I.M.T.A. - Integrated Multi-Trophic Aquaponics (my concept)


Personally, no. There will be different requirements, depending on the size of ‘fingerlings’ and feeder-fish in use. 1/2-3/4 inch inner ‘liner’ net would be my guess, with a larger, 2 inch (FAO recommendation) metal anti-predator mesh combined in it, to protect against seals, sea-lions, sharks, etc.


Question: It looks so far like you guys are talking about freshwater fish. Wouldn’t it make more sense to raise saltwater fish in a seastead? Let’s stop talking about freshwater fish and discuss what types of saltwater fish would be raised in this aquaculture.


Well, the farming operation off Puerto Rico, in usa EEZ, was shut down because of usa regulations. There’s usa companies making fish cages that cannot deploy those cages in usa waters, because of usa regulations.


Uh, Kelp, Crabs and Abalone are all seawater stuff. Type of fish would depend on market area, local water temps, etc.

Deep Blue has cages off Hawaii, last I heard, among others. However, it’s probably more about how you go about getting approval. I would say, the initial setup would need to be set up as a study, with a university affiliation, along with the EPA, FDA, Federal and State Game & Fish/Parks & Wildlife, and whoever else should be involved. Part of the goal is to do so openly, mitigate environmental issues and make a working system, to produce commercial types of fish. However, Making it into a viable ‘something’ that has the potential to produce income, from a unique experience, is the Great American Pass-time.

Nothing of note, so far, but wikipedia (I know, but it’s generally reliable)

United States

Moving aquaculture offshore into the exclusive economic zone (EEZ) can cause complications with regulations. In the United States, regulatory control of the coastal states generally extends to 3 nm, while federal waters (or EEZ) extend to 200 nm offshore.[8] Therefore, offshore aquaculture can be sited outside the reach of state law but within federal jurisdiction.[1] As of 2010, “all commercial aquaculture facilities have been sited in nearshore waters under state or territorial jurisdiction.”[4] However, “unclear regulatory processes” and “technical uncertainties related to working in offshore areas” have hindered progress.[4] The five offshore research projects and commercial operations in the US – in New Hampshire, Puerto Rico, Hawaii and California – are all in federal waters.[8] In June 2011, the National Sustainable Offshore Aquaculture Act of 2011 was introduced to the House of Representatives “to establish a regulatory system and research program for sustainable offshore aquaculture in the United States exclusive economic zone”.

Current species

By 2005, offshore aquaculture was present in 25 countries, both as experimental and commercial farms.[5] Market demand means that the most offshore farming efforts are directed towards raising finfish.[8] Two commercial operations in the US, and a third in the Bahamas are using submersible cages to raise high-value carnivorous finfish, such as moi, cobia, and mutton snapper.[1] Submersible cages are also being used in experimental systems for halibut, haddock, cod, and summer flounder in New Hampshire waters, and for amberjack, red drum, snapper, pompano, and cobia in the Gulf of Mexico.[1]

The offshore aquaculture of shellfish grown in suspended culture systems, like scallops and mussels, is gaining ground. Suspended culture systems include methods where the shellfish are grown on a tethered rope or suspended from a floating raft in net containers.[12] Mussels in particular can survive the high physical stress levels which occur in the volatile environments that occur in offshore waters. Finfish species must be feed regularly, but shellfish do not, which can reduce costs.[12] The University of New Hampshire in the US has conducted research on the farming of blue mussels submerged in an open ocean environment.[31] They have found that when farmed in less polluted waters offshore,[32] the mussels develop more flesh with lighter shells.[31]

NOAA pdf on the subject…



[PDF]Net Pen Final Report - Washington Fish Growers Association
Currently, all commercial net pens in Washington are located within … decisions to consider should one decide to pursue offshore farming in Washington. State.

(Jonas Smith) #26

The issue with setting up operations in an EEZ is that the coastal nation has exclusive control over all economic activities within that zone. Thus commercial fishing operations would be illegal without first getting permission from the coastal nation whose EEZ you are in. That usually means getting permits and/or licenses to operate commercial fishing operations as well as proof that you are in compliance with all maritime safety and pollution regulations.

Furthermore, at least for the US, individual US states have their own territorial waters out to 3nm from the baseline (some have claimed more…Florida claims state waters out to 9nm in the Gulf). So if you are within 3nm of shore you will have to deal with state regulatory boards and committees rather than Federal ones, while also still complying with all Federal rules and regulations.

(Jonas Smith) #27

Also, remember that there is a difference between utilizing aquaculture solely to supply the seastead population with food and utilizing aquaculture as a business. You can probably get away with a much smaller aquaculture operation if you are just worried about putting fish in your population’s bellies, rather than all the complications that go along with commercial operations for profit such as marketing, transport, health regulations, import/export issues, etc.


I.M.T.A. is a means of food production and can be scaled up, or down, to meet the requirements.

I can do it on a scale that provides for me, or larger. I don’t necessarily NEED many permits, unless I commercialize. Even then, it is wholly dependent upon what type of commercialization I might do. As a B&B, I’d be paying hotel/motel taxes, have a food service permit and health cards, and such, but not the same as a commercial fishing company, nor would I need access to a cannery.

I HAVE alternative business models and can flip through a series of them, to find one that works for me.


Thank you, Larry @thebastidge

“Food self-sufficiency is a driver on many fronts: economically, environmentally and socially. Land-based and intergrated multi-trophic aquaculture projects have grown on the back of this, but until now the concept of sea-based IMTA projects, growing more than just algae as vegetation, have been few and far between.”

