QUESTIONS AND COMMENTS RE: The proposed solution (i.e. "feeding the fish") - what is right or wrong about it?

My suggestion to try to remedy the starving ecosystem is naturally to “feed” it. And the most appropriate thing would be to put dead fish back into the areas from which we have removed them. Since the fish flesh has largely been eaten, we need to replace it with the closest approximation that we have to “dead fish.” That would be dead animals and plants, and what I suggest we start with is our food scraps. Ridiculous? Offensive? Perhaps, but fish are now much less plentiful, and they are growing very slowly and dying from ‘uncertain” causes of mortality at higher rates than observed in the past. Fish are small and thin, giving at least the “appearance” of being underfed. Something is seriously amiss in the ocean, and our efforts to date are not resulting in any significant maybe we need to take a completely different tack. Questions arise.

What harm could be caused by feeding food scraps to the fish? What risk would be entailed?

What would be the best way to feed the fish, where and with what?

“I suppose what she means by ‘feed the fish’ is to put more nitrogen into the system. Perhaps we should allow all sewage and nonpoint source pollution to flow into the oceans, unimpeded by such things as buffer zones and sewage treatment? Better yet, let’s also allow atmospheric deposition of NOx to add more N to the ocean! (Isn’t that pretty much what we’re already doing?) By this logic, the increasing frequency of algal blooms and the growing anoxic zone in the Gulf of Mexico are good signs...”

Hostility to new ideas is to be expected. These sorts of appraisals confuse sewage and soot with fish food. I definitely do not want to see an increase in “sewage and nonpoint source pollution” flowing into the oceans or an increase in “atmospheric deposition of NOx”...both of these have damaging effects on natural systems. Runoff that is rich in fertilizers and sewage offers only partial benefit to a few species, if it is too concentrated it causes more harm than good, and it probably never offers a benefit to offshore species, since it is not effectively moved away from the coastline.

“The best way to ensure a ready supply of nitrogen into the seas is to keep pumping sewage into them, and to keep up those fertilizer application rates on the land. A recent article in the ‘Financial Times’ attributes the higher productivity in the North Sea in the 1970s to all the untreated sewage and nitrogen-rich waste poured into the major rivers such as the Rhine. Better pollution control in Germany is blamed for north sea fisheries decline.”

The decrease in nutrient rich runoff might have played a part, but was probably not the whole story since fisheries elsewhere have suffered similar declines over the same timeframe.

“...mate, human poo and industrial waste mixed with agricultural fertilizer is no substitute for insects, spiders, fish, birds, mammals carcasses, yabbies, etc that pour out of a healthy river. Put a worm in your fish tank, not poo.”

This writer makes a point similar to mine - fish actually need solid edibles. Salmon aquaculturists acknowledge this fact - their fish are fed solid food several times a day, pouring liquid fertilizer or organics in particulate form into the salmon pens would obviously be ridiculous and useless.

“The best fishing I ever encountered was off Borthwick’s meat packing plant in Brisbane. The plume of effluent stretched a mile or so down river on an ebb tide. But that was in 1958-1960, and I suspect that the aesthetics police have cleaned it up by now.”

Two good points here: the scraps from the meat plant were attractive food for the fish, and the agenda of the “aesthetics police.” My suggestion that we scatter food scraps in the ocean will strike many as “wrong” because it will be confused with “polluting” the sea, or generally making an unappealing mess. “Disgusting,” partly decomposed food scraps...a revolting prospect, sure to “sicken” the fish and “pollute” the waters(??)

“Feeding the fish food scraps could be dangerous - it might cause unforeseen problems.” “Exactly what do you plan to feed them?”

What are the best food items to offer to the fish? The first and most obvious thing is any fish offal, since that actually is dead fish. But dead land animals and birds contain essentially the same nutrients in the same proportions. So cooked or uncooked, anything from table scraps to slaughterhouse discards, would be appropriate and should be included. Fruits and vegetables and grains are also appropriate offerings because they do contain some protein and the carbohydrate portion is useful as an energy source.

