Self-Sustained Water Pump

Sounds great, go for it....how many gallons per hour of circulation do you think you'll need? Where will you get the money?

Maybe you could go with tidal power as an energy source....?

https://www.researchgate.net/publication/233508188_Tidal_energy_in_the_Bering_Sea

Not much tides nor high in the Baltic sea!

Should be a tremendous tidal force at the mouth....

Not much according to this here:

https://www.smhi.se/en/theme/tides-1.11272

The Baltic Sea contains 21,721 cubic kilometers of water. It has a maximum depth of 459 meters. I don't think you have given much thought to the scale of your proposed project.

Your project would have to be absolutely enormous to turn over enough water to make an impact.

I won't even get into the other environmental repercussions that could occur from such an endeavor.

It is already done for ponds. A windmill turns an under-water propeller moving bottom water to the surface where it gets oxygenated naturally.

Lifting water from great depths requires a lot of energy that you don,t need to expend and a water duct that extends from the bottom to the surface. Oxygenated water is also lighter so will stay on the surface leaving the same problem at lower levels. That is a lot of energy and a lot of hardware when what you are really trying to achieve is to put oxygen into the water at the low level.

Pushing air down to a depth of 459 metres would need a pressure of about 670 psi. Use the air to drive a pump via an air motor and create a flow of water at the low level which you pass through a venturi tube (no lifting, no waste energy expended) You actually need about 1000 psi. as you need a pressure differential between the air motor input and the exhaust outlet which is 670 psi at that depth. Exhaust the air motor through an Airmaster™ type venturi so that it is delivered as micro-bubbles and is absorbed into the water at 100%¹ efficiency. (¹Airmaster claim but I have not seen the evidence and this application is different to what they are claiming)

You can mount the compressor on a raft, with locally generated power or a power cable to shore. A anchor line is needed to stabilise the raft and the pump needs to be attached so that it can slide up and down the anchor cable. A winch and lift line to recover the pump for maintenance. (little chance of fouling as there is no algae at that depth) and an air hose. Simple and cheap to deploy and relocate as required.

Add to that a pressure swing adsorption oxygen concentrator so that what is being pumped down is mostly oxygen, and only about 1/5th as much gas would need to be pumped down.

GA Excellent improvement. Now all we need is the Swedish, Finish, Russian, Estonian, Latvian and Lithuanian governments or a philanthropist with a mission to give us a shed load of money so we can try it out.

We have some sizable anoxic dead zones several places just off the US coast that would probably benefit from such an intervention.

I've seen a small scale version of what you are describing to "stir" a water reservoir to de-stratify the water column. There is no need for the vertical tube, as the bubbles themselves create a local uplift.

I also suspect that it would only be necessary in water depths less than say 50m since there would be insufficient light energy getting below that level for vegetation. (I'll defer to experts on this depth.)

If the situation in that sea is a recent issue, then what is the root cause? Your good intentions may already be doomed due to whatever factor is driving the deterioration.

..."The Oxygen minimum zone (OMZ), sometimes referred to as the shadow zone, is the zone in which oxygen saturation in seawater in the ocean is at its lowest. This zone occurs at depths of about 200 to 1,500 m (660–4,920 ft), depending on local circumstances."...

https://en.wikipedia.org/wiki/Oxygen_minimum_zone

https://oceanexplorer.noaa.gov/edu/lessonplans/loph10_oxygen912.pdf

..."Oxygen is a very important gas in the ocean because of its role in biological processes. Marine plants such as phytoplankton, seaweed, and other types of algae produce organic matter from carbon dioxide and nutrients through photosynthesis, the process that produces oxygen. The upper 10 to 50 meters (33 to 164 feet) of the ocean can be highly supersaturated with oxygen owing to photosynthesis.

Photosynthesis by plants is restricted to the upper sunlit areas of the ocean, but organic matter settles from the surface layer to deeper waters where oxygen consumption by animals and bacteria is a major process. The oxygen content of deep ocean waters is renewed by a process called thermohaline circulation. When surface waters either cool or become more saline (salty), their density increases and they sink to greater depths in the ocean where they can spread over vast distances.