(preliminary figures for a 200 x 350-meter side module)

8.152 tons of vegetables/year
1.703 tons of fish/year

LNG economy | oceanic production | distribution | industry | Power to Gas | oceanic business alliance

So, as to my concept of an IMTA…

I’ve contacted the Washington State Department of Ecology, my letter was booted up to N.O.A.A. Dept. of Fisheries, and I’ve been referred over to Univ. of New Brunswick, CA.

Talk about a roller-coaster-ride… :laughing:


I’m guessing, but, If I have 3 pens of market fish, from fingerlings up to almost marketable, in stages, and 3 pens of bait-fish, with a kelp bed above each pen as well as floating Abalone and oyster(?) pens, with crabs below all 6 pens, I ought to have enough kelp to keep from buying grain-based feed, to keep the entire thing self-sufficient.

All pens may well be submersible spar-buoy types, in order to grow the maximum amount of Kelp.

Maybe elevate the bait-fish pen, capture the desired amount, then feed kelp to the remainder, and submerge the pen. Elevate the market pen and feed the bait-fish to the market fish and submerge it. Fine-tune so that the maximum number of bait-fish of one, or maybe two pens, is the desired amount to feed a pen with some corresponding number of market fish, from fingerlings, to maturity.

It would also be possible to have an additional Kelp bed down-stream, to insure waste mitigation and provide additional kelp for the system.


I’ve got my fingers crossed that the bureaucrats treat you fairly. At least they seem to be doing something – as opposed to saying they need to study the issue for a few more decades…


I know you’re focusing on the conditions relevant to your efforts, but if you would, please comment on which environmental factors play the most important roles.

It seems to me that water temperature, dissolved oxygen, dissolved other plant nutrients, current and even depth (re mooring the things) will all play significant roles. Is that right? Are other things more important? (Leaving aside, for the moment, the regulatory environment if possible.)


One thing of note is that these interconnections and international interconnections are in place and being used, even to help me, and I admit I’m self-educated on the subject. Given that, I would say that either the ongoing ecological collapse and worsening situation with normal commercial fishing is creating a new range of cooperation, or they’re reaching the point that any good idea is worth considering.

When you think about my concept, it seems straight-forward, and, in theory, could be run as an onshore, pond culture, one way, or another. By doing it at sea, I alter the local environment, but it impacts the region, and, at least from observation, anything that brings activity to an area, tends to attract wildlife species, at sea. By having Kelp beds, I will automatically attract fish, birds, etc. I plan to harvest kelp and use it for my purposes, but, like a small farm, raising hay benefits the local wildlife, as well.


After replying to you on another thread re “snarking”, let me be snarky here: google is your friend. Or duckduckgo.com. There’s far more info (in detail) online than JL can give you here. Info which should be in The Seasteading Institute’s public library, at your online fingertips. I would prefer JL give you urls to pages and pages of info, gigabytes of info, than to detail how all that info applies to his aquafarm in particular. Because while interesting, it would likely apply only to his idea, and after reading all the available data you may have other interesting ideas.


For one thing, I’m not overly concerned about dissolved oxygen content, since I plan to use aeration, particularly in the collection and redistribution of wastes. Less mechanical involvement, using compressed air to create the lifting forces and current, than putting a pump underwater and protecting it from the environment.

Current will affect placement of external kelp beds, in order to make a more effective screen to catch and further mitigate wastes that remain in the water, as a result of the process… Sort of a ‘wind-break’ for the particulates, as well as providing another source of kelp, should I need that, as well.


Temperature will affect the variety of chosen species. It’s the reason I’m in contact with various external resources. “The Blob” is having an impact on species viability, as well. Should I get there and not have an adaptable species, and the blob dissipate, I’m empty-handed.

Contrary to normal practice, I’m not necessarily interested in making the most money off the fewest fish. Rather, my goal is a reliable, marketable system and set of seafood products, that can become a steady supply, creating a long-term market. All the niche marketing is subject to collapse at any moment. Invest in, say, Kobia and its’ appeal is replaced with ‘X’, then I’m stuck trying to sell Kobia in a dead market.

Take land-based farmed fish. In most areas there is some demand for catfish, so that might be a choice, but that market is dwindling and I wouldn’t want to have an entire setup full, with nothing to switch to. Alligator has boomed and busted, as have any number of other fish. However, given the choice, for a land-based setup, I’d go with Rio Grand Perch/Texas Cichlid. It’s similar enough to Tilapia, but cheaper and easier to get started with, and limited worry over invasive species issues. I have had them and know how easy they can be to raise, while Tilapia requires special permits and more regulatory oversight.


Deep water aeration system that is actually in use, for a German lake. With modification, this could be done using compressed air, eliminating the need for a submerged pump.

Individual parts

1 Floating tanks
2 Upstream pipe (Telescope)
3 Degassing chamber
4 Mixing device
5 Suction fence
6 Covering fence
7 Downstream pipe
8 Oxygen input
9 Submersible pump with ejector
10 Main ballast tanks


That rather resembles a fish tank aerator. Seen similar systems in closed off ponds where they are trying to remediate from some sort of spill. Then there is the usual method of shooting the water into the air to pick up oxygen. I once saw a floatie with a large propellor right at the surface, on a vertical shaft, churning and throwing the water wildly (fish would not have survived).


This is just the first one that I’ve seen that actually returns the aerated water to the depths, without circulating the entire water column. Should reduce the amount of air necessary, vs other methods. It may also be capable of some solids separation, allowing for further reductions in nutrient losses.