Will carnivores be willing to eat drifting pieces of food? They already do. Farmed salmon, for example, are routinely fed non-living pieces of solid food, and thrive on it very nicely. What if they do not eat it? If any sort of food sinks to the bottom without being eaten by a swimming fish, some opportunistic bottom feeder, such as a crab or a snail, will gladly finish it off. If not, it will be broken down by bacteria and the nutrients will be released into the water to nourish the plankton. One level or another will make use of it. Use of the food by any one of them will ultimately enrich the whole system. Solid food offers a “balanced diet” to the system by nourishing many levels simultaneously unlike the input that we currently offer, which essentially offers nourishment to only the bottom level.

What if the food is rotten? That will not matter. Just because it offends human noses does not mean that it is not nutritious. We find the smell of rotten food (and excrement, for that matter) very disgusting, probably because bacteria living in it could potentially make us ill. This is not true for all species, however, and it is very common to find creatures that are very content to eat, or even prefer, “rotten” food sources. Cold blooded fish will not face the same “bacterial food poisoning” risk that we would. In any case, the individual animal will choose which bites he wants. Seagulls have been very successful for a long time in picking out the safe edibles from our open garbage dumps. Rats also do it very successfully. The fish will be just as happy to take advantage of our leftovers if they are given the opportunity.

What about the risk of infection? There may be dangerous bacteria or viruses in the food. Could it make the fish sick? The chance of causing fish to contract an infectious disease is essentially nil. The fish are actually very sick now - from malnutrition which heightens their susceptibility to infection. If they become better nourished they will be better equipped to fight infections and other health problems. In any case, the “bugs” that bother us are extremely unlikely to ever bother them.

The bacteria that cause infections in humans can generally only reproduce at temperatures that are very close to our normal body temperature. Some can live at lower temperatures in a “spore” state (like tuberculosis), but can never cause an infection unless it is about as warm as a human body. Viruses are a bit different. They are extremely “species specific” and those that infect us could never infect fish. Other species that live with us (e.g. cats and dogs, who have much more in common with us than fish do) never catch our head colds. Fish actually have their own set of viruses and other pathogens that can make them ill. The final group of possible infection-causing bugs are the water-borne bacteria. These can live at seawater temperatures and have been frequently known to contaminate fresh water supplies. They include the likes of typhoid, cholera, polio, hepatitis and E. coli. These types of bugs have been flowing into the ocean forever from contaminated rivers. As far as I can determine, they do not cause illnesses in fish. Therefore the threat of transmission of infectious disease to fish is non-existent.

What about toxic chemicals or pollutants in the food? It will be important not to include any type of toxic waste or useless things such as plastic and paper in with the food. This should not be terribly hard to accomplish since we are now getting accustomed to separating all of our household waste into different parts according to its “recycling” uses. Leave the paper products out of the “green bin” and it will make nutritious eating for the fish.

The threat of “nutrient overload” that was discussed earlier is a highly unlikely occurrence in the open ocean for a number of reasons. First of all, solid food must be used. If the nutrients are added in a purely liquid form they will be only available to the tiniest organisms, and this strategy would be more likely to produce an “overgrowth” of phytoplankton. Feeding several levels of the food web at once will be much more beneficial than merely adding liquid fertilizer. Some liquid will be OK, since phytoplankton levels are probably low, but it is essential to use solid food as well.

Another strategy to prevent the formation of any areas of “nutrient overload” will be to avoid scattering the food in areas close to shore. A sensible plan would be to “put it back where we got it from.” This means carrying food to the formerly rich offshore fishing grounds and scattering it there. It would not be appropriate, and probably would be destructive, to carry out this plan in areas like the tropics which have never supported major fisheries.

“Coral reefs are sickened by runoff/algae overgrowth, you will make it worse. Be careful what you wish for.”

Correct. The goal for those areas is decreased nutrient runoff and certainly not the addition of nutrients in any form, including “solid.”


