Research reviewed by Gram found that biofloc technology did not speed up growth in American shad, which were smaller than control fish. However, the biofloc fish had higher muscle protein, more essential amino acids, and more arachidonic acid, suggesting better meat quality. The study was published in 2026.
Biofloc technology is a fish farming method that uses communities of tiny microbes to clean water and recycle waste into food for fish. A new study published in 2026 looked at how this method affects American shad, a filter-feeding fish. According to research reviewed by Gram, the fish raised with biofloc grew more slowly and ended up smaller than fish raised the standard way. However, their muscle had higher protein, more amino acids that give meat its taste, and more of certain healthy fats. The researchers found that the method did not improve growth overall. They concluded that biofloc farming needs to be adjusted for each fish species before it is widely used. The findings give fish farmers a clearer picture of tradeoffs, but they come from a single study and need further confirmation.
Key Statistics
A 2026 study published in Fish Physiology and Biochemistry found that American shad raised with biofloc technology had significantly lower final body weight and specific growth rate than fish raised in a control system, despite identical feed.
A 2026 study in Fish Physiology and Biochemistry reported that biofloc-raised American shad had higher crude protein, total amino acids, branched-chain amino acids, and arachidonic acid in their muscle compared with control fish.
According to research reviewed by Gram, a 2026 study of American shad showed that biofloc technology reduced lipase activity while leaving pepsin and trypsin activity unchanged.
The Quick Take
- What they studied: The researchers asked whether a fish farming method called biofloc technology, which relies on microbe communities to clean water and provide extra food, helps American shad grow faster and produce better-quality meat.
- Who participated: American shad, a fish that feeds by filtering tiny particles from water. Both groups were fed the same commercial fish food. The exact number of fish was not stated in the study summary.
- Key finding: Fish raised in biofloc tanks were smaller and grew more slowly than fish in standard tanks. Their muscle, however, had more protein, more amino acids that affect taste, and more arachidonic acid, a fat that the body uses in important ways.
- What it means for you: Biofloc farming may improve the nutritional quality of shad meat, but it did not make the fish grow faster. Anyone considering this method for this species should expect slower growth and test the approach on a small scale first.
The Research Details
The researchers compared two groups of American shad. The control group was raised in a standard fish farming system. The biofloc group was raised in water that contained communities of microbes. Biofloc systems use these microbes to break down fish waste and turn it into material that fish can eat, while also helping keep the water clean.
Both groups received the same commercial fish food and were kept under the same feeding conditions. This matching helped make sure that differences in results came from the water system itself rather than from what the fish ate or how they were fed. The team then measured body size, growth rate, digestive enzyme activity, immune and antioxidant markers, the activity of certain genes, and the nutritional content of the fish meat.
Because the study compared two groups side by side under controlled conditions, it can show cause and effect more clearly than a simple observation would. The team’s reported statistical threshold (P < 0.05) means the differences in growth were unlikely to be due to chance alone.
A side-by-side comparison with identical feed is a useful way to test a farming method. It isolates the effect of the water system, so farmers can see what biofloc does and does not change. This matters because many claims about biofloc come from studies on other species, such as shrimp or tilapia, and may not apply to filter-feeding fish like shad.
The study was published in a peer-reviewed scientific journal, which means other experts reviewed it before publication. It used a controlled comparison and reported statistical testing. However, the summary does not state how many fish were in each group, how long the study lasted, or the exact size of the differences. These details affect how much weight the results deserve. The study also tested only one species under one set of conditions.
What the Results Show
The most clear result was that biofloc fish grew less. Their final body weight, total weight gain, and daily growth rate were all significantly lower than those of control fish. In other words, the biofloc system did not help these fish get bigger faster, even though it provides extra food from microbes.
Digestion also changed. Fish in the biofloc group had lower activity of lipase, an enzyme that helps break down fats. Activity of pepsin and trypsin, two other digestive enzymes that break down proteins, did not differ between groups. This suggests that the fish’s digestive system responded to biofloc in a targeted way rather than changing across the board.
The biofloc fish also showed a different pattern of body signals. They had higher levels of one antioxidant enzyme, catalase, which helps protect cells from damage. They also showed higher activity of several genes linked to immune responses and growth, including IL-17, GH, and IGF-1. The control fish had higher levels of a different antioxidant enzyme, superoxide dismutase, and higher activity of IL-10, an immune gene that helps calm inflammation. These shifts suggest the fish’s body was adjusting to its environment, though the study summary does not explain what these changes mean for long-term health.
