Ecosystem Health and Conservation: New Zealand Rivers and Lakes
The New Zealand landscape is characterised by a range of ecological and geomorphic features that give way to extensive, diverse, dynamic and biodiversity rich freshwater systems. These extensive freshwater systems are comprised of mountain streams, braided and meandering rivers, lakes and groundwater resources. There are over 70 major river systems in New Zealand, with 30 located in the North Island and 40 located in the South Island. There are also over 4000 lakes that are over 1 hectare in size (Verburg et al. 2010) These freshwater resources are extremely important for a wide range of reasons; they are recreationally utilised by a great portion of New Zealanders for activities such as fishing, kayaking, and swimming and ecosystems are comprised of a range of native and endemic plant and animal species, many of which are incredibly rare, with some species such as the Black Mudfish for example becoming endangered (Ministry for the Environment, 2013; New Zealand Conservation Authority, 2011) There are a range of both anthropogenic and environmental pressures that currently adversely impact freshwater river and lake ecosystems in New Zealand, or have done so in the past. The most detrimental impacts on freshwater ecosystems in New Zealand are predominately derived from agriculture and farming activities (Department of Conservation, N.D; Ministry for the Environment, 2008; Townsend et al. 2008). The main technique employed to quantify the extent that pressures impact the state of an environment is the identification and use of environmental performance indicators or EPI's. EPI's are essentially parameters describing the potential impact of activities, products or services on the environment (The Global Development Research Centre, 2011).
What are indicators
Since it is not possible to monitor every aspect of the environment, indicators are used in order to simplify the process of determining the current state of the environment. Each indicator can be used in order to look at specific aspects of the environment or used together to give an overall picture of the state of the environment. In order for the indicators to work in such a manner they must be practical, meaningful, and cost effective. For a indicator to fall under the right category and deem it as effective there must be previously recorded data on it, these are obtained from trend analysis that is often done by agencies in New Zealand such as NIWA and the local government. New Zealand currently has two indicators for freshwater. The first covers freshwater found in lakes, rivers, and also groundwater aquifers. This indicator covers a number of factors including the concentrations of nutrients (nitrogen and phosphorus in rivers and lakes, and nitrate in groundwater), concentrations of the bacterium Escherichia coli (E. coli) in rivers and lakes, including freshwater swimming spots, visual clarity in rivers and lakes, water temperature in rivers, dissolved oxygen in rivers, and the richness of macroinvertebrate species (%EPT) in rivers. The second indicator is the demand for freshwater, this is the total consumption of fresh water by humans, known as the total consumptive water allocation.
Previous water quality in lakes- recorded in November 2006
Guide to EPI’s in lake water quality
The trophic level index (TLI) is widely used in New Zealand to measure changes in the trophic status (nutri-ent levels) in lakes. This index monitors phosphorus and nitrogen levels, as well as visual clarity and algal biomass. The Lake SPI index uses submerged plant indicators (SPI) to consider the ecological condition of lakes in New Zealand. Some key features of aquatic plant structure and composition are used to assess the native and invasive character of vegetation in the lakes.
TLI index monitoring of NZ lakes
Using the Trophic level index (TLI) or a modified version, the trophic state was assessed for 134 lakes across New Zealand. Thirteen of these lakes are not currently monitored, and were assessed by survey or by previous records collected by the New Zealand Lake Water Quality Monitoring programme (NZLWQMP) between 1992 and 1996. The results show a reasonably even spread in trophic status within the lakes with roughly half of the 134 lakes shown to be eutrophic or in worse condition. The South Island showed the most lakes in pristine con-dition (microtrophic), due to the lakes usually being deeper and subjected to less land use pressure. The lake records show that the lakes with the highest water quality in the South Island were Lake Tekapo and Lake Coleridge in the Canterbury high country, while in the North Island Lake Taupo, four of the Rotorua lakes and two dune lakes in Northland were oligo-trophic or better.The trophic status of the lakes is shown to be greatly affected by depth, with eutrophic lakes usually being shallower than the more pristine, deeper lakes. This is simply due to the capacity to absorb incoming nutri-ent loads favouring the lakes with greater depth.
