National Objectives Framework (NOF) The National Policy Statement includes a National Objectives Framework Water quality and ecology (NOF), which sets compulsory national values for freshwater to protect ‘human health for recreation’ and ‘ecosystem health’. of the Rangitāiki catchment The NOF has a series of ‘bands’ ranging from A to D, and National Bottom Lines for the following attributes in rivers: To protect To protect human Rangitāiki River Estuary Lakes Āniwaniwa (Aniwhenua) ecosystem health: health for recreation: At risk from: and Matahina Nitrate E.coli • Increasing nutrients At risk from: Ammonia Cyanobacteria • Unwanted plant and algae growth • High nutrient levels causing high algae and macrophyte (aquatic plant) growth • Loss of riparian and whitebait habitat NOF Banding Nitrate • Exotic macrophytes choking waterways River estuaries are dynamic environments with large • Impacts of macrophyte growth on recreation and ecology Ammonia changes in tidal and river flows. About 63 percent of native freshwater fish species use estuaries to swim We describe the health of lakes using the trophic level index Primary between fresh and salt water. contact Secondary contact (TLI), calculated using total nitrogen, total phosphorous, (swimming) (wading/boating) Like many river estuaries, the Rangitāiki has little water clarity and chlorophyll-a. Good aquatic vegetation or macro-algae. TLI results shown below demonstrate that both lakes are Good A A Freshwater usually dominates the water quality of nutrient-enriched, and that Lake Āniwaniwa is classed as B river estuaries. Flood flows and the delivery of sediment eutrophic (poor water quality) and Lake Matahina is classed B and nutrients into estuaries can make it hard for plants as supertrophic (very poor quality). These lakes often have C and animals to live and grow there. unsightly scums of algae and floating plants on the water Poor >MAS surface, which can lead to decreased animal and plant Phosphorus and nitrogen are increasing in the estuary. D diversity, and affect recreation. Primary (swimming) recreational Poor Nitrogen is also increasing in the whole catchment, while contact has a different rating system phosphorus is only increasing in the lower catchment. Good (Band A) to Trophic Level Index to secondary contact based on the Poor (Band D) ratings Discharges and land use influence phosphorus in the level of risk to people swimming. 6 are based on 2014 lower catchment. Good (Band A) rating means there 5.5 annual median levels Nutrients can promote excess plant and algae growth. is less than five percent risk of people Supertrophic of nitrate, ammonia We measure plant and algae growth by measuring the 5 getting sick from swimming. Poor and performance concentrations of chlorophyll-a, the pigment in plants (exceeding Minimum Acceptable 4.5 against safe bacteria that is used for photosynthesis. State) ratings mean there is more Eutrophic level guidelines 4 than five percent risk of people The Rangitāiki Estuary has the highest maximum for secondary TLI Units getting sick from swimming. chlorophyll-a concentrations and the second highest 3.5 contact (wading/ Mesotrophic median concentration of all Bay of Plenty river estuaries. Some sites do not meet the boating). 3 minimum acceptable state (MAS) 2.5 for recreational waters used for Chlorophyll-a Oligotrophic 2 primary contact. 16 12/13 01/14 02/14 03/14 04/14 Median 14 Āniwaniwa Matahina 25%-75% MCI Class Suitability Land use 12 Macrophytes are important habitats for fish and invertebrates for Recreation Min-Max Excellent Urban Grade 10 and play a key role in nutrient cycling. They are monitored Good Exotic Forest using a lake health assessment scoring system called the Good 8 Lake Submerged Plant Indicator (Lake SPI). Fair Indigenous Forest Fair Poor Horticulture 6 Because introduced macrophytes have largely out-competed native species in these two lakes, Lake SPI Pasture 4 GD154465 scores are low. Lake Matahina especially has very few native macrophytes left, and is dominated by exotic species. 2 See Lake SPI scores in the table below. 0 Lake Āniwaniwa Lake Matahina For more information -2 12% 10% Tarawera Rangitāiki Whakatāne Kaituna Ōpōtiki Ōpōtiki Lake SPI Condition % Visit www.boprc.govt.nz/rangitaiki River River River River Estuary at Estuary at Poor Good Poor Good Phone 0800 884 880 Estuary Estuary Estuary Estuary Kukumoa Wharf Email [email protected] Freshwater is essential to life; it sustains the things we value BAY OF PLENTY REGIONAL COUNCIL TOI MOANA Rangitāiki Freshwater is essential to life; it sustains the things we value Nutrients Coastal and freshwater Excess nutrients can cause increased growth of macrophytes The graphs below show total phosphorus and nitrogen loads recreation monitoring (aquatic plants) and algae. The macrophytes can then clog at sites monitored by the Regional Council in 2013. These water intakes, use up dissolved oxygen during the night or as show a general increase in nutrients moving down the Water contaminated by human or animal they decompose, and dramatically change habitat suitability catchment. Nitrate levels are also increasing at Murupara. faeces can contain disease-causing bacteria, for fish and other wildlife. viruses and protozoa such as salmonella, campylobacter or giardia. Average Annual Average Annual These organisms can pose a health risk in Total Phosphorus Load Total Nitrogen Load water used for recreational activities such (2013) (2013) as swimming. Phosphorus load Otamatea Otamatea Avg. Flow Rangitāiki Rangitāiki at SH5 at SH5 Bridge Bridge Whirinaki Whirinaki at Galatea at Galatea Bridge See more at: www.boprc.govt.nz/swimmingwaterquality Bridge Rangitāiki Rangitāiki at Murupara at Murupara Bridge Bridge Rangitāiki Rangitāiki at Te Teko Ecological health at Te Teko 0 1000 2000 3000 Aquatic macroinvertebrates (such as aquatic insects, exotic forest have the highest ecological health, 0 50 100 150 200 snails and shrimp) are very useful for assessing stream health. while the ecological health of streams draining kg/day (m3/s) kg/day A water sample captures a single moment in time, however from pasture is lower. macroinvertebrates are influenced by a wide range of factors Stream health was especially low in the over a longer time period. Rangitāiki River’s main channel on the plains. A healthy macroinvertebrate community is typically found in Other sites, particularly in the lower Rangitāiki, streams with good or excellent health. Monitoring results from had macroinvertebrate communities indicative 2013/14 show that streams draining from native bush and of fair to poor health. Macroinvertebrates are collected from the streambed by disturbing the streambed immediately above a triangular net, which captures all dislodged material (both invertebrates and organic matter). BAY OF PLENTY REGIONAL COUNCIL TOI MOANA Rangitāiki Freshwater is essential to life; it sustains the things we value.