Recently, the release of glass eel fry into several Estonian lakes may have led to their widespread demise in Vooremaa due to non-compliance with suitable water temperatures for the fish, wrote former member of the Riigikogu, Peeter Ernits, on social media. According to a person directly involved in the release, of the 307 kilograms of fry released into five lakes, only 35 kilograms may have perished, which were released into three lakes in Vooremaa.
Ernits claimed that the glass eel fry released into Saadjärv died due to temperature shock as supported by video footage from the lakebed.
"While the tank truck from France consistently had a water temperature of plus four degrees, during the distribution in the freezing cold, they poured ice-cold water over them, probably killing them," Ernits wrote.
Jaanika Kaljuvee, the executive director of NGO Võrtsjärve Kalanduspiirkond, explained to ERR that a total of 307 kilograms of glass eel fry, purchased from France for €86,000, were released into five Estonian lakes.
"Since the tank truck from France had a tire burst on the way and was delayed by five hours, we thought it right that representatives of Saadjärv, Kuremaa and Kaiavere lakes should come to the limnology station themselves to pick up their fry, to reduce the time the fry spent in unnatural conditions," Kaljuvee said. "Apparently, the fatal issue was that the water in the truck's tank was four degrees, but then tap water, which is about nine degrees, was added, and by the time they reached the lakes in Vooremaa, the lake water under the ice was around two degrees. They suffered a temperature shock," Kaljuvee admitted.
However, in Võrtsjärv, where the limnology station is located, and in Vagula Lake in Võrumaa, the fish were released without adding warmer water in between, and these fry should be fine, Kaljuvee believed. "No, there's no problem at all in Võrtsjärv, because we've been releasing under the ice for years, and there's no issue if it comes straight from the tank and the two to three degrees temperature difference doesn't affect the fry."
"But yes, the tap water that was added to the fry released into the lakes in Vooremaa might be the cause, at least that's what we initially think. There can't be any other reason. Because in Vagula Lake in Võrumaa, they also came with their own container and didn't add any water for transport, and nothing happened to their eels, they all went down nicely, wriggling away," Kaljuvee said.
According to her, scientists went to Võrtsjärv to investigate, and more clarity should come in the afternoon. The coordinates of the holes where the fry were released are known, and a camera will be sent to the lakebed from there, where any dead fry – if present – should be visible.
Kaljuvee explained that she has been involved in releasing eel fry into Estonian lakes since 2009. The funds for purchasing the fry are sourced from the state treasury, collected from the fish trap fishing taxes paid by fishermen, and distributed back for fry stocking through the Environmental Investment Center (KIK). The amount varies each year depending on the fees paid.
This year, €86,000 euros were spent to purchase glass eel fry, totaling 307 kilograms of young eels. Of this, 263 kilograms and 340 grams went to Võrtsjärv, 16 kilograms and 770 grams to Saadjärv, 10.32 kilograms to Kaiavere Lake, 7.99 kilograms to Kuremaa, and 8.72 kilograms to Vagula Lake. Thus, the three lakes in Vooremaa, where the fry might have perished, received 35 kilograms of fish fry.
Vakra: It's like transporting gold
Rainer Vakra, the head of the Environmental Board, explained in a social media post and further detailed on Monday in the "Uudis+" show to Lauri Varik, that the agency's employees were present during the reception and release of the eel fry, as the glass eels are purchased through public procurement and at a price ten times lower than their black market value.
"It's like transporting gold, since these would cost €3000-6000 per kilo on the black market, but Estonian fishermen got them for €300 per kilo. Therefore, the Environmental Board also ensures that the same quantity purchased from France actually reaches our lakes, to prevent anyone from stealing them," Vakra said.
The agency also ensures that the fry are released into lakes from where they can reach the world's oceans and subsequently migrate to the Sargasso Sea – the only place in the world where they spawn.
Vakra expressed hope that 85 percent of the eel fry that reached Võrtsjärv were successfully relocated.
In response to a question about whether there will be penalties for those whose actions may have caused the mass demise of the fry, Vakra stated that an investigation will be conducted. However, he added that such releases have been conducted for decades during winter.
"Now we need to see if there was a mistake this time, even though some losses are always expected during relocation," he said. "But we will get more precise data during the investigation."
Editor: Mait Ots, Marcus Turovski