How carp behave beneath the surface

I have spent plenty of time underwater with carp. Sometimes I have been fishing, photographing or just watching. My observations have confirmed that some fish behaviour patterns are exactly the way we thought they are but many things are also completely different.

Carp fisherman consider their favourite fish to be shy and clever. In my experience it is one of the most man-friendly fish.

WRONG: Carp are shy and suspicious

Many carp fisherman consider their favourite fish to be shy. Myy experience is that carp behave very differently from fishery to fishery. Somewhere they might be very confident and curious but in a different fishery they could keep their distance from you. In some fisheries they are so scared of you, that you never see them and you can see only stirred sediment when you come 10 metres from them. But they are definitely one of the most “diver friendly” fish. They are very curious. I never search for carp under the water as I know that they will usually find me, swim around me and follow me like dolphins. An underwater camera on a tripod is nothing suspicious for them. They have no problem even to eat in your company.

Carp respond to the groundbait very quickly

TRUE: Pre-baiting works

I have done many experiments. For instance I left my underwater camera on a tripod for some time without any groundbait. The surrounding area had been attractive for the fish when the sediment were stirred. When the sediment settled down they quickly lost interest even in the camera. The fish came back when I put some groundbait in. They have responded better or worse to various groundbaits, but they have for sure confirmed that it works. The longer I have pre-baited the more confident the carp were but also the more other fish species were attracted including predators. Carp have also responded to the groundbait very quickly. Sometimes I have only emptied the content of my groundbait box, kicked with my diving fin and carp were immediately heading to the food and camera. Also the hook bait has a much higher chance to be sucked in when there is groundbait around than if it is there alone.

The longer I pre-baited the more confident the carp were but also the more other fish species were attracted including predators.

WRONG: Boilies are the top carp food

There is general belief that carp immediately recognise the food with the highest nutritious value, eat it and ignore anything else. So they'd eat high nutritious value food first - boilies. My tests have shown that they eat various free offerings including the ones we don’t use as a bait, but they take boilies as a first bait very rarely. Actually I have seen it maximum of twice. Even if they have tasted the boilies they haven’t searched only for boilies but have preferred the other food. Boilies have been mostly the last food that remained before the camera and it was usually the bait on the hook no matter which rig used. But make no mistake, this doesn’t mean that boilies are a bad bait. It is an excellent bait because of the selectivity. The fact that boilies remains last at the bottom has both pros and cons.

If there is corn at the bottom, carp eat all the boilies, maggots, meat and so on only as a secondary product of corn consumption.

WRONG: Experienced carp are scared of yellow spots

Some anglers don’t use corn as they think, that yellow spots at the bottom are very suspicious and clever carp try to avoid it. It may be like that sometimes, but my underwater observations don’t confirm that. If there was one bait they have always preferred in warm water to the other ones that was corn. If there is corn at the bottom, carp eat all the boilies, maggots, meat and so on only as a secondary product of corn consumption. But again it doesn’t mean that it is the best bait as it isn’t selective. Not only do carp love corn but also many other fish species do too.

TRUE: The rig matters

All the underwater footage that I have made has clarified that the hook bait is, on average, more than twice in the fish's mouth before you get any bite! Sometimes you catch all the carp who touch your hook, sometimes the fish so cautious that you have nearly no chance to have a run. I have repeatedly changed a rig based on the fish's behaviour and quickly landed a fish. No rocket science rig changes were necessary. It was usually sufficient to lengthen the Hair, decrease the hook, soften or make stiffer the braid or shorten the hook link.

You could see that carp were cautious sometimes when they were facing a dangerous situation that they have experienced in the past but that was only sometimes.

WRONG: Carp are clever fish

I had the opportunity to watch same carp two years ago. Sometimes I could watch the same fish every day. Each carp is different and you realise something about their behaviour this way. They have surprised me how much they can eat, how brave they are, how they get in a routine, but I don’t remember a moment when I could consider them as clever fish. They sometimes learnt based on their mistakes but it is not always like that. When filming the fish I made fishing mistakes on purpose to do proper experiments. You could see that they were cautious sometimes when they were facing some dangerous situation that they have experienced in the past but that was only sometimes and they have never been really clever.

WRONG: It is impossible to get a run during many summer days

Many carp fisherman think, that it is impossible to get a run during many summer days. My experience is that if the localisation is done properly you can always get a run. You will be surprised how many “dead zones” without any fish there are in the lake and how there is a high density of fish at some other spots. And you can immediately use it in your fishing. I can show you many video clips where the carp go in to a feeding frenzy when the air temperature is 35 °C. The issue is that people usually shoot with blank cartridges. They fish distant spots when the carp are hidden in 0.5 m depth close to their bank. They fish from the bottom when a Zig Rig presented in the middle of the water column would work. Many of the fish spend all summer in one area.

TRUE: Carp are competitive when feeding

Some fishermen believe in a competitive strategy when the fish are feeding. They believe that fish fight to get to the food and the more aggressive and bigger species push out the other species. It is with some respects under the water like that. You can see roach, rudd and other silverfish leave the pre-baited area immediately when the carp are coming, but the carp doesn’t need to be aggressive. The silverfish know their position as well as when they meet a predator and leave voluntarily. But they don’t swim away to the other side of the lake. They keep very close to the carp tail. When they leave the spot they immediately jump in. You can see under the water mixed shoals e.g. of carp and tench feeding together but I had a feeling that the carp are not comfortable to eat when for instance a pike is around even when she is smaller than them. Beware that when you pre-bait some area for long the predators will come. I have sometimes documented one, two and even three pike before the camera at oncee. So If you don’t have a take for a long time it may mean that pike or even a catfish is around.

The colour of the bait is important but not in the respect we thought.

TRUE: Colour is important

The colour of the bait is important but not in the respect we thought. Some of the theories say that carp suck the fluoro boilies because they are different and attractive or they prefer natural coloured boilies because they are suspicious. Both of these may be true under some circumstances. But my experience is that the same fish may one day prefer the crazy colours and other day ignore them and eat the opposite. It doesn’t depend on the carp's experiences but on the present mood. Our goal is to guess in which mood he is in…

Main lines in the water column really spook carp.

TRUE: Main line in the water column spooks fish

The theory says that the more main lines in the water the more carp are spooked and move away. We are facing this during the carp fishing competitions when the majority of carp move to the area without any lines. It's even worse when you don’t use backleads and the mainline sticks up in the water column close to the rig. My observations are that the carp are sensitive to the line in the water column. They stop feeding and carefully swim away from the area but they also come back soon, eat again but are more cautious. Of course during a competition when there are not only one or two lines but hundreds of them they are stressed and forced to leave somewhere else.

WRONG: All the underwater secrets will be lost

Some people hate modern technology because they are scared that all the underwater secrets will be lost and all fish will get caught as the fishing will be too effective. I don’t have this experience. All the secrets that have been revealed by camera have been replaced by other secrets and questions. The more you know the more you want to know and the more you enjoy your fishing. And what is more, you don`t need any expensive equipment for that. Swimming with carp is easy. You can try it this summer on your own. But be careful as you very likely became obsessed with swimming with carp.

I have been working long term on an underwater filming project documenting the observations I write about in this article. Here is a preview: “The Czech underwater – the secret of new gravel pit”

Radek Filip with the 11.9kg carp in the video above.