The project has focused on reducing the carp population in the Poniente and Levante reservoirs.

The project ‘Control plan for the invasive species Cyprinus carpio, in the El Hondo de Elche and Crevillent National Park 2018′ has come to an end, an initiative developed during 2019, which has had the support of the Biodiversity Foundation of the Ministry for Ecological Transition and the Demographic Challenge, through its call for grants.

The project has focused on reducing the carp population in the Poniente and Levante reservoirs to favor waterfowl such as the marbled teal (Marmaronetta angustirostris) or the white-headed duck (Oxyura leucocephala) that use that environment for their laying. To this end, the extraction of these freshwater fish has been carried out through traditional fishing, mainly in the summer months, when this species is most active. After the application of this measure, the channel through which the water enters and is distributed until it reaches the Poniente reservoir was free of adult individuals capable of reproducing, also in the Levante lagoon its population decreased drastically.

In addition, the two desiccations that occurred during 2017 and 2018 in the Poniente reservoir favored a considerable decrease in the carp population, which although still present in the wetland, has caused a reduction in the harmful effects on the ecosystem.

Another of the actions developed during the course of the project has been the placement of physical barriers to minimize the entry of this invasive species in both reservoirs, however there is still the presence of carp in the Segura River, and therefore, the entry of small carp or fry in El Hondo National Park is expected.

The results of this initiative highlight that it is not currently possible to establish a single measure for the eradication of carp, since it will still be necessary to learn to live with the species. However, they maintain that control of this invasive species is essential and that it should be applied routinely in the maintenance of the wetland. Therefore, it seems that the solution lies in combining small actions with periodic maintenance, although it is not ruled out to continue looking for new measures to help control it.

Within the framework of this plan, one of the aspects contemplated has been the confirmation after months of monitoring of the presence of otter (Lutra lutra) as a resident species in this National Park. This fact provides relevant information given its condition as a fish predator that makes it a natural ally in the control of carp, and could denote symptoms of recovery that are already observed in a remarkable way throughout the Valencian Community. It has gone from being in “danger of extinction” to being considered “vulnerable”.

In addition to this finding, the observation in El Hondo National Park during the winter months of a specimen of spotted eagle (Clanga clanga) in its clearest form, known as the mottled eagle morfo fulvescens, also stands out. This rare discovery is rarely mentioned in these latitudes, highlighting the high biodiversity of one of the most important wetlands in Europe.