Ecological conditions of New Zealand lakes as assessed by the SPI index
The ecological condition of 76 lakes was assessed using SPI, with only lakes in the Northland, Auckland,Waikato and the Bay of Plenty regions being tested, with 14 lakes in Northland being assessed but unavailable for this survey. For levels are established corresponding to the following SPI scores: - Excellent > 85% - High 50-85% - Moderate 20-50% - Low <20%. Few lakes were in the excellent category, with an even spread over the other categories. Six lakes with excellent ecological conditions were the Northland dune lakes Kuhuparere, Pretty, waiporotita, and Te Paki- and the Waikato peak lakes Rotopiko eats and Rotopiko north. However, the trophic state of these lakes is shown to be ranging from mesotrophic to hypertrophic, showing that the ecological state can be independant of the trophic levels.There is no real relationship between ecological condition and lake type, and lake depth. This suggests that many factors affecting ecological condition such as invasive plants and exotic fish can impact any lakes. This information shows that there is no strong relationship between ecological condition and trophic state. Lakes that fared badly in terms of ecological condition correspond to trophic states of eutrophic or worse, while lakes in excellent and high condition had a wide range of trophic states. This is due to the fact that the two indices (Lake SPI and TLI) measure different qualities of lake health. Past studies have found no obvious link between eutrophication and the invasive potential of exotic plants which form a major component of the Lake SPI index.
Changes in trophic state in New Zealand Lakes
Trend in trophic states are provided for 70 lakes. In some areas the length of the record was too short to have been assessed by councils. Changes in trophic state provided by the MfE in this time are based on trend analysis from published reports (Burns et al, 2000) or from change in the reported trophic state since the New Zealand Lake monitoring program began(NZLMP)(Burns and Rutherford, 1998). These cover the period of 1995-2002, with precise periods different for each lake or region. Therefore, caution is need-ed when comparing results. These results also show past change but can not necessarily be used to predict future change. The is due to the water quality fluctuating over time, or shallow lakes showing water quality changes due to the change in macrophyte communities. Nationally, there were more lakes with improving water quality than declining in 2006. However, most of the monitored lakes are in the Canterbury high country and are already previously reported as having near pristine water quality. The findings are also based on the changes in trophic state reported over 10 years, rather than a comprehensive trend analysis of the data.
Changes in Lake ecological condition
Information for ecological condition change (LakeSPI) was available for 44 lakes at the time of the MfE survey. The results shown are based on lakeSPI surveys by NIWA for Environment Waikato and Environment Bay of Plenty (Edwards et al 2005; Scholes and Bloxham 2005). For the MfE report, trends were reported if there was more than a five percent change in LakeSPI compared to the previous surveys. However time periods between surveys in the lakes ranged from 5 to 20 years. Macrophyte surveys in the Auckland Lakes were not interpreted. Waikato and Bay of Plenty saw greater declines in ecological condition than in water quality. 45% of the lakes show a decline in ecological condition, while roughly a third of the Waikato and Bay of Plenty lakes showed a decline in water quality. This decrease in ecological condition may reflect expansion of exotic plants and fish in the lakes. For example, an invasion of hornwood negatively affected the LakeSPI in Lake Tarawera. No significant correlation between trends in TLI and Lake SPI were found. For 21 lakes with information on trends for both TLI and LakeSPI, 13 lakes showed the same trend (improving, declining, or no change) for both indexes. This information may have little value however as the trends for each index are based on different time periods, sample sizes were small and past studies have shown no link between eutrophica-tion and risk of invasive plants(Hughes, 1976). However there is a link between macrophyte communities and water quality, with the collapse of populations resulting in water quality deterioration of water quality, which then improves as macrophytes re-establish. Lakes that are returning to more stable macrophyte dominated state see improvements, such as lake Rotorua where native macrophyte populations are having positive impacts on water quality.
