Anglers have long resisted the idea of commercial trout farming but a select committee recently recommended the Government give the idea “serious consideration”. Clive Barker makes the case for trout farming.
The species of fish used for aquaculture were at one time very limited. Carp were the fish used in pond culture originally in China. The method was transferred and developed in Europe during the Middle Ages. This was to help inland populations to follow the centuries-old law of meat abstinence on Fridays. In addition, there was the period of Lent during which eating meat was also prohibited. The 15th and 16th centuries were called the ”Golden Age” of Carp pond farming.
By the 1700s, river trout stock depletion had become a problem and in 1741 Stephen Ludwig Jacobi established the first trout hatchery in Germany. From this time, anglers have started to depend on cultured supplies of trout to increase or substitute the natural wild trout production.
Fish & Game New Zealand follows this same system of hatchery-grown trout to enhance the recreational fishery eg their 2020 report shows 27,880 trout were released in Northland, 49,000 on the West Coast, 330,000 in North Canterbury and 2900 in Southland. This is just a sample of Fish & Game’s 12 districts that in total had some million hatchery-grown trout released into our rivers and lakes.
Why Fish & Game plus the Freshwater Anglers are so against commercial trout farming is somewhat difficult to comprehend when they are New Zealand’s largest trout farming operator.
Their argument that they have a totally wild river trout fishery seems a stretch.
My recent interest in trout farming has come about from my involvement with the Golden Bay High School Aquaculture Academy. New Zealand, when compared to most other countries, does not have an abundance of freshwater fish species. Australia for instance has four native freshwater fish plus trout and salmon all being farmed, producing employment and export earnings. It seemed an obvious move to introduce trout as a commercial species to be studied and utilised here in New Zealand.
The oceans have seen better days. They are inundated with plastic waste, both single-use and tonnes of plastic microparticles that find their way back into our food. Their water temperature is rising, and acidity increasing, causing other harmful effects. Pollution and overfishing have depleted multiple marine species. Aquaculture of both our marine and freshwater resources must be managed to give food security to future generations.
In 1972 I commenced looking at trout farming, however the new government stopped trout but allowed salmon. Thus in 1976 a salmon culture venture was started in Takaka with two paddling pools. I had to produce our own food for the fish as the intention was to grow the salmon in captivity.
To obtain the salmon fry, some had to be released to sea and in 1978 a formal licence was obtained.
However, by 1979 we developed our own Brood Stock. Thus the farm was free of any outside interference on how salmon were utilised. There were surplus eggs that other salmon farms were able to build from. The salmon industry in some respects is operational today because of this battle to hold salmon in captivity and grow fish to maturity.
One of the advantages of rainbow trout over salmon is they do not die of maturity like Pacific salmon do. Hatchery systems have produced trout for food and sports use for 279 years and other countries are still doing so. Why in New Zealand is only half the potential of trout utilised?
Salmon have been cultured in captivity from the top of the South Island to Stewart Island for 40 years without any sign of a disease; this is because there are no salmonid diseases in our waterways. Fish farms in themselves do not suddenly create a disease, as with all diseases it has to be firstly in the environment.
The biggest threat to our freshwater environment is, in fact, the overseas tourist fisher. It takes only a few hours by air for a fisher to arrive from his home stream to be fishing in a New Zealand stream, and with him arrives a host of possible harmful invaders.
Two recent imports into our rivers and lakes are causing serious concern, according to the University of Canterbury.
Both are water algae. Didymo smothers the riverbed, killing the food supply for fish. A university survey showed that 60 percent of streams that had Didymo algae no longer held fish.
The other algae, Lindavia, is microscope in size (often called lake snow) and is a sticky slime that clings to people’s skin and clogs boat engines and most possibly fish gills.
Poaching of trout is another fear voiced by anglers. Unemployment-generated poverty will always create some poaching as a source of food; however, those fish would never compete with quality farmed trout in either supermarkets or other outlets. Like other products, once they become readily available to the public, black market trade disappears.
Trout are the most versatile of fish, both for culturing and eating. The share of trout and salmon in world trade has increased strongly in recent decades, helping aquaculture become the fastest growing food-producing sector in the world and accounting for 50 percent of world’s fish supply for human consumption (FAO, 2015).
New Zealand is missing out on the employment and export revenue farmed trout would produce and sports fishers would still be able to enjoy their recreational pursuit.