Getting started

Traditionally, tangata whenua have collected information about estuaries to monitor resources, such as kaimoana, and to make decisions about conservation measures, such as rähui. Increasingly, tangata whenua are using scientific tools to help monitor their natural resources and Ngä Waihotanga Iho provides a science perspective for talking about environmental issues and concerns related to estuaries.

Why monitor your estuary?

Traditionally, tangata whenua have collected information about estuaries to monitor resources, such as kaimoana, and to make decisions about conservation measures, such as rähui. Increasingly, tangata whenua are using scientific tools to help monitor their natural resources and Ngä Waihotanga Iho provides a science perspective for talking about environmental issues and concerns related to estuaries.

You will collect information using the science-based tikanga of standard methods. The benefits of using the same (standard) methods every time are that:

  • your measurements can be repeated by different people while minimising the differences in the measurements.
  • careful practice ensures that you collect the highest-quality information that is possible using the methods that are provided in this toolkit.

The environmental information collected using this estuary toolkit can be used for a variety of purposes. You can use it to:

  • measure the environmental quality of your estuary and thereby raise community awareness about particular issues
  • encourage practical actions, such as rāhui or restoration projects, to help address the environmental issues that you have identified in the estuary
  • fill information gaps. The information that you collect using Ngā Waihotanga Iho may be the only environmental monitoring information that is available for your estuary
  • make a baseline survey. This type of survey provides a snapshot of your estuary at a moment in time. It is important because it sets the benchmark by which to determine the extent and rate of future environmental changes. The baseline survey would typically include all aspects of the estuary’s condition: its habitats, waters, sediments, plants, animals and kaimoana
  • highlight an issue to government agencies, or regional and district councils, that have responsibilities for environmental management. Your opinions and concerns will generally carry more weight if they are backed up by information that has been collected using reliable and accurate scientific methods
  • make long-term measurements of environmental change (years to decades). Long-term records are valuable because they can show the effects of events that may not occur very often but that have large and often long-term effects on your estuary. For example, big storms deliver large amounts of sediment to estuaries from the land. The amount of sediment delivered by one large storm can be equal to amounts carried to estuaries over many years.
  • educate your hapü, whānau and tamariki. The scientific tools provided by Ngā Waihotanga Iho can complement traditional knowledge and understanding of your estuary. Many of your tamariki will study science at school and estuaries are an excellent classroom to learn about the impacts of natural events and human actions on the environment.

Observations vs measurements

Environmental information can be based on visual observations or by making measurements. Here’s an example of an observation:

“I think the number of tuangi (cockles) on the sandflat is much less now than last year – they are much harder to find. A lot of silt came down the river in that last storm after the pine forest was cut down. The silt from the pine forest has killed lots of tuangi. Our grandparents used to be able to harvest many more tuangi than we can now.”

Although this observation seems to lead to a logical conclusion, there can be other reasons why the number of tuangi on the sandflat are less than last year or the year before that. The number of tuangi in a given area of sandflat can change naturally from year to year. Young tuangi do not necessarily settle on a particular area of sandflat every year but may shift from place to place. The number of tuangi produced will also naturally vary from year to year. To know how much the number of tuangi can vary naturally each year requires measurements over several years. Measurements will provide a yardstick to judge when declines in tuangi numbers are natural or may be due to some other cause, such as sediment runoff from the land.

Because the likely cause of environmental changes can only be determined if it is supported by robust information, scientific methods are usually emplyed when considering the causes of environmental change. Normally, the more detailed the environmental information is, and the more it is supported by measurements from sampling or surveys, the more it will be regarded as evidence by a regional council.

Ngā Waihotanga Iho as a Educational Resource

Ngā Waihotanga Iho is targeted at high school students in Years 9 - 10, but younger students can use many of the tools in Ngā Waihotanga Iho with the help of adults. Also, hapü and community groups may choose to use estuary monitoring as part of communal activities for their tamariki education. The toolkit is ideally suited to meeting the achievement aims and objectives of the Science learning area in the New Zealand Curriculum (NZC). However, Ngā Waihotanga Iho also lends itself to cross-curricular teaching and learning, with obvious links to other learning areas such as Technology, Social Sciences and Mathematics. In this way, a study of the local estuary can become a golden opportunity for an integrated unit within a school programme.