Current water quality in lakes (November 2010)
TLI index in NZ lakes
Of the currently monitored lakes, 112 have nutrient data between 2005 and 2009 available. Of these lakes - 44% have high to very high levels of nutrients, indicating that the water is degraded. - 33% have low levels of nutrients It is found that 11 of the 112 lakes are shown to be “hypertrophic” or saturated with nutrients and the water quality is extremely degraded. In these lakes, algal blooms are very common and the aquatic animals are unhealthy or at risk. Some recreation can take place on the surface of these lakes (sailing) but swimming activities are generally restricted due to prolific weed growth and poor water quality.
Factors affecting lake water quality
The nutrient status of lakes is highly related to their depth and the type of land use and human activities in the catchment feeding the lakes, as mentioned previously.
Deep lakes have a greater ability to absorb incoming nutrients before showing signs of deterioration in wa-ter quality. The monitored lakes that have high levels of nutrients are generally shallower, while the moni-tored lakes with the lowest nutrient levels are almost always deep lakes in the mountain country of the South Island, that do not coincide with intensive farming or urban activity.
Similarly, levels of nutrients like nitrogen and phosphorus with the associated algal blooms are usually high in lakes in pastoral catchments. Algal concentrations reduce water clarity, with natural catchment lakes having clearer water than those with pastoral catchments. Lakes in mountainous terrain may have visibility underwater of >10m, although this can be lowered naturally due to tannins leaching from beech forest or from fine glacial sediments.
Recent trends in water quality
Trends in water quality for 2005 through 2009 were recorded for 68 lakes, and it was found that 19(28%) of the lakes deteriorated while 8(12%) had improved. This pattern varied across lakes with different land uses. 40% of lakes with mainly native catchments had showed signs of deterioration, while only 25% of pastoral catchment lakes were found to have deteriorated. This may however give a biased view in favour of pastoral lakes; it is important to note that despite these improvements, pastoral lakes have the highest numbers of hypertrophic lakes by a large percentage, while the native forest cover has the greatest percentage of olgotrophic(near pristine)conditions.However it can be suggested that there is some improvement. However,as is shown below in freshwater quakity of rivers, there are a large fluctuations in nutrient levels and other EPI's due to variation in land-use intensity in pastoral catchments. It may therefore be too early to recommend that improvements in land management is having positive effects on the health of the nations lakes.
Other factors affecting lake water quality
Natural factors like air temperature and wind are also important influences on water quality in the lakes. Algal blooms are usually more common in lakes in warmer climates (lower elevations in the north) and during summer. Wind creates waves and currents, especially in shallow lakes, lifting sediments from the lake bed into the water. This can reduce water clarity and increase the amount of nutrients available for algal blooms. The clarity and appearance of lake water can also be affected by soil type, with lakes in peaty soil (Westland, Waikato) having a naturally brown stained appearance.
Of 155 lakes that have data on ecological condition available: - 37% have poor ecological condition (no submerged plants) - 33% have high or excellent ecological condition
River condition indicators
Types of nutrients
Total phosphorus, dissolved reactive phosphorus
TP is a measure of phosphorus encompassing the various forms that exist in New Zealand waterways. These include phosphate that is stuck to sediment and well dissolved reactive phosphorus that is more readily available to plants. TP is an important measure due to phosphate entering the waterways while bound to sediment from run-off. Over time this is released, and “dissolved reactive phosphorus” is made readily available to aquatic plants and algal growth. This is a big issue in slow moving rivers, where phosphorus can feed weeds and algae for a number of years after release. A lot of the phosphorus in rivers is due to erosion, fertilising from sheep and dairy farms, while years of top dressing has altered the low phosphate condition of New Zealand soils. Other sources include dairy factories, freezing works, and pulp and paper plants.
