Introduction

~440 billion shrimps are farmed each year [1]. This is over 5x the total number of all farmed land animals put together [2].

Many farmed shrimps suffer from conditions that can and should be addressed, such as poor water quality, high stocking densities, inhumane slaughter methods, and avoidable mutilations (such as eyestalk ablation) [3].

Shrimp Welfare Project is an organisation of people who believe that shrimps are capable of suffering and deserve our moral consideration [4].

We aim to cost-effectively reduce the suffering of billions of farmed shrimps.

This post is essentially an expanded version of our 2025 Funding Proposal. 
If you want the TL;DR version of this post, I'd recommend reading that.

(Shr)Impact and Vision

Shrimp Welfare Project has four workstreams, two of which we consider our Core or Foundational workstreams - those are Corporate Engagement and Farmer Support. Two more are relatively new, but we think they have a lot of potential, and those are Research & Policy, and Precision Welfare.

For each workstream, I want to talk you through:

• Our mission statement for the workstream
• The problem we’re trying to solve through this workstream,
• The strategy we’re taking to solve the problem,
• The successes we’ve had so far
• And our vision for 2030

Core: Corporate Engagement

Catalysing industry-wide adoption of pre-slaughter stunning by buying and deploying electrical stunners to early adopters to build towards a tipping point that achieves critical mass.

Problem (and Context)

When we started Shrimp Welfare Project, we planned to originally work only directly with farmers.

However, we soon became aware that unlike a lot of fish farming, which is often produced and consumed domestically, shrimps instead were bought and sold on the global market. In particular, most shrimps are farmed in the Global South (in places like Ecuador, India, and Vietnam), and then exported to countries in the Global North (such as those in Europe and the US).

We were cautious not to over-update on this, as we didn’t want to step on the toes of other work being done in these spaces (like cage-free initiatives), but we felt it was prudent to acknowledge this reality when determining how to improve shrimp welfare.

However, there were other issues we were facing. Even if we were able to ask for changes at the demand-side level in Europe (in particular, in the UK), we didn’t know how we could push for these changes when we had very little leverage. It was hard to mobilise public support for shrimp welfare, and it was hard to convince large producers to make a change to their practices.

Strategy

After a year or so of working on this problem, we established our current strategy: the Humane Slaughter Initiative.

First, we established Shrimp Welfare Project as a Good Cop brand - partnering collaboratively with industry to make positive changes.

Second, we needed to find a “crisp, clear Ask”. We knew from the success of Cage Free, and the relative struggles of the Better Chicken Commitment, that Asks benefit from being crystal clear and easy to communicate, as well as resonating with people. For shrimps, we felt that a couple of Asks fell in this category - ending eyestalk ablation, and implementing pre-slaughter stunning.

As eyestalk ablation is only performed on the broodstock shrimps (and therefore a tiny percentage of the overall shrimp population), we felt that it was more prudent to advocate for pre-slaughter stunning as our primary Ask (though we often discuss eyestalk ablation as an issue that retailers may be inclined to address, as a “foot-in-the-door”).

After some research, we determined that electrical stunning was likely the most humane stunning method for shrimps. But we knew that asking for retailers and producers to invest in expensive equipment - just because a small group of people had asked them to - was unlikely. But early on there was a unique opportunity in being an EA-aligned organisation. In particular we felt that ideas that many donors might find strange - such as the idea of buying equipment for the industry - would be an idea that EA-aligned funders wouldn’t find aversive, especially when we ran the numbers and realised how cost-effective this intervention would be in averting suffering for billions of animals..

This also made the Ask much more palatable, as it meant we were approaching retailers with both an Ask, and a solution - identifying a problem and offering to solve it for them.

This also removed barriers to implementation - even relatively forward-thinking retailers often can’t push an initiative through internally without some leverage. They need to be able to convince their higher-ups that this is worth doing and convince their suppliers to invest in the necessary changes and take on the added expense. By offering to buy these stunners directly (and offering to only do it initially, conferring an early-mover advantage), we removed these barriers to implementation. 

I should say we were also aided here by ongoing conversations in the UK around crustacean sentience, thanks to the UK Animal Welfare Sentience Act that was passed in early 2022, in large part thanks to the work of the NGO Crustacean Compassion.

Ultimately, our goal here is to establish pre-slaughter stunning as the “new normal” in the industry, rather than us continuing to buy stunners indefinitely.

