Summary
- Bivalve aquaculture improves animal welfare as a substitute for meat, fish, and other marine food.
- Possibly improves economic welfare in developing countries.
- Can be financially risky.
- There is a huge opportunity to scale.
- Improves water quality and reduces climate change because they are a carbon sink.
- Second-order effects are likely to be beneficial.
Bivalve aquaculture means farming oysters, mussels, scallops, and other edible molluscs.
Bivalve aquaculture has multiple moderate benefits as summarized above. This means that it tends to fall between the cracks when EAs evaluate its effectiveness, because we often focus on maximizing a particular goal. Indeed, searching for “aquaculture” (not even bivalve aquaculture) returned very few “hits” on this forum.
This is an initial look into this cause area; approximately 10 hours was spent mainly on looking at sources.
Note: I may submit this to the Cause Exploration Prizes contest.
Animal welfare
Bivalves taste good (should be self-evident), and are healthy: “oysters, mussels, scallops, and clams are good for you. They’re loaded with protein, healthy fats, and minerals like iron and manganese.”
Eating bivalves causes less suffering than an equivalent amount of chickens, pigs, cows, and most other animals. Depending on what it substitutes for, it would also reduce crop farming and associated rodent/insect deaths, which are more sentient than bivalves.
Non-EAs are receptive to a proposal to substitute bivalves for other meat. They are not receptive to proposals to go vegetarian/vegan. Bivalves are also healthier than plant-based meat. Therefore, bivalves are the most effective way to reduce overall animal suffering.
Developing countries
Note: Epistemic confidence is low, and requires more research.
But it’s quite likely that bivalve aquaculture can have an enduring positive impact on developing countries. This report claims widespread benefits in Vietnam, for example: “There exists an opportunity to rapidly advance and sophisticate oyster aquaculture in Vietnam by exploring the full economic potential that has environmental, social, and sustainability benefits.”
Even if distribution isn’t developed enough for export, bivalve aquaculture can still provide highly nutritious food locally, as protein is generally rarer.
Financially risky
Note: Epistemic confidence is low, because these are comments on a preliminary request for feedback - more research needed.
Bivalve aquaculture has tail risk, e.g.:
“There are a ton of tail risks that can go wrong and wipe you out. Big one is disease, and the bigger the scale the harder that problem is. A lot of unknown unknowns.”
“Intensive aquaculture is tricky, diseases and anoxic conditions can wipe out entire crops.”
Counterintuitively, this is great for its attractiveness as a funding cause. It means that risk capital is valuable, and also means that the optimal risk-neutral level of bivalve aquaculture should be higher than it is now. It also means that we can be creative in how we approach spending money. For example, paying for insurance policies might be more impactful than investing directly.
Lots of room to scale
“Across the world there is an estimated 1.5 million sq km (579,000 sq miles) of coastline suitable for growing bivalve shellfish. According to Willer, developing just 1% of this could produce enough bivalves to fulfil the protein requirements of more than one billion people.”
It’s possible that a lot of this coastline is located in areas with bad governance. And not all of these places would be accessible or economically viable. But this is a tractable problem (scaling/new technologies) and shows that room to scale is unlikely to be the bottleneck.
Note: more research could uncover the amount of suitable coastline, and a breakdown of whether this coastline is in developed or developing countries, and whether they are already used for other things.
Environmental benefits
Bivalves are great for removing algae, and can clean up polluted water. This is an effective selling point for non-EAs, making cooperation easier with favorable political winds.
They can also ameliorate climate change: “Marine bivalves [...] sequester carbon in their shells as calcium carbonate and may be used to mitigate the effects of climate change.” See also: “The animals that are the source of this food require no feeding, need no antibiotics or agrochemicals to farm. And they actively sequester carbon.” I’m informed that EAs do not care about climate change, but many non-EAs think of climate change as a very high priority. This makes it easier to gain allies for more effective operations and impact.
Second-order effects
Note: epistemic confidence is lower here, as not much time was spent looking into these relative to other areas.
Most second-order effects or minor effects seem positive to me. For example, bivalve farming reduces starvation risk, because it’s likely to be an orthogonal food source, contributing to a balanced food security portfolio.
Additionally, focusing on developing countries before they have "meat-lock-in" seems pretty valuable. This would save “future animals”.
How tractable is it?