Nitrate nitrogen contributes to water nutrient levels which can be excessive, causing aquatic plant growth that is problematic. Also too much nitrogen(Nitrate) can be toxic to young infants and livestock when occurring in drinking water. Sources include over-application of inorganic fertiliser, septic tanks and leaky sewerage systems. Nitrification of ammonia by bacteria in soil also leads to nitrate entering waterways.
Ammoniacal nitrogen (ammonia) is a contributor to overall nutrient levels, and it can be toxic causing low-er reproduction and growth or death of fish and other aquatic lifeforms at high levels.
Changes in irrigation
This image gives us a small reflection on how they need past data to make reflections on changes, and how drastic these changes may be in particular areas. Since one of the biggest implications of indicators is a lack of accurate trends.(http://www.mfe.govt.nz/environmental-reporting/fresh-water/river-condition-indicator/index.html)
Total phosphorus concentrations vary across the country. Higher total phosphorus is widespread in the mid to upper North Island, while for the South Island the monitoring data shows higher concentrations in the east coast and southern parts of the Island.
The figure shows phosphorus levels in four different land cover classes. Median TP concentrations in rivers surrounded by urban and pasture land are significantly higher than those with indigenous land-cover type. Median urban dominated river reaches have five times the levels of phosphorus than those with indigenous cover. Rivers in pasture catchments have 3.5 times that shown in indigenous cover, while those with exotic cover have 2,5 times the levels associated with indigenous catchments. Pasture dominated streams show the widest range of concentration, and such variability may be due to erosion risk, and differing land-use intensities associated with varying pastural farming types.
Dissolved reactive phosphorus
Higher concentrations of dissolved reactive phosphorus (DRP) concentrations were found to generally ocurr in the Waikato and also through parts of the Hawkes Bay region as well as the Manuwatu. The figure shows the modelled DRP concentrations as evident in four different land use covers. The models used in the MfE report this data was sourced from predict that rivers within urban, exotic forest and pasture cover have levels 2-3 times higher than are shown in the indigenous cover. Rivers and streams in the pasture catchments have the widest range of concentrations, with a range of from highest to lowest. This variability may be due to the range of different land-use intensities that are associated with the different pastoral farming types.
The figure shows the estimated concentrations of Nitrate in New Zealand, with higher concentrations oc-curring in the lowland regions of the Canterbury Plains, Southland, Waikato, the Hauraki Plains, Manawatu plains and Taranaki.Note that most Nitrate enters the waterways is converted from ammonia (animal urine) by bacteria in soils. Due to long term build up of nitrates trading schemes have been introduced in the Lake Taupo catchment.
Site data collected shows that high concentrations of ammoniacal nitrogen (ammonia) generally occur in lowland plain areas, regions of the Waikato and Hauraki palins, Manawatu, Canterbury Plains, Southland and Bay of Plenty areas. Catchments with predominantly indigenous land cover has a median concentra-tion of 0.005mg/l. However, actual concentrations may be lower as this is the lowest level detectable. Me-dian concentrations in pastoral catchments are shown to be twice as high at 0.01mg/l, and urban regions more than six times higher at 0.031mg/l. The highest concentrations occur within a small number of pas-tural area catchments, with a high variability, due to the range of land use intensities.
