THE QUESTION OF TROUT: CONSERVATION SCIENCE AND EXOTIC SPECIES
By Jane Carruthers FRSSAf
Given the current emphasis on preserving biodiversity and the enormous financial and physical effort spent in trying to counter the detrimental environmental effects of invasive plants and animals, it is salutary to recall that here in South Africa and elsewhere not long ago many such introductions were regarded as scientifically valuable. Indeed, their propagation was done in the name of ‘nature conservation’ and deemed worthy of research funding and investment in expensive facilities. Humans have always moved species around and the modern translocation of many of them was the consequence of lobbying by the acclimatisation societies of the 19th century. Founded in Europe, they spread into the colonial regions of the world where, for many reasons – economic, utility, sport, nostalgia and aesthetics – exotic biota were imported, treasured, nurtured and encouraged to spread.
One of these species was a member of the Salmonidae and currently named Oncorhynchus mykiss – the rainbow trout. It was first described for western science in 1740 by Georg Steller, a young German naturalist, from specimens that the natives of the Kamchatka peninsula, whom he encountered on his expedition with Vitus Bering, referred to as mykyhs or mykizha. Steller was delighted to discover this ‘lively fish … [that] … tastes better than any other fish on Kamchatka except for the king salmon’. In 1792 taxonomist Johann Walbaum placed it with the salmon as Salmo mykiss. Some decades later, US army surgeon and naturalist George Suckley, who set out to classify the North American salmonids, first used the term Oncoryhnchus (hooked snout) in 1861 but did not apply it to rainbow trout which he left in the genus Salmo. The taxonomic history of trout is extremely convoluted because the salmon family is complex and over the years there have been as many lumpers (trout as a single species) as splitters (16 trout species). Although their taxonomic placement was often questioned, however, the rainbow and closely related cutthroat trout remained Salmo, and thus separated from the Pacific salmon, Oncorhynchus, until 1989.
This reassignment by the American Society of Ichthyologists and Herpetologists of some trout into a new genus created enormous controversy, and indeed anger, among the public. Much of this came from anglers who were after steelhead, a form of rainbow trout. They were incensed at having their prize ‘game fish’ removed from the historical and more prestigious (some argued) salmon genus and placed with ‘a commercial species that could be unceremoniously scooped up in net like the other Pacific salmon’. According to Halverson, they have a point, as there are distinct elements of difference between the two. However, the matter is even more intricate as Peter Alagona, an environmental historian based at the University of California, Santa Barbara, has pointed out. Steelhead and rainbow are the same species, Oncorhynchus mykiss, except that steelhead behave like salmon if they have a clear river up which to travel and spawn while rainbow are happy to live and breed in impounded rivers and dams. According to US law, steelhead is endangered, while rainbow, being common and abundant is not. The argument has been made that if all the dams in the state of California were destroyed and restored into open rivers, there would be an abundance of steelhead. So, Alagona posits that among the more than 20 modern ways of determining species, there is also what might be considered an ‘administrative species’, a separation based on location, human interference and national legislation.
Disentangling human and biological history can be fascinating in terms of how it reflects culture and society and reminding us that there is no static position. Nature conservation and trout in South Africa is a case in point. Douglas Hey (1914-2008), a Fellow of the Royal Society of South Africa, and a man regarded as a worthy scientist and nature conservationist, spent a lifetime studying rainbow trout and how best to get them to flourish in South Africa. In 1942, he was appointed curator of the hatchery at Jonkershoek, near Stellenbosch, an area that had been selected for trout introduction many years previously. Hey’s father, Sydney, was notable in the Piscatorial Society of the Eastern Cape, and his son earned his masters and doctoral degrees from Stellenbosch University on the topic of the fertility of trout ova.
In 1867 the government of the Cape Colony had passed Act 10 ‘for encouraging the introduction into the waters of this Colony of fishes not native to such waters’. This was not successful until the Western Districts Game Protection Association was formed in 1890 and took on the task. Its members persuaded the Cape government to pay for importing trout and Ernest Latour, a professional pisciculturalist, was brought out from England and employed by the government to manage the project. The first hatchery was in Newlands in Cape Town, but it was moved to Jonkershoek, now the property of Cape Nature, in 1893. In 1897 Latour began the propagation of rainbow trout. It was a task highly acclaimed not only as national science, but nature conservation of the highest order. Arthur Harrison, a leader of what came to be called the Cape Piscatorial Society, was awarded an Honorary MSc in 1960 by the University of Cape Town, hailed in the citation for keeping ‘alive our awareness of nature in an industrialised world’.
