"We caught a few specimens during experimental trolling, but that was so insignificant that it is safe to say that Peipsi smelt numbers are at historical lows," senior researcher Külli Kangur from the University of Life Sciences told Postimees. 

Although the population has fluctuated through the decades, Kangur said there has been a general trend of decline for the past 80 years.

This summer, many fish died due to irregularly hot weather, but water pollution and a rise in nutrients also contribute to the demise. 

Twenty years ago fishermen caught around 11,000 tons of fish from Peipsi, but catches from the transboundary lake have yielded only 4,000 to 6,000 tons in recent times.