Our Fascinating Fish

One of many small streams flowing into Wairarapa Moana

One of many small streams flowing into Wairarapa Moana

There are around 50 native freshwater fish species in New Zealand and 25 of these have historically been found in Wairarapa Moana.  Most of these species are endemic (found nowhere else in the world). You probably won’t know many of them because they are small, cryptic and nocturnal.

 You can read about the native freshwater fish of Wairarapa Moana under the following sections:

 

Fish under threat

Many of our fish species are far less common than they used to be. Several are now extremely rare in Wairarapa Moana, and one—the grayling—is extinct. Grayling are extinct from all of New Zealand. Almost half of the fish that live in Wairarapa Moana are classified by the Department of Conservation as “Declining”. Factors that contribute to species decline are outlined in the Threats and Issues section.

Types of habitats

Wairarapa Moana provides a diverse range of habitats for freshwater fish such as lakes, wetlands, large rivers and small streams.  Lake Onoke and the lower reaches of the Ruamahanga River also provide estuarine (salty) habitats. While some species are found throughout all of these habitat types others may be restricted to just a couple, or one. These include wetland specialists that are unlikely to be found in lakes, rivers or streams.

Freshwater and saltwater - diadromy

Most of the 25 species recorded in and around Wairarapa Moana are considered to be  diadromous. This means the fish must normally migrate between freshwater environments (rivers, streams, lakes) and the sea in order to complete its life cycle.  In some diadromous species, the life history is obligate. This  means that migrations must be completed for successful reproduction to occur (e.g. eels, lamprey and grey mullet). However, in other diadromous species—some whitebait and some bullies—these migrations are facultative.  In this case reproduction is sometimes possible in freshwater, as long as suitable lake habitat is available. Lakes are thought to act as a surrogate sea in these instances, providing appropriate resources for raising larvae and juvenile fish, and the lakes of Wairarapa Moana may function in this way for some diadromous species.

Diadromy is a key concept when considering the fish of Wairarapa Moana. The majority of native fish must pass through Lake Ōnoke twice during their lifetime. This includes those species and/or individuals that use Wairarapa Moana as the conduit to riverine habitat upstream. In some cases these fish—such as both eel species but also others like redfin bullies and kōaro—will travel through Lake Ōnoke and then over 150 kilometres to the headwaters of the larger rivers associated with the Tararua Ranges (the Ruamahanga and Waiohine rivers).

Estuarine fish

Several non-diadromous species (don’t require any migrations to reproduce) are found in Wairarapa Moana. There are also five species that are probably more appropriately termed ‘estuarine species’ or ‘marine wanderers’ (as opposed to purely freshwater species). While some of these species are typically limited to the estuarine environment of Lake Ōnoke, others are known to penetrate at least as far inland as the tidal influence around the southern end of Lake Wairarapa.

FEATURE FISH

Read about a selection of native freshwater fish by going to the Feature Fish page. 

Our other fish….

You’ll need to check other websites for information about the following native fish. But they are all species that are found around Wairarapa Moana.

 Banded kōkopu (Galaxias fasciatus: Family Galaxiidae)

Grey mullet (Mugil cephalus: Family Mugilidae)

Redfin bully (Gobiomorphus huttoni: Family Gobiidae)

Upland bully (Gobiomorphus breviceps: Family Gobiidae)

Cran’s bully (Gobiomorphus basalis: Family Gobiidae)

Bluegill bully (Gobiomorphus hubbsi: Family Gobiidae)

Giant bully (Gobiomorphus gobioides: Family Gobiidae)

Shortjaw kōkopu (Galaxias postvectis: Family Galaxiidae)

Kōaro (Galaxias brevipinnis: Family Galaxiidae)

Dwarf galaxias (Galaxias divergens: Family Galaxiidae)

Torrentfish (Cheimarrichthys fosteri: Family Pinguipedidae)

Lamprey (Geotria australis: Family Geotriidae)

Yellowbelly flounder (Rhombosolea leporina: Family Pleuronectidae)

Stargazer (Leptoscopus macropygus: Family Leptoscopidae)

Kahawai (Arripes trutta: Family Arripidiae)

Estuarine triplefin (Forsterygion nigripenne: Family Tripterygiidae)

 

Other websites for fish information

Department of Conservation – freshwater fish page http://www.doc.govt.nz/conservation/native-animals/fish/

NIWA – Freshwater fish species list  http://www.niwa.co.nz/freshwater-and-estuaries/nzffd/NIWA-fish-atlas/fish-species


Content on this page was last updated: 15/02/2017 9:49am