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Our Upcoming Test for Improving Dissolved Oxygen

Updated: Jul 29


As part of our strategy for building Version 2 of our Welfare Standard, we are conducting a small-scale test into the efficacy of changing feed quantities to help improve dissolved oxygen. This blog post summarizes our plans and reasons for conducting the test.


Picture of feed bags drying. These bags are suspended in the water, where carp will access the feed through small holes on each side.


Objective

  1. Test the hypothesis that reduced excess feed will improve dissolved oxygen.

Sub-objectives:

  1. Identify a feeding quantity that will fulfill Objective 1 and not negatively affect fish welfare or growth.

  2. Produce a case-study based impact evaluation of setting a baseline feed quantity as a change mechanism for volatile dissolved oxygen


Test Overview

Six to ten farms (ponds) will be chosen to participate in a test where half will be randomly assigned to control and the other half assigned to treatment. Treatment farms will receive a quantity of feed based on the body weight of the fish inside the pond (see below). This new feed rate will be in line with existing literature and expert opinion, which suggests a reduced quantity is better compared to normal farmer practice. Control ponds will see the farmer decide the feed quantity as they would ordinarily.


This test is part of our process of assessing change mechanisms related to improving dissolved oxygen. It is built to be an early-stage examination of the efficacy of reduced excess feeding as a method of improving dissolved oxygen, as well as to test our hypothesis that poor dissolved oxygen is a product of high phytoplankton levels, which itself is a product of eutrophic conditions facilitated by nutrients from the feed.

Table of feed quantities based on fish size to be used in the test


High-Level Timeline

June 2022

  • Draft protocol.

July 2022

  • Initiate pre-test (protocol tested with one farmer in order to identify flaws early).

  • Interview farmers on their views on the test and what incentives (if any) FWI will be required to provide to incentivize compliance.

August 2022

  • Survey farmers and identify 100 that are eligible to participate.

  • Identify a total of 6-10 farmers who are interested and eligible to participate.

  • Randomize into treatment and control groups.

  • Finalize protocol.

September 2022

  • Test farmers sign the contract.

  • Initiate test.

December 2022

  • Conclude test, or decide to continue for longer if needed.

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