Here’s a dialogue with a marine biologist about the risks associated with the proposal...

You say that we shouldn't dump toxic chemicals or pollutants. This is obvious. But when suggesting that much of our other garbage would be okay to dump (less paper and plastic) you make the point that we shouldn't worry too much about what types of food, rotten or otherwise, we dump...

There is a big difference between rotten and toxic. Rotten is normal, and is not toxic. critters that have ingested toxins - they originated in the likes of industrial waste - and are definitely a problem which we need to work to minimize.

That's why, if we are going to fertilize the sea, we actually have to be VERY careful about what we dump into it.

I agree.

Along the same lines, you suggest that things that make us sick may not affect the fish. What you didn't point out is the opposite may also be true: pesticides that are relatively benign to us, (such as those found on our orange peels, etc.) may be detrimental to some aquatic organisms. There is the chance right? We just don't know what will happen. So, again, we must be very careful about what we dump into the sea.

There is the're right, but it's a risk-benefit scenario, it's far from perfect - it's a real mess and some risk will have to be taken to try and salvage it. The food additives that don't kill us, we'll just have to hope they don't they make the fish seriously ill either.

I didn't understand your argument about how "the chance of causing fish to contact infectious disease is nil." If they are malnourished, aren't they more prone to infection and disease? Furthermore, there is good evidence that SOME aquatic animals are VERY prone to infection from terrestrial diseases. In "Sea of Slaughter", Mowat points out how many whales were killed by poking them with sticks that were dipped into rancid meat (a substance likely to be found in our garbage?). Apparently, the whales have little to no resistance to pathogens of terrestrial origin.

I tried to explain the extreme unlikelihood of human pathogens causing illness in cold-blooded fish. (Right now fish are malnourished and are experiencing high rates of infection and disease, caused by pathogens naturally occurring in the ecosystem, that are ideal for making fish sick. This poses more threat than "human" or terrestrial pathogens could.) I said "fish"...I never said "mammals" and you are right that they would face a theoretical risk of infection. Some things, like tuberculosis and other warm-blooded infections, could very well pose a threat to marine mammals - hopefully seals and whales would not actually eat the food scraps (I think it is a bit unlikely) and therefore not be exposed...but if they are, there's that "risk-benefit" scenario again.

Regarding the extreme susceptibility of whales to infection from contaminated wounds, that concerns me for another reason. What do you think about the practice of the conservationists of shooting all these endangered whales with a device that cuts out a blubber sample? I think it is extremely ill-advised, since it could introduce a life-threatening infection. Regarding the risk from the rancid meat, mammals like whales can generally handle bacteria in their digestive tracts much better than bacteria entering the body through skin breaks.

You alluded to how rats and seagulls have long been successful at picking out safe edibles from our garbage. The question is whether seagulls and rats are desirable. These species seem to be particularly well adapted to scavenging. Is the same true of every species in the entire ocean? Or would one or two "weedy" species take over and outcompete the other, already weakened populations?...I guess the question I raise here is whether you are interested in the conservation of the oceanic ecosystem, or would you be happy to see just ANY life (read: "rats-of-the-sea") in the ocean? There is the distinct possibility that we could screw thing up EVEN MORE by dumping our garbage in the ocean.

It's a bad problem and it is a crude one. The solution is also crude. We do not have the luxury of controlling what biodiversity might or might not survive - it will never again be what the "pristine" system was. And which species WE find most "desirable" is not the over-riding concern, believe it or not. Our current practices, if continued, guarantee a severe loss of "biodiversity" in the near future. (Regarding the "rats-of-the-sea", if lots of them grow, then lots of them will poop and die, and feed other levels of the web, thereby nourishing the whole system.)

If global warming is what we're worried about, then enhancement should take the form of liquid nutrients, since phytoplankton (the CO2 users, the O2 producers) are more likely to take up nutrients in that form. If no nutrients ever work their way up into fish-flesh, all the better; keep the nutrients where the plants can have 'em. By putting in big chunks of food, we may be trapping the nutrients in the big-end of the food chain, where it might be a) caught in food-web cycles and never reach the primary producers; or b) caught up in fish nets and never reach the primary producers.

