NASA Tournament Lab


Protecting the Natural Flavor of Catfish

Blue-green algae can cause off-flavors in farmed catfish, leading to costly harvesting delays. How can USDA-ARS eliminate these off-flavors?

Challenge Overview


The United States Department of Agriculture’s Agricultural Research Service (USDA-ARS) seeks to identify methods or technologies capable of reducing or eliminating instances of off-flavor in farmed catfish raised in ponds. The Protecting the Natural Flavor of Catfish Challenge will award a total prize purse of $60,000 for the most compelling approaches for preventing or eliminating these off-flavors which cost farmers millions of dollars each year. 


The Problem

Exposure to certain varieties of blue-green algae, also known as cyanobacteria, can cause undesirable changes to the flavor of farmed catfish. This off-flavor delays the harvest for roughly 50% of catfish ponds each year in the United States. Annually, this delay alone can cost catfish farmers millions of dollars in lost revenue and expenses to maintain the fish until flavor quality returns.

USDA-ARS scientists, as well as industry experts, have worked for decades to find new solutions for this problem. While methods to combat off-flavor in catfish have been identified, they are only partial solutions, requiring repeated treatments to reduce off-flavor occurrence, and providing no guarantee of successfully eliminating off flavors. Frequently, preventative treatments are not applied; when off-flavor is detected, harvesting of the pond is delayed as the farmer begins the treatment process and waits for flavor quality to be restored.


The Challenge Breakthrough

The USDA-ARS seeks to identify methods or technologies capable of reducing or eliminating instances of off-flavor in farmed catfish raised in ponds. Innovations that address pre-harvest management techniques or pre-/post-harvest treatments are of interest. Proposed approach must reduce off-flavors in catfish to a level that is undetectable to professional flavor testors.


What You Can Do To Cause A Breakthrough

  • Click ACCEPT CHALLENGE above to sign up for the challenge
  • Read the Challenge Guidelines to learn about the requirements and rules
  • Share this challenge on social media using the icons above. Show your friends, your family, or anyone you know who has a passion for discovery.
  • Start a conversation in our Forum to join the conversation, ask questions or connect with other innovators.

Challenge Guidelines


In the United States, nearly 400 million pounds of farm-raised Channel and Blue catfish are harvested annually, primarily in the Mississippi delta region. Prior to harvesting, sample fish are captured and tested to ensure high quality. One of the most important evaluations performed is taste. Professional food tasters briefly cook the fish in a microwave and taste it, without seasoning or other preparations, in order to evaluate the innate flavor of the fish.

Unfortunately, exposure to compounds from varieties of blue-green algae, or cyanobacteria, can cause unpleasant tastes in catfish, described by taste testers as “earthy” or “muddy”. If a sample fish is found to have these off-flavors, there are several options.  The pond can be left alone and fish retested after several months to see if flavor has improved, or the pond water must be treated to remove these algae before harvesting can proceed. Treatments can take weeks to months before they are fully effective at removing the off-flavor from the fish. Both approaches result in lengthy and costly harvest delays.

Research has identified several effective methods for treating affected catfish ponds but these methods are generally not implemented until an off-flavor fish is found. One potential method is to relocate the entire school of catfish to a new pond with water uncontaminated by blue-green algae. The downside to this, apart from the additional cost to the farmer, is the additional stress placed on the fish - stress which itself can impact the flavor and texture quality of the harvested fish. Another treatment method is the application of algicides like copper sulfate or diuron to the affected pond water. While effective, public perception of additional chemical usage can limit deployment, as can the potential for unintended consequences for the overall pond ecology.

A Global Aquaculture Alliance article estimates that US catfish farmers lose as much as $47M a year due to off-flavors.  Since additional costs caused by off-flavor can account for as much as 17% of total production costs, the development of new tools to help catfish farmers maintain the natural flavor of the catfish is critical.

USDA-ARS, working in conjunction with the farmed catfish industry, has researched this topic extensively and believes that input and insight from the global innovation community can positively impact this persistent problem.