Ngā Waihotanga Iho embraces many of the guiding principles and values that underpin the NZC by providing tamariki with:

  • a community-based learning context that has relevance and meaning for them
  • ways and means of identifying and addressing future-focused issues in your community, such as ecological sustainability and citizenship for the common good of all people
  • opportunities for communities to become involved in scientific activities that respect and complement local iwi histories and traditions and that encourage connection to the environment.

The young people of today are the decision-makers of the future. To help them live, learn, work and contribute as an active member of the community, the NZC promotes the development of five key competencies:

  • thinking
  • using language, symbols and text
  • managing self
  • relating to others
  • participating and contributing.

Using the toolkit will give tamariki learning experiences within their school programmes that can effectively develop all of these competencies and contribute valuable information for ongoing monitoring and action related to the future health of your estuary.

In each of the modules that make up Ngä Waihotanga Iho, curriculum links are suggested for Level 5 of the NZC, the expected level of achievement for most Year 9 and 10 students. These suggestions in no way preclude teachers from using the materials for other year levels.

Toolkit structure

Ngā Waihotanga Iho is divided into six modules each with a different monitoring theme for different aspects of your estuary's environment. Each module begins with introductory background information including a short narrative from the hapü members of Ngāti Hikairo and Ngāti Whanaunga. These narratives relate to their values, concerns and observations of environmental changes in regards to each module's theme. Each module then provides methods for measuring and monitoring particular aspects of your estuary that relate to the module theme.

The modules

Habitat Mapping: This module will show you how to collect information to describe and monitor habitats in your estuary. Habitat mapping is an important part of understanding your estaury. It provides the necessary context or 'big picture' for the environmental changes that you may observe. For example, how much of the estaury is covered by mudflats, sandflats and saltmarshes, and where each of these habitats is located.

Sediment: In the Sediment Module you will learn how to describe sediment types, measure how quickly sediment is being deposited (the sedimentation rate), and measure large-scale changes in the topography or the shape of estuary features, suck as banks and channels. This module also provides guidelines on how to collect and store sediment samples and cores that you may want to have analysed for metal and organic chemical pollution.

Plants: In the Plant module you will learn how to describe the plant communities in your estuary and to monitor how they change over time. In particular, you will be able to monitor the spread of plant communities at specific sites, determine changes in plant abundance and measure the growth of individual plants over time.

Shellfish: This module provides tools to (i) identify common types of shellfish and animals living in the sediments, (ii) monitor changes in the size (area) of shellfish beds and (iii) monitor shellfish size.

Fish: In the Fish module you wil learn how to measure the size, structure and abundance of young fish that use the estuary as a nursery. You will also learn how to monitor recreational and customary fisheries in your estuary.

Water Quality: The Water Quality module will show you how to measure and monitor basic water quality properties in your estuary. This module describes how to collect a water sample and provides step-by-step instructions to measure temperature, salinity, dissolved oxygen, pH and water clarity.

Making a start

There are many reasons why you might want to undertake environmental monitoring of your estuary. We recommend the following steps to identify objectives and to develop a estuary monitoring action plan (E-MAP) before you head out into your estuary.

Step 1: General discussion and hui

Discussions about the environmental issues for your estuary should be open to all hapü members who want to contribute. However, it is essential that people stick to the kaupapa of the hui in order to achieve maximum benefit.

As is the nature of hui, there can be flexibility depending on your needs. However, there should be two main purposes; 1) a general discussion about environmental concerns within the estuary, 2) decision-making about who's going to lead the mahi.

We recommend several resources for the hui: •

  • aerial photographs of your estuary
  • topographic maps
  • reports from regional councils or other research organisations, such as NIWA, that relate to your estuary. They provide a guide as to what research has been done before in your area
  • a whiteboard and whiteboard markers for writing down key issues for everyone to see. It will help keep everyone on the kaupapa and can also trigger memories for useful discussion
  • a person to record minutes. The recorder should put together a final copy of the minutes and distribute to all participants after the hui is completed

Some discussion points

  • Discuss issues and concerns regarding your estuary. Your kaumātua and kuia can provide long-term perspectives on how your estuary has changed over time. The same applies to hapü members who have lived away from the estuary for a while, who may more readily identify the changes that have occurred very slowly over time.
  • Define the key environmental issues for your estuary. This will help you identify what monitoring tools you're going to need.
  • Agree on your long-term vision and goals. An example of a goal could be restoring karepö (seagrass) to a sandflat. Another related goal might be to enhance the science education of your tamariki by incorporating the sandflat monitoring into their school studies.


