After reading posts, and advice from ewest, I felt like a blocking net had tons of merit. Since I haven't needed it yet in a grow out pond, I thought I would try this first.

First pics are of partial bag of Tilapia I picked up at Overton's on Monday. After talking to Todd, I selected a bag that had a close 50% mix of large to small Tilapia.


Next pic is of 2 blocking nets set up before dumping Tilapia. The 8' space between the 2 nets is where I overnighted the 90 pounds of Tilapia that were to be released into the big puddle. Left of the left net is where I dumped the 10 pounds of mixed Tilapia.


Saturday morning, I pulled the outside net, as released the 90 pounds of tilapia. I then zip tied the 2 seine nets together, and moved it out as far as I could, which was around 40'. The 10 pounds were then confined to this area. I'm hoping to get a protected spawn in this area, and then release them when the hatch are large enough to survive.


Worse case senario, I have the same amount of Tilapia I started with only larger. Best case scenario, is a protected spawn from an area that requires no maintenance since it's actually part of the big puddle.

The Tilapia were hitting pellets this am, and like Brian I found 4-6 areas I think were the start of spawning beds. I'll confirm that later this week.

Allen, that looks great, I can't wait to see how your setup works. How are you going to transfer the tilapia from the "Compound" to the bid puddle? Are you worried about any predators getting past the net and crashing the buffet?

One other thing, how deep is the "Compound?" Is your blocking net going to stay out all summer long? Are you worried about it getting damaged?

Last thought, Robbie Hall is one tough worker!!! You choose wisely......

I'll just pull the net after I confirm whether this deal works or not. I can't imagine it still being there by July. The water in this cut is very clear, and other than FHM and a few small BG, there was nothing in it. If a LMB jumps the fence, I'll just seine him out. The cut is about 4' deep in the center, and about 100' long.

Robbie loaded all the fish at Overton's, helped reset a feeder deck, move 3 feeders, and sprayed fence rows for 10 hours this weekend. She's a very lucky woman to have me.

go with that.....

Good job Al and thanks for the pics and report.

Al, 6-8" tilapia will reproduce more, faster. As they reach 3/4 pound in size, a single male will defend a pretty large diameter around it's nest (as much as 10' depending on clarity)

Rex, I was initially planning to try to sex the Tilapia and keep the numbers a little more manageable. I'll try to do that soon, and hopefully reduce the numbers in the area to a prom instead of a rave.

I really needed to get those fish in the water, or I was going to try it last Friday when we picked them up. We'll see in the next week or two if the spots are indeed nesting areas, then I'll go from there. To me, 7 or 8 pairs would be the perfect scenario for size of this location.

Al...Have you asked the tilapia if they will cooperate? lol They will go over or under most nets if they want. I can't sex the buggers, no matter what the size, with or without dye. Like an LMB, I only know a female if it is holding eggs/fry.

Rex, glad you said that about sexing them. Exactly what I was thinking too, but I didn't want to appear fisheries challenged. I do the same with LMB.

I'm fine if a few get through. Funny thing is when I released the 90 pounds, about 15 stayed overnight and were nose to the net the next morning. I guess they missed their buddies.

We'll see how it goes, but no harm no foul if this doesn't work. This cut is where I'm putting in a grow out pond next year, so I know those won't get out.

FWIW, Overton can and will provide either sex Mozambique tilapia by inspection as fast as he can net them - I have pictures somewhere and M/F was evident to me.

For years I stocked all male Mozambique tilapia in our forage pond for algae control w/o risk of over-population.

Al, I will try to dig those pictures out of my old files if I can find them.
IIRC, Todd was showing Brian M/F ID when we were at his farm last week?
G/

Al, here's pictures of M/F ID for sexing your Mozambique tilapia. Overton's hands on ID for my photos many years ago.
I have stocked tilapia for so many years, I take them for granted...

Male Mozambique Tilapia


Female Mozambique tilapia

http://www.pondboss.com/forums/ubbthreads.php?ubb=showflat&Number=103583&fpart=1

These are tilapia but you can get an idea of what Todd is saying.

Male on left , female right.

Awesome idea! Interested to know how this turns out.

Thanks for the info guys.

I felt like should add something I neglected in the initial post. I'm trying this for 2 reasons:
1) To see if I can
2) Forage for my CNBG

Since my electroshocking and removing 180 pounds of LMB, I've dedicated this year to CNBG. My thought was to release the Tilapia fry as soon as they were free from the female's mouth and actively roaming on their own. Hopefully, the CNBG will eat them as soon as they hit the big puddle.

I in no way expect these newly hatched Tilapia to really help the FA, because I hope they get eaten. Even if this works, I'll continue to annually stock 10 - 15 pounds per acre of adult Tilapia to help control FA.

If the blocking net has large enough mesh, won't the YOY swim thru it on their own?

