Caracterización de la ictiofauna tras el establecimiento de un estado turbio en un lago somero vegetado de aguas claras

Shallow lakes are known to present either alternative states, clear or turbid water condition. Both scenarios can usually be found in the Pampa Plain, but less frequently a previously clear lake is witnessed to become a turbid environment. Kakel Huincul is a shallow lake that supports important recreational fisheries. Previous ichthyological contributions for this system indicate the existence of seven fish species inhabiting a clear water environment. Unfortunately, the lake has become very turbid in the last decade and the possible changes in the fish assemblages associated with this have not yet been assessed. In this context, we aimed to explore the fish fauna of this ecosystem after the onset of its turbid condition and to assess some relevant limnological parameters, based on a monthly survey performed from May 2022 to April 2023. Water was characterized by high values of both dissolved oxygen (8.9 ± 1.6 mg/L) and electric conductivity (6538 ± 2205 µS/C), whereas turbidity permanently oscillated within a high turbid range (145.6 ± 99.0 NTU). A total of 16 fish species were collected. All collected specimens belong to native species, except for the common carp Cyprinus carpio. The common carp and two Loricariidae species are first records for this lake. The occurrence of the previously unreported invasive common carp could be linked to the recent transition from clear to turbid water phase experienced by this ecosystem.