A way we like to think about this is that we aim to catalyse industry-wide adoption of pre-slaughter stunning by deploying electrical stunners to early adopters, in order to build towards a tipping point that achieves critical mass.

Achievements

So far, we’ve signed agreements to provide 17 stunners to producers, altogether totalling ~3.3 billion shrimps impacted per year.

In other words, this is where most of Shrimp Welfare Project’s direct impact currently comes from.

Additionally, working with these producers has enabled us to help convince 7 retailers so far (including Tesco and Sainsbury’s), to commit to electrical stunning across their whole supply chain.

2030 Vision

We see the Humane Slaughter Initiative as currently being in a “Growth phase” - we have an intervention that works and impacts over 1,500 shrimps per dollar per year. 

This is really exciting, but over the next few years we want to take this intervention from Growth to Scale. 

Our Vision is that by 2030, we’ll have reached a tipping point of industry-wide adoption of our interventions, halving our expenses by passing costs onto the industry.

We want to do this by primarily focusing on providing stunners that lead to retailers publishing stunning commitments in key regions, ultimately reaching a tipping point where supplying to these countries just becomes a basic market requirement.

As a result of this, we expect the number of stunners we provide over the next five years to follow something akin to a bell curve, where we provide an increased number of stunners in the next few years, but then fewer overall as more countries default to stunning.

Additionally, the availability of shrimp stunners on the market is currently quite limited, and can’t really be used in certain contexts (like not having stunners that can work for smaller farmers, or not having stunners that can directly integrate into other pond-side equipment such as harvesters). We’re hoping over the next few years to try to encourage the market to innovate in this space.

Our countries of focus for retailer commitments currently are the UK, Germany, the Netherlands, Sweden, France, and Spain.

We hope to have deployed a minimum of 50 stunners to hit this tipping point. 
(Note that this is referring to stunners we pay for ourselves. We’re hoping the total number of stunners worldwide is higher than this as the industry begins to buy them themselves. If we believe the number needs to be higher to reach the tipping point, this number will increase).

To summarise - by 2030, we want to transition from Growth to Scale by passing the costs of stunners onto the industry.

Core: Farmer Engagement

Developing and implementing cost-effective, evidence-based interventions that can scale and reduce chronic suffering by impacting multiple welfare factors.

Problem (and Context)

Now, while we were very excited about corporate engagement work, we continued to explore direct farmer support work. This was for a couple of reasons:

Firstly, 50% of the world’s shrimps are produced by small farmers. Choosing not to work with this section of the industry leaves a lot of potential impact on the table.

Secondly, direct farmer work (especially in Lower- and Middle-Income countries) is relatively unexplored, and we felt we might be able to provide some significant knowledge value to the movement if we tried to work on this problem.

However, there’s a reason corporate engagement work dominates the animal advocacy space. It’s just really hard to engage with small farmers in a way that can be scaled and is as cost-effective as corporate engagement work.

Strategy

To solve the problem of trying to find a cost-effectively competitive intervention in the farmer support space, we set out to develop an intervention which:

1. Alleviates chronic suffering: The amount of suffering we can reduce depends primarily on two main factors: duration and intensity. We felt that in comparison to our stunners work with corporates, which focuses on reducing extreme acute suffering for shrimps, we could likely make a bigger difference with farmer work by addressing chronic suffering. Additionally, this kind of allows us to “hedge our bets” in terms of how much suffering we’re reducing, as we’re very uncertain to how a shrimp would choose to trade-off between duration or intensity of suffering.
2. Is Single-Application: To bring costs down, we wanted to find interventions that would essentially be a “one-off”, where we do something at the farm or pond level that has an impact over multiple cycles. This is ultimately the same insight we had with buying the stunners: you buy them once and they can be used for multiple years. We felt that to be similarly cost-effective, we’d likely need to find an intervention that worked like this for farmers.
3. Impacts multiple welfare outcomes: Like stunners, we felt that a successful intervention needed to be incredibly focused and simple in order to scale. However, just because an intervention is focused in its execution doesn’t mean it needs to only be targeting a single welfare issue. We wanted to find an intervention that once applied would be multi-pronged in its welfare outcomes. Examples of this are things like removing sludge from the bottom of ponds and lowering stocking density, which both tend to reduce disease outbreaks and improve water quality across a number of parameters.

