Barometric is the pressure within the atmosphere of Earth and is the weight of the atmosphere as it is pressed down on everything on Earth, constantly changing from low to high. But what does this have to do with fishing and how it affects it? It is because fish can feel the weight of the air as it presses down on the water. They sense the pressure changes in the air due to their swim bladder, which controls how buoyant they are. The barometric pressure helps tell you how the fish will be feeding and acting.
How Barometric Pressure Affects Fishing
During Low Pressure
Low pressures do not last that long so once the falling pressure has stabilized to a low-pressure system you will find that the fish are going to retreat to the deeper water. They do this to equalize their swim bladder. The fishing will slow down during this time because they have a lack of interest in feeding because they are uncomfortable. They will feel the results of the low pressure more if they are in shallow water so that is why they go deep. If you want to catch any fish during this time you will need to use slower-finesse presentations in the deeper water.
When you are trolling, downsize your lures and slow down. The fish are not inclined to use a lot of energy to chase the bait. Try a nymph pattern that is drifted just off the bottom in slack water at the end of a run. In the smaller mountain lakes, you should use small flies that are suspended just off the bottom in the deeper water. This could help encourage an opportunistic fish to strike at your bait or lure.
Falling Barometric Pressure
As much as a day in advance, fish can sense an oncoming storm. They react by becoming very aggressive because they understand that feeding during storm periods, or low pressure, can be challenging for them. You recognize that the barometer is going to drop because of clouds that are starting to roll in so this is a great time to use presentations and fast-moving bait.
If you are trolling a large lake, make sure that you use fast trolled lures like plugs. The reason is that they will cater to aggressive feeding. If you are fishing from a river, use minnow patterns or large streamers in a fast run. The active trout will chase down your fly and catch themselves on your hook. This is one of the best times for you to go fishing if you want to catch fish.
Once the barometer pressure has stabilized you can revert to average again. This is a good time to try out some new fishing techniques because the fish are back to their normal feeding habits. This is when the fishermen will have to search for the fish using other natural elements like the current or wind to help find the fish. This equals fair weather and normal fishing and a great time to not only try out new techniques but also to test baits and lures.
After the storm has passed the pressure will start to rise but the fish will still continue to remain slow so they can adapt to the pressure changes. It will take a couple of days for their feeding habits to get back to normal. As long as the water temperature remains cold, it will take the fish longer to adapt to the new temperatures. As the storm passes it seems to push food back into the water for the fish to feed on. When you are fishing a river, it can push a variety of insects for the fish to feast on. Use a terrestrial fly pattern to catch the fish.
When you are fishing larger water bodies and the pressure is rising, you will most likely find fish that are stacked up in the same time zone in the water column. It is a good time to irritate the fish by using some lure that provides vibration. You should also use irritant scents like anise and garlic to get those fish to bite. Use retrieved lures or slow trolling lures for this type of barometric pressure. It is not a good option to fish near the surface of large bodies of water as the fish will down deeper.
Why Some Fish are Affected by Barometric Pressure and Others are Not?
There are some fish that are more affected by barometric pressure, such as redfish, trout, grouper, tarpon, and snapper. The reason is that they have large swim bladders. The ones that are not usually affected are the ones with the small swimming bladder like the Spanish mackerel, dolphin, and wahoo. The reason is that the fish with a small swimming bladder have a body density that is close to the surrounding water so their comfort levels are not altered drastically.
The fish with the large swim bladders are affected because there is less pressure on their bladder so when there is not as much pressure squeezing it, it will expand a lot. As the bladders expand, the fish start to become uncomfortable so they try to relieve the discomfort by absorbing more gas in their bladders or they move lower in the water. They are not really worried about eating because all they want to do is stabilize the pressure in their bladder and feel good. Some will just settle on the bottom and ride out the changes. Luckily for the fishermen, low pressure usually does not last long.
The best time that you want to go fishing is when the barometric pressure is between 20.90 and 30.90 with the pressure falling rapidly. This is when you will find the fish feeding and most active. To check the barometric pressure, you can always check online but it is easier if you have one of those hand-held barometers so you can always know what it is, even when you are fishing.