Whitebait is a term used to collectively describe the juvenile form of a number of small native1 fish species2 that are edible. They are usually 25–50 mm long and often travel together in schools along coasts, in estuaries3 and up rivers. Whitebaiting is the activity of catching whitebait. This is usually done in rivers with fine meshed fishing nets. Historically, scoop nets were used. People eat the entire fish including the head, fins and gut.
Galaxiids
In New Zealand, the term whitebait includes the juvenile form of five species of the fish family4 Galaxiidae or galaxiids:
- Inanga (Galaxias maculatus)
- Kōaro (Galaxias brevipinnis)
- Giant kōkopu5 (Galaxias argenteus)
- Shortjaw kōkopu (Galaxias postvectis)
- Banded kōkopu (Galaxias fasciatus)
Galaxiids are mostly small freshwater fish found in the southern hemisphere. The adults mainly live in rivers and streams and often prefer native forest surrounds. The galaxiids lay their eggs in freshwater, and after hatching, the larvae6 are swept down to the ocean where they grow. The young then move back up into freshwater in large shoals known as runs. Whitebaiters set nets along the river’s edge hoping to catch this delicacy. Whitebait commands high prices – it is the most costly fish on the market and is known to whitebaiters as white gold. To learn more about the five whitebait species go to the interactive New Zealand native freshwater fish.
The inanga life cycle
The most common species of whitebait is inanga – also known as the common galaxias or matamata to the people of Waikato-Tainui. The life cycle of the inanga is the best understood of the five species of whitebait.
- Eggs: The eggs are laid during spring tides (higher than average tides) in autumn on the banks of the river in vegetation7 flooded by the tide, near estuaries.
- Larvae: The next spring tide causes the eggs to hatch into larvae, which are flushed out to sea.
- Juveniles (whitebait): After about 6 months at sea – floating as part of the ocean’s plankton8 mass9 – they return to the rivers and move upstream to live in freshwater, and they grow into adults.
- Adults: The adults swim back down the river to spawn10 in or near the estuaries. When spawning11 takes place, the water appears to boil with the numbers and activity of the fish.
The adults are about twice the size of the juveniles. Inanga usually live for about a year.
Catching whitebait
Whitebaiting is a seasonal activity with a limited time period. It occurs when the whitebait are migrating upstream in spring. There are strict controls about net size and rules against blocking the river to channel whitebait into nets. This is to ensure sufficient numbers of whitebait are maintained – they are able to pass through to become adults to spawn the next generation.
Whitebait are sensitive to objects in the river and are good at dodging nets. Whitebaiting therefore requires some skill. Nets are generally small, open-mouthed and hand-held (slightly bigger set nets may be used where whitebait are more plentiful). Nets on a long pole (scoop nets) have to be attended by the whitebaiters so they can lift the catch out as soon as it enters the net. Otherwise, the whitebait quickly swim out again.
Other species are sometimes caught in whitebait nets such as smelt (Retropinna retropinna). These are often referred to as ‘number 2 whitebait’. Juvenile bullies (whalefeed) and glass eels12 (juveniles of longfin and shortfin eels) also get caught as they migrate upstream.
Threats
Whitebait runs are smaller than they used to be due to a range of factors. The main problem is a decline13 in the quantity and quality of habitat14. This is caused by barriers for fish migrating into tributaries15 and lakes (such as floodgates, culverts and weirs16), draining of wetlands17 and other changes in land use. Degradation and loss of their spawning grounds is also a problem. Livestock trampling and lack of shade over riparian (streamside) spawning areas kills whitebait eggs. Declining18 water quality associated with land use change and intensification has also probably affected whitebait numbers.
It is interesting to note that the largest whitebait runs occur in South Westland – where there have been fewer changes in land use and there has been no decline in water quality.
Nature of science
Investigations in science often lead scientists to understand associated problems. For example, scientists studying whitebait realise that culverts in streams and rivers hinder whitebait from their migrating behaviour. Scientists are now designing structures to put on and into culverts to help whitebait negotiate these obstacles.
Activity idea
In Saving taonga students learn about eels and/or whitebait and how human activity has impacted on their lives. They learn about some of the obstacles these taonga19 face and about possible solutions for the problems.
Useful links
An article from Stuff about New Zealand whitebait and the threats they face.
Learn about the work of children from lower North Island kura20 who are taking part in a conservation21 programme to rejuvenate inanga populations22 – Youth help restore ‘at risk’ inanga.
View a summary of whitebait fishing regulations in all New Zealand including the Chatham Islands from the Department of Conservation.
- native: A species that lives naturally in a country, as opposed to species that have been introduced by the activity of humans.
- species: (Abbreviation sp. or spp.) A division used in the Linnean system of classification or taxonomy. A group of living organisms that can interbreed to produce viable offspring.
- estuary: A partially enclosed body of water where freshwater mixes with saltwater from the sea.
- family: A classification grouping that ranks above genus and below order (kingdom > phylum > class > order > family > genus > species).
- kōkopu: A type of native fish. There are three known species in New Zealand – giant, banded and shortjaw.
- larva: An immature form that some animals (such as insects, crustaceans and amphibians) pass through before metamorphosing into an adult form.
- vegetation: Plant life.
- plankton: A group of marine organisms including single-celled and multi-celled organisms.
- mass: The amount of matter an object has, measured in kilograms.
- spawn: The act of reproduction of aquatic creatures such as fishes, amphibians, crustaceans and mollusks. The mixing of the sperm of a male and the eggs of a female of the species. In mycology, the mycellium of mushrooms.
- spawning: The laying of eggs by aquatic animals like fish, frogs, crustaceans or mollusks.
- glass eels: Transparent juvenile eels. Eel larvae – leptocephali – change into glass eels.
- decline: The gradual and continuous loss of something such as bird numbers or sea ice.
- habitat: The natural environment in which an organism lives.
- tributary: A stream that flows into a larger stream or another body of water.
- weir: 1. A low dam built across a river to raise the level of water upstream or regulate its flow. 2. A fence or enclosure of stakes set in a stream for trapping fish.
- wetland: An area of land that is saturated with water, often referred to as a swamp or bog. Wetlands may be seasonally or permanently water-logged with vegetation adapted for life under those soil conditions. Wetlands are known as repo in te reo Māori.
- decline: The gradual and continuous loss of something such as bird numbers or sea ice.
- taonga: Within the Māori world view, a taonga is a treasure that represents whakapapa in relation to a kin group’s estate and tribal resources. Amongst many things, a taonga can be a living creature, a landscape, an object or a song. Taonga are important to the mana (honour and prestige) of the iwi associated with them.
- kura: Māori term for school or education. (Kura has other meanings for different contexts.)
- conservation: The protection, preservation and careful management of a species, habitat, artifact or taonga.
- population: In biology, a population is a group of organisms of a species that live in the same place at a same time and that can interbreed.
