Barometric Pressure Effect on Crappie Fishing By Bernard Williams

A majority of anglers including myself believe barometric pressure plays a major factor in the feeding activity of crappie. I have an uncle that swears “fish don’t bite when the barometer is falling”. I’ve disproved his theory time and time again. I decided to do some research on the subject and see what the scientists and their studies have to say about barometric pressure on fish.
While most studies that I could find were done on bass, it’s pretty much the same, because bass and crappie are of the panfish family. I could not find anything to prove my belief that barometric pressure changes cause fish to clam up and not feed. What I found was eye-opening; it was not the highs or lows that made the difference, it was the weather and sky conditions that saw significant increases in feeding activity. Scientists warn that not only barometric pressure, but other conditions coupled with pressure changes caused the increased feeding activity.

The Fish Studies

Dr. Ralph Manns, a fishery scientist and angling authority conducted a study in early 2013 and concluded, “One of the most persistent myths in fishing is that barometric pressure controls the activity of gamefish. Although many researchers have tried, scientific studies have been unable to demonstrate that such a relationship exists. Every scientific report we’ve seen, in which barometric pressure was studied, reached a similar conclusion: no direct relationship is evident. There is no way to isolate just barometric pressure influences from other weather conditions. Significant barometric changes are rare without accompanying changes in wind, temperature, and sky conditions”, says Manns.
Dr. Manns goes on to say, “The typical weather front is preceded by dropping barometric pressure and increasing cloudiness, while postfrontal conditions usually are clear skies, bright sunlight, and higher air pressure. Although barometric pressure might directly trigger gamefish responses, no mechanism for detecting these changes has been seriously postulated by scientists.”

Barometric Effects on Feeding and Fish Relating to Cover

Dr. Manns field study on feeding and how fish relate to cover during different pressure levels is outlined in the chart below:


Dr. Manns says, “The vast majority of our strikes took place when the barometer reading was neither particularly high nor low (between 29.30 and 29.70). High or low barometric readings, by themselves, were not consistently indicative of fish activity or catchability. Solunar influence and other factors may have affected the barometric data. These results don’t necessarily mean that falling barometers increase fishing success or that rising barometers increase offshore activity.”

Group-Up and Schooling Fish


“Schooling behaviors are apparently associated with increased feeding. When the barometer was high, 54% of the fish observed were aggregated (groups of 3 to 15), 12% were schooled (moving synchronously), while 44% were alone or paired. When the barometer was low, 57% were aggregated, 5% were schooling, and 38% were single or paired. When the barometer was rising slowly, 64% of observed fish were aggregated, none were schooling, and 36% were paired or alone. When barometric pressure was falling slowly, 53% were aggregated, 20% were schooled, and 28% were alone or paired. If it weren’t for other factors affecting fish activity, the data might suggest that a falling barometer, approaching storm, increasing cloudiness, or a combination of these and other factors increased feeding activity.”

Cloud Conditions

Dr. Manns results of cloud effects on feeding activity shown below:


Dr. Manns says, “We monitored the location, movement, and apparent feeding of fish under various cloud conditions. Under overcast skies, fish were observed farther than 46 feet from shorelines in 23 percent of cases, while 19 percent were offshore under broken skies (50-80 percent sky coverage), 33 percent under scattered clouds, and 32 percent under clear skies. When we analyzed the relationships between weather trends and fish proximity to cover, no trends appeared. Virtually the same percent held close to cover before and after a frontal passage, though more were found in cover after the front passed,” according to Dr. Manns.

What Really Effects Fish Activity

According to Dr. Mann’s study, “The only sure biological fact is that adult fish that have recently fed heavily and are digesting food tend to be inactive or neutral regardless of any environmental factor, including barometric conditions. The length of time since many of the fish in an area fed heavily and the time required to digest that meal are perhaps the most important clues to when a significant proportion of any fish population will next become active.”

Air Pressure Effects

Dr. Mann clearly states, “The possibility that air pressure alone controls fish behavior is considered, distinct limitations appear. A fish with a gas bladder needs only to swim up or down a foot or two to experience as great or greater a pressure change than that created by all but the largest natural pressure changes—typhoons and hurricanes. A fish might notice that it’s floating or sinking a few inches in response to a change in air pressure, but it experiences larger pressure changes as it changes depth a few feet while hunting prey or moving to a new location. If air pressure or depth changes, a fish with a gas bladder slowly and naturally adapts bladder pressure to reestablish equilibrium. Depth adjustment of a few inches easily re-establishes balance and makes it unlikely that fish sense pressure changes for long periods. Depth changes likely override the perception of small changes in air pressure.”

Conclusion

I know what you’re saying, what does this guy know. I presented the actual scientific study as is. You make your own conclusion. I do know one thing; if I want to go fishing, I don’t care what the barometric conditions exists. I’m going fishing, period. You make your own call. You have proven a scientific study that says, “It’s more reasonable and likely more accurate to consider weather and sky conditions rather than barometric pressure in explaining fish activity and inactivity”. Bernard - Magnolia Crappie Club