USDA-ARS has identified three different points in the process where new methods or technologies could be implemented to address off-flavors in catfish:

  • Pre-harvest management practices: new methods/technologies that work to prevent the development of off-flavor causing blue-green algae in catfish ponds
  • Pre-harvest treatment technologies: new methods/technologies to remove off-flavor from catfish once it has been detected in sampled fish prior to harvest
  • Post-harvest treatment technologies: new methods/technologies that would allow processors to remove off-flavors from catfish after harvesting

Ideally, proposed approaches will meet the following performance criteria:

  • Reduce or mask off-flavor compounds to a level undetectable to professional flavor testers (~100ng/kg)
  • Cost the same or less than current treatments (currently ~$177/acre-ft, which translates to ~$8000 per pond. The average catfish pond is a 10-acre pond, 4 ft deep)
  • Maintain catfish well-being
  • Be neutrally or positively viewed by consumers
  • Environmentally safe for both pond and surrounding areas
  • Safe for operators and other personnel

USDA-ARS believes that exciting new technologies and innovations are possible and welcomes the global community to provide insight in all forms to this topic, regardless of approach.



ARS will award up to $60,000, to be split among the top-scoring and eligible submissions, with at least one prize winner in each category. Each prize awarded will be up to $30,000 and no less than $5,000.

  • Category 1: Pre-Harvest Management Practices
  • Category 2: Pre-Harvest Treatment Technologies
  • Category 3: Post-Harvest Treatment Technologies

Furthermore, it is the intention of ARS to facilitate the implementation of new technologies in the field to the benefit of the industry. To that end, ARS will consider post-challenge discussions between ARS scientists and winners, engaging with winners in joint publication efforts or in collaborative work to further develop proposed technologies. The USDA-ARS Office of Technology Transfer will assist with cooperative research agreement options as warranted.



Open to submissions              August 20, 2020

Submission deadline               December 15, 2020 @ 5pm ET

Judging                                           December 15, 2020 - February 23, 2021

Winners                                         Announced March 2, 2021


How do I win?

To qualify for an award, your proposal must, at a minimum:

  • Prevent, eliminate, or mask off-flavor in farmed catfish
  • Have supporting data, or a strong scientific rationale
  • Be safe for the fish, the environment, and users


Judging Criteria

Section DescriptionOverall Weight
Impact on Off-Flavor: Describe the impact your technology has on off-flavors. Does the proposed approach provide for a positive impact on off-flavors?25
Innovation: Describe how your technology is different from the competition/alternatives. Does the proposed approach use a novel technology or an existing technology used in a novel way?20
Evidence: Describe the evidence to support the efficacy of your approach. Do the presented data and/or scientific rationale support the claims of elimination of off-flavors in farmed catfish? 20
Environmental Impacts: Describe the environmental impacts of your technology. How does the proposed technology avoid negative environmental impacts?15
Scalability: Describe how your technology could be implemented in the field. Can the proposed technology be deployed at industrial scales? Would the proposed technology be cost-effective at scale?15
Technical Maturity: Describe the technical readiness of your technology. How developed is the proposed technology? 5



Participation Eligibility:

The Prize is open to anyone age 18 or older participating as an individual or as a team. Individual competitors and teams may originate from any country, as long as United States federal sanctions do not prohibit participation (see: If you are a USDA-ARS employee, a Government contractor, or employed by a Government Contractor, your participation in this challenge may be restricted.

Submissions must be made in English. All challenge-related communication will be in English.

No specific qualifications or expertise is required. Prize organizers encourage outside individuals and non-expert teams to compete and propose new solutions.

To be eligible to compete, you must comply with all the terms of the challenge as defined in the Challenge-Specific Agreement.

Registration and Submissions:

Submissions must be made online (only), via upload to the website, on or before 5:00pm ET on December 15, 2020. All uploads must be in PDF format. No late submissions will be accepted.

Intellectual Property Rights:

As detailed in the Challenge-Specific Agreement – Innovator agrees that: (i) all Submissions become The United States Governments’ property and will not be returned; and (ii) Challenge Sponsor and its licensees, successors and assignees have the right to use any and all Submissions, and the names, likenesses, voices and images of all persons appearing in the Submission, for future advertising, promotion and publicity in any manner and in any medium now known or hereafter devised throughout the world in perpetuity.