The most encouraging result was in the meat itself. Fish from the biofloc group had more crude protein, more total amino acids, more flavor amino acids, more branched-chain amino acids (which are important for muscle), and a higher essential amino acid index. They also contained more arachidonic acid. Taken together, these results suggest that biofloc may improve the nutritional and taste qualities of shad meat even though the fish were smaller.
The study found that biofloc changed how the fish’s body handled stress, immune activity, and growth signals. The higher levels of growth-related genes in biofloc fish are interesting because they point to active biological responses, yet these responses did not translate into bigger fish. This suggests that growth may be limited by factors beyond the genes studied, such as how much energy the fish gets from its food or how much it spends on other body functions.
The improved meat quality is also significant for consumers. Protein content, essential amino acids, and fats like arachidonic acid all affect how nutritious a food is. Flavor amino acids affect how meat tastes. Together, these results suggest that biofloc could be a way to produce shad with a better nutritional profile, even if the farming method does not boost total output.
Biofloc technology is often promoted for improving water quality and cutting feed costs, and many studies on shrimp and some fish species report better growth. This study adds to a growing body of evidence that results depend heavily on the species. Filter-feeding fish like American shad may respond differently because they naturally eat small particles and microbes from the water. The authors’ conclusion that biofloc needs species-specific adjustment fits with this broader view. Gram Research analysis suggests that claims of universal benefits for biofloc should be treated with caution.
The study summary does not report how many fish were used, which makes it harder to judge how reliable the differences are. It also does not state how long the study ran. A longer study might show different growth patterns, and a larger one might confirm or change the size of the effects.
The study tested only one fish species under one set of conditions, with one commercial feed. Results may not apply to other fish, other feeds, or other water setups. The changes in gene activity and immune markers were measured at one point, so they do not show whether these effects last or whether they affect health over time. Finally, the meat quality results describe nutrient content, not how the fish would perform in a full diet or affect human health in the real world.
The Bottom Line
Based on this study, biofloc may improve the nutritional and taste qualities of American shad meat, which is a useful finding for producers focused on quality. However, the study shows with reasonable confidence that biofloc did not increase growth for this species, so farmers should not expect faster or larger harvests from this method alone. Because this is a single study, the evidence is promising but preliminary. Farmers should run small pilot tests before making large changes.
Fish farmers who raise American shad or similar filter-feeding fish should pay attention, especially if they are weighing the cost and effort of setting up biofloc systems. Researchers studying sustainable aquaculture will find the species-specific results useful. Consumers interested in the nutritional content of farmed fish may find the meat quality results relevant. People who raise other fish species, such as shrimp or tilapia, should not assume these findings apply to their animals.
Fish farmers would likely need to run trials across at least one full growing cycle to see how biofloc affects size, meat quality, and costs in their own system. The study summary does not state how long the fish were raised, so exact timelines are unclear. Any benefits to meat quality would only show up at harvest, while changes in growth or immune health would be seen during the rearing period.
Frequently Asked Questions
Does biofloc technology make fish grow faster?
A 2026 study of American shad found that biofloc technology did not improve growth. Fish raised in biofloc systems had significantly lower final body weight and growth rates than fish in standard tanks, even when fed the same commercial diet.
Does biofloc farming improve the nutritional quality of fish meat?
The 2026 study reported that American shad raised with biofloc had higher crude protein, total amino acids, and arachidonic acid in their muscle. These results suggest biofloc may improve meat nutrition, though the study tested only one species.
What is biofloc technology in fish farming?
Biofloc technology uses communities of microbes in the water to break down fish waste and turn it into material fish can eat. It also helps keep water clean. Researchers say its benefits depend on the fish species being raised.
Is biofloc farming a good choice for every fish species?
Research published in 2026 suggests biofloc results vary by species. American shad, a filter-feeding fish, grew more slowly in biofloc systems. The study’s authors concluded that biofloc needs species-specific optimization before it is widely adopted.
Want to Apply This Research?
- Track each batch’s average body weight at set intervals, such as every two weeks, along with feed amount and water quality readings. Comparing biofloc and standard tanks side by side will show whether growth differs in your own setup.
- If you farm fish, set up a small pilot comparison with one biofloc tank and one standard tank using the same feed and feeding schedule. Log the results in the app so you can compare growth and feed use before scaling up.
- Keep a long-term record of growth, feed conversion, water quality, and harvest quality for each batch. Review the data every season to see whether biofloc continues to improve meat quality without reducing growth. Adjust feeding and water management based on what the records show.
This article summarizes a single research study on American shad raised in experimental fish farming systems. The findings may not apply to other fish species, farming setups, or feeds. This information is for general education and is not professional advice for commercial fish farming or human nutrition decisions. Consult a qualified aquaculture specialist or nutrition professional before making changes to a farming operation or diet.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.