Salmon in Aquaponics?

[Sylvia Bernstein]

Portable Farms just announced a "Salmon Aquaponics System" - (portablefarm dot com slash farm2011 slash salmon-aquaponics).  I'm pretty surprised by this as I thought salmon were salt-water fish.  The entire web page just talks about dealing with temperature differentials.  Anyone have any idea what is going on here?  Why wouldn't you just call that a Trout System?

[Chip Pilkington]

Hi Vlad,

That could be very well be the case for farmed fish. My experience is only with fish caught in the wild, not farmed. The trout coloration I mentioned before was in a location with an over abundance of crayfish. In fact, the technique used was to bounce a fresh, unpeeled crayfish tail down the spillway and hold on with both hands. The trout were huge with a redish orange tint to the meat. Kokanee in the lakes I've fished obviously don't have the same diet as their salty cousins (krill, herring, etc), however, they have the same red meat. It's been consistent throughout every lake I've ever caught them in and I'm sure the food sources varied. 

I don't know why, just know what color I see after fillet time. I'd love to give kokanee a shot in the system if I ever find my way back to the States for more than a holiday.

[matthew ferrell]

I have seen experiments done with salt water on lettuce, I do not know when they will be written up, and at the ranges they did, which you could taste, the was no ill effects on the plants.

There is also this guy:

http://fof.centralstory.com/bruce-swift-fish-farmer

Averan said:

salmon start off in freshwater streams and live there for the first couple years of their life.  you'd basically be raising trout-sized fish.

i don't think their passive heat-exchange idea is that crazy actually, just unnecessary and ineffective!  if someone really wanted to raise cold-water fish during warm summers, they should consider running the return lines underground for cooling.

that said, i think there's potential for salt-water systems growing kelp and salmon!  you'd have to cultivate an entirely different ecosystem of microorganisms to break down waste into fertilizer.

[matthew ferrell]

We do it with carotenoid additives.  Unfortunately it only looks good on the uncooked fillet.  After heating it bleaches out too. 

You are correct, krill meal has tons of it.  Plants also produce carotenoids.   You might notice the connection in the word carrot and carotenoids.  Carrots are high in beta carotene(Vitamin A). 

Fun fact: farm raise Panaeus shrimp that aren't fed enough carotenoids turn clear or blue. 



Vlad Jovanovic said:

Well, according to "the net" ...The colouring seems to be due to carotenoid astaxanthin, a lipid soluble pigment (phytochemicals). Comes from a diet high in shrimp, krill or other small mollusks. Or in the case of most farmed salmon, artificial coloring agents in their food.

Wonder how the folks mentioned above do it?

Jon Parr said:

Laine, I must have blurred that sentence of Chilean salmon farms and copper pit that you can see from your house, into one thought. So, Salt Lake City. That makes more sense.

I'll check my friend's progress with the hatchery. I know it is not built yet, red-tape rolls slow.

Thanks PeterD for those links. Interesting that Bruce calls coho the broiler chicken of the sea, on account of it's fast growth. Wonder how fast it does grow? I also wonder what he feeds them to get the meat red. I'll have to look that up.

[matthew ferrell]

Should have looked through the whole post.  Bruce Swift was already mentioned.  I'll try and get the salt water numbers out of those fellows... again.

matthew ferrell said:

I have seen experiments done with salt water on lettuce, I do not know when they will be written up, and at the ranges they did, which you could taste, the was no ill effects on the plants.

There is also this guy:

http://fof.centralstory.com/bruce-swift-fish-farmer

Averan said:

salmon start off in freshwater streams and live there for the first couple years of their life.  you'd basically be raising trout-sized fish.

i don't think their passive heat-exchange idea is that crazy actually, just unnecessary and ineffective!  if someone really wanted to raise cold-water fish during warm summers, they should consider running the return lines underground for cooling.

that said, i think there's potential for salt-water systems growing kelp and salmon!  you'd have to cultivate an entirely different ecosystem of microorganisms to break down waste into fertilizer.

[Dino Pantelidis]

I don't know much about salmon specifically, but I do know of an aquaponics facility operating in Canada using trout as the fish of choice. It's obviously a cold water species but from what he has told me the trout and lettuce do very well together.

In Ontario and Quebec trout is readily available as fingerlings while tilapia is next to impossible to locate.
I believe my contact buyers trout in bulk (rather than going through the efforts and expenses of becoming a hatchery)
Raises his trout to plate size. Once they are ready he markets his product by selling smoked trout filets.

Trout works well for him - again I don't know much about salmon.

Cheers
Dino

[RupertofOZ]

Trout are a staple fish for most aquaponicists in the Southern states of Australia...

 

I've run batches of 200 at a time.... (100kg harvest weight).....but in a big tank, with lots of air and filtration...

[David R. Russell]

There is one possible way to rear salmon as part of an aquaponic operation.  However, the colder temperature requirements for the salmon in contrast to good root temperatures for the plants make for some significant challenges.

One solution, for something that is larger than a hobby system, is to attach a recirculating aquaculture system for rearing salmon or other cold water species such as arctic char to an aquaponic system.  In such a system, discharged water for nitrate control would not come back to the cold water RAS system.  Flow would be one way and be sized to meet the evaporation and transpiration needs of the aquaponic system where plants and a warm water species could be grown.   Where I live( Maine), average water needs for evaporation and transpiration is about 4 liters/ square meter of plant growing area.  For a greenhouse with 100 M2 of plant growing area, this would work out to about 400 liters or 0.4 cubic meters per day.  My water is from a well and has a temperature of about 9 C (48 F), which has some “free” chilling ability for keeping a well insulated RAS system cool. 