After doing lots of scoping work, we found that we could have the most impact by not trying to find a “universal” intervention that we could apply across all farms (in large part, due to the huge variety of ponds and farming systems for shrimps, even within a specific country), but instead finding small “pockets” where shrimp farming was particularly plagued with a certain issue.

Achievements

2024 was our first full year of implementing what we’ve come to call the “Sustainable Shrimp Farmers of India” (SSFI) program, where we offer to remove sludge from the bottom of shrimp ponds if the farmer also agrees to lowering their stocking density. 

So far, we’ve removed sludge from 100 acres and counting. On average, shrimp farms in India are stocked at 100,000 shrimps per acre, and run an average of three crops per year, so SSFI has impacted approximately 30 million shrimps. This work, like stunners, should be thought of as having recurring impact for a certain number of years ^[1].

You’ll probably have noticed that the scale of shrimps impacted here is significantly lower than our corporate engagement work, but we think the impact (and cost-effectiveness) per shrimp is much higher. 

Our costs with the SSFI program are much lower. It costs us around $90 currently to remove sludge from an acre, meaning we impact approximately ~3,300 shrimps per dollar per year ^[2].

But where I’m really excited about this program is for the potential for farmer support work at scale here. A lot of 2024 was us testing running this program (after developing in 2023), and the SSFI team put a lot of work into automating and reducing costs for much of the work (i.e. buying our own sludge motors, working with farmer “leads” in villages to connect us with farmers, having our own contracted team to do the work), meaning we think we can scale up this program significantly. In 2025, we’re aiming to remove sludge from a further 300-500 acres of ponds.

Additionally, working directly with farmers just gives us a fantastic on-the-ground understanding of the reality of shrimp farming, which is extremely valuable insight in general, but also provides a huge amount of credibility with the industry. In general, there is great synergy between our farmer and corporate work. The corporate world really likes that we have this on-the-ground work directly at the farmer level, and farmers are really excited that we’re an international NGO that engages with the global industry.

2030 Vision

The SSFI team is not one to shy away from ambitious goals. At our latest team retreat (which we call Shrimposium), they set themselves the following Vision for 2030.

First of all, they want to be removing sludge from 1,000 acres per year by 2030. Additionally, they’ve begun testing charging farmers for sludge removal at a reduced cost. They believe that by 2030, our sludge work will be self-sufficient in terms of cost, and not require donations to operate.

Additionally, we’re exploring the synergies between sludge removal and certain strains of seaweed. Farmers are often reluctant to remove sludge from their ponds as they believe it acts as a sort of fertilizer for their shrimps. This is generally not true, and causes lots of toxic gases for shrimps. (It seems like sludge does function as a useful fertiliser for growing certain strains of seaweed. We’re hoping that by 2030, we will have helped farmers dedicate 100 acres of ponds to growing seaweed, using the removed sludge as fertilizer and allowing the shrimps to live in cleaner waters.)

Next we’re in discussions with The Centre for Responsible Seafood (TCRS). This is an organisation that is also interested in the subset of farmers we’re interested in working with (farmers who are unable to get certification due to their current poor farming practices). TCRS want to launch Farmer Improvement Programs in India to help these farmers. We’re aiming to collaborate with TCRS, and make shrimp welfare part of their Farmer Improvement Programs.

Additionally, our annual retreat (Shrimposium) last year highlighted to the wider team the fact that Corporate Engagement has struggled with engaging with large producers in India, largely because we’ve taken a mostly top-down approach, speaking to retailers in Europe, who have then put us in touch with their producers. India however supplies mainly to the US, so we haven’t been connected to many Indian producers so far. However, we believe that we may be able to use this to our advantage, approaching Indian producers directly, and potentially using this as an in for our work with US retailers. Therefore the SSFI team have set themselves a couple of goals:

• Firstly, to have between 5 and 10 stunners for producers in India.
• But secondly, the new stunners that we want to encourage the market to develop, we’re hoping will be much more suitable to the Indian context. So we’re hoping that we can have these on the market in the next few years, in which case, the SSFI team would want to have deployed 15-30 in India (likely through farming clusters).

Finally, the SSFI team are constantly experimenting and learning. When it came to defining our 2030 vision, they wanted to emphasise that it’s quite possible that the main thing SSFI is doing in 2030 isn’t something we’ve even tried yet. So we’ve left space in our vision for ongoing exploratory work.

