I’m posting a handful of snapshots boat electrofishing in the rivers that spill into the Ionian Sea. Western Greece is often described with postcard words—gorges, plane-tree galleries, turquoise springs—but for a freshwater biologist the real poetry is in the fish.
These river and lake basins sit in an ecoregion of unusually high endemism. In plain terms: many of the species we net here exist nowhere else on Earth, restricted to a single basin or to a tight cluster of neighbouring basins. Each river is its own little evolutionary archive, shaped by histroical isolation, ancient geographical barriers, limestone karst and local ecological dynamics. You can feel that history in the bucket: a familiar “Mediterranean” fish assemblage, yes—but also odd local forms, subtle variations, and those small, secretive fishes that only make sense once you’ve seen the ecosystems that produced them.
Boat electrofishing looks dramatic (and, inevitably, people ask if it’s “fishing”....). It isn’t sport; it’s scientific sampling—carefully standardised, short pulses, tight safety protocols, capture technique and quick handling so fish can recover and swim away. The routine is half choreography: the skiff sliding along a run, the anode poles probing the margins, dip-nets ready, data sheets getting damp, GPS logging each transect. Meanwhile, we’re also reading the river: flow, substrate, cover, riparian conditiosn, the scars of water abstraction, the shadow of barriers, the die-back of the platanus trees due to an alien fungus invasion; the occasional surprise of an alien species where it shouldn’t be.
And still—despite multiple pressures and degradation—these Ionian rivers can feel astonishingly alive and wild. Every survey reminds me that conservation here isn’t an abstract idea. It’s local, basin by basin, decision by decision. Protect the habitat, and you protect an entire, irreplaceable lineage.
Fish Pictured here include (in order of appearance): Economidichthys pygmaeus - Goby, Knipowitschia sp. - Goby; Squalius peloponensis - Chub; Luciobarbus graecus (with D. Kommatas) - Barbel; Dicentrarchus labrax - Sea Bass; Luciobarbus albanicus - Barbel; Knipowitschia sp. - Goby; Liza (Chelon) ramada (in net) - Mullet; Salaria fluviatilis (juv.) - Freshwater Blenny; Alosa fallax - Twaite Shad.
My colleagues: Alexandros Ntakis, Dimitris Kommatas, Vassilis Pappas, Anthi Economou and Petros Chronopoulos. Some pics taken by Vassiliki Vlami who was also on one of the trips. And again my thanks to HCMR, we are so grateful to work there...
You are also welcome to download one of our recent papers on the fish assemblages within this Ecoregion:
And a map by my good colleague Theocharis Vavalidis from the above paper. The major river basins where HCMR does electrofishing using a boat are numbered as so: 1) Kalamas, 2) Acheron, 3) Louros, 4) Arachthos, 5) Acheloos, 6) Evinos, 7) Mornos, 8) Pineios, 9) Alpheios, 10) Pamissos, 11) Evrotas.
