I am going to make a giant assumption, that having read part 1 of this story , you are in agreement with me that bass are a problem in the Trout areas here in KZN , and that something needs to be done about them. If you haven’t already agreed with the above, then you probably won’t be reading this anyway.
The biggest issue here, is that nobody knows how bass spread. There are however some theories. I will list those here, and then alongside each theory, suggest an appropriate measure to stop the spread.
Theory no 1: Bass eggs on Duck’s feet:
I find this one hard to believe. But because I don’t know it to be untrue, let me not write it off as nonsense. If this is indeed how bass spread, there is little that can be done (no…. I wont propose shooting all ducks). What does remain true however, is that the fewer waters that have bass in them, then the less chance there is of a duck flying from a bass dam to a trout dam, with an egg stuck on its feet. With this in mind, I propose paying attention to bass invaded waters in the general upland areas, even if they have no prospect of ever being a decent Trout water. By “paying attention to them”, I refer to whichever of the other measures mentioned below which might be practical.
Theory no 2: The farm mechanic stocks bass.
I have a sneaking suspicion that this problem is right up there …one of the main ones. If I generalise, I can say that farmers who are INTERESTED in their Trout fishing on their farms, seem to be less inclined to suffer a bass invasion. I can only assume that they lecture their staff on the value of their Trout water, that they care who fishes there, and by what method, and that they control access. In other words they EDUCATE. KZN does not have a “keep bass out” sign anywhere. I think it is time!
Theory no 3: Bass swim up a flooded spillway.
I believe in this one. We forget how strongly any fish can swim up a current. After a summer freshet, a dam spillway flows strongly through the grass or vlei for a few hours, giving bass a passage up to the next impoundment. One or two of these storms every year, and eventually a bass will swim up. The solution , when bass exist in the dam below, is to put stainless steel mesh barriers across spillways, and keep them clean.
NFFC volunteers erect a bass screen on a spillway in the Kamberg
Theory no 4: Water pumped from one dam or river to another transfers bass eggs.
This is not a theory. We have proof. Eremia dam was invaded this way in 2015, and in around 2013/4 Sourveldt received bass from the little Mooi River that has bass in it. This requires some study on how to screen the pump intake finely enough to stop bass eggs, but without causing suction vortex and pump cavitation. Once we have that worked out, it will be back to “Education” to ensure that the solution is put in place when farmers do have need of water transfer. To get that right, farmers will need to value their Trout fishing resource, as described above.
Those are all my theories.
Next is to understand the enemy to come up with some eradication/control measures. I did some googling a while back, and this is what I learnt about bass:
- They live for up to 15 years, sometimes longer, and breed every year in that lifespan.
- They lay eggs when the water temperature gets to around 18.5 degrees C
- They like to lay eggs in shallower water where the sunlight penetrates to the lake bottom…about 500mm to 1.5 m in depth .
- The male protects the nest and an area of about 3 square meters around it.
- Larger Trout love eating bass hatchlings
- Breeding bass shoal stupidly and expose themselves to danger in the margins when their mind is on breeding.
We can use this information to empower ourselves in the struggle against bass as follows:
- We can stock Trout in bigger sizes, and at the very time when bass are hatching (9 to 12 inch fish in late November). The NFFC already does this on select dams with some measure of success.
- We can wait for the water temperature to get to 18.5 degrees, and then open the valve and drop the water level two metres to fry bass eggs in the hot sun! You can only do this if the water is not needed for irrigation, and if the dam has a valve. The NFFC has been doing this at Eric Kietzke dam with the blessing of the landowner, for 3 years now.
Eric’s dam before :
Eric’s dam after:
We learnt this via the grapevine from farmers in the East Griqualand area who have done the same. We also know it to work, in that the Mearns Weir on the lower Mooi River, which has a constantly changing level has a particularly thin population of bass. There are also American reports of bass struggling to breed in resevoirs where level fluctuates.
- When we have a drought, and dams which we would not normally be allowed to empty, are empty anyway, we can strike with a piscicide (fish poison) and opportunistically win back some waters.
- We can fish for bass, or even cull them with a throw net, when they are shoaling stupidly in summer.
- We could sponsor a masters program to study other methods. I can’t help wondering if shading dam margins, or rigging up vicious looking decoys (like “Billy the bass” on steroids) to scare off potential egg layers, or some other clever things might be possible.
The total onslaught:
My time in the army was a real waste of time. What I did gain was a “balsak” which still serves as an excellent tackle bag, and the concept of the ANC’s so called “total onslaught”. Whether or not the ANC did have a total onslaught strategy or not, I like the concept when tackling a problem as diverse and difficult as the spread of bass. I think we need to borrow the idea, and employ as many of the ideas and tactics mentioned in this article, all at once. I think that only if we do that, are we likely to achieve success in this endeavour. An endeavour that otherwise seems as hopeless as holding back the sea with a fork.
I illustrate my conviction that such a total onslaught is required with this sad story:
When the Spring Grove dam was built above Rosetta, the authorities had the foresight to have an impact study done. That study revealed that the Inchbrakie Falls constituted a natural fish barrier.
That natural barrier protected the Trout fishery above the falls, from an inundation by other warm water species from below. The dam would flood this barrier, allowing warm water species to migrate upstream.
A study was done, and a loss of economic value by such an inundation was calculated, and it was deemed justified to spend something like R10 million building a fish barrier. The dam was given the ‘go-ahead’ with the condition that such a barrier be built.
