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What's happening in Resource Management

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#1
Herewith a few posts from another subject to kick start this thread. Bass fishing is increasing in popularity but the majority of waters available and the resources are coming under increasing pressure from various facets. SA does not YET have an inlands fisheries policy thus we as anglers have to adopt a legal proactive approach to ensure improvement and sustainability of our bass waters and the fish that reside in them. The industry is economically huge yet lacks the clout required to achieve this for the good of all.
Broad subject with many views, I'm sure!


Posted: Thu Aug 30, 2012 8:34 am by Brenden
morning chaps, Theewaters was 100% the year before last, last year it got to 90%. it is a very good thing for a dam when it goes down so low, a whole new ecological system is grown on the banks and the dam gets to flush out. I will be attending a meeting on behalf of WCBAA and SABAA at Villiersdorp Library on monday at 10h00 with Department of Water affairs regarding the Theewaterskloof resource management plan.
Please gents whatever you do, do not move fish from Eikenhof to Theewaters, Francois Claasen if anyone knows him, has advised that moving fish from a dam that does not have the same gene pool can cause more damage than what it is worth. The ultimate plan is to get Franscois to breed stock from theewaters and introduce the fingerlings from that gene pool back into the system. I will send feed back after the meeting on monday.


Posted: Thu Aug 30, 2012 9:12 am by Riprap
Brenden, that's very interesting - albeit that it's illegal to move fish anyway, the gene pool issue has been discussed before, herewith the link: <!-- l --><a class="postlink-local" href="http://www.bassfishing.co.za/bassingnews/modules.php?name=Forums&file=viewtopic&t=6425">modules.php?name=Forums&file=viewtopic&t=6425</a><!-- l -->
It's not as though we have the luxury of a wide gene pool to begin with so I would be very interested to know on what basis this has been determined?


Posted: Thu Aug 30, 2012 9:24 am by Brenden
thanks for that rip rap, i think what francois was trying to say is that Eikenhof fish are stunted and it may take a while to get that fish to grow past the sizes that they are. I am no Biologist and i do speak under correction, Lets discuss Albert falls that had only florida strain bass, since they put northerns into the dam and the fish interbread there are no more florida bass left in Alberts. The whole dam now has an interbread northern strain. Moving fish without really understanding what effect it could have could do damage. Im sure the biologists can help out we have a few in our midst. eg Guy.
i do know that we are looking into the whole research thing in our wc dams with Olaf. So i suggest we wait for the okes with the degrees to assist and advise before we do anything.


Posted: Thu Aug 30, 2012 9:49 am by Riprap
Fair enough Brenden. It would be great if some of the fundis could enlighten us a bit more also the concept of "compensatory growth" could be discussed? Basically this means that a stunted fish will catch up and grow to it's genetic potential if giving the right environment!?
I assume the Eikenhof fish are not genetically challenged, just their environment has resulted in the stunting - this is a management issue.
Sorry to go off topic.


