Ōngātoro/Maketū Estuary Median chlorophyll-a concentration 2006-2011 At risk from: • Increasing nutrients and sediment Water quality and ecology of the • Nuisance plant and algae growth Kaituna/Maketū and Pongakawa/ • Loss of whitebait habitat Estuaries are dynamic environments with large changes in Waitahanui catchments tidal and river flows. About 63 percent of our native freshwater fish use estuaries to swim between fresh and salt water. Nutrients from the land wash into nearby streams and often end up in estuaries. Nutrients can promote excess plant and algae growth. We measure this growth by checking the concentration of chlorophyll-a, the pigment in plants that is used for photosynthesis. More chlorophyll-a generally means more abundance of weed and algae. The Ōngātoro/Maketū Estuary has a higher median chlorophyll-a concentration Chlorophyll-a concentration ranges for than any other Bay of Plenty river estuary. Bay of Plenty river estuaries 2006-2011 Chlorophyll-a 16 Median Cyanobacteria 14 25%-75% Cyanobacteria (also called blue-green algae) are a group 12 Min-Max of bacteria that have chlorophyll and behave like plants. 10

They occur naturally, but can ‘bloom’ under certain 3 8 conditions. Some species of cyanobacteria produce toxins

mg/m 6 which may be harmful to humans and other animals. 4 Summary Cyanobacteria generated in Lakes Rotorua and Rotoiti 2 • Nitrate is increasing in the Kaituna River Trophic level index of Lakes Rotorua sometimes spread into the Kaituna River, usually during 0 andT Rotoitirophic L2010-2014evel Index • Water quality is usually good for swimming summer months. Productivity, as indicated by chlorophyll-a, -2 Tarawera Rangitāiki Whakatāne Ōngātoro/ Ōpōtiki Ōpōtiki at five of six monitored sites 6 Supertrophic in the estuaries has remained low in comparison. River River River Maketū Estuary at Estuary at Estuary Estuary Estuary Estuary Kukumoa Wharf • Water quality in Lakes Rotorua and Rotoiti s 5 is improving Eutrotrophic n i t Estuary productivity 4 • Stream health is generally ‘excellent’ in upper Mesotrophic Macro algae like Gracilaria chilensis (red algae) catchments, but only ‘fair’ closer to the sea T L I U have been blooming in the upper Waihī and 3 • The Kaituna River Re-diversion and Oligotrophic Maketū estuaries. These algae are a feature of Ōngātoro/Maketū Estuary Enhancement changing conditions such as excess nutrients 2 Project will improve the health of the estuary. and changing salinity. 2010 2011 2012 2013 2014 Rotorua Rotoiti Upper catchment - River and estuary Lakes Rotorua and Rotoiti Lake macrophytes (aquatic plants) are important restoration habitats for fish and invertebrates and play a key role in We describe the health of lakes using the trophic level The Kaituna River Re-diversion and nutrient cycling. They are monitored using a lake health index (TLI), calculated using total nitrogen, total Ōngātoro/Maketū Estuary Enhancement assessment scoring system called the Lake Submerged phosphorous, water clarity, and chlorophyll-a. Project is re-diverting 20 percent of the Kaituna Plant Indicator (Lake SPI). Lake SPI values greater than River flow back into the Ōngātoro/Maketū TLI results show Lake Rotorua to be eutrophic (nutrient 75 percent are considered excellent; values 0-20 percent Estuary to improve estuary health. enriched) which leads to poor water quality. Lake Rotoiti are considered poor. is classed as mesotrophic (average water quality). See more information about this project at Introduced macrophytes dominate in both Lake Rotorua www.boprc.govt.nz/kaitunamaketurediversion Lake and estuary eutrophication can produce unsightly and Lake Rotoiti. The 2013-14 Lake SPI results in the table scums of algae on the water surface, lead to decreased below show that both lakes are in moderately healthy GD154465 animal and plant diversity, and can also affect ecological condition. recreational water use. Lake Rotorua Lake Rotoiti Extensive work to reduce nutrient run-off and improve 23% 21% For more information water quality in the lakes is ongoing. The TLI for Lake SPI Condition % both lakes has improved because of this work. Poor Good Poor Good Visit www.boprc.govt.nz/kaitunamaketu Phone 0800 884 880 Email [email protected]