New: Research & Policy

Facilitating and “locking-in” impact by determining our most cost-effective Asks, filling the welfare gap in the literature, and pushing for progressive policy change from corporations, certifiers, and legislation.

Problem (and Context)

Research actually isn’t new for Shrimp Welfare Project – we’ve had a research workstream almost since day one. But the application of our research into a more tangible “outcome-oriented” workstream by adding Policy to the mix is relatively new.

With research, we’ve been trying to achieve two things:

Firstly, determining what our Asks should be, and secondly, closing the “Welfare Gap”, i.e. trying to get the studies funded to answer some fundamental missing questions in the literature.

Policy, on the other hand, is a way we can “lock-in” impact long-term. A good example of this is our new primary focus on retailer commitments. These policies will continue to be impactful even if Shrimp Welfare Project steps away.

Additionally, some policy moves don’t have direct impact, but can lay the groundwork for future impact. For instance, the Animal Welfare Sentience Act of 2022 in the UK didn’t have any immediate impact on animals, but it did open the door for conversations about shrimp welfare and was hugely influential in making the UK our first choice for corporate engagement work.

Strategy

What are examples of concrete work in this workstream?

Well we’ve published a number of research reports on our website–Shrimp Welfare Index, Shrimp Welfare Report, The Alt Shrimp Market, Consumer Attitudes towards Shrimp Welfare, Shrimp Paste and Animal Welfare, and additional Articles and Outreach efforts–which helped to answer some of our key uncertainties (and hopefully can be useful to other organisations in this space). We also convinced Open Philanthropy to fund a robust study at the University of Stirling to validate the effectiveness of electrical stunning in a lab and real-world setting.

And in policy, we published a document called the Shrimp Welfare Index, which I think can kind of be thought of as a “Better Chicken Commitment” for shrimps. However, it’s designed to be flexible, with no specific parameter being a “deal-breaker” and work across a number of different farms and contexts. 

We’ve also been members of Eurogroup for Animals for several years and are collaborating on projects with them, as well as being a part of the Aquaculture Stewardship Council’s Technical Working Group for the introduction of shrimp welfare into their current standards.

2030 Vision

Where do we see this going forward?

We expect the Vision for Research & Policy to be much more in flux than our Humane Slaughter Initiative or SSFI, in large part because it’s a relatively new workstream for us, and we imagine we’ll need to change our plans as we learn more.

But tentatively, this is how we imagine what this future might look like.

Firstly, we’re aiming for a major aquaculture certifier (most likely the Aquaculture Stewardship Council, ASC) to require electrical stunning by 2035. This date is influenced by the fact that ASC only updates its certification every 5 years, and in this most recent iteration, we considered it a win that ASC even acknowledged electrical stunning as an approved stunning method (the industry representatives in the Technical Working Group had a lot of pushback on this). So we’re hoping that in the 2029 revisions, stunning will be enough of a norm in the industry that requiring it to be certified will be less of a stretch (and ASC would likely also implement a multi-year phase in, which we expect would mean that this would be around 2035).

Secondly, we’d have conclusive published academic results on the effectiveness of electrical stunning. The data we’ve seen behind closed doors is very positive, and we’re very optimistic about this. Once the data is published and publicly available, this should remove some reluctance from retailers and industry to adopt electrical stunning at scale.

Next we want the European Food Safety Authority, who have a mandate from the European Council to publish a report on crustaceans in the next few years, to include some shrimp welfare recommendations (i.e. by making the concrete recommendation that pre-slaughter stunning is a requirement, and that ice slurry on its own is just a slaughter method and not a stunning method).

We want Seafood Watch - a sustainable seafood advisory list - to also include shrimp welfare as part of their evaluation they use to make recommendations to consumers. This would likely be using our Shrimp Welfare Index.

Speaking of the Shrimp Welfare Index, we’d want at least 2 retailers (likely in the UK) to have adopted the welfare index in some form into their policies (like I said, this is kind of like our Better Chicken Commitment, so we’re setting the bar somewhat low at this point and essentially see this as testing and learning). We’d also want to have some accredited monitoring body knowing how to evaluate the welfare index, so that it can’t be adapted without robust verification.

And finally, the project on trying to encourage the development of new stunning equipment (which I mentioned as part of the Humane Slaughter Initiative and SSFI goals), is primarily being led by our Research & Policy Lead, Shannon.

