SPATIAL REPRESENTATIVENESS OF EDNA SAMPLES IN A LARGE AND SHALLOW LAKE: IMPLICATIONS FOR MONITORING FISH ASSEMBLAGES

Representative sampling is a central goal in ecological research, biodiversity monitoring, and environmental management, yet accurately characterizing community structure in large, heterogeneous ecosystems remains challenging. We applied habitat-specific environmental DNA (eDNA) assays and real-time quantitative PCR (qPCR), to identify the optimal sampling effort and the spatial dependence of sampling representativeness for whole-lake level monitoring of fish assemblages in Lake Balaton, the largest shallow lake in Central Europe. Samples were collected in a spatially stratified systematic design to cover all habitat types and spatial and environmental gradients in the lake. Rarefaction and autosimilarity analyses showed that only a small proportion of samples was sufficient to capture taxonomic richness and to yield representative patterns of species composition and relative abundance. Detection of rare and traditionally underrepresented taxa, including benthic and large-bodied species, was consistently effective. Redundancy analysis identified the inshore–offshore gradient as the primary driver of community structure. Although latitude and mesohabitat type were statistically significant, their influence on assemblage structure at the whole-lake level was minimal. Overall, eDNA-based surveys offer a powerful and efficient tool for large-scale biomonitoring in Lake Balaton, requiring neither high sampling intensity nor fine spatial resolution to achieve representative assessments.

Presentation Preference: Poster

Primary Presenter: Anna Szolnoki, University of Veterinary Medicine Budapest (szolnoki.anna@blki.hu)

Authors:

Anna Szolnoki, University of Veterinary Medicine Budapest; HUN-REN Balaton Limnological Research Institute; National Laboratory for Water Science and Water Security, HUN-REN Balaton Limnological Research Institute  (szolnoki.anna@blki.hu)

Kai Feng, HUN-REN Balaton Limnological Research Institute; National Laboratory for Water Science and Water Security, HUN-REN Balaton Limnological Research Institute; Institute of Hydrobiology, Chinese Academy of Sciences  (feng.kai@blki.hu)

István Czeglédi, HUN-REN Balaton Limnological Research Institute; National Laboratory for Water Science and Water Security, HUN-REN Balaton Limnological Research Institute  (czegledi.istvan@blki.hu)

Attila Mozsár, HUN-REN Balaton Limnological Research Institute; National Laboratory for Water Science and Water Security, HUN-REN Balaton Limnological Research Institute  (mozsar.attila@blki.hu)

Didier Pont, Institute of Hydrobiology and Aquatic Ecosystem Management, University of Natural Resources and Life Sciences  (didier.pont@boku.ac.at)

Bálint Preiszner, HUN-REN Balaton Limnological Research Institute; National Laboratory for Water Science and Water Security, HUN-REN Balaton Limnological Research Institute  (preiszner.balint@blki.hu)

Péter Takács, HUN-REN Balaton Limnological Research Institute; National Laboratory for Water Science and Water Security, HUN-REN Balaton Limnological Research Institute  (takacs.peter@blki.hu)

Alice Valentini, SPYGEN, Savoie Technolac  (alice.valentini@spygen.com)

András Specziár, HUN-REN Balaton Limnological Research Institute; National Laboratory for Water Science and Water Security, HUN-REN Balaton Limnological Research Institute  (specziar.andras@blki.hu)

Tibor Erős, HUN-REN Balaton Limnological Research Institute; National Laboratory for Water Science and Water Security, HUN-REN Balaton Limnological Research Institute  (eros.tibor@blki.hu)