The maximum feed load  (a measurement of recirculating aquaculture intensity) for control of nitrate at levels safe for salmon is about 3 kg of feed for every cubic meter of water usage.  Using this figure and the figure for makeup water, the cold water RAS system could support a daily feed ration of 1.2 Kg of feed per day(3*0.4=1.2).  The plants, using the ballpark figure of 100 grams of feed per square meter of plant growing area require a feed ration of about 10 Kg of feed per day (substantially more than what could be supplied by the fish in the cold water RAS system).  To make up the deficit, a warmer water species as part of a true aquaponic could be used.  In this scenario, fish in the cold water recirc system, which is chilled with water for meeting the evapo-transpiration needs of the recirc system, would receive about 12% of the fish feed and the fish in the aquaponic system would receive 88%.  Thus plants are still the major crop, the warm water fish of the aquaponic system is the secondary crop, and cold water fish a much smaller tertiary crop.

This is just one option.  Personally I would forget salmon for such a system (temp of 12 C and cooler needed for successful reversion to freshwater form after smoltification) and arctic char (max temp of 14 C), and instead produce rainbow trout (up to 18 C).  The trout are faster growing, convert feed better, can utilize a higher degree of plant proteins, and are cheaper to buy and produce.  At 18 C, the trout could be tied into an aquaponic system and be the sole species for feed input to the system.  The problem with salmon is smoltification (pre-adapation for life at sea).  Prior to this point, 18-20 C is doable.  Afterwards, for reversion to freshwater form, cold temperatures are needed.  Landlocked salmon strains have the same problem.  They just go deep to access the cold temperatures below.

If the desire is to have a red salmon like flesh with a taste and texture very similar to salmon, I recommend that one grows rainbow trout as a steelhead(same species).   I know of one large commercial producer that produces trout both in freshwater cages and in seawater cages to a harvest weight of about 2 Kg (4 lbs).  Both groups are fed a pigmented diet containing astaxanthin (synthetic but identical to the pigment found in nature).  Natural sources of astaxanthin from algae and yeast can also be bought, but is more expensive and will require custom feed manufacturing of self manufacture.  Both groups are sold as steelhead trout and taste great.  The nice thing with trout is that temperatures can be as high as 18C (not a bad match for lettuce and manageable from a temperature standpoint without breaking the bank in regards to the need for chilling). 

The figures above are for example only.  Differences in percent protein in the diet, food conversion, growing practices, specific plant needs, and environmental conditions could alter figures significantly.

[Laine Houberg]

Salt water lettuce, how interesting. Do you know if it desalinates the water ? If so Im sure there are a lot of people who'd be interested in desalinating their water that way. Id love to see more info or a link if you have one to share. I think salt water would be a great topic on its own, you should start a thread.

matthew ferrell said:

I have seen experiments done with salt water on lettuce, I do not know when they will be written up, and at the ranges they did, which you could taste, the was no ill effects on the plants.

There is also this guy:

http://fof.centralstory.com/bruce-swift-fish-farmer

Averan said:

salmon start off in freshwater streams and live there for the first couple years of their life.  you'd basically be raising trout-sized fish.

i don't think their passive heat-exchange idea is that crazy actually, just unnecessary and ineffective!  if someone really wanted to raise cold-water fish during warm summers, they should consider running the return lines underground for cooling.

that said, i think there's potential for salt-water systems growing kelp and salmon!  you'd have to cultivate an entirely different ecosystem of microorganisms to break down waste into fertilizer.

[Meg Stout]

I lived near Lake Pend Oreille in Northern Idaho, where the land-locked Kokanee salmon live their entire lives in fresh water. The Kokanee are mostly feed for the amazingly huge trout Pend Oreille is famous for - I seem to recall it was illegal to keep any fish less than 20 pounds, since these "smaller" fish are still considered babies.

I imagine salmon are still edible during their fresh-water phase. They can't possibly be smaller than mature bluegill. Does anyone know how the flesh of a freshwater salmon compares to the salmon we are accustomed to buying in stores?

[George]

The book Four Fish contains some discussion of recirculating systems containing Salmon but instead of land based plants, seaweeds, mollusks and plankton would be cultured.  I believe it's all or mostly theory at this point but they were talking about landlocked systems using genetically modified Salmon.  Food for Salmon would be cultured within  the system at a very low point on the food chain which would still provide Omega 3, a vegetarian Salmon food.  However, I believe that once genetically modified Salmon are approved for market it will be business as usual, utilizing the lowest cost methods available.  It's an interesting book about Cod, Salmon, Sea Bass and Tuna.  There is some information about Barramundi in the book.  It sure would be nice if Barramundi and Jade perch were available in the U.S.

[Meg Stout]

OK, have since checked out the *huge* kokanee sports fishing business. Kokanee basically live where trout live, and get to be about a foot long and a few pounds each.

 

I saw a qurey from someone hoping to set up a kokanee aquaponics system back in 2006, but the thread ended and I didn't see where it went from there.

[Sergey Dekhtyarenko]

My 2 cents on the salmon / trout
1. they are related species
2. they need a high level of oxygen
3. the oxygen content in water decreases with increasing temperature
4. trout grown at a temperature> 19 degrees C only with the addition of pure oxygen into the water (not air), which is very expensive.
5. Trout need clean water and does not tolerate even a small amount of ammonia / nitrite.

Attention to the question:

what plants will grow well in a small content of nitrites / nitrates and low temperatures?

There are also nuance.

Tilapia and catfish - do not need lots of oxygen and beautifully maintained high levels of ammonia / nitrites, but they need the warm water.