Cheri van Schravendijk-Goodman is involved in research focused on the activity of whitebaiting. Whitebait are a very popular eating fish, and many people participate in the activity of whitebaiting, which is seen to be a very Kiwi thing to do. For tangata whenua, whitebait have been an important food source for several centuries.
Whitebait (also known as matamata to Waikato-Tainui) is a collective term used to describe the juvenile form of five galaxiid fish species – the giant kōkopu, banded kōkopu, shortjaw kōkopu, kōaro and, the most common one, inanga. Most of these fish species spend their larval cycle in the sea, returning to freshwater as whitebait, swimming up rivers in runs (large shoals). In the Waikato region, the whitebait fishing season operates from mid-August through to the end of November.
Whitebaiting can be a fiercely competitive activity, and prices for the fish can be lucrative. A growing number of structures and stands have been built along waterways where people go whitebaiting. In some places, people also build baches or semi-permanent dwellings. There are indications that some dwellings can have an impact on the river, particularly if sewage systems are discharging directly into the waterway and also through the unintentional spread of pest plants like alligator weed. Because of where they are located, some structures can also impact on potential spawning habitat and habitat for other fish and birds.
Sustainability of the fishery is complicated by a range of very complex issues including poor spawning and adult habitat loss (such as wetland drainage) and degradation (such as channelisation of streams and loss of riparian forest/wetland vegetation); disconnection between the main stem of the river, tributaries and lakes due to culverts, weirs and floodgates; poor water quality and the impacts of introduced fish like koi carp and trout. Because whitebait are also food sources for other animals, smaller whitebait runs can affect other species on the river.
Effects on iwi
Whitebait have always been an integral part of life for those who have grown up in the lower Waikato communities. Declining numbers of whitebait and other native fish such as tuna (eels) affects the ability of marae and whānau to maintain their manaakitanga (hospitality) through the provision of this traditional kai at tribal hui and other significant events. Declines in the fishery also affect associated cultural activities that whānau participate in while fishing, such as teaching and information exchange between kaumātua (elders) and younger whānau members.
Staff from the Waikato Raupatu River Trust (WRRT) and the Waikato Regional Council (WRC) have just completed a mapping exercise at Te Pūaha o Waikato (the Waikato River delta) to map and photograph all structures and stands along that part of the river associated with whitebaiting. The aim of the mapping was to gain an understanding of the types of whitebait structures and stands on the river and where they are located and to identify traditional fishing areas, traditional structures, whitebait spawning areas and wāhi tapu (places of significance).
The outcome of this baseline survey is to provide a map showing all points of interest relevant to whitebaiting. This will be used in discussions with relevant management agencies and local communities as they work towards improving the status of the whitebait fishery and traditional Waikato-Tainui interests and practices associated with it.
Whitebait habitat restoration project
Information about whitebait spawning areas from the baseline survey in conjunction with other projects by NIWA scientists will be used to identify areas of the river where improvements can be made to the habitat and movement migration pathways of galaxiid fishes. This will include restoring wetland and other spawning habitats and enhancing adult habitats. It will also include removing or fixing barriers that prevent inanga and the other fish (kōkopu and kōaro) from moving into tributaries and lakes of the river where they live and grow.
Over the next 5 years, there will be a number of hui during which tribal members will be able to provide feedback on the research. Kaitiaki will also participate in training related to restoration of these habitats and in environmental monitoring.
Nature of science
Scientists often work with other groups such as marae, hapū and community groups to understand what is happening – in this case – to the ecology of the river. People often have anecdotal information that can help scientists to see the bigger picture.
The mapping project was funded by the Waikato Raupatu River Trust (WRRT) and the Waikato Regional Council. A special acknowledgement to WRC staff Gannin Ormsby, Richard Barnett and Aaron Jeffries. Members of the fisheries kaitiaki rōpū, tribal members from Te Pūaha o Waikato and Huakina Development Trust were involved in the project.
The Whitebait Habitat Restoration project is funded by the Waikato River Authority. The WRRT and the National Institute of Water and Atmospheric Research (Dr Cindy Baker and Dr Paul Franklin) are co-leading this project with support from tribal members and local community champions. Special acknowledgment also to Dr John Quinn for his support and advice.