Macroinvertebrate community composition
Macroinvertebrates are a biological indicator involving numbers of aquatic animals such as insects, worms and snails, which respond quickly to changes in water quality, habitat and catchment condition. Types and number of taxa present in a waterway can give a broader indication of water quality than water chemistry alone. This method is useful as it allows conditions to be assessed due to the length of the macroinvertebrate life cycle, while water quality sampling can only give an indication of the time of sampling, possibly missing intermittent pollution events. A life cycle of a year or more allows measurements of stresses or pollution occurring in the aquatic ecosystem and provides a biotic measure of river pollution. The macroinvertebrate community index(MCI) scores diversity of taxa through pollution tolerance, with those taxa that are characteristic of unpolluted conditions scoring higher. Therefore high MCI scores = better river conditions, while some variation in quality due to sedimentation from bank erosion reducing water quality may not be detected. The current MCI as shown in figure(23) is based on data collected over a five year period up to 2011, showing generally higher MCI scores in indigenous areas(west coast of the South Island, central North Island). The lowest MCI scores were found in the upper north Island, the Manuwatu plains and lowland Southland. Analysis of the effects of land cover shows that about half of streams in urban catchments are in poor condition, with urban land cover being significantly worse than the other land-use covers. Predictably, rivers and streams in catchments with indigenous cover have the highest MCI scores. Rivers and streams in pasture catchments have a high variability due to the wide range of environments, land-use intensities and management practises including riparian planting improving MCI scores.(http://www.mfe.govt.nz/environmental-reporting/fresh-water/river-condition-indicator/macroinvertebrates.html)
MCI long term change
Macroinvertebrate communities vary naturally, due to temperature, vegetation and stream flow. Compari-son to an undisturbed state through modelling of these factors allows the estimation of the effect of human activities on the MCI, which is due to the altering over time through development, damming or removing water or discharges. This allows a comparison against a “reference condition”. Relative to other parts of the country there have been significant changes in the areas with agriculture, urban land-use (east of the south Island, lower North Island, inland Waikato). Areas like the west coast of the South island, eastern Bay of Plenty and the Coromandel remain relatively undisturbed.
Water quality is estimated from models based on hundreds of modelling sites over a five-year period up tp 2012, and are different from suitability for swimming networks.The figure shows estimated concentra-tions that are higher in Auckland, the lowland plain regions of the Waikato and Hauraki plains, Manawatu plains and low lying areas of Southland. Some point sources (urban wastewater discharge, farm effluent treatment ponds) are not identified in the model, and may show higher levels of E.coli.
Summary of key findings of the river condition indicators
Of the monitored parameters, all are either stable or improving at most monitored sites. Four parameters show stable or improving trends in 90% of sites. In contrast, nitrate concentrations are found to be increasing in about a quarter of sites. Long-term patterns and time lags show difficulties in attributing changes in water quality to any particular action, but the results suggest a general improvement in land management and wastewater treatment practice. Of the nutrients measured, nitrate was found in the highest concentrations, with increases shown in a quarter of monitored rivers. The greatest source of nitrates is animal urine, with ammonia in urine nitrified rapidly by bacteria in soil, which then leaches into waterways as nitrate. It was found that the rivers and streams of urban areas had the highest concentrations of bacteria and nutrients, with the lowest macroinvertebrate health. That in mind, water quality at the relatively small number of sites monitored in the urban environment is improving generally, with urban streams accounting for less than 1% of the total length of NZ rivers. Macroinvertebrates are a good biological indicator of river condition, and reflect impacts such as changes in water quality and habitat. Conditions of macroinvertebrates showed no change at most sites, however they are declining in more places than increasing. Urbanization and agriculture have lead to significant increases in phosphorus levels and nitrogen concentrations in many areas, however these remain relatively low in comparison with other countries in the OECD.
The current state of New Zealand's lakes and rivers as a whole is very difficult to determine. Currently there is a lack of data to determine weather or not the state of New Zealand's lakes and rivers is improving or degrading. Although the data that is available is very site pacific and gives a good reflection of human affects to these waterways, the lack of data still hinders the ability to come to meet a conclusion on the true quality of the waterway as a lack of data is directly linked to a lack of indicators.
