Delicious feisty, fighting aliens5th May 2020
Trout are originally from the northern hemisphere, but they are a highly sought-after species for epicureans and anglers alike, so they have been introduced worldwide. Their popularity as a fly-angling species makes their introduction into dams or lakes well worth considering. But consider carefully.
The global picture
There are no naturally occurring trout species in the southern hemisphere, but, as a result of their popularity and associated economic benefit, they have been introduced to over 45 countries, and now inhabit waterways in every continent bar Antarctica. Interestingly, although trout are not native to the south, they can’t truly be viewed as un-African, as there are indigenous populations in the high-altitude waters of the Atlas Mountains in Morocco.
There are many species of trout (Brook, Cutthroat, etc.), but it is really just the North American Brown Trout (Salmo trutta) and the European Rainbow Trout (Oncorhynchus mykiss) that are of interest in South Africa.
The widespread introduction of trout species throughout the southern hemisphere provides more than enough evidence that they offer benefits in terms of both economic and social wellbeing. On a macro scale, countries such as New Zealand and Chile have made trout, and fishing for them, major contributors to their economies. On a more localised level, areas such as Dullstroom, and even individual estates and timeshare facilities, have made trout fishing their virtual raison d’être.
In the past, Dullstroom made itself the poster child of trout fishing with private estates, commercial venues and even a municipal dam stocked with fish, but the appeal and influence are wider than simply ponds with trout in them.
Trout support a smorgasbord of culinary delights from the classic trout almondine to Milly’s famous trout pies in Machadodorp and, with that, industries ranging from hatcheries to smokehouses. The subtle taste and firm texture of the pink flesh provide a foundation for a plethora of dishes, and every chef worth their salt has their own take on this delectable fish.
It’s not just the culinary arts, though. Trout – and fishing for them – has spawned any number of South African books related to the species, from Tom Sutcliffe’s My Way with a Trout to Duncan Brown’s Are Trout South African? Trout may not have evolved in South Africa, but South African society and culture have embraced them nonetheless, to the point where they have greater influence than might be imagined. Even a few cabinet ministers dabble in the piscatorial arts as a direct result of trout.
Because trout originated in the chill climes of the north, they are very specifically cold-water inhabitants, with ideal temperatures for most species between 13°C and 16°C and a critical thermal maximum (CTM – the temperature at which trout cannot survive) of about 26°C. This means that in sub-Saharan Africa they have only successfully been introduced to relatively unspoiled high-altitude waters with elevations of about 1,500 metres above sea level, such as the Aberdare Mountains of Kenya; the Eastern Highlands of Zimbabwe; Nyika and Zomba in Malawi; Lesotho; and – in South Africa – the highlands of the KwaZulu-Natal Midlands, Mpumalanga, Eastern Cape and Western Cape. Trout are at home in both riverine and still-water environments like dams, lakes and ponds, but they need running water to breed, so landowners who stock trout in still waters may need to regularly restock with fish from hatcheries.
Are trout invasive?
Although technically identified as ‘invasive’, there are different schools of thought. The limitations of temperature range mean that trout are unable to populate waterways where summer temperatures rise too high, so they do not compete with most of our indigenous fish, but they have had a negative effect on the populations of some of the cooler rivers – the Berg River Witvis is Extinct, and the Redfin Minnow and Maluti Minnow are, respectively, Threatened and Endangered.
But we can’t blame only trout. Agricultural water abstraction, pollution and other invasive species such as Smallmouth Bass and Sharptooth Catfish have taken an equal or probably more severe toll. More to the point, there are streams where Redfin Minnows or Cape Kurper exist side by side with the trout. So it seems the jury is still out. Yes, trout have had some negative influence on our biodiversity, but they are not Public Enemy Number One. Protection of biodiversity requires a far more widespread approach than simply picking on the trout, particularly given their social and economic benefits.
Movement, transportation and stocking of fish, any fish, is restricted in terms of biosecurity considerations mostly laid out in the National Environmental Management Biodiversity Act (NEMBA). The regulations are in a constant state of flux, and vary to a degree according to location. What this means is that you really need to get local advice before you stock new waters, or transport fish.
So, should we stock trout on our estate?
Trout fishing provides considerable potential in terms of both added value and targeted marketing. As with everything, there are some downsides. Trout are not indigenous, so permits are required for their movement and stocking, and they are also severely restricted in terms of temperature tolerance so, no matter how much you might like to have them in your pond, if your location isn’t high enough and cool enough, it simply can’t be done. You also need to consider that they are not able to breed in still water, which means they will require regular restocking, with the associated costs and associated red tape for permits.
But the good news is that trout have been successfully introduced in many parts of southern Africa, with considerable economic and social benefits. For the most part, fly-anglers (the majority of those targeting trout) come from high LSM sectors, and the sport generally appeals to more intellectual and professional people – specifically the target market for many developers.