I don't like the liquid nutrient idea , that's far more likely to make a mess of things than the chunky food. Solid food will feed many levels at once and therefore provide a "balanced diet" for the system in a sense. (Carnivorous fish takes a few bites, some lands on bottom, crab or snail crawls over and eats some, crumbs are broken down by bacteria and nutrients released into the system for the benefit of the phytoplankton - of course ammonia is also excreted from the gills of the fish for the benefit of the phytoplankton...) Just put back the closest thing that we have to the thing that we took out (dead fish).

Nutrients cannot be trapped in the big-end of the food chain, without the existence of healthy lower levels, there is no big-end (that's actually what we are starting to see now in the ocean).

If we do dump our garbage in the ocean, we need to be VERY careful about what we put. I'd suggest that this needs to be studied before implementation...

You are right. But we'd better not "study" this thing to death. It's just a matter of looking at all of the data that already exists and considering it in a new light.


Some other comments received...

“If we want to keep the fish, we’d better learn how to do it...They need some kind of caring which could very well include feeding.”

“Although I think your hypothesis has merit and probably contributes to part of the problem, I don’t think it (or the proposed solution) is the underlying panacea to all of our problems, or all of the oceans’ problems, On a bigger picture, I can’t help but see this as the temporary translocation of nutrients, not a net loss.”

Of course it’s not a panacea for “all of our problems” but “feeding the fish” could be a very important piece of the puzzle. A “temporary translocation of nutrients, not a net loss?” - that’s very hard to determine with any certainty, a significant amount of nutrient has been translocated from the ocean ecosystem to the land system...has the amount returned been equivalent to the loss? Maybe, maybe not, but the “form” in which it has been returned appears to be inappropriate for “feeding” the system as a whole...too much, for instance, is now concentrated in eutrophied coastal waters in some places.

“Here is a challenge. Design a fisheries management system that preserves coastal fleets...your solutions, should your ideas be acted on, just mean cut fishing will pay us to feed fish.”

It should not be a complicated thing to fit an out-of-work fish dragger with a pump to gradually disperse food waste from its fish hold into the waters where it formerly fished. Feed the stocks for a while, and when they appear to be increasing in health - fish them as well. Feed the fish year round, and arrange a fishing schedule in any number of ways. Stagger areas, feed two weeks, fish a week...whatever. It might “preserve” coastal fleets better than our current tactics. “No-one will pay” to feed fish? Why not? The Canadian government has paid out-of-work fishermen in Atlantic Canada billions of dollars to do nothing since the collapse of the groundfisheries. Surely the money would be better spent on something constructive that might actually have a chance of “rebuilding” the fish stocks. Societies pay for appropriate waste disposal programs, of course you should be paid for this one.

“So the "solution" is to take a system that is askew, due to largely anthropogenic causes, and "solve it" with more anthropogenic dependence. That to me defies logic in more ways than not.”

No. The "solution" is to use logic. What is the actual impact of fishing on the system? Fishing removes live/dead fish. If the fish had not been removed, their bodies would ultimately have fed other fish. So if we want to counteract the "impact" of fishing we need to put back the dead fish. But we don't have them. So what is the closest approximation that we do have to dead fish? Dead animals, perhaps? Food scraps? It's the idea of lessening the "impact." It sounds to me like current thinking about returning nutrients to the sea accepts random amounts of sewage and fertilizer dumped at the coastline as being good enough. “THAT TO ME DEFIES LOGIC IN MORE WAYS THAN NOT.”

“It sounds like the same old short-sighted human dominated concept of nature.”

Yes. Many things sound like that, including thinking that the ocean exists as an inexhaustible food producer for humans.

“Have you done calculations to figure out the volume of scraps needed to do the job?”

No. That's a secondary issue. First, determine whether or not the ocean is "starving?"

Debbie MacKenzie

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