Case study: Waikato
The Waikato region warrants further analysis due to the obvious poor water quality in the hypertrophic lakes. Further research reveals that the water quality of rivers and lakes in this region varies; some water-bodies are in excellent condition, some are satisfactory or better in some ways, but not so good in others; while some rivers are in good shape at the headwaters, but are of poor quality downstream. Less devel-oped areas with native bush or exotic forest are in good condition, while the well developed areas where pastoral farming is common put pressures on rivers, resulting in poorer water quality. While some aspects of water quality are satisfactory or excellent including pH, dissolved oxygen and total ammonia, various contaminants such as nutrients nitrogen and phosphorus, fine suspended sediments and various microbes(E.coli) from dung are responsible for poor water quality in lowland waterbodies. In the Waikato river hydro-lakes and several of the shallow lakes in the river floodplain have elevated levels of nitrogen and phosphorus, supporting the growth of algae (eutrophic conditions). According to the MfE report, nine out of 11 lakes in the Waikato are declining in quality or have no change, while only two have improving quality. It is also worth noting that Lake Taupo at the headwaters of the Waikato river is declining in quality.
Waikato trends past and present
Although the declining water quality has been highly emphasized among the Waikato's lakes and river systems, there are some improvements. In the 1970s the Waikato rivers treatment for sewage improved remarkably, this lead to a major decrease in the concentrations of E.coli below the town of Cambridge. More recently since the early 1990s many of the regions rivers have been monitored. The monitoring of the rivers showed that Ammonia was decreasing, not in the Waikato river but in many other of the rivers in the region, although the decreases have been outweighed by the substantially larger amounts of other forms of nitrogen that have been entering the waterways. Along with this increase in nitrogen there has also been a increase in phosphorous. These increases are not in all waterways although, with one-third of monitoring sites not showing a increase in nitrogen over the past 20 years, and half have not showing a increase in phosphorus. Overall since monitoring began, there has been a steady rise in the Waikato region of approximately 2% a year of both nitrogen and phosphorus.The lakes in the region have shown very similar trends to the rivers. Lake Taupo is a very large lake and hence has seen little change compared to other lakes in the region since monitoring on the lake began in the 1970s. Lake Taupo has seen a gradual increase of approximately 1% a year for nitrogen, phosphorus, and algae. Lake Waikare is a example along with several other flood plain lakes in the Waikato region that have seen serious decline in recent years, with reports of algae increase by as much as 10% a year, ecology in these lakes has also been noted to be changing drastically.
The most important aspect of water quality in the Waikato river is the increase in concentrations of con-taminants from the headwaters at Lake Taupo to the mouth at Port Waikato. Variables turbidity, nitrogen and E.coli al have excellent quality at the head of the river, followed by deterioration downstream. 230km from lake Taupo the water is generally unsafe for swimming due to turbidity (submerged obstacles) or levels of E.coli creating risk of illness. There is also a marked increase in nitrogen and phosphorus concen-trations, which combined with impounding the water in the hydro lake results in increasing the levels of algae in the river, and algal blooms.
The tables below shows the importance of the different sources of nitrogen and phosphorus in three major rivers in the Waikato region. Sewerage and industrial wastewaters contribute roughly 9% of the nitrogen load and 18% of the phosphorus load carried in the Waikato river. The dominant source of these nutrients is diffuse run-off from farmland. Recent improvements due to wastewater treatment have markedly re-duced the nutrient loads from major point sources such as Hamilton sewerage. However improvements such as these are countered by increases in nutrient loads from farmland, leading to consistent increase in nutrient concentration. Land use is also an important source of nutrients in other rivers.
Lakes in the Waikato region can show a wide range of water quality values, and this is illustrated in table 7, for three lakes of different water quality. Lake Taupo is comparable to the large lakes of the South Island and is the biggest and deepest in the region. Other lakes in Waikato are smaller and shallower, with differ-ent water quality from Taupo. Lake Rotomanuka near Ohaupo is a shallower lake of better quality, while Lake Waikare has high levels of nutrients and algae, with murky water, and due to potentially toxic blue-green algae a health warning is in place. Lake Rotomanuka has levels of contaminants in the middle range of these three lakes.