It’s no good to know that this is beneficial if it’s too hard. Luckily, “Bivalve aquaculture has proven highly successful in Vietnam. Species are easy to farm and require low-level skills, training, and technology to produce healthy and conditioned animals that are nutrient-packed and ready for the local markets and tourists. Previous ACIAR investment in Vietnam has supported the establishment and rapid growth of the edible oyster industry, which is now thriving, and demonstrates just how important this industry now is as a reliable and nutrient-packed food source.”
If it’s not technically hard, then where is the bottleneck? A possible bottleneck could be a lack of qualified marine biologists. But it’s more likely that this is a billion-dollar philanthropy bill lying on the ground, that no one has picked up because we’re all focused on maximizing single cause outcomes.
Note: needs more research to find out the biggest constraints on increased bivalve aquaculture.
How big is the opportunity?
Bivalves are more expensive than farmed animals at the moment. For example, retail prices at my store:
| Scallops | $49/kg (Australian dollars) |
| Beef | $28/kg |
| Pork | $18/kg |
| Chicken | $13/kg |
This price gap indicates that if there was a large increase in the supply of scallops, there is still ample latent demand to clear the market quantity. Personally, I enjoy the taste of scallops, oysters, mussels, clams more than the meats like beef, pork, chicken. I believe that most consumers would have the same palate, except for a few countries like the United States that have idiosyncratic food preferences.
Who is already working on it?
I haven’t talked with experts in the field, and would love to find out more about this. This is a high priority area for additional research, in order to “catch up” to the knowledge frontier.
Conclusion
Bivalve aquaculture is a high impact cause that has multiple benefits, is more robust to evaluation errors, and is neglected because of its “jack of all trades” positioning. It is a high priority for additional research and funding.
This is an exaggeration IMO. EAs care about climate change, but often don't prioritise it, because they care about other things even more. If everything more important than climate change was solved, I think EAs would be working pretty hard on climate change.
Yeah, I think this meme is both damaging and mistaken and I'm disappointed to see it crop up again here. There's plenty of evidence against such a broad assertion.
Great idea- in the UK, frozen mussels are just £3/kg vs. £1.75/kg for the cheapest frozen chicken.
I wonder if they could be genetically engineered or breed to taste differently or be bigger, given that some techno economic assessments suggest that creating cultured meat is going to be expensive.
One idea for reducing the cost is to automate the culling and grading process.
Nice analysis – thank you for posting!
While I agree that bivalves are very likely at most minimally sentient, I'd feel more comfortable with people promoting bivalve aquaculture at scale if the downside risks are clearer to me.
Do you have any sense of exactly how unlikely it is that bivalves suffer?
https://www.animal-ethics.org/snails-and-bivalves-a-discussion-of-possible-edge-cases-for-sentience/#:~:text=Many%20argue%20that%20because%20bivalves,bivalves%20do%20in%20fact%20swim
I found this discussion interesting. To me it seems like they feel aversion -- not sure how that is any different from suffering -- so it is just a question of "how much?".
From a welfarist perspective, and under the assumption that going vegan/vegetarian isn't an option, one challenge might be:
"Should we promote grass-fed beef consumption instead?"
A very rough estimate (might be off by orders of magnitude):
I'm super uncertain if I'm comfortable with giving mussels approx. 1/20'000 the moral worth compared to cows. Even after reading, for example, this blog post arguing The Ethical Case for Eating Oysters and Mussels.
[Edit: If bivalves mainly substitute fish, then this challenge might be missing the issue.]
Substitution is unclear. In my experience it's very clear that scallop is served as a main course protein in contexts where the alternative is clearly fish, or most often shrimp. So insofar that substitution occurs, we'd mainly see substitution of shrimp and fish.
However, it is not clear how much substitution of meat in fact occurs at all as supply increases. People generally seem to like eating meat and meat-like stuff. I don't know data here but meat consumption is globally on the rise.
Brian Tomasik wrote this analysis of bivalve suffering. I think it offers some good reasons not to conclude that it's super unlikely.
It might be that how much weight/likelihood to place on bivalve suffering is ultimately quite subjective though (e.g., I think I would place more weight on it than as expressed in the article because of different intuitions about how much different processes matter as evidence of suffering).
I don't find the case against bivalve sentience that strong, especially for the number of animals potentially involved and the diversity of the 10k bivalve species. (For example, scallops are motile and have hundreds of image-forming eyes—it'd be surprising to me if pain wasn't useful to such a lifestyle!)