On a global scale, these dense waters form in the North Atlantic Ocean near Iceland and Greenland, as well as near Antarctica. The dense waters spread throughout all the oceans over periods of tens and hundreds of years, transporting high oxygen concentrations in the deep sea.

The various processes affecting oxygen in the ocean are evident in its profile from the surface to the seafloor (see figure on page 79). Surface waters are high in oxygen due to exchange with the atmosphere and to photosynthesis. Oxygen content also is high in deep waters because of thermohaline circulation and the slow rates of oxygen consumption at those depths. The waters with the lowest concentrations of oxygen are often found at middepths of 200 to 2,000 meters (656 to 6,560 feet) beneath the surface in a region known as the oxygen minimum zone.

Oxygen plays a very active role in the chemistry and biology of coastal waters, and its concentration is a major indicator of water quality. In many areas of the world, large quantities of nutrients enter coastal waters from agricultural fertilization and domestic wastes. These nutrients stimulate the rapid growth of phytoplankton. When the organic matter produced from these nutrients settles into the deeper waters of bays and estuaries, its decomposition can deplete the waters of oxygen. The result can be fish kills and the formation of hydrogen sulfide gas (H2S), which is poisonous to many types of organisms."...

http://www.waterencyclopedia.com/Re-St/Sea-Water-Gases-in.html

"This vertical profile of dissolved oxygen in the Pacific Ocean north of Oahu, Hawaii shows the high values in the upper 200 meters due to air–sea exchange and photosynthesis. The oxygen minimum zone is between 600 and 2,200 meters. The high-oxygen waters near the seafloor originated at the sea surface near Antarctica and Iceland about 500 to 800 years ago. (Note: The figure can be rotated 90° clockwise to yield an orientation similar to other depth profiles in this encyclopedia; that is, portraying depth along the vertical axis rather than along the horizontal.)

It seems the Baltic Sea is experiencing the same problems as the rest of the world, and right here where I live....the runoff from civilisation is fertilising the sea water and promoting rapid algae growth which in turn depletes the oxygen content leading to fish die offs and toxic algae blooms....

"Environmental status [edit]

Further information: Baltic Sea hypoxia

Phytoplankton algal bloom in the Baltic Proper, July 2001

Satellite images taken in July 2010 revealed a massive algal bloom covering 377,000 square kilometres (146,000 sq mi) in the Baltic Sea. The area of the bloom extended from Germany and Poland to Finland. Researchers of the phenomenon have indicated that algal blooms have occurred every summer for decades. Fertilizer runoff from surrounding agricultural land has exacerbated the problem and led to increased eutrophication.^[60]

Approximately 100,000 km² (38,610 sq mi) of the Baltic's seafloor (a quarter of its total area) is a variable dead zone. The more saline (and therefore denser) water remains on the bottom, isolating it from surface waters and the atmosphere. This leads to decreased oxygen concentrations within the zone. It is mainly bacteria that grow in it, digesting organic material and releasing hydrogen sulfide. Because of this large anaerobic zone, the seafloor ecology differs from that of the neighbouring Atlantic.

Plans to artificially oxygenate areas of the Baltic that have experienced eutrophication have been proposed by the University of Gothenburg and Inocean AB. The proposal intends to use wind-driven pumps to inject oxygen (air) into waters at, or around, 130m below sea level.^[61] "...

https://en.wikipedia.org/wiki/Baltic_Sea#Environmental_status

So, you are not alone in this endeavor...

"Since a couple of years I am heavily involved in working out a scheme to decrease the eutrophication of the Baltic Sea by oxygenation of the often anoxic deepwater. Together with colleagues I recently showed that about 70 % of the phosphorus (P) entering the water column of the Baltic Proper come from the anoxic bottoms. Thus, oxygenation of the anoxic bottoms would stop this major P source! This and much more is described in the featured publications listed in the left column."

https://www.researchgate.net/profile/Anders_Stigebrandt

Once you have properly identified what exactly is the problem, not just the cause, you might be able to come up with a more innovative approach...so you must ask yourself what is it exactly that is the problem....so, what exactly is the problem?