Freshwater is essential to life; it sustains the things we value BAY OF PLENTY REGIONAL COUNCIL TOI MOANA Kaituna Maketū & Pongakawa Waitahanui Freshwater is essential to life; it sustains the things we value Animal and insect life Nutrients National Objectives Framework (NOF) (macroinvertebrates) Excess nutrients can cause increased growth of macrophytes The National Policy Statement includes a National Objectives All of the sites monitored in these catchments in 2014 Benthic macroinvertebrates (such as aquatic insects, snails and algae. The macrophytes can then clog water intakes, Framework (NOF), which sets compulsory national values had nitrate and ammonia levels that were within the and shrimp) live on or just below the stream-bed. use up dissolved oxygen during the night or as they for freshwater to protect ‘human health for recreation’ and ‘A’ or ‘B’ band for both nitrate and ammonia. This means decompose, and dramatically change habitat suitability ‘ecosystem health’. that current levels of nitrate and ammonia in the water Macroinvertebrates are vital to stream food webs as they for fish and other wild life. are unlikely to have an impact on sensitive wildlife. feed on algae, aquatic plants, dead leaves and wood, or on The NOF has a series of ‘bands’ ranging from A to D, and each other. They are in turn preyed upon by other animals Nutrient loads change depending on the land use in the National Bottom Lines for the following attributes in rivers: such as fish and birds. catchment and the amount of water in the water-body. The graphs below show total phosphorous and nitrogen To protect To protect human A water sample captures a single moment in time, however ecosystem health: health for recreation: macroinvertebrates are influenced by a wide range of factors loads at sites monitored by the Regional Council in 2013.   over a longer time period so they are very useful for assessing These graphsA vshowera gthate Anutrientsnnual in T theota riverl Phosphorous increase as Load Nitrate E.coli it flows from Ōkere Falls to Te Matai.   stream health. Average Annu(a2l0 T1o4t)al Phosphorous Load Ammonia Cyanobacteria A quick way to assess ecological health is by calculating Average Annual Total Phosphorous(2014) Load (2014) Kaituna at Okere Phosphorous load the Macroinvertebrate Community Index (MCI) which Average flow Kaituna at Okere Phosphorous load involves checking which invertebrate species are present Pongakawa at Forest Nitrate Good (Band A) Average flow NOF Banding and how abundant they are. Pongakawa at Forest Pongakawa at SH2 to Poor (Band D) Ammonia ratings are based Invertebrates have been monitored in 15 streams in the Pongakawa at SH2 Pongakawa at Old Coach Road on 2014 annual Kaituna/Maketū and Pongakawa/Waitahanui catchments. Primary contact (swimming) Pongakawa at Old Coach Road Secondary contact median levels Average MCI scores show that 12 streams are in either Waitahanui at SH2 (wading/boating) of nitrate, excellent or good condition, and three streams are in fair Waitahanui at SH2 Good A Primary (swimming) Kaituna at Maungarangi ammonia and condition. No streams are in poor condition. Streams with recreational contact has Good Kaituna at Maungarangi A performance excellent health are mostly in the upper parts of the Kaituna at Te Matai B a different rating system to secondary contact against safe catchment, while streamss in fair condition were at Kaituna at Te Matai 0 50 100 150 B >MAS based on the level of bacteria lower elevation and closer to the sea. Phosphorous = kg/day Flow = m3/s Poor 0 50 100 150 risk to people swimming. level guidelines Phosphorous = kg/day Flow = m3/s C Average Annual Total Nitrogen Load Good (Band A) rating for secondary contact (wading/ Average Ann(u2a0l 1T4o)tal Nitrogen Load means there is less than five percent risk of D Average Annual Total Nitrogen Load (2014) Poor boating). (2014) people getting sick from swimming. Poor Kaituna at Okere (exceeding Minimum Acceptable State) ratings mean there is more than five percent PonKgaaiktuanwaa a att O Fkoerreest risk of people getting sick from swimming. PonPgoankgaawkaa awta F aotr eSsHt2 Some sites do not meet the minimum PongakawaP aotn Ogaldk aCwoac aht RSoHa2d acceptable state (MAS) for recreational Pongakawa aWt Oalidta Choaancuhi aRto SaHd2 waters used for primary contact.

KaituWnai atat hMaanuuni gaat rSaHn2gi

KaitunKaa aittu Mnaa uant gTaer Managtai i

Kaituna at Te Matai 0 500 1000 1500 2000 2500 MCI Class Suitability kg/day for Recreation 0 500 1000 1500 2000 2500 Excellent Grade kg/day Good Good Fair Coastal and freshwater Fair recreational monitoring Poor When contaminated by human or animal faeces water can contain disease-causing bacteria, viruses and protozoa Land use (such as salmonella, campylobacter or giardia). Urban These organisms can pose a health risk in water used for Exotic Forest recreational activities such as swimming. Indigenous Forest The most common illness is gastroenteritis but respiratory Horticulture illness and ear and skin infections may also occur. Pasture Macroinvertebrates are collected from the streambed by disturbing The Suitability for Recreation Grade gives a general picture Water quality the streambed immediately above a triangular net, which captures all of water quality at a site, and is updated annually. monitoring results 2014 dislodged material (both invertebrates and organic matter). See more at: www.boprc.govt.nz/swimmingwaterquality

BAY OF PLENTY REGIONAL COUNCIL TOI MOANA Kaituna Maketū & Pongakawa Waitahanui Freshwater is essential to life; it sustains the things we value