Bivalves are basically nature's cultured seafood.
I've seen a few people wondering how this relates to our work at ALLFED (@JoelMcGuire , @George Vii , @Brian Lui).
Bivalves can be grown in sinergy with seaweed in what is know as integrated multi-trophic aquaculture (IMTA) systems, which promise a consistent feedstock, in situ, with the co-benefit of recycling aquaculture waste (ref). They are also resilient to food trade restriction and the pests that affect land crops. They look like they could be significantly more resilient to changes in climate than land crops, thus being useful to counter falling agricultural yields in two ways like most resilient foods: 1) resilience - the higher the production of this food is prior to an abrupt food production shock, the smaller the overall fall in food production capacity, 2) response - the fall in agricultural yields could be countered by rapidly scaling production of this food post-catastrophe.
These are the things that we have yet to ascertain though. Uncertainty remains, but there definitely seems to be potential for bivalves and IMTA to compete in price and speed with other resilient food options, indeed contributing to a resilient food portfolio. It mostly depends on how growth rates would be affected by changes in climactic conditions. Because bivalve cultivation is not very complex technologically it looks like it could not only contribute to resilience and response against global catastrophic food shocks involving an agricultural collapse, but also those originating from a loss of critical infrastructures.
In short, I agree with the post and believe there could be significant potential for bivalves to increase food security overall and as a resilient food for extreme scenarios and would like to see more work on this. I proposed a project to look into this but we haven't yet got around to working on it (so many important projects to do, so little time... We could use a little help). Below I paste the rationale for working in this topic I wrote for my bivalve project proposal:
Ramping up bivalves could have significant potential food for GCR, seeing as to how they’re somewhat similar to seaweed (which is very promising as such),
General info here
Technical info here
Production and price info here
Clams cost approx 6 USD retail/person/day (on the medium side of cost). Of these calories 50-70% is protein
Bivalves are a big part of the US fishing industry. You can explore some of the risks to them by looking over the recent history of their cultivation in the US and globally.
Ocean acidification, waste water outlets, garbage dumping, and storm water runoff are threats to pop-up farms over the next few decades. After that, acidification combined with temperature and pollution could be too damaging, either to farming efforts or to the quality of the food.
Ocean currents near shore can produce lower pH (e.g., 7.65 as opposed to global avg 8.04 (edit:8.1, not because I believe it but because that's the consensus) from upwelling, colder, more acidic water on the west coast of the US) in coastal waters. Bivalves are sensitive to increased acidity of ocean water. Their fertilization rates decrease and their juvenile mortality increases. There might be an effect on their maturation size as well.
Ocean average pH decline has one estimate pinning it at 7.8 by 2094. It is currently 8.1 and dropping. That avg allows wide variation in the availability of carbonate and calcium ions for shell formation in different waters across the globe. Heat maps show largest declines in availability of carbonate near the poles and with unequal distributions around the equator. Measurement data from 2006, I think, shows recent changes in carbonate chemistry occurring in the top 200 meters of the ocean, where marine ecosystems are most productive.
I believe that marine biologists would agree that loss of shell-forming organisms in the ocean would create a ripple effect throughout the world's oceans. The discussions I have reviewed so far suggest that sea butterflies, a shell-forming marine animal that is food for larger fish we know, will die out under certain environmental stresses, emptying the ocean of their predators. That pathway to a die-off of marine life is identified repeatedly. Maybe because it matters to the commercial fishing industry. Without sea butterflies, the major food source for fish that we like to eat will be gone. The question then is whether ocean chemistry will allow widespread bivalve production for a significant time period.
I can't find consensus estimates of the timing of marine life die-offs triggered by the loss of sea butterflies. pH avg change models from NOAA suggest that pH reaches 7.8 before the end of the century. That is below the point where the shell dissolves off a sea butterfly (sea snail) body. Is that pH enough to kill all bivalves? I don't know, but you could probably answer that question easily.
Interestingly, the only public claim of the likely death of marine life as a whole within this century that I could find credits multiple simultaneous stresses on marine life, including a massive poisoning of plankton by pollutants riding on micro-plastics that plankton consume combined with a loss of shell-bearing organisms at a global avg pH of just 7.95. The source of that claim pins the outcome as occurring by 2050. That is not a consensus opinion but there's not much to contradict it, just lack of research and lack of attention. An implication of that claim is that the ocean is no longer supplying oxygen to the atmosphere.