Not the cause, not the result,,,,the problem....

https://www.floridaocean.org/blog/index/id/14#.Wvb-94gvyUk

https://www.sciencedirect.com/science/article/pii/S0025326X18300572

http://www.fau.edu/newsdesk/articles/septic-system-study.php

Badly phrased question! What is the problem should be what are the problems. There would appear to be two obvious ones which require differing solutions. If 70% is caused by anoxic bottoms then 30% has a different cause, most likely high nitrate run off from agriculture. Solutions are needed for both. The cheaper option for solving the 30% run off problem is to legislate at reduction in the amount of fertiliser or change the type of fertiliser so there is a more efficient take-up by the plants. A more costly solution is the intercept the run off and clean it where it enters the Baltic. If excesses could be recovered and reused what would mitigate the costs. The 70% problem could be solved by oxygenating the bottom layer. But how?

See my earlier post for the first bit of brain storming. Not mentioned earlier a wide thin rectangular venturi (say 20metres by 0.3m) with an Airmaster™ type venturi wing inserted would be far more efficient than a conventional round venturi and would suit this application much better by giving a wider dispersion). Now for the second uncosted off the cuff suggestion piece of kite flying. The algae bloom is too dispersed to be of practical use but if you could skim some of the bloom and utilise the collected algae to create biofuel on the 'anoxic bottoms air injection raft' (Abair) then maybe the thrust from the oxygenation pump flow could drive forward motion required for skimming. Currently algae biofuel is not commercially practical and neither is bloom skimming but you did ask for innovative solutions. This would have a short term effect of reducing the affects of the bloom and uses a symptom (the bloom) to power the solution (oxygenation).

So the problem is excess phosphorus...?

https://www.researchgate.net/publication/236836909_Phosphorus_Mitigation_to_Control_River_Eutrophication_Murky_Waters_Inconvenient_Truths_and_Postnormal_Science

https://www.nature.com/articles/s41467-017-00232-0

Ok,,, so what about limiting the bioavailability of phosphorus....maybe we can just treat the phosphorus in situ.....?

https://www.ncbi.nlm.nih.gov/pubmed/27888776

Most of the runoff is not from farming but septic tanks...same here in Florida...this is changing as more development takes place...

Pogo Quote

"We have met the enemy and he is us."

____________

thewildotter

Wow, that looks really expensive....

".... If water is flowing downward the water will be heavier inside the pipe due to increased salinity (the pipe prevents mixing with surrounding water). If water flow is initiated upward, the water inside will be lighter due to the decreased salinity. ..."

.

...er...what? If there is no mixing through the pipe wall or other exchange, how is the salinity changing?

Also, the chart provided shows only a very small inversion just under the surface of the larger overall salinity gradient. Inceasing salinity with depth should serve to stabilize the picnocline, not provide opportunities for unpowered mixing.

What am I missing here?

The salinity at the top is higher (i.e. denser), due to evaporation - so, once flow downwards is initiated, it will continue.

Likewise, vice versa-

(Theoretically, however. I wonder what is the min height difference for a 'worthwhile' flow?)

From the charge provided, there looks to be less than a 0.1 PSU difference between the salinity shown at the most shallow point and the point of least salinity. That point of least salinity appears to occur at a depth of about 35m . The chart begins to indicate salinity around 10m. with no indication closer to the surface. Below about 35m salinity increases markedly and becomes higher than any salinity indicated for shallower depths by about 40m.

There does not appear (from the chart provided) to be a salinity gradient favorable to sustained natural circulation below about 35m. Perhaps during summer months the salinity near the surface is much greater due to carrying away much surface water. The chart though is from the middle of winter which is probably why the temperatures near the surface are below those anywhere else in the column.

I bet there are regularly conditions at certain places at certain times of year where this type of scheme could work between the surface and certain depths. There might even exist some places where this type of scheme could work between the surface and some depth more days of the year than it wouldn't.

Has this been implemented successfully anywhere yet? Kudos if it has. Best wishes to anyone who is en route to such implementation. To me, the differences attempting to be leveraged are too small and the places where those differences occur too variable for any prospective gains to ever justify the likely costs.

There does not appear (from the chart provided) to be a salinity gradient favorable to sustained natural circulation below about 35m.

You are exactly correct. (Good eye, and thanks for keeping me honest. )

The plot I included was from the Arctic Ocean, and is a bad example. Unfortunately, the Baltic Sea, I suspect, would be similar.