  • Decide who will lead the monitoring. This is an important decision because these people will need to be committed to ensuring the monitoring takes place. Obvious people to consider are your kaitiaki, or maybe a teacher from your local kura. Ideally, two or three hapü members should share responsibility for the monitoring. This means that the effort is shared and that more than one person ‘knows the ropes’. In the long term, this will help ensure that the monitoring continues. Your iwi may also have an environmental or resource management team. These organisations can provide useful advice and/or support.
  • Identify a core group of hapü members who will assist the kaitiaki/monitoring leaders with the monitoring.
  • The monitoring leaders should prepare a brief statement of the hapü’s concerns about the estuary. This will be used to develop an Estuary Monitoring Action Plan (E-MAP).

Step 2: Develop a Estuary Monitoring Action Plan (E-MAP)

This action plan will be developed by the monitoring leaders, but you may also consider doing this in consultation with scientists from government/research organisations, or your iwi environmental management team. Your E-MAP should include specific details about:

  • the objectives for the monitoring
  • what you want to monitor
  • what methods or tools you will need to use from the various modules
  • training for the monitoring team to learn how to use the tools correctly. Including ‘hands on’ training in your estuary before monitoring begins
  • suggested monitoring sites
  • how often you will monitor and when (this will depend on your monitoring objectives and what you want to monitor, but there are recommendations in each module for the best time and frequency at which to monitor)
  • what equipment you will need and who is going to be responsible for looking after it. This will also be informed by the monitoring methods you wish to use
  • who is responsible for collecting and maintaining the data records. It's a good idea to have more than one copy of these records
  • the health and safety considerations and requirements when working in your estuary.

An important part of developing your E-MAP is to construct a baseline habitat map. This will provide the 'yardstick' to measure habitat changes that occur in the future. The Habitat Mapping module describes how to construct a baseline habitat map using existing information and then details how to ground-truth that map in the feild to check the locations and boundaries of habitats. Ground-truthing your map is an important step in developing your E-MAP because it will help you to identify appropriate locations for monitoring transets and sites. A habitat map will inform and provide the basis for developing your E-MAP but be prepared to change your E-MAP if necessary. For example, you may find through your monitoring that changes are occurring slower or more quickly than first thought and you need to change how often you monitor; new issues become apparent and you need to monitor other aspects of your estuary; or some environments turn out to be too hazardous to monitor, such as soft muds.

Some practical matters to consider before starting field work

Consult your regional council

Before you start monitoring you should talk with your regional council, as they may be able to provide assistance and advice. There may also be specific rules in the Regional Coastal Plan regarding monitoring activities, such as collecting sediments, plants and animals and installing marker pegs. If you want to monitor fish in your estuary, you will also need to obtain a Special Permit from the Ministry of Fisheries (MFish). The Fish module provides information on how to obtain an MFish Special Permit for users of Ngä Waihotanga Iho.

Sites of cultural significance

When carrying out estuary monitoring it is also important that you are aware of sites of cultural significance, especially wahi tapu. This is mainly so that you have an understanding of areas that should not be visited or disturbed and so that you are not ignorant of sites that are tapu.


Most of the monitoring tools included in Ngā Waihotanga Iho will require you to make measurements at a particular time during the tide. Some measurements will be made at high tide, low tide or mid tide. You will need to know in advance when high and low tides will occur so that you can plan your monitoring work. Information about tides in your area are available from a number of sources, inlcuding local newspapers, the LINZ website ( and the NIWA Tide Forecaster (

Be aware that:

  • high and low tide times given in some tide tables are in New Zealand Standard Time (NZST). During the summer, when daylight saving applies, add one hour to the NZST values •
  • the times of high and low tides inside your estuary will occur later than predicted at the estuary mouth. In many estuaries, the time of low tide can be substantially delayed (by up to an hour or so) compared to the open coast. This delay occurs because of the time required for the tide to travel up the estuary from the open coast.