EDIT: there is one area where there is some consensus, it's that the coral reefs of the world will all be lost by 2050. That is a tipping point for ocean ecology.
Given the lead time of any plan to increase bivalve farming, jellyfish might do better as food from the ocean once the larger problem is recognized after the first global famine of the century is over. There will probably be multiple food shortages, mishandling of those shortages, and lack of preparation for further shortages this century that approach a global famine at least once and probably twice.
In the meantime, people everywhere will probably prefer fish like salmon and tuna and shrimp as seafood rather than exclusively bivalves.
Speaking for myself, I'm allergic to shellfish. Bivalves are a common allergen food. After trying some cricket flour in a protein bar, I developed a case of hives. Apparently an allergy to shellfish implies an allergy to insects because of some kind of biological similarity.
Thanks, I didn't know most of this information!
Also, I see two claims:
The first one sounds quite serious and potentially very serious. The second one sounds catastrophic?
I didn't know the magnitude of the risk was this big. Is this a cause area that could benefit from more funding or research, too?
Hi Brian, short answer, yes. Of course.
Look into jellyfish as a food source.
The death of the oceans is progressive and predictable, if you assume that causes of it continue into the future.
Thanks for the reply Noah. Are you working on this field or a related one?
Sure, I think you guys (and those folks at the UN) and the general topic of food security is incredibly important.
I am not working in this area professionally, nothing even close to it.
This is super useful information, thank you so much!
This cause may serve another purpose: accelerating recovery from catastrophe.
If bivalves are relatively resistant to reduced sunlight events, then building up a robust aquaculture economy where bivalves are raised in kelp forests (as is sometimes done), could help us not starve in such an event.
Allfed has probably considered this.
In general, I think it makes sense to be very bullish on for-profit EA schemes with low risk of harm / at least moderate expected effectiveness. I'm not sure if this is one of those cases, but if it is, I think that's a decent reason to press the fund button.
There may be a case for pursuing this in developing nations in particular. https://forum.effectivealtruism.org/posts/M44rw22o5dbrRaA8F/why-and-how-to-start-a-for-profit-company-serving-emerging
Food security appears to be pretty precarious across the world (from a cursory view eg it seems like US doesn't even have strategic reserves https://www.americansecurityproject.org/food-insecurity-why-the-u-s-needs-a-strategic-food-reserve/) & could easily lead to pretty bad outcomes; many an empire has been crushed by simple famines (including conflict). We probably shouldn't assume that competent "hard men" to step up and take the reins, as people seemed to expected during covid.
Building up uncorrelated food portfolio seems under explored & not just for lack-of-sunlight type scenarios that Allfed have seemed primarily focused on. I'm not sure if bivalves fit this, but it definitely seems plausible that it's sufficiently uncorrelated and should be explored further.
Most biorisk ppl seem to be largely focused on humans; vaccines, bunkers, PPE etc. But biorisks among the global food supply is also a massive failure point (crops are often clones or single species & are a lot harder to PPE lol).
Anyway, coupling the animal welfare case with global poverty/health & food security seems like an interesting combination. One could focus on regions where food security is low, malnutrition & poverty are high, and where factory farming has yet to gain a foothold.
When developing nations' protein intake increases as their GDP rises, if they already have robust bivalve industries, they may be far less likely to be as chicken/pig heavy as current western nations. Especially if one seeds good sustainability messaging years prior etc.
Arguments around it being hard to get people to change their dietary habits are far less strong for these regions.
Somalia, might be an interesting candidate given current events & copious coastlines. Even in non-famine times you could possibly see benefits of reduced iodine/iron/zinc/protein deficiencies. Improving IQ, immunity, fertility etc https://ourworldindata.org/micronutrient-deficiency
Or Senegal given it's already established oyster industry and Wave's strategic placement (if relevant)
There are probably many more ways than one to approach this:
- Teaching the skills so locals can grow themselves (some charities already do this we could likely evaluate their operations to see how they stack up against other interventions. I believe some focus on teaching women, so there might be additional benefit of financial empowerment)
- Focus on methods for scaling/efficiency (since people have expressed concern as to the number of mussels that equate to a cow in caloric terms, perhaps there are larger species or growth tech that could reduce their downside uncertainty)
- Insurance for farms.