The three lakes mentioned above are similar to the majority of the lakes in the Waikato region, with catchments containing many areas of pasture. Loads of nitrogen and phosphorus are assumed to be 50-60% higher in lake Taupo than levels prior to farming. The other lakes are more well-developed in the catchment areas, so it could be expected that nutrient loads are even higher. Dynamics of inflowing water and lake concentrations show that in lake Rotomanuka,the phosphorus concentrations of lakewater are less than the inflowing water, suggesting nutrients are lost to the bottom of the lake, and are unavailable to algae living in the water. In contrast, lake Waikare has high concentrations than the inflowing water, suggesting release from phosphorus stored in the bed of the lake at an earlier time period. This can be linked to the collapse of the lakeweeds which would otherwise stabilise the bottom sediments. Eventually however, the store of nutrients is likely to be depleted. In many waterbodies concentrations of plant nutrients nitrogen and phosphorus are increasing, due to the extent and intensity of pastoral farming, which is the dominant source of nutrients in the waterbodies.
Dairying and the clean streams accord
The dairying and clean streams accord describes a VEI that is effectively an agreement between Fonterra, the Ministry for Agriculture and Forestry, Ministry for the environment and local government NZ.
Clean streams accord- aims and objectives
The Accord sets out five targets for dairy farmers:
1. Dairy cattle to be excluded from 50 percent of Accord-type1 streams, rivers and lakes by 2007, rising to 90 percent by 2012.
2. Fifty percent of regular crossing points to have bridges or culverts by 2007, and 90 percent by 2012.
3. All dairy farm effluent discharges to comply with resource consents and regional plans immediately.
4. All dairy farms to have in place systems to manage nutrient inputs and outputs by 2007.
5. Fifty percent of regionally significant wetlands to be fenced by 2005, rising to 90 percent by 2007.
Clean streams accord-performance
There has been a range of successes and shortcomings to the Accord nationally. In terms of stock access to waterways, assessment by the On-farm Environmental and Animal Welfare shows that 68% of Fonterra suppliers have waterways that fit in the definition of the accord. This can be compared to a national figure of 84% in 2010/11, similar to the previous year. This suggests that the accord may be ineffective in deliver-ing targets to meet the accord in this area. The 2012 target of 90% of regular stock crossings to have bridges or culverts in place has been achieved. The 100% target of compliance for dairy effluent has not been met; however some improvements have been made, with an increase in compliance from 2009/2010 at 65% to 69% in 2010/11. This includes a national level for significant non-compliance reducing from 16% (2009/2010) to 11% (2010/2011). Full compliance varied from 40-95% in the same timeframe, with im-provements in the Waikato from 52-66%, Tasman from 73-92% and Canterbury with 59-65%. Increase in significant non-compliance occurred in the Bay of Plenty (10-14%), Malborough (5-25%) and Southland (13-18%). Southland is a significant problem in this area due to it being a significant dairying area. The biggest shortcoming of the response to the accord may be the failure for 100% of dairy farms to have nutrient management plans in place by 2007. This has not been achieved. However, some improvements can be reported with 46% of farms having a plan in place by 2010/11. Also, 99% of farmers have nutrient budgets, which is the main precursor to a nutrient management plan. Therefore it can be suggested that nutrient management plans may eventuate in the near future, de-pending on the efficiency of the parties involved to achieve goals through working with the relevant stakeholders through mutually achieved problem solving and regional compliance.
Comparisons with the EU-EPI's
WEI water exploitation index
Total abstraction per year/ long term available resource)
UWWT treatment and outlook
The EEA countries show that the implementation of directives has reduced the point source nutrient dis-charges, which has similar to actions initiated in the Waikato locally. The graph shows the effects of these reductions.