In New Zealand, we have semi-diurnal tides, which means that we have two high tides and two low tides each day.


Before conducting field work it is important to consider the weather conditions for the day(s) you intend to work in your estuary. Sometimes the weather will dictate the most suitable times to do field work. It all depends on what you are trying to measure and whether the equipment you are using is easy to handle in all types of weather. Checking the weather to ensure that you and your team members will be safe for the duration of your field work is a common sense action.

Weather forecasts are available from a number of sources. These include:

  • Maritime New Zealand VHF radio forecasts, as well as local Coastguard forecasts, which are announced on Channel 16 (or 20, 21 and 23)
  • MetService (
  • NIWA weather (
  • Victoria University METVUW ( provides weather forecast charts for up to ten days in advance
  • Sky TV’s Weather Channel (channel 98)
  • Newspapers, television and radio news broadcasts.

Dangerous marine animals

New Zealand has a number of marine animals that may cause harm, so it is important to have an understanding of these creatures. It is perhaps more important to respect the fact that you are in their home, so if you see any potentially dangerous animals, it is best to avoid them. Continue your work at another monitoring site and return later.

Two species of shark – pioke (rig) and school shark – are found from time to time in estuaries, usually in deeper water and channels. Stingrays and eagle rays use estuaries and shallow coastal waters as nurseries and for feeding. Stingrays often come onto shallow tidal flats at high tide to feed. They have sharp barbs on their tails, which they use to defend themselves if threatened. With the exception of the Fish and Water Quality modules, you will do most of the field work at low tide. This means that you are very unlikely to come into contact with any of these animals. Just take care when walking across channels.

Mussels, oyster beds and rocky reefs can be very sharp and cuts can become infected. So, take care to avoid cutting yourself on them.

It may also be useful to ask your kaitiaki, kaumätua or kuia if they know of any potentially harmful animals in your estuary.

Safety first!

Ngā Waihotanga Iho is a public resource designed by NIWA for use by the public. The inherent nature of monitoring estuaries is associated with environmental and safety risk. Before undertaking monitoring, identify all hazards or threats of harm and risks, and establish safety controls to eliminate, where possible, any risks associated with the hazards identified. If risks cannot be eliminated, every effort should be made to minimise the likelihood of harm occurring.

Once identified, hazards should be monitored regularly to determine if the safety controls are working or not. If controls are not enough to keep people safe, consider implementing further safety controls or changing the location or types of measurements take.

The best way to manage safety hazards is to korero (discuss) and agree to a safety plan with everyone involved in the field work. Don’t leave anybody out – all concerns should be addressed. Be sure to capture the safety plan on paper. That way it can be shared and added to by anyone who may not be present.

Examples of hazards that may be encountered by those using Ngä Waihotanga Iho, and therefore considered for inclusion in the safety plan, include, but are not limited to:

  • incoming tides, which can submerge tidal flats to swimming depth within an hour or two
  • mudflats made of soft, muddy sediments which are difficult to walk on and may result in a person sinking to waist depth. Avoid working in such areas unless you have suitable equipment and training
  • weather conditions, which can change quickly. Be prepared for rain or shine to avoid getting too cold or hot
  • submerged habitats such as mussel beds and oyster-encrusted rocks, and debris such as trees or branches, as well as man-made rubbish such as partly submerged glass or metal.

It’s a good idea to consult your kaumätua, kuia and kaitiaki when selecting monitoring sites; they may know the local conditions and locations that should be avoided or tidal phases that are likely to be unsafe. Many of the monitoring tools in the kit have been designed for use at low tides (generally 2 hours either side is ok). Always consider changes to water levels and never work alone. Ensure all members have appropriate footwear for protection from sharp objects and appropriate protective clothing to deal with both hot and cold weather. Take a first aid kit with you.

The Health and Safety at Work Act 2015 (HSWA) details everything you need to know about your responsibilities, should you want to know more specific information. The WorkSafe NZ website (, will also provide some useful information.