New: Precision Welfare

Navigating the evolving landscape of the industry, aiming to steer the trajectory while still in the early stages of transition, using Precision Aquaculture to monitor and optimise for welfare outcomes.

Problem (and Context)

And our final workstream we’re calling “Precision Welfare”. Essentially, here we’re trying to futureproof our interventions. 

Currently, the vast majority of shrimp farming is in ponds in Asia and Latin America, but the rise of in-land Recirculating Aquaculture Systems (RAS) and other super-intensive systems, and more specifically the use of AI to automate and intensify aquaculture in these systems (Precision Aquaculture), could change that reality in the near future.

In a way, we can think of this like we’re witnessing the beginning of a Factory Farming 2.0, and we should be making decisions that reflect that, aiming to shift the trajectory while it’s still in its early stages. Therefore, trying to figure out interventions that could apply to RAS farms has been on our radar for a while now.

Additionally, we’ve been trying to resolve the issue that in order for robustly good welfare, multiple inputs must be optimised at the same time. 

But as we’ve already mentioned, having an Ask made up of multiple inputs is historically complex, and monitoring compliance across a range of variables is hard.

Strategy

This work is in early stages, but in general we expect to take the insights we’ve learned from Corporate Engagement and Farmer Support work up to this point and try to apply them to this new space.

Ideally, we are searching for an intervention that is simple to communicate but impacts multiple welfare factors and can be scaled up.

Our primary insight so far is based on the idea that most welfare Asks are based on Welfare Inputs (i.e. Cage Free, or Low Stocking Densities), where the Theory of Change outlines that if these things are in place, then this likely leads to improved welfare.

However, we think it’s possible that there are certain metrics that could be measured, that are instead Welfare Outcomes. So, rather than Welfare Inputs, this would reflect a holistic view of welfare, and yet would be simple to communicate. In particular, it seems like AI would be really well placed to monitor and optimise for Welfare-focused Outcomes.

Additionally, we want to use this opportunity to engage with Precision Aquaculture as it’s emerging within the industry, with the hope that we can steer the direction of its overall application in shrimp farming.

We can also leverage Shrimp Welfare Project’s already existing positive reputation in the industry, as well as my PhD in Machine Learning that I completed back in 2019 (which I never expected to be useful when I co-founded Shrimp Welfare Project in 2021, but life can be surprising).

20(26) Vision

So for this worksteram, because we’re in such early stages, I tend to think of our vision as a 2026 Vision, rather than a 2030 one. And this will be developed as we learn more.

But we have two key goals we want to have achieved by next year.

The first is that we want to have clearly defined what we consider these Welfare Outcome Metric(s) to be, and to be confident that they cannot be optimised at the expense of welfare in other ways.

This is a question we’re working on internally, but additionally, we’re hoping that these are developed independently of Shrimp Welfare Project, so that we have some credible distance when advocating for them within the industry. In particular, there are a couple of projects ongoing which we believe might fit the bill. CrustaWohl, which is a research project in Germany, is looking for chronic stress indicators in shrimp farming. And Nofima, which is a research institute in Norway, has found that bioluminescence could be used as an indicator of stress in aquaculture.

And secondly, we want to have at least one RAS farm that has (counterfactually) committed to Precision Welfare to optimise for these welfare outcomes. We've already had some promising conversations in this space, including with companies in Singapore, Germany, and the US. 

We’re also now members of the Global Dialogue on Seafood Traceability, working with other organisations to try to get welfare parameters included as part of seafood traceability standards.

Absorbency Plans

Great - now you have an overview of Shrimp Welfare Project’s default trajectory and vision for 2030, I finally want to highlight a number of ways we think we can productively absorb more cash.

~$50k-250k+

Scaling the Humane Slaughter Initiative (High)

The first is what has essentially been our default trajectory for funding over and above our funding gap for the last year or so, and that’s Scaling the Humane Slaughter Initiative. Our framing for every additional dollar up until this point has been that we’ll use it to buy more stunners. 

This idea is nice and clear to communicate, though we want to add a bit more nuance to it now, in that additional funding may not go directly to a specific stunner, but instead we plan to use additional funding to scale the Humane Slaughter Initiative in a way that maintains cost-effectiveness. 

