When Do Carp Spawn in The UK?

when do carp spawn uk

If you are wondering when carp spawning occurs in the UK, you are at the right place. The short answer is that they tend to spawn as early as April, and some would go as late as August. However, most of carp spawn between May and June. If you are looking to understand the intricacies of carp spawning, there is so much more to learn, and we will cover everything in this article.

Below we explain everything you need to know about carp spawning behaviour.

Recognising Carp Spawn Season

Carp exhibit particular behaviour during spawning season, making it easy for you to recognise when they start spawning. Below we outline some tell-tale signs that you can look out for to tell when it’s their time to spawn.

Fish Following Each Other and Thrashing in Shallow Water

Fish shoal up occasionally throughout the year. However, this behaviour gets slightly adjusted when it is spawning season.

You will likely see a female fish that is plump leading the way, and it will be followed by smaller, leaner fish with larger fins than the female. These are usually the male fish that will fertilise the eggs after they have been laid.

You are likely to notice this happening in areas where there is shallow water and weed. This behaviour is usually because the fish like to lay eggs in places they can use as shelves for fertilised eggs. If the carp seem to be thrashing around or jumping, they are likely doing this to induce the female to lay eggs which they will fertilise with their milt (sperm).

how long do carp spawn for
Carp crashing into each other as they spawn.

As someone new to carp fishing, it can be challenging to recognise the spawning season. However, experienced anglers have often seen it before and know when it’s time to reel their rods in and let the fish do what they’ve got to do.

Aggressive Carp

Carp often appear to be fighting during spawning season. However, what you see is male carp trying to get into position to catch the release of eggs from the female carp. There can be up to seven males fertilising the female’s eggs.

Spawning will likely happen over a few days. Once the eggs are fertilised, the micropyle will close, absorb water and enlarge before the eggs become sticky.

It’s this aggressive behaviour that leads to cuts, dislodged scales and other marks on the carps body following spawning. For that reason, you should always carry some good carp care treatment with you to apply to any spawning cuts and marks.

carp spawning marks
Carp with marks that are most likely from recent spawning.

Presence of Spawning Nodules

You will recognise spawning nodules as small spots and lumps that can be seen on the pectoral fins and head of the carp if you happen to catch one that is close to spawning.

The nodules are rough to the touch but do not affect you in any way if you touch them. If you notice these nodules, you can know that spawning is imminent.

No Response to Bait

Carp tend to feed less when they are spawning throughout Spring and Summer. Therefore, it is unlikely that they will respond to bait if you try to fish at this time. Instead of trying to catch carp, you can just watch the spawning fish. It’s very rare that you get the opportunity to see such fish up close, so reel your rods in and leave them to it.

Most carp venues will now close for the duration of spawning. However, after the spawning season, carp will be starving and it’s a great time to head back out in search of a few fish.

When Exactly Do They Spawn?

As we have already highlighted above, fish spawn from April to August, which is typically the later stages of spring to late summer. The timing will depend on factors including the climate and weather, which is why you will notice that the UK government still adhere to the close season on the rivers. It is best to leave the carp alone at this time to allow them to spawn.

Carp Spawning on Nash Church Lake

Spawning will happen when a female carp reaches sexual maturity. This will most likely happen when the carp is two years old, but this can vary depending on how much food they will receive, the availability of oxygen, and water temperature.

They will ideally start spawning when the water reaches a temperature of 18°C. This might happen earlier in the year but might not last long as the temperature quickly falls below 18°C again. If this happens, the carp may continue spawning but with lower success rates.

Note that carp will start spawning when temperatures rise. Still, it is unethical to try fishing at this time because the carp should be allowed to reproduce without human interference, and they are vulnerable.

How Does Spawning Happen?

The female carp will ovulate under the right conditions. The eggs will hydrate, and the female will lead the males to where the eggs will be laid. The males will bump into the female, stimulating them to release the eggs. The males release milt at the same time, fertilising the eggs.

A female carp produces around 100,000 eggs daily per kilogram of body weight. Some may lay up to one million eggs over the spawning season.

However, since nature has a way of regulating itself, you will often find that the success rates of the spawning season will depend on the current water population. The eggs are vulnerable and can be preyed on by fish, bacteria, and algae. Therefore, they may get eaten before they hatch. If the water has a high carp population, more eggs are likely to get eaten, which means fewer of them hatch and vice versa.

The eggs will often hatch three to eight days after fertilisation, depending on the temperature of the water.

How much weight do carp lose after spawning?

It usually depends on how big the carp are but they are known to lose around 15% of their body weigh after spawning.

After successful spawning, you’ll often find the carp are much leaner, being wider around their head and thinner towards the tail.

Following spawning, they’ll be well up for some bait and it won’t take them long to put the weight back on ahead of the long, cold winter.

A lean, spawned out mirror which should usually weigh about 5lb more than it did here.

Conclusion – Carp Spawning in the UK

The carp spawning process happens between April and August. During this time, the male and female carp will produce and fertilise eggs that will soon produce fry. These fish will eventually grow into carp that will be integrated into the ecosystem.

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