- Be ambitious and go for scale with a for-profit approach.
It also sounds like something environmentalists might also support, so perhaps lends the possibility of also raising capital from rich conservationist types, rather than solely EA funds.
These are good thoughts.
Yeah, I'm surprised I haven't seen more on crop bio-risks. They also seem way more targetable as a potentially deniable act of war (and with a less clear ladder of escalation). I.e., you can create viruses / fungi that'll disproportionately impact your enemies crops / animals but that's harder to do for humans. USA depends more on corn than China (I think).
I like this idea of "protein lock in", seems like a potential sub-cause of its own if it hasn't already been explored.
Why would you fund bivalve rather than fully plant-based alternatives to meat? I guess you could also replace bivalves with plant-based alternatives, right?
I'd like to see evidence for each of these three claims, as I don't think they're all (wholly) accurate.
And, as discussed a bit in other comments here, I also have serious concerns about what bivalves experience.
Supposing bivalves are in fact capable of suffering, might it still be economical to farm them in a way that causes almost no suffering? Presumably they don't suffer from confinement the way most animals do...
Decent discussion on Twitter, especially from @MichaelDello
https://twitter.com/brianluidog/status/1534738045483683840
To me the biggest challenge in assessing impact is empirical question of how much any supply increase in meat or meat-like stuff leads to replacement of other meat. But this would apply as well to accepted cause areas of meat replacers and cell culture.
Thanks for posting! I think it's great to think about ways to use the large differences in suffering per calorie depending on what species is being farmed to our advantage to increase animal welfare.
This is a better source about it being difficult to influence dietary change https://rethinkpriorities.org/publications/effectiveness-of-a-theory-informed-documentary-to-reduce-consumption-of-meat-and-animal-products (via method of documentaries)
The greater tractability of dietary change to increase bivalve consumption(reducing other animal consumption) is likely the strongest point in support of bivalve farming. I think(85%) that influencing people to substitute for bivalve consumption will be quite similar in difficulty to influencing people to go more veg*n. Some people who identify as vegan also consume bivalves anyways so this may not be an either/or though. Nudging people away from the worst in suffering per calorie is always better so it.
On price I don't think(65%) scallops(which you compared) are the cheapest of the bivalves? May be better options!
This is an interesting point! Animals require a lotta farmland for food. I'm not sure there's any strong agreement though that reducing amount of crop farmland is good for animal welfare compared to counterfactual re-wilded land, or the counterfactual how the wild animals in the farmland would have died anyways.
xD Be careful with this point there seems to be a tradeoff between cleaning polluted water and health, from that article:
I interpret the linked post about receptivity to proposals to go vegetarian/vegan as providing evidence that people are receptive to these proposals. It states:
If the number of vegetarians is flat, yet people are abandoning the diet, this requires a constant inflow of new vegetarians to balance the outflow. The whole point of the post is that people are receptive to trying a vegetarian diet out, but that they struggle to maintain it long-term.
The claim in this post that "non-EAs are receptive to a proposal to substitute bivalves for other meat" does not provide any evidence in favor of the assertion, which might just be a missing link.
I think it's important to make this claim about receptivity to bivalve/meat substitutions more specific. Is this population of non-EAs members of the general public? What countries do they live in? How often, and how much, and for what kinds of meat would they consider bivalves an acceptable substitute? Will they pay more to substitute bivalves for other meats on a pound-for-pound basis, and if so, how much more?
Shellfish consumption tends to be aggregated with seafood consumption in general, but the USA consumes a moderate amount of seafood relative to other countries. It's not clear to me what you mean by the USA having "idiosyncratic food preferences." I was only able to find this data on American oyster consumption specifically. While low, I think this is better explained by a combination of the high cost of oysters and the fact that America has a great deal of non-coastal land a long tradition of ranching, and excellent farmland, making cheap, high-quality meat widely available to the population.
I suspect that meat freezes and ships much better than shellfish. I have no reticence about eating a steak from a cow slaughtered 2,000 miles away, but I think of "Midwestern sushi" as a rare example when combining a location name with a food name (i.e. "Washington cherries," "Argentinian french fries," "French pastry") as making the food sound worse rather than better.
I would want to see a deeper investigation into the tractability of upscaling shellfish aquaculture, a stronger argument on the market failure explanation for why normal market mechanisms are inadequate to motivate increased production, and better information on people's receptivity to bivalves as a meat substitute.