Title in all intellectual property rights, if any, and all inventions, patents, patent applications, designs, copyrights, trademarks, trade secrets, software, source code, object code, processes, formulae, ideas, methods, know-how, techniques, devices, creative works, works of authorship, publications, and/or other intellectual property (“Intellectual Property”) developed by Innovator as part of the Submission will remain with Innovator, subject to the following conditions:

If Challenge Sponsor notifies Innovator that Submission is eligible for a Prize, Innovator will be considered qualified as a finalist (“Finalist”). To receive a Prize, Finalist must agree to grant The United States Government an irrevocable, royalty free, perpetual, sublicensable, transferable, and worldwide license to any Intellectual Property developed by the Innovator as part of or demonstrated by the Submission and to use and permit others to use all or any part of the Submission including, without limitation, the right to make, have made, sell, offer for sale, use, rent, lease, import, copy, prepare derivative works, publicly display, publicly perform, and distribute all or any part of such Submission, modifications, or combinations thereof and to sublicense (directly or indirectly through multiple tiers) or transfer any and all such rights. Notwithstanding granting The United States Government such license for any Intellectual Property demonstrated by the Submission, Finalist retains title (e.g., ownership) of such Intellectual Property.

Additional Information

  • By participating in the challenge, each competitor agrees to submit only their original idea. Any indication of "copying" amongst competitors is grounds for disqualification.
  • All applications will go through a process of due diligence; any application found to be misrepresentative, plagiarized, or sharing an idea that is not their own will be automatically disqualified.
  • All ineligible applicants will be automatically removed from the competition with no recourse or reimbursement.
  • No purchase or payment of any kind is necessary to enter or win the competition.
  • Void wherever restricted or prohibited by law.
Updates 4

Challenge Updates

Teamwork Makes the Dreamwork

Sept. 17, 2020, 9 a.m. PDT by Natalie York

Have you thought about a forming a team to compete in the Protecting the Natural Flavor of Catfish Challenge?

Teams can be formed directly on the challenge page by connecting in the forum.

Some of the advantages of forming a team include:

1. Accountability

Those deadlines are less likely to get away from you when you’re working with a group.

2. Shared workload

You know the old “divide and conquer?”  It works well for challenges! By finding a solid collaborative stride, a group of just three people can churn out a lot more than one person working alone.

3. Camaraderie

It might be hard for other people to relate to your lone wolf journey toward incentive competition conquest, but your team will be right there with you! A source of inspiration, motivation, and perhaps even fire-under-your-butt lighting, teammates can provide a huge emotional advantage. Just think - new internet friends!

4. Specialization

Maybe you’re a real visionary with an incredible concept, but are stuck on how the “nuts and bolts” fit together? Yeah, YOU need a team. Teammates who have the skills and special working knowledge can be a huge resource. And the benefits go both ways!

Rome wasn’t built in a day. Your team will take some time to come together, so be sure to get ahead of it and start recruiting, reaching out, and networking about the challenge now. The forum is a great place to start. Also, feel free to browse the entire HeroX Community by specialization by checking out 

All About the Forum

Sept. 3, 2020, 9 a.m. PDT by Natalie York

Maybe you've had some questions, thoughts, or ideas about the challenge so far -- but you're still wondering where to take them? In fact, there's a quick, easy-to-use way to ask questions and start conversations about the Protecting the Natural Flavor of Catfish Challenge: the challenge forum.  

Interested? Simply go to the forum to see what people are already saying. If you'd like to start a new conversation, click "New topic" (pictured below) and begin crafting your message. 

This is a great way to start connecting with other community members around different aspects of the challenge, gain insights, and even collaborate! Keep in mind that HeroX regularly checks in on the forum, so it's also a great way to get in touch with us about any questions (or suggestions) you might have. 

Hope you found this helpful! 

Best of luck, and have a great weekend.

A Resource to Get You Started

Aug. 26, 2020, 2:27 p.m. PDT by Natalie York

We're happy to share a very helpful resource that USDA has provided us with: 

Off-flavors in pond-grown ictalurid catfish: Causes and management options, researched and written by Craig S. Tucker and Kevin K. Schrader.

This article will provide you with a comprehensive understanding of how off-flavors occur and current tools available to manage off-flavors.

To download this article, head over to the resources tab:

While your there, feel free to add additional resources that you have utilized to share with other innovators.

Welcome to the Community

Aug. 24, 2020, 6 a.m. PDT by Natalie York

Welcome to the Preserving the Natural Flavor in Catfish Challenge. We're happy to have you following along and participating!

To get started, head back to the challenge page and click ACCEPT CHALLENGE. Once you accept the legal agreement, you will officially be signed up as a competitor!

Remember, if you're feeling stuck, the forum is a great resource to collaborate with others and get answers to your specific questions.

Good luck!

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