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ARA Program Updates: Adjusted Visit Frequency, Improved Measurement System, and Tentative Oxygen Findings

Updated: Jun 20

FWI’s farm program, the Alliance For Responsible Aquaculture, is now approaching its third anniversary. In that time, it has onboarded 195 farms—135 of which are still active in the program today—and improved the lives of an estimated 1.8 million fishes.

Given the novel field that is Indian major carp welfare, this program has and continues to make significant changes to how it runs. This post discusses two of the most recent ones, which were rolled out in March 2024:

  1. An adjusted farm visit frequency, which we implemented to shift resources to the farms that exhibit a greater proportion of issues.

  2. An improved dissolved oxygen (DO) measurement system (the Winkler method), which we implemented to increase the accuracy of our DO measurements.

Relatedly, in the three months we have been using this more accurate DO measurement system, we have found DO levels to be higher (better) than previously measured. While this finding is still tentative, we discuss some of its implications below.

Our then-ARA team member, Vivek, at one of the first ARA farms three years ago. 

Vivek is now the Fish Welfare Expert at FWI’s R&D department.

How the ARA Currently Helps Fishes

Before discussing the changes, we wanted to first summarize the ARA’s current approach (readers already familiar with this can skip to the next section).

Farmers who join the ARA commit to lower stocking densities (3000 fishes per acre at the grow-out stage¹) and to maintain water quality in our required ranges. They aren’t provided with any immediate incentive to do this—rather, they generally seem to see the value in improving practices in a way that will a) potentially lower morbidity and mortality rates, and b) give them access to the regular free water quality monitoring our team provides.

Once farmers have enrolled, we visit their farms regularly to take measurements, and, where there are issues, to provide the farmer with corrective actions. An outline of this process can be seen below:

The process of helping fishes through water quality improvements at the ARA.

For more information on this process, see our Impact Page.

Programmatic Improvement # 1: Adjusted Visit Frequencies

In the previous ARA model, we visited every farm once a month. However, the rate of poor water quality issues is not evenly distributed amongst farms: Some have much many more issues than others. But under the previous model, farms with lower rates of water quality issues were visited as frequently as those with higher rates.

In order to increase the number of water quality issues we are able to detect (and thus to hopefully enable us to help more fishes), in March 2024 we adjusted our visit frequency to different farms based on their rate of prior issues. Now, farms with higher rates of past issues are visited more frequently. The different grouping of farms and their adjusted visit frequencies are listed in the table below:


Water quality out of range 

in the last five measurements 

Adjusted visit frequency (Eluru)

Adjusted visit frequency (Nellore)


3 or more 




Every 3 weeks

Every 2 weeks


1 or less



The farm groupings and their corresponding visit frequencies. Eluru and Nellore are the two different regions where ARA farms are located. Note that the difference in Group 2 frequency between our programming regions Eluru and Nellore are due to differences in farm set-up and their historical prevalence of poor water quality issues.

Farms are sorted into different groups every month, ensuring that our visit frequency is responsive to the changing (and hopefully, improving) practices on a given farm.

Programmatic Improvement # 2: Improved Dissolved Oxygen (DO) Measurement System

Dissolved oxygen (DO) is a crucial water quality parameter for fish welfare, and thus amongst the most important measurements we collect at farms. Initially, we monitored DO using handheld meters (primarily this one; also see the picture of Vivek above). However, we later found them to be less accurate compared to the Winkler titration method, which we then subsequently switched to.

We began a one-month trial of the Winkler method on February 14, and after we found it to be promising we rolled it out completely in Eluru (one of our two regions; we didn’t roll it out in the other because we wanted to test its suitability for field-based operations first). We expect the Winkler method will enable more accurate DO measurements going forward.

ARA Fish Welfare Expert Vivek (middle) trains Data Collectors Sanjay (left) and Nagaraju (right) on the Winkler method, a more accurate method for measuring dissolved oxygen.

Tentative Dissolved Oxygen Findings After Implementing Programmatic Improvements

Over the three month period we have been using the Winkler method we have observed an unexpected change in the measured DO levels. Specifically, the percent of out-of-range DO measurements was on average 17 percentage points lower in those months compared to the corresponding months in 2023. The table below displays these figures:


March ‘23

March ‘24

April ‘23

April ‘24

May ‘23

May ‘24 (until May 27)

% of DO measurements out of range







The percent of dissolved oxygen measurements out of range in different months of 2023 and 2024. In 2023, we took measurements using a handheld meter; starting in March of 2024, we began taking measurements via the Winkler method.

The reduction we’ve observed in out-of-range DO measurements may have various implications. First, it may mean that there is actually a lower prevalence of welfare issues than we previously thought.

Second, it is some evidence that our adjusted visit frequency (programmatic improvement # 1 above) has not yet proven successful at enabling us to identify more issues. It is currently unclear to what extent this is caused by the Winkler method measuring DO levels as higher (more in-range) than the handheld meters, vs there being some flaw in our new visit frequency system, vs some other factor that we’re not currently aware of.

As of now, we believe we need more data to determine a probable cause for these changes. We’ll keep our blog posted as we resolve these questions—stay tuned for our next post!


Are you an Indian national excited about fish welfare and working with farmers in the field? Consider joining us as a Data Collector at FWI’s Eluru office.


¹ We think it is appropriate to measure densities in units of area rather than volume because most farms are on average the same depth, but this is something we are looking into further.

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