Status of Chinese Carp Fisheries in Tunisian Freshwater Reservoirs: Threats and Opportunities

Abstract

The current paper aims to diagnose the state of fisheries of three Chinese carp species whish have been introduced in Tunisian reservoirs since 1981: (silver carp Hypophthalmichthys molitrix, herbivorous carp Ctenopharyngodon idella and bighead carp Aristichthys nobilis) and seeks to study the benefits and risks associated with their introduction. Chinese carps cannot reproduce naturally in freshwater reservoirs. Eventually, artificial breeding operations and seeding of the dams with farm-produced fry are carried out by the Technical Centre of Aquaculture every year. Statistical analyses have shown a strong correlation between the landed quantity and the number of fries stocked each year. The impact assessment showed that the risks and benefits associated with the introduction of the three species are variable. Regarding their benefits, it was clear that the herbivorous carp has provided effective and sustainable control of the extensive development of aquatic vegetation in the eutrophic reservoirs and canal systems. The value of the other two species, though, remains less obvious, particularly for the bighead carp. The consequences of their introduction on ecosystems and native species seem to be negligible, especially when the densities are low. Eventually, it seems judicious to increase the stocking of the herbivorous carp, silver carp and bighead carp in Tunisian reservoirs.

Characterization of socio-economic fishing activity in tunisian reservoir: sidi Saad (center of Tunisia) as a case study

“…[6][7][8][9] The main species exploited in the Tunisian reservoirs are carp Cyprinus carpio, barbel Barbus callensis, roach Rutilus rubilio, rudd Scardinius erythrophthalmus, catfish Silurus glanis, eel Anguilla Anguilla, mullet (Mugil cephalus and Chelon ramada) and pikeperch Sander lucioperca. [1][2][3][10][11][12] Production in Tunisian reservoirs increased from 831.5 tons in 2000 to more than 1073.194 tons in 2020, of which 37.6 % came from the reservoir of Sidi Saad. 3,9,13,14 On the other hand, extensive inland fish farming offers to fishermen the opportunity to profitably production of fish species.…”

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“…[6][7][8][9] The main species exploited in the Tunisian reservoirs are carp Cyprinus carpio, barbel Barbus callensis, roach Rutilus rubilio, rudd Scardinius erythrophthalmus, catfish Silurus glanis, eel Anguilla Anguilla, mullet (Mugil cephalus and Chelon ramada) and pikeperch Sander lucioperca. [1][2][3][10][11][12] Production in Tunisian reservoirs increased from 831.5 tons in 2000 to more than 1073.194 tons in 2020, of which 37.6 % came from the reservoir of Sidi Saad. 3,9,13,14 On the other hand, extensive inland fish farming offers to fishermen the opportunity to profitably production of fish species.…”