Want to raise fish high in omega-3 fatty acids

[DonnaRae]

I am completely new to aquaponics and have lots of beginner questions. I have searched the forums for information on this topic, but didn't find an answer, so I am bringing it to the "Fishy Questions" section.

I want to raise fish that are high in omega-3 fatty acids. I have read that a couple of kinds of perch found in Australia are high in omega-3s, but I don't believe these fish are available in the USA. From what I have gleaned, tilapia and catfish are higher in omega-6 fatty acids, which can actually contribute to poor heart health if they are out of balance with omega-3s. I'd like to find a fish that is high in omega-3s that can be successfully raised in an aquaponics environment.

Thanks in advance for help with this!

Donna in Oklahoma USA where it is a gray, cold day and I would rather be at a sunny beach!

[bsfman]

From what I have gleaned, tilapia and catfish are higher in omega-6 fatty acids, which can actually contribute to poor heart health if they are out of balance with omega-3s. I'd like to find a fish that is high in omega-3s that can be successfully raised in an aquaponics environment.

Hi DonnaRae, if you do some Googling on the topic, you may find several studies that attribute the higher Omega 6 ratios in farm raised catfish and tilapia to being fed primarily a corn based diet. Even salmon that are farm raised have a higher omega 6 level than wild ones. Evidently the omega 3 levels are the same as wild caught, but the higher omega 6 levels throw the ratio out of kilter. Not surprisingly, even free ranged chicken eggs have a higher omega 3 content than factory farm eggs - perhaps because of the high percentage of corn in the factory farm chicken feed versus the insects and green shoots the free rangers dine on.

The solution is probably to feed your tilapia or catfish a diet that mimics what they would eat in the wild. Easier said than done, I know, but it can be done. Insects, vegetables and greens all provide nutrition without corn.

In Oklahoma, you may be able to raise Black Soldier Fly larvae. They are high in protein and if fed the occasional serving of fish guts or whole trash fish, the BSF larvae reportedly contain very high omega 3 levels. Presumably that will be assimilated by the fish too.

[foodchain]

I have read. Not actually tested, but read that colder water fish are better for this. I have also read that salt/marine or even brackish water are an option. How you would do this in AP is beyond my skill level. However, please note that this is what I have read...not actually tried.

Different types of critters in my system have their pros and cons, more of an aquaculture salad than going all one way with one species. This gives me a selection of flavors, textures and applications. So in effect if one is lower in a given area, the idea is that another will make it up.
My logic may be off, but so far so good.

I do know a lot has to do with diet, and water quality. I get surprisingly different results with growth and such by minor adjustments in diet.

[DonnaRae]

bsfman & food chain, thanks for the tips and ideas. I have been doing a fair amount of googling and you gave me something things I hadn't thought to look for, like information on fish diet & omegas. I wonder how the corn shortage will affect what fish farmers are feeding?

I will look into yellow perch, too. I know that wild perch do great in Oklahoma.

We had a brutally hot summer this year, and it had not even occurred to me that raising fish would not be a year round activity. I had to go to the mountains for the entire month of July because it was so hot here. Fish would certainly not have made it in the 100+ weather. Glad I found this forum!

Thanks,
Donna

[davidstcldfl]

Hi Donna, welcome to the forum...

You can try feeding purslane to your fish...it's high in omega 3 and vitamin c.

[bsfman]

Here are links to abstracts for a couple of studies which found that though omega-3 had a beneficial effect on cardiac health, omega-6 had no problematic effect on cardiac health (hence the ratio is also irrelevant to cardiac health). The important thing is evidently to get enough omega-3.
http://www.ncbi.nlm.nih.gov/pubmed/17876199
http://circ.ahajournals.org/content/111/2/157.full

[DonnaRae]

Hi Donna, welcome to the forum...

You can try feeding purslane to your fish...it's high in omega 3 and vitamin c.

Thanks, David...,

Purslane contains, I think, ALA OMEGA-3s which are found in plants, and I believe EPA which comes from animals is most beneficial for heart health. That's an interesting idea that fish eating purslane might convert the ALA to EPA. Back to the Goog!

[bsfman]

You can try feeding purslane to your fish...it's high in omega 3 and vitamin c.

Thanks for this info! I've never tasted nor, far as I know, even seen purslane. Might just give it a try! Found some links to seed sources.
http://www.sandmountainherbs.com/pur...reen_leaf.html
http://www.wildgardenseed.com/index.php?cPath=49
http://www.highmowingseeds.com/produ...&cat=83&page=1
http://www.territorialseed.com/product/959/s

Have you any experience growing purslane, David? Would it work okay in a floating raft system?

[foodchain]

If you were to run a test culture on this, feeding purslane to one tank and not the other, how would you test your crop to determine concentration then? Or if the conversion works?

[bsfman]

If you were to run a test culture on this, feeding purslane to one tank and not the other, how would you test your crop to determine concentration then? Or if the conversion works?

You'd have to pay a small fortune to a commercial food lab to do the analysis on your fish. Not worth bothering with unless you are selling fish commercially.