• Population status assessment of six threatened freshwater fish species of Greece and of two top alien invasive fish species

We conducted a seven-day field trip in October-November 2021 to assess the current status of the threatened Boeotian riffle dace, Thessaly goby, Prespa trout, Aegean minnow, Vistonis shemaja and Doiran bleak, as well as of the aliens Prussian carp and Pumpkinseed, targeted with both conventional fish sampling and the environmental DNA method Fifteen sites (in 13 river basins of Greece) were sampled, located in Central and Northern Greece

• Corfu killifish trial translocation

The translocation involved a twostage transfer of a total of 84 wild adult Corfu killifish spawners to a spring habitat in the Acheron basin from an adjacent freshwater-fed canal in 2021 and 2022. Post-release monitoring in 2022, 2024 and 2025 utilizing electrofishing, netting, and underwater cameras, confirmed the successful establishment of a breeding population, evidenced by larvae and juveniles. This also demonstrates the potential of urban aquatic refugia as critical shelters of threatenened natve fish from invasive species.

• Safety fish stock acquirement

Ιn 2021 and 2022, we collected, transferred and acclimated individuals of the dwarf goby Economidichthys trichonis and the Greek stickleback Pungitius hellenicus to closed circuit systems. Dwarf goby transfer was marked by mortalities with transport stress and intestinal parasitosis identified as the main cause.

Similarly, the post-transfer of sticklebacks was marked by mortalities with acclimation to much higher aquarium temperatures compared to the in situ ones and non-feeding (with subsequent parasitosis) as the main causes. After a modification of our protocols, a second attempt was made with anti-parasitic treatment and proper food available. As a result no mortalities occurred and fish stocks have been established.

• Launching of the AFRESH website