Backyard Aquaponics
A place to discuss aquaponics

I'm really just jotting down some thoughts here, but if it generates some discussion, then fine.

Aquaponics, as we practice it and dicsuss here on the forum is, with the odd exception, not likely to be a commercial venture in it's own right.

As I said, there are the odd exception, and for those with projects underway, I wish you best and know some will succeed because of your niche situation.

Now, it sounds like stating the obvious, but they generally don't succeed because the value of their produce is insufficient. However, what is generally not considered here is that all these products are freshwater products essentially (both the fish and the vege produce). Now, from observation over the years, the expensive fish in the fish market are not the freshwater fish, nor are the most expensive veges the ones that everyone is growing.

Maybe, with food prices as they currently are, the only way to do aquaponics commercially is with saltwater products, i.e. higher value crops than are available in freshwater.

I'm not claiming this as an original idea, it's really just a type of what's called Integrated Aquaculture and it's been around for a very long time in various forms. However, these days, it's almost always constructed to provide a way of remediating aquaculture facility waste water, thereby meeting environmental requirements.

What if you constructed a system to grow both the fish and the plants as economical crops ?

The fish side is reasonably well known and there are some higher value saltwater plant crops out there (higher value at least than lettuce or basil). Some are;

- samphire (and the southern hemisphere season could cover for the off-season in the northern hemisphere, where it is eaten in some quantity)
- seaweeds for agar and other setting/thickening agents
- seaweeds for food consumption (nori for example)
- more that I can't think of off the top of my head

The seaweeds at least would require a shift from what we think of as a growbed.

Don't assume this needs to be near or at the sea, necessarily. Australia has a wealth of inland saline waters that are begging for a use as a resource and in a recirc system the problems with cation and anion differences with seawater could be managed.

It wasn't that long ago that marine aquarium tanks at home were almost impossible to have, whereas now they are very common place. Maybe this is one evolution direction for aquaponics as well ?

a link to what one mob in America are retailing their seaweed into the herbal treatment enthusiast crowd;

http://www.alcasoft.com/seaweed/pages/catalog.html

Samphire? Is that worth something? There's plenty out in the wheatbelt.

They were looking at doing something out in the wheatbelt putting trout (yeah I know they grow in fresh too) into really salty water before pumping it back through some areas where saltbush is growing. There was a write up in a salt land agronomy newsletter a couple of years back.

I don't know how successful the seafood has been in the inland areas, there's been talk about it in the past in many circles but does it actually work, has anyone done it?

I doubt if growing salt water species [fish or plants] would get off the ground commercially as they can be farmed more cheaply in big quantities in the ocean, as say salmon and trout in Tasmania.
California also has seaweed farming off shore

Interesting train of though Chilli. I had thought down these lines before, not commercially but in a backyard sense. For instance estuary species like flathead and bream to be raised in AP salted to 3ppt or above at all times the only problem I couldn't overcome was what plants could survive or rather thrive in 3ppt or above......

Grow seaweed and make seasol for using in the freshwater AP system or garden.

Unfortunately there is not really a lack of room in the ocean to grow seafood, so doing it on land is very unlikely to ever be profitable.

Freshwater is obviously a different story.

Actually, Pia Winberg & Wollongong University did a year long trial with a saltwater aquaponics system a few years ago down Nowra way....

And identified the potential commercial viability of Ulva, and several others species... (Neori, Bonnemaisoniacea)...

As an aside.... Australian imports of seaweed products rose 5 fold over the last decade... to a value of $14million....

And the leading importer of seaweed products.... and seaweed consumption....

... are the Irish... who have a long history of seaweed cuisine.... (Pia also wrote a paper on this topic)

There are some new varieties of rice that are more salt tolerant but yes, seaweed is the one salt water plant that most consider first. Size and scale would have to be massive for a profitable seaweed forrest as some species grow over a foot a day but another extremely profitable ag crop that would be compatible would be abalone as seaweed is all that they eat. This is where most of the seaweed harvesting, that you see, goes to feed this food crop. But other farmed mollusks including clams, oysters, scallops and mussels might be integrated as basically water purifiers for salt water species of fish, even shrimp or lobster as bottom feeders. These would eat the uneaten food and process waste. Some of these groupings are already being used in conjunction with each other in salt water pen fish farms- fish, mollusks, then seaweed to reduce the impact that fish farming has in the ocean.
The two biggest benefits ocean farming has over land lock farming are the tidal wave movement- self cleaning and zero cost- and minimal infrasture costs. The down side is access as everything must be ferried to the site and weather can play a huge factor in that as well.
There is one salt water species that is also as adept in fresh water as well that few know about but it would be an extremely dangerous animal to work with as it is reconized the world over as a man eater- the Bull shark. It would never be allowed here in the U.S. but in a third world country, that may also be a viable AP crop as shark's fin is very expensive, although it is beginning to lose some of it's status.

I believe Mote Marine is currently growing aquacultured Pompano and then running the effluent through large beds of mangroves and other local saltwater aquatic plants.

They are planning on selling the fish and using the plants for costal restoration. Of course they are doing this as an experiment, not a viable buisness but its another step in the right direction.

i had a guy over here in FL tell me about 10 years ago that he was farming Saw Palmetto bushes. Now if you know what these are, you know it is a small, palm like plant with thorns all over it. The thing is, here in Florida they are EVERYWHERE!! All over the side of the street, corners, pretty much an all over native species.

So I ask...what kind of sense does it make to have 10 acres of saw palmetto??? They're all over the place!!

Turns out that everytime somebody wrecks their car into one, anytime a fire burns one, any time ANYTHING happens, the state buys a new plant from a grower and replaces it as they want to keep the natural plants/look to the state.

So every time somebody runs into one of these things, this guy is making $10-$20.
He's a multi millionaire right now.

Rediculous but he found his niche and went for it.

Samphire retails in London for £10-14/kg wet - lotta chefs use it and I've heard of some in Victoria being interested.

Yeah, I'm going to try and find out about that place. It was written up in Austrasia Aquaculture as well and I think our friends at that institution were a player as well as they've done lots of good ISW research. The main problem is the lack of potassium in the water, buggers up the fishes osmoregulation processses and they get stressed and die. That's why in recirc you could control K levels.

Yeah, mmmm - very hard to get EPA approval for stuff as there are so many other people that want to use that environment as well. Unless you go a long way out (either depth or remote coastline), which increases your costs substantially.

Also, there can be too much out there and it becomes self-destroying. There industry watchers out there now stating to make the call that China's offshore cage aquaculture is going to self-implode as there are too many of them spreading disease and continually losing crops. Although the number of cages has increased significantly in the last few years, production has actually dropped in that time.

Yep, I'm of the opinion that once you go above 3-5ppt, you may as well go straight to 35ppt.

Rupe, thanks for that - I'll follow up her work.

I'll send you some PDF files of her papers Chillie...