In the tropics, the salinity should be greater on the surface due to evaporation and the temperature should be warmer due to solar heating. In the polar regions, there is not much solar heating and the salinity is apparently lowered, I suspect, due to fresh water from ice melting.

Here are typical profiles for tropical regions where the perpetual salt fountain might work. AFAIK, nobody has actually built one, but the process occurs naturally and is known as "Salt Fingering".

https://en.wikipedia.org/wiki/Salt_fingering

http://www.hurricanescience.org/science/basic/water/

So, you are correct, not practical for polar regions.

Thank you for clearing that up. I knew I had to be missing something. Cool phenomena. Thanks for sharing.

I applaud your desire to help save the Baltic Sea but, I suggest that you redirect your imagination and energies toward a more realistic goal.

Perhaps finding a way to supply potable water to the most arid areas of the world, one at a time.

The <...speculate...could extract energy from the water flowing off the airlift tube thru some kind of turbine or water wheel, if there was enough elevation between the pump outlet and the sea surface...> part is a fallacy. One would simply add more energy harvesting devices alongside the <...Stirling Engine...> instead.

Any idea how much power this concept would need in order to make any difference?

<...bottom fauna dies from lack of oxygen...> Is this a man-made intervention into a natural process of evolution?

".... Is this a man-made intervention into a natural process of evolution? ...."

If you consider 'man' to be a product of and thus a part of nature then 'man-made' is just another 'natural process', so the distinction would be merely symantic.

If on the other hand, 'man' is unnatural in current status, having sufficiently severed connections with nature as to no longer be part...or perhaps disowned by nature..

...then this would just be man-made intervention attempting to recover from man-made damage (or avert further damage) to a large exploitable food source for a growing population. That damage, the anoxic zones can be show w8th reasonable certainty to be caused by our steadily entensifying efforts to feed our burgeoning population, specifically large amounts of fertilizer run off.

"you pump air down into the intake, located at the bottom of the tube."

It's not necessary to pump air to the bottom - put a smaller tube inside the main tube, introduce air thru smaller tube, adjust length (depth) to maximise flow. Your compressor may not compress enough to get to the bottom. Once flow is happening, it can only come from the inlet, at the bottom -

What about just sinking some electrodes down in the depths and generating a current that would split water molecules into oxygen and hydrogen, capture the hydrogen and release the oxygen at depth....this seems the cheapest most direct approach....A modular nuclear battery that produced electricity in the daytime and hydrogen at night while oxygenating the depths of this eutrophicated cesspool of death....

Nice idea, but electrolysis of sea water does not yield largely oxygen and hydrogen, it produces largely chlorine and hydrogen.

Some form of desalination would likely be required.....

Maybe, but the Baltic Sea is very low in salinity...

https://en.wikipedia.org/wiki/List_of_bodies_of_water_by_salinity

"... the Baltic Sea is very low in salinity..."

'Low' is relative. The Baltic may have low salinity compared to some other seas, but it does not have low salinity compared to tap water.

I know. There is no great Sea of Tap. However the comparison to tap water is useful in realizing that even tap water with less than 400 ppm salinity (compare to Baltic Sea salinity quoted in ppT not ppm) will still off-gas chlorine gas predominantly and preferentially to oxygen until chlorine has been depleted to far more scarse levels.

There are probably easier ways than desalinating though to get to oxygen production by seawater electrolysis. With Le Chatelier's in mind, since NaOH is a nonoffgassed product, preloading the electrolysis chamber with NaOH and using containment that doesn't allow NaOH to escape (yet lets out gas and lets in feed water) liberation of Chlorine could be inhibited such that separating the H from O in OH- becomes favorable.

OK just for a moment, what if we let the process produce the chlorine and kill off the bacteria that are consuming the oxygen, a sort of backhanded approach...?

1. Excess nutrients are applied to the soil.

2. Some nutrients leach into the soil where they can remain for years. Eventually, they get drained into the water body.

3. Some nutrients run off over the ground into the body of water.

4. The excess nutrients cause an algal bloom.

5. The algal bloom blocks the light of the sun from reaching the bottom of the water body.

6. The plants beneath the algal bloom die because they cannot get sunlight to photosynthesize.

7. Eventually, the algal bloom dies and sinks to the bottom of the lake. Bacteria begins to decompose the remains, using up oxygen for respiration.