Posted: Thu Aug 30, 2012 12:02 pm by Brenden
I Agree, maybe we should cull some fish from Eikenhof and introduce fodder fish and then grow a healthy stock. i dont know how true this is, but i was once told that the eikenhof fish are stunted because of a lack of fodder, which Guy did explain, due to the PH level of the dam being to high i think. this ph doesnt allow too many organisms to live therefore not maintaining a healthy eco system. correct me if i am wrong. like i say i go on what i hear in the discussions. I think if the fundis would advise us properly on what to do it could be beneficial. I also dont think that there is a lack of fish in theewaters, i beleive that since we introduced the gill christella, the fish have been following the bait fish. in the old days twk had loads of blue gill and the bass related to that, now the bass are following the shoals of gill christella and could be anywhere in the open water. Every wondered why you can catch 10 fish in an area to find not one their the next day when you return? this is because the fish moved after the bait. what twk needs is for the weed to grow back like the old days and a healthy stock of blue gill. then the bass will relate to this and not move around so much. this is just my opinion.
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BWG
#2
I recall a post on this site some time ago about the Eikenhof/ Theewaters transfer of bass and as far as I remember a large number of bass were taken from Eikenhof to Theewaters. Eikenhof’s problem is too many bass and no bait fish. Not sure about the ph though. :blue-rolleyes:
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#3
Hi, good to see some interest in water management for the future.. thanks Brenden for getting involved. I am not sure about Eikenhof cos I have never been there so it must be someone else's evaluation of that situation. My opinion would share the idea that fish are stunted because of a lack of food and too many small fish and they are not likely to be genetically stunted. Hybridisation between northern and florida strains of bass has most likely occurred in 90% of dams in this country and it is not a simple to task to identify the different strains. If fish have been moved from Eikenhoff in the past then in my opinion there is no problem with doing the same again if the right legal procedures are followed. I think if we are to improve fishing in theewaters again, we need to improve the primary productivity of the dam and work hard on removing carp and barbel (which is nearly impossible).. i.e dont put them back when u catch them. As for dams with large populations of small stunted fish, removing fish within a slot limit has been shown to improve the situation. for example, take fish out between the sizes of 150 and 350mm or something like that. My 2c
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#4
tguyp Wrote:Hi, good to see some interest in water management for the future.. thanks Brenden for getting involved. I am not sure about Eikenhof cos I have never been there so it must be someone else's evaluation of that situation. My opinion would share the idea that fish are stunted because of a lack of food and too many small fish and they are not likely to be genetically stunted. Hybridisation between northern and florida strains of bass has most likely occurred in 90% of dams in this country and it is not a simple to task to identify the different strains. If fish have been moved from Eikenhoff in the past then in my opinion there is no problem with doing the same again if the right legal procedures are followed. I think if we are to improve fishing in theewaters again, we need to improve the primary productivity of the dam and work hard on removing carp and barbel (which is nearly impossible).. i.e dont put them back when u catch them. As for dams with large populations of small stunted fish, removing fish within a slot limit has been shown to improve the situation. for example, take fish out between the sizes of 150 and 350mm or something like that. My 2c

If I read this correctly moving fish within a certain slot limit from Eikenhof (within legal parameters, etc etc) will probably be a win-win situation for both TWK and Eikenhof.
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#5
PDV Wrote:I recall a post on this site some time ago about the Eikenhof/ Theewaters transfer of bass and as far as I remember a large number of bass were taken from Eikenhof to Theewaters. Eikenhof’s problem is too many bass and no bait fish. Not sure about the ph though. :blue-rolleyes:

I'd be very surprised if the Eikenhof issue is due to pH. We measure irrigation water Ph's all over Elgin frequently and there is hardly a difference between Eikenhof and what you'd find in the Palmiet (Mofam); Applethwaite and Lorraine. It most probably more due to the numbers and ratio off bass to fodder fish. Guys often catch bluegill in Mofam, Applethwaite and Lorraine, but I haven't seen a Eikenhof bluegill ever. I've been told they are there, but clearly not in big numbers.

Interestingly; the irrigation board had to drain Eikenhof to a very low level this year for maintenance. The dam is now overflowing and had probably the best 'winer flush' it's had in many years. Maybe this would help?
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#6
[/quote] If I read this correctly moving fish within a certain slot limit from Eikenhof (within legal parameters, etc etc) will probably be a win-win situation for both TWK and Eikenhof.[/quote]

Agree!

Guys, some time ago I got this article - can't remember where.... The guys in the US spend a lot of time and dollars looking after their fisheries .... This article explains the issue of breeding FI or Tiger Bass as they call it - cross between Northern and Florida stains....

I hope its permitted to post here??

Building a better Largemouth Bass - By Barry W. Smith

Americans have always been very adaptive and innovative. If we need something, we build it. We built 4-wheel drive pickups to get us in and out of deer camp, Corvettes to attract the “Honeys,” and M-1 Abram tanks to chase down Iraqis. We bred horses to run the Kentucky Derby and horses that will cut cattle in a stockyard, dogs that will point quail, dogs that will break the ice to retrieve a duck, and dogs that will tear off your leg if you try to steal our lawnmower. Why then, with all the billions of dollars spent on bass fishing, hasn’t someone built or bred a better bass?

For more than three decades many fishery biologists and bass anglers have touted the Florida largemouth bass as the answer to trophy largemouth bass management. As California’s state record largemouth bass began to increase during the late 1960s and 70s (the results of earlier Florida largemouth bass introductions) everyone wanted to jump on the bandwagon. Nearly every state in the southeast outside the native range of the Florida largemouth bass and its intergrades (Florida and South Georgia) watched their state rod and reel record increase as a result of Florida largemouth bass introductions.

During the last 30 plus years there has been considerable research on the Florida largemouth bass, which has produced some consistent and interesting information, recorded in the scientific literature. Here are a few quick facts.

In southern latitudes, Florida largemouth bass live longer and grow faster than northern largemouth bass after age two. Outside of southern latitudes, Florida bass grow slower than native (northern) bass.

Florida largemouth bass are not cold tolerant, rapidly decreasing temperatures can cause mortality. Stocking Florida largemouth bass in northern latitudes can have possible negative impacts on native largemouth bass populations.

Florida bass are significantly more difficult to catch on artificial lures than northern bass. This difference in catchability is measurable at age one and increases, as the fish get older. Catchability is a genetic trait that is passed on from parent to offspring. An aggressive feeding brood bass will produce an easy to catch offspring.

Behavioral differences have been observed between Florida and northern largemouth bass. Floridas appear to be more skittish and in combination with northerns occupy more offshore areas of the lake.

The northern-Florida cross (F-1) is gaining in popularity in the South because of its fast growth rate and aggressive feeding behavior. How are these bass produced and what is a true F-1?

“F-1 or Tiger Bass production has to begin with pure stocks of Florida and northern largemouth bass,” says Don Keller of American Sport Fish Hatchery in Montgomery, Alabama. “We not only keep both strains separate, but we use PIT tags and external fin clips to identify strains and each individual brood fish,” notes Keller.

PIT tags are tiny transmitters that are inserted into the body cavity of the fish through a special hypodermic syringe. The tag does not have a battery, but its signal can be read with a special scanner whose magnetic field causes the tag to transmit a unique16 digit code. This allows the biologists to track data such as strain, sex, age, growth rates, and production from each brood fish. Each strain is then fin clipped by removing either the right or left pelvic fin as an external mark.

“American Sport Fish maintains more than 1,000 pounds of brood largemouth bass,” claims Keller. “We feed these bass approximately eight thousand pounds of live fish each year, primarily goldfish, koi, shad, and tilapia. Our brood bass are in top condition when it is time for spring spawning.”

Brood largemouth bass are removed from the hatchery ponds in early February and separated into males and females of each strain. A select number of these fish are spawned in the early spring in laboratory conditions where the length of daylight and temperature can be controlled. Pairs are placed in spawning vats and eggs are deposited on artificial spawning nests. Eggs are then removed and hatched in shallow troughs. Once the tiny bass fry begin to swim, they are transported to production ponds where they grow to two inches long before they are harvested.

When water in the ponds reaches prime spawning temperature (68 to 70 F), pairs of largemouth bass, usually female Florida largemouth bass and male northern largemouth bass, are placed in clear spawning ponds. Pairs are encouraged to spawn on artificial substrate so that eggs can be removed and hatched in the laboratory. Spawning here begins just as it would in your pond or lake with the male largemouth bass establishing a nesting site. He then entices a female to join him and after considerable courtship behavior, she deposits part of her eggs and he simultaneously fertilizes them. In the first spawning for the female, approximately half of her eggs will be deposited. This female may spawn multiple times; each subsequent spawn will contain fewer eggs.

In natural conditions the male largemouth bass will stay on the nest fanning the eggs and protecting the newly hatched fry. These fry cannot swim or eat, as they have not yet developed fins or mouthparts. They get their nourishment from an attached yolk sac or oil globule. It usually takes four to seven days for them to begin swimming and feeding on tiny insects (zooplankton). The male will remain with the school of largemouth bass fry guarding them from predators until they reach a size of approximately 3/4 inch. Then the fry become fair game for the male and other bass in the pond. The school soon breaks up and the little fingerlings are left to fend for themselves.

After spawning, Keller says that brood fish must be carefully separated by strain. “Producing F-1s is a lot more involved than just spawning a single strain or producing bass from a mixed genetic brood stock. We go to great lengths to insure the genetic integrity of our stocks. Our Florida strain largemouth bass brooders are from proven trophy lines and our northern largemouth bass have been selected for 15 generations for their aggressive feeding behavior. We produce a true F-1 and because of brood selection, a unique F-1 that we have trademarked TIGER BASS,” says Keller. “There are some hatcheries that claim to produce F-1s, but what they really have is an unknown mixture of Florida and Northern genetics, the Heinz 57 of bass,” exclaims Keller.

Now the next time you hear some one talking about F-1 or Tiger Bass, you will have a little better understanding about what they are and how they were “built.”

Barry W. Smith is a “certified fisheries scientist” and is co-owner of American Sport Fish.

:blue-rolleyes: :blue-rolleyes:
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BWG
#7
morning chaps, thanks GK and Guy for the input, like I said i only go on what i have heard, the same goes for steenbrass dam. it also has stunted bass i believe, but the trout that were stocked there in the 70s grew to imense size. I will see Dean Impson on monday and will discuss the possibilities of obtaining a permit to do a move of bass. As long as we have the fundis to advise us. Guy if possible i will give you Dean number after the meeting if he agrees, then you can just assist with the information. WCBAA has put funds aside to do developement and for conservation, so im sure we will be ok from the SABAA side of things. Vincent did represent BFSA at our last divisional meeting where we did tough on this subject. have a lovely friday gents
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#8
no problem Brenden, I have the equipment to move fish if and when permission is obtained.. and GK has made a good observation Smile we can use one dam to fix the other.. potentially!
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#9
Can you also try get permission to stock Eikenhof with Vlei/Blue Kurper ?
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#10
Sorry PDV for re-posting, but we did touch on Tiger Bass some while back so herewith the thread for those interested - interesting article, thanks for bringing it in.

<!-- l --><a class="postlink-local" href="http://www.bassfishing.co.za/bassingnews/modules.php?name=Forums&file=viewtopic&t=5792">modules.php?name=Forums&file=viewtopic&t=5792</a><!-- l -->

Here's the thing. We can't expect our bass (and other species) to manage themselves. Eventually nature sorts it out and the fittest survive! Sometimes such as with Carp, they change the environment which results in other species battling to survive. Wriggleswade had a huge population of bluegill but as the Carp dominated the dam so the bluegill dissappeared - haven't seen one in ages and they were the basis of the food chain. In my own pond I had to shoot the one and only carp to get my bluegill going again!

We also have round herring (gillchristella) and the young bass gorge on them and yes they follow them around but a mature bass won't expend the energy to chase these things down and they go hungry. Some fish are eating young carp but it's not commonly found in the gut??

A few years back I would drink the water in our local dam but after seeing what flows in (from the Municipal side) I would never dare now! This bades well for the Carp and the damn things are a problem - anyone got some young Bull Sharks for me?

So everything is interactive and cause & effect - whatever we do (and we have to do something) we need to understand the expected results.
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BIG FISH EAT LITTLE FISH....
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#11
Valrath Wrote:Can you also try get permission to stock Eikenhof with Vlei/Blue Kurper ?

Very important!!



RipRap - yes, that's where a saw it - makes a lot of sense!
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BWG
#12
stocking fish species into a dam that they do not already occur in (wrt. kurper sp.) is not an easy thing to accomplish and it is unlikely that permits will be issued... anyone can apply through Cape Nature or whoever is the responsible authority but I wouldn't expect a positive answer(in my opinion). Even where indigenous fish species are concerned you would need to prove that the parent stock came from the same catchment etc. This is in place to ensure genetic integrity of populations
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#13
"genetic integrity of populations" - now there's something worth discussing at length.

tguyp - Ja, it was proposed that Vlei Kurper be stocked into Wriggleswade as well but they must come from above the catchment for this same reason and a permit would have to be applied for.
So, it might be possible to translocate fish legally (by permit) provided their "genetic integrity" is maintained.

Where the papgooiers? How many of your dams have been buggered up by illegal bass introductions? :blue-rolleyes: :blue-rolleyes:
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#14
"genetic integrity is maintained" - Interesting... :blue-rolleyes:
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#15
Was just wondering, seeing as many dams have so called "undesirable" species in them, has any study ever been done on just how many species illegally occurr in our dams and rivers? Only certain environmentally sensitive areas seem to make the news nowadays!
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