This means for example, that we could use the money to expand the Humane Slaughter Initiative team, such as hiring additional retail engagement leads, or additional in-country coordinators, like in Latin America or even in China. 

We also think our previous self-imposed rule of only buying a single stunner per producer is unnecessarily cumbersome, and we’re more likely to achieve our tipping point quicker (and thus pass costs onto industry quicker), if we can deploy more stunners faster, and have therefore decided to lift this rule.

Traceability (High)

Our second idea is working towards a 3rd party verification program for stunned shrimps. This would likely be through the standardisation of a built-in counter for shrimp stunners (and the implementation of this in traceability standards) as well as acknowledged peer-reviewed best practice protocols. This badge could serve as a method of verifying that shrimps have been stunned in the first instance, but also could be integrated into wider certification schemes in the future and can enable retailers to demonstrate that they’ve met their commitments.

Shrimp Welfare industry Marketing Campaign, Conference, or Webinars (Low)

Thirdly, our 2030 Vision for Communications is that ‘shrimp welfare’ becomes normalised in industry spaces (similar to how concepts like Sustainability are now often considered a given in industry spaces). By default, we don’t have an allocated comms budget for this goal (outside of hiring a full-time Communications lead), but with additional funding, this vision could be assisted by the Communications Lead having a budget to do things like financing a marketing campaign, or funding a conference or webinars, or other similar tools to help legitimise shrimp welfare within the industry.

~$250k-1M

Large Stunner commitment (Medium)

Within the $250k+ range, the first idea is similar to “Scaling the Humane Slaughter Initiative”, but highlights that more cash enables more ambitious projects within this goal. For example, with over $250k, we could offer to buy 5+ stunners for a single producer in exchange for a unique opportunity (such as making a deal with a producer in Ecuador who supplies to the US, thus opening the door to the US market). Similarly, we could use a significant amount of cash to offer to stun the whole supply chain of a retailer / seafood supplier (adding some rocket fuel to our default “act fast” incentive to accelerate adoption).

New Stunners (Medium)

And the second is putting some cash behind the project of incentivising the development of new stunner designs to solve the bottlenecks we currently face. This might look like us paying for the development of a new stunner directly, or committing to buy a certain number ahead of time.

~$1M+

Creating Market Incentives or, Shrimp Stunning Credits (High)

This is the idea we’re most excited about at Shrimp Welfare Project to accelerate our impact.
However, the write-up of it ended up being very long and not in keeping with the brief style of the rest of this post. We've therefore written up this idea in a separate post. 

We also think it perhaps makes sense to have a separate comments section for this idea anyway, as it's the idea we're most keen to solicit feedback on.
Also for further clarification, this idea is in the $1M+ bracket as an “at scale” idea… the MVP and Pilot of this idea is more in the $50-250k bracket.

Supporting Us

Thanks for reading this far! If you're interested in engaging with our work further, here are a few ideas.

Stay Connected: The best way to follow Shrimp Welfare Project's progress is through our Newsletter, which we publish every 1-2 months. We share updates on corporate commitments, research publications, events, job opportunities in aquatic animal welfare, and other relevant resources. For more frequent updates, follow us on LinkedIn, Facebook, and (new) Instagram, where we also feature our "Shrimp Fact of the Month". We also now have an online shop, if you want to wear your (Shr)Impact on your sleeve!

Amplify Our Impact: Every additional dollar enables us to expand our impact for billions of farmed shrimps. Whether you're interested in funding our Humane Slaughter Initiative, supporting our Sustainable Shrimp Farmers of India program, or helping us develop market incentives, we have shovel-ready projects at various funding levels. Our absorbency plans detail how additional funding can accelerate our path to industry-wide adoption of humane practices by 2030. You can donate to Shrimp Welfare Project here or reach out to me at aaron@shrimpwelfareproject.org.

Connect in Person: I'll be attending AVA (US) and EAG London in the coming weeks. If you're also attending, I'd love to meet for a 1-on-1 about our work and vision for improving the lives of billions of farmed shrimps!

1. ^{^}

   Note the "per year" impact of this intervention is less clear than of the stunners work, as sludge slowly reaccumulates (unless the farmer continues to remove sludge on a regular basis)

2. ^{^}

   ~100,000 (shrimps per acre) x 3 (crops per year) = ~300,000 shrimps
   $90 per acre = ~3,333 per $ p.a.