It's 1/4" so I'm not sure. If this works, I'll dedicate a better net with a larger weave. Great thought. That could really be a time saver. Right now, I'm planning on netting and tanking the large males and females, pulling the net, and restarting if they spawn.

Al, I would be concerned most of your fry will get eaten by fellow tilapia rather than making it to your CNBG when the tilapia are concentrated...they have a strong craving for the babies, plus females will hold longer/reproduce less often due to the fry predation threats present. Fry will easily swim through a 1/4" mesh as they will be about 1/4" long when released. Any way it goes Al, you're gonna have fun with it!

Rex, that's exactly the point. I'm not out one penny to try this and if it works, no telling what species I may try next.

An old blocking net trick ! Dang I am giving away my secrets.

Once you have adults and babies (YOY to free swimming stage)behind the net and you want to separate them try this. Slowly reduce the size of the enclosed area by closing the net inward (closing a circle). Take each end of the net and walk them slowly to meet in the shallow water then move to a little deeper water as you close in the net more (shrink the circle). When the circle is reduced to a small size move it (with the larger fish still enclosed) back to shallow water and slowly redeploy the net by seining backward. Many of the yoy will be outside the net and be subject to predation by the outsiders.

Ha Ha! Eric, you're not giving away secrets, you're being a helper bee. That's what makes this forum work.

Heading to farm Friday, so I'll see what I have then.

Another thing you can do if a lmb gets in there, Do the circle bit again. At some point, that sucker will almost always jump the net.

Wear head and at least eye protection...tilapia will launch several feet in the air when crowded, but it is a blast to watch the eruption!!

The trick is to go slow with the net.

We had the big rain roll through early today, hopefully I won't have a big muddy mess in the morning.

Allen, how much rain did we get?

A little over an inch there.

Plan failed miserably. I got to the farm today, and the net had gotten tangled in weeds, and was down about 6" in one spot. The Tilapia were gone.

The 2 big cold snaps really stopped all action at the beds for the last 10 days and I never thought the temp would be an issue this late in April. Several nights in the 30's had the Tilapia huddled up in the deepest part of this gut, and they never seemed to move away from that area after the first few days.

I may try this again, but not this year. I still think the plan is valid, but better preparation on my part, and waiting a little longer would have helped.

Oh well, nothing ventured, nothing gained.

Sorry to hear it Al. Most of my endeavors have turned out to be experiments.

Mine too.

It's easy to roll the dice on something like this when you're playing with the house's money. I wish all my hair brain failures were this painless.

Allen, you can always help me with my experiments, its cheeper that way!!!

Great idea. I have some GSF I want to breed with genetically superior CNBG to create a super strain. I'll bring them over this week. You don't need to be there.

One thing that helps avoid tangled nets getting pulled down is to use rigid plastic netting. That (RPN) attached to a few poles with cable ties and pushed into the bottom is much stronger. Plus if you buy it in rolls when you are through you can cut it loose , roll it up and away you go. RPN is also much more durable for long term deployment.

Thanks Eric. I bought a roll, and have successfully used it around some drain pipes with t posts. I was hoping to see if this Tilapia thing worked by the middle of May then go ahead and make it more perminant.

I know we haven't had near the weather that a lot of places have had, but the cold fronts just keep rolling through. Highs in the 80's tomorrow, then 40 Thursday night, have had my fish unsettled. My Tilapia left the nests as fast as they built them.

Al, that just might be an interesting experiment. I have found that ounce for ounce, a GSF can out fight a CNBG.

Last year I built several 8' circular "pens" out of that plastic barriers netting. These pens held around 10 pairs of 3-6" tilapia. I then made it a point to throw feed to them once a day. They bred prolifically and nothing got to them. The holes were more than big enough for the free swimming fry to swim through. The whole thing cost me about $50 and it is reusable.

Best part? It was incredibly easy to net those fish out of the pens in the fall and overwinter them in my barn for next winter using a closed system. This year, I put them all back in, but no pen needed. They are about 12" and several pounds! They can take care of themselves.
I did this because it can be hard to get tilapia early enough in Spring and they can be expensive now.

Just a thought.

Thanks BigSprig. I agree, I think the rigid netting is the way to go. Looking back on this, I think the weather got me more than anything else. It's been a weird year for everybody, and the Tilapia stayed unsettled. I will try this again.

Just wanted to say this is a brilliant idea, even if it didn't work. I was already planning to build the pond with several fingers to it and this just convinced me I had to go this route. This would give me 3 or 4 areas I could experiment in very easily.

BigSteve, I'm blessed to have 3 guts/fingers in my big puddle. The Tilapia deal was tried because of these, and I also use them for aquatic plant testing. I have Arrowhead and American Pond Weed growing out in one right now. I'll play with them there, and their easily controllable if they don't turn out well.

The gut where the Tilapia were is now a plant nursery for the rest of the puddle.