When the dam was under construction, budgets were being strained, and it is alleged by friends who attended meetings, and heard this first hand, that engineers proposed scrapping the fish weir because “There is no difference between Trout and bass anyway”. Interested and affected parties declared that a lawsuit would ensue if the pre-condition was not adhered to.
So the weir was built.
The lake thrown by the fish barrier on the Mooi River.
My conjecture is that it was built in a “wham, bam, thank-you mam” way. I say that because locals I spoke to had no idea why it was being built. Others who challenged the effectiveness of the proposed design were also brushed off. No signs were erected prohibiting transfer of species above the weir. No public education or engagement was entered into.
And now, not much more than a year after its construction, largemouth bass (seen with my own eyes), and allegedly smallmouth bass (I have not seen them), exist in the impoundment ABOVE the weir.
R10 million down the drain…completely wasted.
If this was a first world European country, the authorities who built the dam, would be forced by a court of law to spend whatever needed to be spent, and do whatever necessary, to reverse the damage they have done.
I for one, am truly saddened.
If you are as concerned as I am about the big bass problem, and if you feel that something should be done, please drop a comment here, or on facebook, or mail me on “truttablog at gmail.com” . In that way we can measure if this problem is worthy of action, or conversely if it touches so few people that it warrants abandonment.
Note that in all this, there is no attack intended on bass and bass fishermen on some wide scale: It is merely tackling bass invading waters in which, to the best of my knowledge, there is no economic or social value attached to bass fishing, but where bass threaten to erode that value found in Trout waters.
Because Trout and bass are being labeled as “alien invasive” by authorities in South Africa, they are together on the same side of the battle lines. That is perhaps the reason that little is being said by Trout fishermen about the bass problem. But a more likely reason is apathy, or some other failure on the part of us fly-fishermen to galvanise into action. I say that, because the unwanted, unchecked spread of bass in the uplands of KZN has been going on for thirty years. Those, by the way, are 30 years in which Trout have not “invaded” anywhere at all.
So why, might you ask, is so much being said about Trout being alien invasive, and NOTHING being said about bass?
I don’t know the answer. I can guess that Trout somehow have a colonial connotation about them, but that’s as solid a reason as I can dream up.
Now before any bass fishermen get over excited, know that I have nothing against bass fishermen, and bass in our warmer water areas. In these areas, bass fishing has an economic value. But in the higher altitude “Trout” areas, Trout fishing has a value that is being eroded by the invasion of bass, and the economic value of Trout fishing is not being replaced by a similar economic value of bass fishing. (No bass fishermen that I know of book into lodges in these areas specifically to go bass fishing. Examples of Trout fishermen booking into a venue for the purpose of flyfishing for Trout are too numerous to mention)
There is simply no logic to the silence surrounding the problematic spread of bass in our area.
So what does the problem look like?
When I was a schoolboy, our family visited the Underberg area on holiday. We used to queue each morning at the Underberg Himeville Trout Fishing Club office (UHTFC) to speak to Bill Hughes, and before him Bob Crass, and book water for the day. Some of the waters had bass in them. North End and Palframans spring to mind. There may have been one or two others, but not many more. Now, 30 years later, you struggle to find waters that DON’T have bass in them. Not entirely co-incidentally (and sadly!) , you no longer have to queue outside the offices of UHTFC to book water, and a whole social flyfishing fabric has wasted away.
As a varsity student, I remember one dam in the Kamberg that had bass in it: “Morrass vlei”.
Today you can add:
Windmill; Goose ; Eremia ; Prosperity; the Little Mooi; Sourveldt lower dam; Bracken Waters; Rey estates 2 dams; Airstrip; Meshlyn main dam; and more.
A bass lurks in the shallows of a previously hallowed Trout water.
And remember that in this example I am addressing just the Kamberg valley.
The beautiful Kamberg Valley
When you start tallying dams throughout KZN the list is enormous, and includes some previously famous and treasured Trout waters.
I don’t know about you, but I am horrified!
Remember that the Trout don’t breed in these stillwaters and need to be stocked. The bass, on the other hand, breed like crazy, and once they are in there is very little chance you will ever get rid of them. You can empty the dam and poison it, but farmers understandably don’t want to empty their irrigation dams. Poisoning water is also a touchy subject.
So why are bass a problem. Why can’t we have bass and Trout in the same water?
We can, but most flyfishermen I know, go after Trout, and don’t want to be catching bass. Bass almost seem to have a self defense mechanism wherein they breed like crazy in the face of competition. It seems that way, because when they invade a Trout dam, fishermen report catching literally hundreds of bothersome bass, the vast majority of which are tiny. Now Trout eat small bass (and get very fat on them!), but bass eat small Trout too. So to uphold a Trout venue, when it has bass in it, one needs to buy and stock larger Trout (9 to 12 inch stock fish). These larger fish are mighty expensive. Unless it is a small impoundment, most fishing clubs or lodge owners would drop the stocking of Trout because of the cost, and voila…another Trout water just became a bass water.
So how do bass spread, and what, if anything, can be done about the problem? I will make an attempt at this subject in part 2, but for now I wanted the enormity of the problem to sink in.
* Yes, Trout are spelled using a capital “T” and bass with a lowercase “b”. This is because I am prejudiced, biased, and unscientific.
Bass fisherman compared to Trout fishermen, as depicted by Jack Ohman in his book “Fear of Fly fishing”: