Pongola Game Reserve Fishing Report

February 2010

General

Just when we thought the fishing was going to get tough, it all turned around on us. The answer was doba doba style. Chris Diggs and his group visited Mpalane on the first weekend and did extremely well with a 3, 5 kg being the biggest using this method. I also found live bait working better than it has in months using it on a cork or free swimming.  I found adding a couta duster or some flash seem to improve strikes dramatically.

The water clarity has improved and we have been catching well on spinners, rapalas and fly. We are finding the shallow water (1m or less) working well till about 08h00am and then to the 5-8 m water afterwards. Obviously the reverse for the afternoon session. They have also been letting out water and we have found that all the exposed reed and Hydrilla banks are a definite to fish as the bait fish are taking cover in these areas. By casting literally on top of these areas and pulling the bait through them is a sure way of catching.

We had some return fly fishermen here for 3 days just as the water was clearing. The first day and a half proved fruitless but with a little bit of guiding from me, helped them get into some fish. The last morning was absolutely great with a 3, 2 kg; 2, 5 kg and couple smaller ones caught and released. Clouser minnows (un-weighted) in a variety of colors including blue and grey seemed to be working best. The shallow waters produced most of the strikes, though the drop offs at the pump station were just as exciting.

Going back to the launching fees I mentioned last month, I must apologize. The Pongola Game Reserve (Karel Landman Trust) is implementing the idea, meaning that the launching fees will only be applicable when launching from our slipways i.e. Mvubu Bay and Mpalane Bay. That is to say if you are staying at any of our lodges the fees are applicable. We have reduced the rate to R50 per boat per day and not R100 anymore. The invoice books have arrived and we will implement this from the 1st March. The slips have to be filled in upon arrival, but only need to be paid on the day of departure. Remember this money is going to the benefit of you in the long run. The income will also be available to fund small projects if necessary. Please look at this as a positive and not a negative idea.

Anyway a short report this month as I have added an interview with Angela Bownes, who is monitoring the Hydrilla on Jozini dam.

1. Quick history and background on your research.

2. Possible problems with Hydrilla on Jozini and spreading to other dams.

3. Funding?

4. Anyway guests can assist with the program?

5. Possible affect on tiger fish (breeding, size).

6. Any reason why only the KZN campsite is spraying down the boats for Hydrilla and not private launch area- esp. as they were set up a couple of years ago?

7. Long term affects it might have on the dam.

8. Most important question - do you fish?

1. Hydrilla (Hydrilla verticillata) is native to Asia, south-east Asia and Australia. South African Hydrilla is most closely related (from DNA sequencing) to Malaysian and Indonesian Hydrilla which has lead to the assumption that it was probably introduced through the aquarium trade. Hydrilla often used as an aquarium plant and S.A. gets much of its aquarium stock from Malaysian suppliers. First discovered in Jozini Dam in February 2006 and a biological control programme for the plant was initiated in April 2006. Hydrilla is a major weed in the U.S.A. and so we are piggy-backing on their 30 years of biocontrol research. Two insect biocontrol agents that were released in the States (a leaf-mining fly and a stem-boring weevil) were brought into quarantine in S.A. for host range testing to determine whether they will be safe for release in S.A. Indigenous plants closely related to Hydrilla are the primary focus of testing because we know from the research conducted in the U.S. that they are host-specific. A third candidate biocontrol agent (also a leaf-mining fly) from Singapore i.e. close to the region of origin of S.A. Hydrilla is also being tested. The results so far are promising and all looks good to complete testing of the fly by the end of the year and the weevil by the end of summer 2011. Once testing is completed, we submit a release application to the Department of Agriculture and the Department of Environmental Affairs.

2. Spread to other dams is a major concern. One of the primary control efforts was to try and contain the problem to Jozini and prevent spread to other dams. Hydrilla can tolerate a wide range of environmental conditions which is how it earned its name 'perfect aquatic weed'. It therefore has the potential to establish in and invade dams throughout the country. Any visitors to Jozini should be aware of the potential vectors for spread i.e. boats, boat trailers.

3. We receive funding for the biocontrol research from the KZN Department of Agriculture and Environmental Affairs (Invasive Alien Species Programme). The Working for Water (WFW) Programme is managing the containment programme i.e. spraying of boats

4. I suppose guests could assist by spreading the word and having an understanding of invasive alien plants in general and their threat to native biodiversity. And don't throw your aquarium plants into a dam/wetland/river! If they visit other dams and see a problem plant that looks similar to Hydrilla, please send a photo or sample to me.

5. Hydrilla usually out-competes and displaces all other vegetation which reduces biodiversity and alters native ecosystems. These alterations will affect all other consumers in associated communities. Dense infestations change water chemistry for example dissolved oxygen, pH etc. All these factors suggest that tiger fish and their prey could be negatively affected by Hydrilla infestations. The presence of aquatic macrophytes can have a beneficial effect (providing food for herbivorous species and nursery sites) but the portion of the water column occupied by these plants can influence the presence and size distribution of fish. Research done in the States has shown that feeding by certain predatory fish is hampered by the presence of dense mats of Hydrilla. In short - Hydrilla in Jozini can definitely have a negative effect on tiger fish populations.

6. I had no idea that boats were exiting private launch sites without being sprayed. These were set up by the KZN DAEA - Invasive Alien Species Programme and it was my understanding that the landowners would be responsible for doing the spraying? I'm really not sure about that and it is a big concern that boats can leave without being sprayed down to remove Hydrilla fragments from trailers etc.

7. Long term effects - see 5. Adverse effects on native ecosystems and biodiversity. Economic impact includes clogging of water intake pipes and hindering water irrigation operations. Negative impact on recreation - interference with propeller driven boats and good fishing!

8. Although not an AVID fisherman, I do fish. I have in fact caught a few tiger fish in the dam and a massive barbel. Those were the days when I used to come to Jozini with colleagues so it was a bit of work and play. Now I come on my own so it's just work, so haven't done any fishing for a while!

Thanks Angela for the information and hard work you putting in. If anyone wants to get hold of Angela you can at BownesA@arc.agrinet.za

I would also like to say cheers to Jacques, skipper and guide at Nkwazi Lodge, and welcome to Willard who seems to have the tiger fever already!

 Captain Chris