If there is an adjective that suits a catfish (Silurus glanis) is the largest. As a fish it is enormous, very large, so large that it is not strange to come across fishermen boasting of catches of more than 2.3 meters and even exceeding 100 kg. They also bring these as problems. After all, it is included in the invasive exotic species catalog due to the damage it causes to other native creatures and habitats. It’s also huge as a business: every year fishermen go to fishing grounds lured by the hope of catching one of these huge fish with their rods, bringing in millions of euros.

In the Ebro, they know well these three aspects of catfish: big fish, greedy invader and lucrative business, traits that do not always go well together.

Millions of catfish. The enormous size that catfish reach not only makes them a fearsome predator for other fish, amphibians, waterfowl, or rodents that might fall into their jaws. Their “XXL size” also makes them a highly appreciated prize by fishermen and thus a rich source of income for the towns near the marshes where they live. This was also noticed by Luisa Serra, president of the Caspe Fishing Sports Association, who shared some data with La Sexta in 2019.

Nearly 100,000 people moved into catfish fishing in 2018 alone, according to data Serra revealed for the Research Team, which even traveled to the Mequinenza Reservoir in Aragon to address the problem. The data is impressive, but not as impressive as the calculation of its economic impact. Serra mentioned that “indirectly” catching the monster fish brought more than remarkable benefits: about “nine million euros.”

Don’t say sport fishing, say economy. This is not the only data that helps provide insight into what sport fishing means for some of the Ebro’s riverside populations. In 2017, mayors of some towns downstream from Zaragoza noted concerns about the General Fisheries Plan, which imposes fishing obligations. Kill hunted specimens of invasive species to control their populations and protect the local ecosystem in this way. On the list were catfish or carp, the two most sought-after trophies by anglers looking to get just a few. selfies with their prey.

“What they like is to catch a good specimen, take a photo so their success can be seen, put mercromin on it and release it,” said Jesús Senante, mayor of Caspe. Aragon Newspapera newspaper stating that sport fishing created a six million euro job in the town alone. Fishing enthusiasts from Central Europe actually travel to the lower Ebro in Aragon, giving rise to campsites, shops, restaurants, hotels, rural accommodation… all with sport fishing at the core.

local finance. “Fishing tourism accounts for a third of our economy,” Senante said. He’s not the only one showing concern. Mequinenza council member Magda Godia also defended this in her statements. Newspaper To review the exotic species catalogue, with a view to reducing the impact of the scheme. “Common sense should prevail and regulations for this should include socioeconomic criteria as well as purely environmental criteria.” he insisted.

He announced that in 2015 alone, approximately 20,000 tickets were issued for fishermen interested in placing their rods and hooks in the Ebro reservoirs, whether in the Aragon Sea or in the Ribarroja press. In 2016, there were even those who openly wondered about the possibility of catfish being considered a native species. Aragon’s 2023 “fishing information leaflet” details places in the Ebro basin where fishing of invasive exotic species is allowed “under a voluntary catch and release regime” and includes catfish, carp or alburno.

At the center of illegal fishing. Catfish and carp fishing in the Ebro waters has attracted the attention of even illegal fishermen. Four years ago, the Civil Guard announced the arrest and investigation of 23 people who allegedly captured samples to later send to Romania. During the operation, 8.8 tons of fish that were stored in warehouses without health checks and were not suitable for consumption were intervened. Shortly afterwards, police seized another four tons of catfish and carp in the same river, following the same methods and with the same destination.

A job (and problem) created. Whether considered a socioeconomic factor or an environmental problem, two facts about catfish are clear. The first is its inclusion in the invasive exotic species catalogue; this indicates that it was voluntarily introduced precisely because of its attractiveness for sport fishing; Second, it has a notable and well-studied impact on the Ebro or Guadalquivir ecosystems. The University of Córdoba (UCO) warned that this “threatens natural habitats and the local economy.”

The last nuance is important and shows that these invasive species, no matter how appreciated they are in sport fishing, leave a negative balance that exceeds their environmental footprint and completely affects the economy. “It threatens the biodiversity of Doñana National Park, which is an area of ​​great biological importance and also of economic importance for red crab and sapwood hunting,” reminds the coordinator of the UCO study. Cordoba Day.

“Opportunistic, greedy and aggressive”. That’s how the invasive exotic species catalog describes the catfish, a creature that feeds on other fish but also includes amphibians, crabs, rodents or waterfowl in its diet and “significantly alters the trophic structure of ecosystems.” This”.

In line with the warning of UCO experts, the document also emphasizes the “negative impact on domestic fishing resources” of animals exceeding 2 meters in length and weighing more than 100 kilograms, which were found in the Danube and Volga decades ago and reached the following points. Mequinenza reservoir due to its attractiveness for fishermen.

Pictures | Joe Pell (Flick) and Wikipedia

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*An earlier version of this article was published in November 2023.