Nutrients in freshwater
Phosphorus from wastewater, detergents. Decreasing. Nitrates from agriculture, decreasing. Due to the effect of measures to reduce agricultural inputs of nitrate. Due to a small reduction in inputs(1%)and higher outputs.
Gross nutrient balance
This environmental indicator shows the levels of nutrients in kg/ha. It is worth noting that most gross ni-trogen balances show decline in estimates between 1990-2000. In the EU there has been a significant increase in nitrogen output rates (10%).
Biological qualities of lakes
Cyanobacteria levels in phytoplankton communities, and the implications of eutrophication as a result
Emissions of organic matter
organic pollution discharges to water in central Europe and the accession countries have significantly de-clined since the 1990’s, with quantities still high resulting in high pressure on the aquatic environment Hazardous substances in rivers
Other EPI's in the EU
Hazardous substances in lakes
Nitrogen concentrations in rivers
Ammonium concentrations in rivers
EU and NZ
There are a number of similarities between these two areas in terms of EPI's, however the WEI index which measures water extraction as per reknewable resource may be absent from NZ. There are comparisons between the gross nutrient balance and the nutrient budgets described in the clean streams accord; however there seems to be more evidence of land management plans being carried out in the EU with reductions in nitrate inputs while increasing outputs being successful.There is generally stronger evidence for stronger improvements being made environmentally. The stand-out factor is nitrate levels; this is a big problem in NZ while the EU has brought about reductions through management practises. This emphasises the main failing in NZ in terms of environmental accords.
Policy and implications for freshwater resources in NZ
The work of the New Zealand Conservation Authority (2011) describes the various policies and frameworks that were designed to conserve ecosystem health of freshwater resources in New Zealand, both currently and historically. Overall it is upheld that collectively, conservation legislation protects a network of areas for their natural and historical values and that effort has been made to extend this network so that it is representative of terrestrial ecosystems and habitats. Finally it is noted that protection of a representative range of freshwater ecosystems and habitats has received little, if any attention and has not been achieved suggesting limited success of current management and conservation initiatives. To summarize, there are four main pieces of legislation noted by The New Zealand Conservation Authority (2011) that have historically been aimed at protecting and conserving New Zealand’s freshwater resources.
National Parks Act 1980
It is noted that the general purpose of the National Parks Act 1980 is to preserve ecological systems or natural features that are beautiful, unique or scientifically important as it is in the countries best interests. Two specific purposes or national parks are that native plants and animals be preserved and the park’s value as ‘soil, water and forest conservation areas are maintained’.
Reserves Act 1977
The purpose of the Reserves Act 1977 includes the survival or preservation of a representative range of all classes of natural ecosystems that originally gave New Zealand its recognizable character.
Conservation Act 1987
The Conservation Act 1987 promotes the preservation of indigenous freshwater ﬁsheries and the habitats of freshwater ﬁsh species, but river and stream protection speciﬁcally has generally not been highlighted as a priority in the establishment and management of protected areas. Though worthy of acknowledgement is the fact that the preservation of the habitats of the specially adapted and valued biota is promoted.
Freshwater Fisheries Regulations 1983
Regulation 68 of the Freshwater Fisheries Regulations 1983 enables the Minister of Conservation to declare any water to be a faunistic reserve, where the introduction of any plant and the taking or killing of any freshwater fauna is prohibited in faunistic reserves without the Director General of Conservation’s approval.
Resource Management Act 1991
The above legislation suggests true power and ability to promote the conservation of ecosystem health regarding New Zealand freshwater resources. However, the implementation of the Resource Management Act 1991 made the pieces noted above essentially redundant. Moreover it is upheld that these legislations truly promoted the protection of these resources where as the RMA 1991 only works to mitigate effects of utilisation of these resources, and the impacts that some anthropogenic activities may have. Compared to previous legislation and policy initiatives it is relatively less effective in the conservation of this resource as it does not preserve it regardless, giving it complete protection from potential impacts.
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