 "
My view is that
our river systems are under severe threat. There is one
reason for this crisis - ignorance."..." The speed of the
decline is the most alarming factor." ..." the greatest damage is caused
by the wealthy trout lobby who are more concerned with their exclusive
sport than with the environment." ..." What is envisaged is the establishment
of a statutory body... " Pat Hopkins - PICA Journalism award for
Environment, Wildlife and Conservation.
 for
full response
"...Studies..have shown that 'large' predator species such
as trout and other gamefish species, have had a serious impact on
indigenous fish populations."... "At this point in time where most suitable trout
waters have been stocked already I personally would be extremely
cautious and circumspect about introducing trout or any other alien to
any new or unstocked waterbody or area."... Dr Paul Skelton
SAIAB
for full response
Managers of
NZ's [New Zealand's]
trout fisheries, the Fish and Game Councils, now have a policy of not
liberating trout into waters that do not already have trout in them.
Note, that virtually all of New Zealand's trout fisheries (all based on
introduced species) are self-sustaining, and management stocking for
angling is undertaken in very few waters. Dr
Bob McDowall National
Institute of Water and Atmospheric research.
for full response
Most of our river
surveys have indicated that trout have a negative effect on
our indigenous fish populations. For instance in the case of the
threatened
Treur River barb (Barbus treurensis), their distribution is sharply
ended by
the presence of trout beneath a small waterfall (Christmas Pools). Dr
Johan
Engelbrecht, Conservationst
for full response
"Our attitude to trout in this province
from purely a nature conservation
perspective is negative as both rainbow and brown trout have established
invasive populations in mountain streams here at the expense of
indigenous
fishes and other fauna. However, we acknowledge that socio-economically
the rainbow trout has been an asset in this province. Dean
Impson, Western Cape Nature Conservation Board
"There are of course other considerations
as well, such as the small matter of South Africa being a signatory to
the (International) Convention of Biological Diversity, which means that
it would not be possible, at least morally, for a government department
to allow the introduction of a foreign species into waters which are
free of alien species. [They] will have been aware of WCNCB's policy
regarding trout; that no trout should be stocked into rivers where no
legally stocked trout exist."
for Johann
Brummer's full response. A reply to Nick
James letter.
|
In a career that now spans more than 50
years working as a fishery research and management biologist in
California in
the U.S., I have never observed an instance in which biological
integrity has
benefited in any way from such introductions. Ecosystems harbor no
vacuums,
and when a foreign organism is introduced into them, something has to
'give'."... "It appears that sport angling is losing its popularity and
that it
may prove to be a diminishing social phenomenon..." Dr Phil Pister,
Conservationist, USA
for full response
From the positive side,
introduction of trout has improved
the quality of fisheries and brought much need income to
rural economies. The introduction of trout, I feel can
be justified IF the habitat it is introduced is isolated
and holds no endemic or endangered species and it can be
proven that trout will have no impact. The latter is
almost impossible to achieve..." "... I have always taken the bottom line that
if the introduction is not necessary or justified it should
not be sanctioned." Dr Ian Cowx Chairman of the FAO/EIFAC Working group on Stocking
and Introductions
for
full response
"...
Of special concern in some areas, are
so-called "put-and-take" trout angling systems where trout
abundances are kept artificially high (i.e. higher than the "trout
carrying capacity" of the stream). This stocking approach put the
resilience of the native biotia to disturbance under continuous stress..."
"... species other
than trout were considered to be "trash" fish and were treated
with contempt and disgust. Cases exist where Incomati Chiselmouth and
Large Scale yellowfish were removed in large numbers from streams
because they were considered to be in competition with trout. Dr Neels
Kleyhans, Conservationist, DWAF
for full response
We
had a very bad experience here [Plettenberg Bay] about two years
ago when a developer wanted to do a twenty chalet development ... he
built two breeding facilities and stocked these with fry in order to
release them in the stream on the property, the Salt River. This he
claimed was done with "verbal
consent" from CNC at Jonkershoek, a fact which they denied when it
came down to the crunch." Johann Brummer
(Councillor Plettenberg Bay)
for full response and see James
for reply.
"Firstly unlike a great many alien species in the country,
trout (both rainbow trout and brown trout) are not in the true sense
invasive. They have highly restrictive temperature ranges which prevent
movement into lowland and high temperature environments."...
"There are a huge number of aliens which are far more invasive, far
more dangerous and far less useful than the humble trout..."
"...I am simply going to carry on monitoring the environment which
my beloved trout and a host of other species inhabit, and try to
preserve them for everyone and everything." Tim
Rolston Ultimate Angling
|
" Species such
as the Clan William Yellowfish which are under threat from alien fish
make much more exciting fishing species than the aliens and efforts
should be directed towards their conservation and to the eradication of
aliens." "... in the USA the costs of invasive alien species
topped three trillion US $ in 1999! If that is not sufficient argument
for the eradication of aliens and the prevention of deliberate
introductions then I do not know what is." Prof
Bryan Davies, UCT
for full response
"There is no way in which these
fish can be effectively impounded and will spread to the detriment of
indigenous fish species..." "...there is no reason why the environment and the rights of others to
have
a pristine environment should be sacrificed for the profit and enjoyment
of
a few. Johann Brummer (Councillor Plettenberg Bay)
for full response
"Due to the high concentration of
trout, intensive feeding and treatment for disease on trout farms, water
quality problems may arise from such farming units.
Relatively high volumes of good quality water are required for trout
farming." Dr Suzan Oelofse, DWAF
Directorate: Water Quality Management.
for full response
"They [streams with trout] include
the bulk of the most pristine, the healthiest and the least damaged of
all southern Africa’s river headwaters and much of the best catchment
around them - in spite of the presence of trout for almost a
century"..."The authors of this
anti-trout crusade publish under a cloak of authority, representing
formal academia. From behind a screen of academic credibility, their
summations go a great deal further than one might expect from an open
mind presenting objective data." Wolf
Avni Trout Farmer
for full response
"Most of Lesotho has been reduced to trout waters - only six
populations of the Maloti minnow exist and this is mainly due to rainbow
trout"
"I
think what should be done, and it should be spear headed by
conservation organisations (WCNC/National Parks), is that areas
should be identified as high conservation value and aliens should
be removed or not stocked in these. Other areas should be allowed
as legitimate trout, bass whatever rivers and managed by angling
associations with guidance/collaboration with nature conservation
organisations." Roger Bills, South African Institute for Aquatic
Biodiversity
for full response
"At times developments are proposed that may appear to be
contradictory in terms of 'pure conservation'. One should then consider
"bio-control", the use of an exotic organism to eradicate a
pest: if the exotic control organism can be shown to have a negative
impact that is controllable, and less than its positive impact, it is
acceptable in the context of an almost out-of-control problem. If the
'control' or 'income earning method' is also self-sustaining, well even
better." Nick James, personal
viewpoints
See reply from Johann Brummer
|
The controversy over trout introductions has come to focus much of the current awareness
on the
impact of alien species both plant and animal. Trout and other alien
species were introduced into foreign regions during the last century for both
recreational and aesthetic purposes without knowledge of the future impact
these may have. In regions where trout are indigenous, the sport of
fly-fishing is big business as a sporting activity
and a tourist attraction. The spread of trout into areas where they did not
exist has in some cases generated revenue. The impact of trout in these areas
has generated debate on whether the revenue is worth the impact. Time has shown us that alien species have had
no beneficial impact on the environment in which they have been introduced. Time
is a cruel teacher as much that has been done cannot be undone.