The pressure of recreational anglers on government at that time was considerable and in the late 1940s there were, apparently, some 60 000 members of the Transvaal Anglers’ Union alone. Resources were set aside to promote and distribute trout in the streams and rivers not only of the Cape but elsewhere in the country too. The Trout Acclimatisation Society in the Transvaal Colony received a government grant after 1902; brown trout Salmo trutta, a European species, was imported to the Boschfontein Hatchery in Natal in 1890, and Pirie, near Kingwilliamstown, was another site of trout introduction in the late 19th century.
In charge of the Transvaal project in the 1940s was Dr S.S. du Plessis who, like Hey, was also a pisciculturalist and indeed, he had worked with Hey at Jonkershoek, studied at Stellenbosch University, and was groomed for the job. In 1948 Du Plessis, as professional officer, with Norman Dkhoza – the only other staff member – as labourer, began the Provincial Fisheries Institute in Lydenburg and it soon assumed prominence and more employees were appointed.
What is ironic in the South African situation is the fact that caring for and promoting trout was the task of the nature conservation authorities – they are neither indigenous nature and rather than conservation, they demand propagation. The situating of trout and aquaculture of this kind in nature conservation came about because of bureaucratic history not science. The 1910 Union constitution gave provinces the responsibility for ‘game and fish preservation’ which, at that time was a simple matter of dispensing hunting and fishing licences and determining closed seasons. After a legislative change in 1945, provinces were obliged to institute properly constituted and separated departments for nature conservation and, without ado or reconsideration, trout research and propagation fell into their ambits. Hey, Du Plessis and others seem to have had no hesitation in being blind to the fact that trout, and trout fishing, were environmentally destructive, while expressing concern about other introduced species like Himalayan tahr and jointed cactus. Even the introduction of Australian Acacia species was regarded as an industry, not nature conservation.
However, logic has recently prevailed and, currently, recreational angling has been reassessed as a commercial enterprise and thus no longer the task of nature conservation authorities. Some people are thankful for this realignment, others are not. Trout fishing is a dominant industry in some parts of the country, attracting businesses to rural locations and providing employment. Although trout are not listed on our national list of invasive fish-water fish species, they are considered by the IUCN to be among the world’s worst one hundred invasive species.
South Africa can regard itself as fortunate in that although many of our free-flowing rivers and streams have been inappropriately dammed in order to accommodate the recreational requirements of anglers, and trout may well upset the ecological health and biodiversity of some of our inland waters, the country did not – as did the US – employ rotenone to destroy every other species to cater for the needs of anglers and their obsession with trout. In 1962, helicopters, airboats and drip stations poured tens of thousands of litres of rotenone into the Green River (which drains most of southwestern Wyoming and part of northeastern Utah) to secure it for rainbow trout. It was not the only occasion; even earlier, in the 1950s, the Russian River in California was poisoned for about 500 km in order to introduce Oncorhynchus mykiss, and there are other examples too. These shocking events are well told by Halverson in his marvellous book and they are object lessons in reminding ourselves from time to time that biology is cultural and that it, and conservation science, is subject to human whims and tastes.
Alagona, P., After the Grizzly: Endangered Species and the Politics of Place in California (University of California Press, 2013).
Brown, D., Are Trout South African? Stories of Fish, People and Places (Picador Africa, 2013).
Halverson, A., An Entirely Synthetic Fish: How Rainbow Trout Beguiled America and Overran the World (Yale University Press, 2010).
Herbst, E., The History of the Cape Piscatorial Society
http://www.piscator.co.za/CPS2/wp-content/uploads/2014/05/The-History-of-the-CPS.pdf (Accessed 29 March 2016)
McCafferty, J.R., Ellender, B.R., Wey, O.L.F., and Britz, P.J., ‘The use of water resources for inland fisheries in South Africa’, Water SA 38(2), January 2012