including 3 reference sites and 6 ‗restoration‘ sites where riparian management has been implemented or is planned) (ii) ‗random sites‘ selected using a probability-based survey design to provide an unbiased estimate of the regional condition of perennial non-tidal wadeable streams on developed land (60 sites sampled once each year for 3 years–180 sites in total; this cycle is repeated every 3 years); and (iii) ‗reference sites‘ in undeveloped (native forest) catchments to provide a baseline against which to measure change (24 sites sampled annually since 2005). The sites include wadeable hard-bottom streams with stony beds, and wadeable soft-bottom streams with beds dominated by sand and silt. Some long-term sites on rivers that are not wadeable have been retained while appropriate non-wadeable monitoring protocols are developed.