8. The decomposition causes the water to become depleted of oxygen. Larger life forms, such as fish, suffocate to death. This body of water can no longer support life.

https://en.wikipedia.org/wiki/Salt_water_chlorination

https://en.wikipedia.org/wiki/Eutrophication

:... let the process produce the chlorine and kill off the bacteria...."

um....what's the goal again?

I don't know that living bacteria would learn about or respond well (or at all) to punative measures taken against bacteria responsible for anoxic zones. Also, a key component of mens rea is mens which bacteria lack.

I doubt higher organisms that get things like oxygen and nutrients from the water will fare well if chlorine gas levels are high enough to kill most bacteria....

...so unless the purpose is something along the lines of "if bacteria won't play nice, then no one is going to play at all", chlorinating the oceans like a backyard salt water pool is probably not a great idea.

Unanswered Prayers(global elimination of eutrophication)

So, many years ago I was all enthusiastic about carbon sequestration to offset the fossil fuel use by humans. My favorite implementation involved iron seeding areas of the Pacific Ocean to generate algal blooms. The thinking was that the algae would use huge surface areas of the Pacific to perform photosynthesis to separate carbon dioxide into carbon and oxygen. The oxygen would be released into the upper surface of the water and into the air. The carbon would accumulate in the algae which would eventually die, sink to the bottom and be sealed away from oxygen exposure by silt for geologic time. This technique would have a very large impact relative to its costs. Unfortunately, the Pacific did not live up to its name and provided a much stronger transport of oxygen to the middle water column than expected. This transport was amplified by organisms eager to harvest the energy stored in the carbon raining down by eating it and using respiration to release the energy. This respiration frustrated the overall effort by releasing carbon dioxide back into the water. Very little carbon made it down to the bottom of the Pacific to become future fossil fuel eons later as was hoped. Luckily for me I discovered that someone else had gone down this rabbit hole and all I had to do was read about their misfortune.

Fast forward to today, I discover this thread with a simple and ongoing answer to the problem of interception of carbon in mid water column, eutrophication. But, horror, of horrors, the thrust of the effort here is to stop eutrophication since it involves death, stink, and lowered local biological diversity. No one seems to acknowledge that the preponderance of oxygen everyone is so eager to provide will go toward oxidizing carbon which clearly was about to be sequestered into carbon which could ultimately become fossil fuel. Many recognize that the stopping of massive eutrophication will be crushingly expensive so some turn to governments to force the unwashed, eutrophication loving masses to pay. Some realize that the cost is so overwhelming that it is not politically viable and recommend instead that the OP focus on providing potable water to arid places since we have such a shortage of humans already demanding fossil fuels. If they had potable water the desert could support more of them raising the single largest multiplier of carbon use.

Sometimes I think our best and brightest sell their wisdom in order to purchase more knowledge. Sometimes I just understand that wisdom is always rewarded with unpopularity and people learn to cope with that fact by suppressing any expression of their wisdom. Resist that trend. Gaia is your friend. She is old and wise. Do not try to raise human population to outvote her. Her vote is the only one that counts. Do not enlist governments to fight Gaia, it will only accelerate and exacerbate your total defeat. Life is unsustainable without Death. If you whack the local death tarbaby at eutrophication, it will whack you back with progressively higher levels of global atmospheric carbon dioxide. Admit defeat with grace. Do not continue in denial that human population must and inherently WILL be limited. Bless your albatross, Ancient Mariner.

thewildotter

So your proposed solution is an army of one-eyed, one-horned, flyin' purple people eaters??

Purple People Eater Army

Nah,

That's not the reason that they came to land.

They all got jobs in a rock-n-roll band.

We need something more effective and less gory.

How about ending tax incentives for

children beyond two?

