Every year, sometime between August to November, various articles are published about the state of our whitebait fishery. These usually begin with a reference to the “good old days” when whitebait were so plentiful that they were used as fertiliser in gardens and chicken feed.
The audience is either taken on a journey of doom and gloom, in which whitebait numbers have decreased to levels beyond recovery and extinction is imminent; or regaled with a good news story about how numbers have increased from last year in (enter your local region or waterway).
Whatever you choose to believe, there is enough anecdotal evidence from yesteryear that the whitebait catch isn’t as bountiful as it used to be. What has caused this apparent decline?
First, let’s get a better understanding of what whitebait actually are.
The term “whitebait” is a collective noun for the juvenile fish of five native species, including kōaro, īnanga, banded kōkopu, giant kōkopu and shortjaw kōkopu, with īnanga generally making up most of the whitebait numbers. The whitebait lifecycle begins when adults spawn in autumn/winter in vegetation lining our streams, wetlands and lakes. These eggs hatch and wash out to sea.
Subsequently, schools of juvenile fish — often termed “the whitebait run” — begin swimming back upstream during spring. Whitebait are transparent, gelatinous-like creatures that even the most experienced ichthyologist (fish biologist) struggles to identify to species-level in the field.
From the very beginning, the odds of survival are stacked against whitebait (around 90% of newborns are considered to naturally perish).
Appropriate conditions (e.g. flood flows) are first required to wash the larvae into the marine/estuarine environment where the journey begins. Juvenile fish are subjected to continuous pressure from a range of predators including shorebirds flocking near stream and river mouths, to eels lurking around every stream meander and undercut bank. Introduced fish also pose a threat. Mosquito fish nipping at the juveniles’ fins and whitebait makes a bite-sized snack for trout.
Predation also comes in the form of “white-baiters” who temporarily take up residence on waterway margins, sweeping nets through the water column and, on a “good” day, collecting thousands (10’s of kgs) of wriggling whitebait.
If whitebait manage to navigate these vast predation pressures, they then face the issue of finding a good home – the problem is that like all of New Zealand, houses are difficult to come by.
In the case of whitebait, habitat loss and modification are a constant occurrence. This can come in an array of scenarios from a perched culvert preventing access upstream, to stream and wetland removal, and the degradation of spawning habitat through river flood controls and development.
Changes in the distribution and abundance of whitebait species have been recorded in different catchments from both habitat modification/loss and fishing. So which pressure has caused the decline? The conclusive answer remains elusive and the situation is not straightforward. It’s likely that the decline can be attributed to a combination of factors, and the magnitude of each pressure is variable for different catchments and species at different times and locations across the country.
Research is desperately needed, but currently limited. However, with three of the five whitebait species classified as At Risk (declining) and a fourth considered Threatened (nationally vulnerable), there is an increasing risk that one or several of these species will soon become extinct.
It’s a real possibility that current and future research may not be able to provide enough clarity as to the magnitude of the different causes of population decline in time to save all or even just one species.
It is curious to note, as we talk of native species extinction, the difference between native whitebait and introduced trout. Whitebait Fishing Regulations (1994) are one of the only documents which provide some degree of protection to whitebait.
However, there is no “quota system” in place, and “whitebaiters” are free to collect as much whitebait as they can in the time allocated. Some are able to collect enough whitebait to sell and profit from their catch. Where else in the world are you able to legally hunt an At Risk or Threatened species for profit?
In contrast, introduced gamefish, such as trout, have a level of habitat protection under the Resource Management Act (1991); require a licence to catch, and if you’re a recreational fisher-person caught selling trout, you can receive a prison sentence or hefty fine.
It seems absurd that there are stricter regulations for introduced species than native Threatened and At Risk species.
New Zealand has a dark history of species extinction with the loss of numerous birds, reptiles, amphibians and fish. Many other species are facing a similar fate, although they don’t have the added threat of being served at the dinner table.
It seems illogical that past mistakes continue to be made, particularly at a time when the world is becoming more conscious of our resource use and footprint on the environment. Change is required now, otherwise in years down the track, sometime between August to November, various articles will be published about the whitebait that use to run and how we failed to protect our whitebait fishery.
For further information please contact Kieran Miller
30 October 2018