By Scotty Kyle
I am what some humans call a “common carp”. Scientists call me a Cyprinus carpio. I trace my lineage back 2 000 years to when the Romans first captured some of us in the Danube River and then started one of the first recorded aquaculture projects. My own ancestors have all stayed true to our forefathers in shape, form and colour, but those who were taken on the commercial route ended up as “mirror carp” – which have some very large scales amongst the normal sized ones – and “leather carp” who have large numbers of tiny scales. Some of the “domesticated” carp ended up in the far east and began a new line of “Koi”, but these are simply brightly coloured (and sometimes highly valuable), “common carp”, the same species as me and, given a chance, we can all breed together.
Our name has recently been changed from a common carp to the Eurasian carp. We are the freshwater fish that have had the greatest impact on the history of Europe, being seen by different groups of people as a massive threat, a great commercial species, an important food source, or an exciting fishing target. My original carp ancestors, from rivers entering the Black Sea 2 000 years ago, were and still are a dark golden coloured, elongated, torpedo-shaped, large fish. We can grow to 120 cm. (47 in.) and a record of 45.59 kg. (100.5 lbs.), but we are more commonly caught at 40-80 cm (15,8 -31.5 in.) and 2-14 kilograms (4.4-30.9 lbs.).
We are omnivorous, feeding on anything from aquatic vegetation to insect larvae and worms plus anything we find to be digestible in between. We often form quite large shoals, but larger specimens are usually found in groups of 4-7 individuals. We first spawn in spring each year and can produce 300 000 eggs per spawning, but, because we can spawn several times a season, large females can easily produce over 1 000 000 eggs per season. We are among the “top ten” freshwater fish species for aquaculture but are also listed officially among the world’s 100 “worst” invasive species.
The original distribution of Eurasian carp was from the Black Sea eastwards into Asia, but we have now spread, or been spread, into over 60 countries and all suitable continents. Current areas with high carp numbers are northern North America, a band across South America below Brazil, southern Africa and southern Australia. We are exclusively a freshwater species and generally prefer turbid (murky) waters rich in nutrients as opposed to clear water areas low in nutrients. We favour lakes, dams and slow-moving areas of rivers with muddy bottoms and densely vegetated areas. We are also one of the few species that can modify our habitat, and this is why we are seen as an invasive “pest” in many countries.
Our reproductive capacity combined with being able to feed on a wide variety of, often common, food items can quickly create very high densities of our species and, as we often feed by “grubbing” in the muddy substrate, we can rapidly and permanently transform historically clear water systems into muddy waters. This can, in turn, drastically change things like natural fish species composition and sometimes threaten uncommon and rare indigenous fish species with restricted distributions.
We generally prefer warmer water areas, are not fond of freezing conditions and often enter very shallow water during hot weather and after dark. We actively feed through the night and can often be seen, but rarely caught, when slowly cruising the margins of the rivers and dams at night or on calm days, driving anglers crazy. While we can survive extreme cold, as long as we have open water areas to escape to, we prefer warm water and this time of year is the worst for us as we often fall prey to unscrupulous and devious anglers. People in temperate areas can only really fish for us in summer but, in warmer areas into which we have been introduced, such as Australia, South Africa and parts of USA, we can be caught throughout the year.
For hundreds of years we were man’s undisputed friends. People built ponds and spent much thought and money “farming” us and developing new and better “strains” of carp. They bred us so that our bodies grew, our heads shrank and we developed colours that made us very obvious to any predator. They created industrial foods for us and built-up fisheries and, in many areas, relied on us for much of his daily protein needs. More recently, however, our amazing fecundity and habits have swamped some indigenous fisheries and modified waters to such an extent that they have become unsuitable for some sport anglers.