And celebrating our volunteer anoxic estuaries.

thewildotter

A Modest Proposal

Maybe we should pick one of these locations which has limited circulation to run another experiment like the one which failed in the Pacific. Encourage algal blooms with trace elements just to see how fast we can get it to accumulate carbon rich sediments. Choosing a location which has already significantly depleted its available oxygen means you do not have to wait as long for startup. The local biodiversity has already suffered all or most of the impact of going anoxic. Get some quantitative data about how much carbon can be squirreled away per area in a certain time at what temperatures with which additives. It would also be valuable data to plan for terra forming other planets, moons, etc. to greatly improve our chances of surviving astronomical catastrophe such as an asteroid impact, a solar flair, or a gamma burst by having starter populations out of the target zone.

My guess is that we will be discouraged relative to billions of years of naturally accumulated fossil fuel. Knowing the actual numbers would go a long way toward accessing how much population carrying capacity we actually have for long term sustainability. We then can arrive at a sensible population stasis target and start the most gentle incentives first until we can project success. Anything else is courting catastrophic population collapse and maybe even extinction.

thewildotter

I'm guessin' you don't live at the water's edge....seen a massive fish die off in person....had the choking fumes from a toxic algal bloom consume your everyday existence...had to deal with the stench of sludge buildup on a daily basis....and other unpleasant results from this runoff problem....We want to fix the problem, not make it worse....

I used to play on sand dunes where the commercial fishermen dried their nets. I hiked barefoot for miles along strips of thousands of rotting dead fish washed up after red tides just to look at all the different fish species. Powerful stuff. Some of our small local lakes were eutrophied with stinky, bubbly, lumpy, thick fluorescent green algae mats totally covering them. I hunted snakes for pets and frogs for fried frog legs there.

I guess it is an acquired taste. To be honest, I do not think I could stand any of those experiences today. I have become old and partial to dry, sterile, odorless air. I avoid buses in favor of walking miles in the Texas heat because a woman (or a man for that matter) might get on wearing perfume.

Anyway, I get your point but I figure those still there are snake bit and gonna die anyway(figure of speech).

thewildotter

Your Own Source Lends Credence to My Proposal

At 9:14 in your last video, he says, "Before the extinction event the Earth's atmosphere was CO₂ heavy. After the extinction the carbon dioxide level dropped precipitously as did the temperatures. " Looks like he believes that algae can dramatically cause what so many say we need. I sure think it is worth some study to see if we can manage this effect to bail us out of(or vaccinate against) any surprise "global warming" catastrophe. If we are careful and lucky we may be able to get the atmospheric carbon dioxide decline without the geological extinction event. We probably do not need or want a precipitous drop so by titrating the phosphorus injection and controlling the geographic scope of a precision algal bloom we may be able to tune in an appropriate adjustment to offset our fossil fuel consumption blamed carbon dioxide increase. Geographically limiting the scope of the bloom might also make "instant" fossil fuel in the target area which we could use without as much exploration and drilling expense leaving some older, less accessible fossil fuel in the ground instead for a net zero change in our fossil fuel consumption.

thewildotter

If it was profitable to make algae into any useful product it would already be happening, as it is in some niche markets, but on the scale needed, not so much....

..."From 2005 to 2012, dozens of companies managed to extract hundreds of millions in cash from VCs in hopes of ultimately extracting fuel oil from algae.

CEOs, entrepreneurs and investors were making huge claims about the promise of algae-based biofuels; the U.S. Department of Energy was also making big bets through its bioenergy technologies office; industry advocates claimed that commercial algae fuels were within near-term reach.

Jim Lane of Biofuels Digest authored what was possibly history's least accurate market forecast, projecting that algal biofuel capacity would reach 1 billion gallons by 2014. In 2009, Solazyme promised competitively priced fuel from algae by 2012. Algenol planned to make 100 million gallons of ethanol annually in Mexico’s Sonoran Desert by the end of 2009 and 1 billion gallons by the end of 2012 at a production rate of 10,000 gallons per acre. PetroSun looked to develop an algae farm network of 1,100 acres of saltwater ponds that could produce 4.4 million gallons of algal oil and 110 million pounds of biomass per year.

Nothing close to 1 billion (or even 1 million) gallons has yet been achieved -- nor has competitive pricing.

Today, the few surviving algae companies have had no choice but to adopt new business plans that focus on the more expensive algae byproducts such as cosmetic supplements, nutraceuticals, pet food additives, animal feed, pigments and specialty oils. The rest have gone bankrupt or moved on to other markets."...