That said, I love oysters, and if we can altruistically make them cheap enough that I can eat them on the daily, that alone will make the EA movement a success as far as I am concerned.
It's not clear this is good rather than bad. Plausibly the population effects dominate, and they could be bad. Also, even the population effects are complicated and may be very context-specific, e.g. from Fischer and Lamey's Field Deaths in Plant Agriculture:
See also Brian Tomasik's How Does Vegetarianism Impact Wild-Animal Suffering? and Crop Cultivation and Wild Animals among others, from a suffering-focused/negative utilitarian perspective.
The effects on wild aquatic animals are also complicated.
This class of wild animal welfare considerations affecting personal choice just seems like a lot (my concern does not apply to all of wild animal welfare, such as large scale policy or programs which seems good to research or explore).
I’m not sure what we can do with this right now.
One of the links advises eating rainforest cleared beef.
I’m down with eating beef because in many farms it’s possible beef cows have good lives.
But intentionally destroying rainforests just hurts from a lefty perspective. I can feel this in my bones. I think most EAs have the same aversion.
Is it good to have a system that brings about lots of sentient creatures and then kills some of them (ignoring the fact that this system feeds us)? Opinions may, of course vary, particularly between purist consequentialists and others; In my opinion it's bad. This is one of the reasons I oppose factory farming, even though I believe every life to be "net positive".
Again I'll just note that Tomasik's view stems from strictly consequentialist ethics. I'm not sure I view suffering caused by a creature's natural habitat in the same light that I view suffering caused by humans.
I challenge you with a counterfactual: countries develop a comparative advantage in meat alternatives which is (as far as we know) not conscious, such as soy and its processing. This should enable the nations become affluent more easily, because not many people would have to farm (efficiency gains would be relatively low) but industrial processing machinery will be invested into.
Do you think that instead of bivalves, maybe even investments into affordable oyster imitations could raise the living standards in developing countries better?
I don't understand this. More easily than what? What's your story for why people aren't doing this already, if it would make them more affluent?
Than if the people had to farm the bivalves. It may be also labor intensive. I think that it is knowledge, know-how, coordination skills, problem attitude norms, and credit constraints. People, in some cases, do not process agricultural products because they do not know how. They may, in these cases, also not have the knowledge that it could be beneficial for them (health-wise) or that they could sell (including abroad, if they knew how to fill in import-export and get quality certified). Increased efficiency requires coordination (e. g. bulk fermentation) which can be limited due to the norms that value solidarity/empathy in experiencing problems rather than outperforming others in solving them. Investment into farming and processing efficiencies can be limited due to limited access to credit.
So, the solution can be info on how they can increase plant-based efficiencies and gain credit financing while seeking to preserve local attitudes toward animal farming (good relationships, sharing fields or houses).
Thanks for these super helpful comments! I plan to incorporate some of the feedback into my draft, but I'm not sure of the etiquette on this forum - is it ok or not ok to edit the original post with additional information?
Also would like to share my thoughts on some of the comments:
I'll be giving some critique below, but nevertheless, thank you for the idea and the analysis!
I think the animal welfare section of this post would benefit from more rigor. (not sure about the other sections; haven't read them yet)
Neither the linked article nor the quote sounds very credible or scientifically convincing to me.
To me this seems highly non-obvious. Maybe explain why you think so?
Also, I suspect this depends a lot on one's moral weights assigned to different species, which (I guess) varies hugely across different people.
It's good that field deaths are included in the analysis.
But one may also want to count the second-order effects of bivalve aquaculture (note that I have no knowledge about this and don't know if this will significant change the conclusions).
This also seems non-obvious to me.
This is a really bold claim and would deserve much more argumentation. Consider, for example, doing a cost-effectiveness comparison with the popular EA animal welfare interventions, if you'd like to argue for this.
Again, thank you for the post, and please don't take this comment as an attempt of dismissal; just pointing out where I think it could be improved :)
That's interesting. Could you maybe show some estimate for how substituting bivalves for some other food results in X bivalves suffering instead of Y rodents and Z insects?
Do you have a source for people being more receptive to the former than the latter? I can't imagine a single person I know saying "ok, I'll only eat muscles instead of all other meat if it will cost the same."
I think a stronger case may be made for substituting fish with bivalves, though this is again anecdotal.