In the Pongolo River in South Africa, for example, there is a series of floodplain pans and, if you fly over them, you can see that some have clear water and others are muddy due to high densities of my clan. With over 50 indigenous freshwater fish species in an originally clear river, our impacts have been enormous. Our feeding in the muddy floodplain has changed the nature of the fishery and the African tiger fish, which mostly feeds by sight, has all but disappeared from some areas. Sadly, for us, some of the pans still contain numbers of Nile crocodile – we do not like them but they love us. At night the crocodiles patrol slowly around the shallow margins of the pans, (as do we) and, all too often, we bump into each other with a very unfortunate outcome.
Getting rid of us, if we are breeding, is not easy and is virtually impossible in large water bodies. People should, thus, be very careful before introducing us into new waters as, once in, we are there to stay.
While many people view carp as a “pest” and a serious problem, another large and growing group of recreational anglers see us as a wonderful and yet challenging part of, or addition to, the natural fish population. Due to our numbers and size, we have created an almost fanatical group of enthusiastic and specialised “sport” anglers focussed exclusively on us. In Europe, where other fishing opportunities are often limited, we fill a large and important gap for thousands of fishing enthusiasts.
Although we can feed on a variety of sources, we are picky eaters and often “play” with food, examining it closely before swallowing it. This results in very few carp being caught on artificial lures, which mostly move too quickly and, if “mouthed” are clearly inedible. Sadly, fly fishing can be different as many of these people are careful, intelligent and resourceful. With fly fishing, we are occasionally caught by accident when anglers are fishing for other species such as trout, though they are usually found in clear water and faster moving areas of slower rivers.
From our perspective some unscrupulous fly anglers become irritated when they can catch no “game” species, but then spot large carp feeding in weed-beds in backwaters. We often slowly move through such beds nibbling plants and sucking in insect larvae, but occasionally rise to the surface and gulp in air or an insect larva. This is when a “despicable”, but very careful, fly fisher can sneak up and very delicately almost drop a fly into the mouth of a carp. We will also often engulf something that looks possibly edible but the result of either is that “all hell breaks loose” with us being hooked and then forging powerfully off through the weeds and heading for open water. We consider this to be truly unsporting and, while we usually make an extremely determined first run, we often tire quickly and, unless we can find cover, can be landed on quite light tackle as we have no teeth and generally move slowly, though strongly.
A recent development is that bow-hunters have begun to target us. We spend much time, in calm conditions in fairly clear waters, “sunbathing” in shallow water, among rocks or plants or along banks. This makes us a perfect and valuable target for these people. They claim that they are removing the top breeding alien fish and protecting the sport fishery, but they clearly enjoy it and will often eat us.
Most of us who are caught, however, fall prey to bait fishers. While these fishers hotly debate what the best bait is, the reality is that we will happily eat a wide variety of “natural” baits like worms and insect larvae, but, we will also easily be enticed to eat many “commercial” or “special” shop bought baits. Favorites of ours are canned sweet corn and special shop-bought “carp” baits which are all too easy to obtain and place on a hook and very difficult for us to ignore. Most people fishing for us angle from banks of dams and slow flowing rivers. We are alert and sensitive to movement and so, for bait fishing anglers, stealth and care are essential in order to fool us, especially the more experienced larger carp.
The best anglers locate a good-looking spot in a dam or river, possibly near dense vegetation, and then they cast towards it. They then sit almost motionless, often chumming by throwing handfuls of bait into the area where they cast as this can bring us in from quite a distance away. These anglers are careful not to create any disturbance in the area and they also give us time to play with and then swallow the bait. Unwittingly, as we then slowly swim off the angler simply tightens his line until we are often well hooked. We may not be the most exciting fish species to catch, but we do give enormous pleasure and hours of fun to many people otherwise unable to fish.
Some fish are immoralized in songs and poems, but, while carp have and continue to play an important part in man’s lives, little is written about us beyond technical manuals on fish farming. The truth is, however, that it usually takes a lot of time, effort, know-how and the right approach and equipment to catch a large carp and it takes quite an experienced angler to achieve this.