Read it all....⇓

https://www.greentechmedia.com/articles/read/lessons-from-the-great-algae-biofuel-bubble#gs.s0NTK7s

Dead Zones and Crowdfunding vs Political Kabuki Theater

So, there is a third video in the same series where the narrator says that scientists hope that algae can be used to save the planet again so I was scooped. It does not comment on the how but it is obvious from the second video of the series that boosting phosphorus has a good chance.

Your comment "If it was[were] profitable to make algae into any useful product, it would already be happening,..." has a key word... "profitable". Lowering the global carbon dioxide level is hard to monetize. Al Gore is ostensibly trying but I am suspicious that he(Mr. "I invented the Internet") and his political minions and clones saw this kernel of truth and decided to run history's largest scam based on that promise to get into the winfall tax revenue flow with zero or negative intent to deliver. I weary of pv, ethanol, ... tax and spend and actual damage to the environment rather than the panaceas promised. I swear off buying "good intentions" from politicos with no clear downside for them if they (even choose to) fail. Big government and oppressive globalists are a far greater (and currently manifesting) threat to our quality of life than ecological catastrophe. And the former may easily turn out to be a primary cause of the latter.

Also, I perceive that most those niche marketing plans involve growing algae on land or with some expenditure proportional to the active area. They are missing the key point of recruiting huge expanses of ocean with trace element seeding and not paying for some structure(holding pond, whatever) at some high rate per unit area for that infrastructure. That is why I like existing dead zones(eg. the OP's) as the test tube. Alternative Dead Zones candidates might be already nuclear, heavy metal, sewage, salt, petroleum, pesticide, PCB, and/or 57 variety industrial waste contaminated as long as the algae doesn't much care and you make sure the instant fossil fuel does not become a mobility vector for the contaminants.

Expenses could perhaps be crowdfunded and/or results based, philanthropically funded. Sediments could be measured and analyzed for unoxidized carbon content. Zealots trying to force the unwilling/unable to pay via taxes could then be told to put their money where their mouths are and to shut up at the polls. Then the altruistic could contribute with less fear of paying for kabuki theater, progressive tax oppression, and net negative ecological impact.

thewildotter(justifiably jaded by disingenuous politicians)

"....justifiably jaded by disingenuous politicians ..."

i think the department of redundancy department is going to take issue with your appropriation of their work, I think.

.

'^{Jaded' implies some justification was involved just as "politician' implies some disingenuity is involved.}

I wouldn't put a lot of weight in what that guy has to say, not too realistic....and there's no point in trying to drag politics into this....This is the reality we're dealing with....

"... I wouldn't put a lot of weight in what that guy has to say, not too realistic.. ..."

Agreed. The biology related opinions of someone whose comments indicate he doesn't realize salamanders are vertebrates should probably be taken with a large grain of salt.

Ha ha, and so on....

This approach probably makes more sense, take a look!

https://www.ecori.org/green-economy/2016/7/29/seaweed-farming-takes-root-in-southern-new-england

Seaweed farming is something certainly worth looking into, and there is some activity underway....but you really have to create a local demand for the product....

https://food.ndtv.com/food-drinks/seaweed-can-help-feed-the-world-but-will-we-eat-it-1239466

I think the big problem with your idea is nitrogen. It dissolves in water too, and then as the water rises, it comes out of solution. If a fish "inhales" this nitrogen rich water, it can get the bends. Fish can die or be severely injured by the bends.

In order for people

In order to get the bends, a rapid depressurization is typically required.

Why are the fish suddenly making mad dashes to the surface? Note that even at reduced nitrogen levels, sufficient nitrogen for the bends could be absorbed by spending sufficient time at depth ..

The water makes a quick dash to the surface, with the bubbles of air powering it up. and when it gets there, its super saturated. Sure its super saturated with oxygen too with is great but at the surface the nitrogen is slowly coming out of solution and it also comes out of solution in the blood vessels in fish gills. (Nitrogen is slowly dissolved in water and slowly released too). The fish gills are processing a lot of water so they are very efficient at absorbing the nitrogen. Fish get the bends in the tailwaters of big dams when a plume of water is released for the same reason. I was told this about 20 years ago when people were talking about big trompes and their problems.