Europe-wide protected species now not detectable after the environmental disaster within the Oder – Muricas News

Christian Wolter is aware of precisely the place to look, however he doesn’t discover something. Along with two colleagues, the scientist from the Leibniz Institute for Freshwater Ecology and Inland Fisheries (IGB) swings right into a fishing boat close to Reitwein (Märkisch-Oderland) to go fishing with an electrical rod and touchdown web. On the stage of a so-called parallel construction, which changed the previous groynes six years in the past, he hopes that, round two months after the devastating fish die-off on the border river, the uncommon Baltic goldfish might be caught in his web.

A whole lot of tons of useless fish had been found within the Oder in August. Based on consultants, because of the discharge of various, apparently very saline sewage, together with excessive temperatures and very low water, an alga that usually prefers brackish water and whose bloom was poisonous for the creatures within the river had multiplied.

The Baltic Goldsteinbeisser is barely about eight to 12 centimeters tall, is darkly marbled and has shiny golden scales on the flanks. What each angler is extra more likely to dismiss, causes enthusiasm amongst scientists. Fish ecologist Wolter has chosen the Oder, which isn't obstructed by weirs, as his most popular analysis space to review the dynamics of fish. “I found a gold wolffish for the primary time in 2003 within the Uckermark part of the Oder, after which 5 years later an entire inhabitants close to Reitwein,” he says.

For him, it's not shocking that this species felt at dwelling on this part of the Oder: the previous groynes had silted up for many years, and the river’s banks had been very shallow. Baltic Goldwolffish would love the water-streamed sands. “This fish, which is protected all through Europe, is definitely native to components of Jap Europe and western Asia. The Oder is its westernmost distribution space,” explains Wolter.

So as to not destroy this beneficial ecological habitat, the previous groynes had been changed in 2016 at a value of hundreds of thousands by a management construction parallel to the present – the ensuing shallow water space was preserved, the Baltic goldwolf continued to really feel snug, biologist Wolter had checked final 12 months.

Collectively together with his two colleagues, Wolter has been touring alongside the Brandenburg Oder part for weeks to research the fish inhabitants after the environmental catastrophe. “We discover many juvenile fish, however hardly any bigger, perennial animals, most of which had been affected by the poison disaster,” he makes clear. This spring, 40 % of the fish caught on the 52 checked factors within the river part of the “Decrease Oder Valley” nationwide park had been giant, partly grownup specimens. “Now it’s not even three %,” says Wolter.

Sobering end result

A end result that additionally pursuits nationwide park supervisor Dirk Treichel. “Exactly as a result of the present investigations give us a direct comparability to the stocktaking in spring, it's straightforward to infer how critical the harm is that was attributable to the environmental catastrophe within the Oder,” says the conservationist. The Oder is the spine of the one German floodplain nationwide park and has critical results on natural world, in accordance with Treichel.

Scientist Wolter went out twice to fish hunt at Reitwein, the fish, which had been briefly shocked by the electrical rod, had been dropped at the financial institution in giant water tubs, recognized, measured after which put again into the water. A dozen completely different species similar to chub, roach or pike are found, together with just a few bigger specimens. “Throughout the poison disaster, they in all probability survived within the lush reed beds and facet arms,” ​​suspects the fish ecologist. Nevertheless, Baltic goldfish aren't included.

“This end result is definitely sobering,” says Wolter. Within the spring of 2023 he desires to search for the gold loach within the Oder once more. The scientist factors to the Polish river financial institution, the place new groynes are being constructed. “The brand new buildings are taller and longer than their predecessors. In consequence, the circulate circumstances within the Oder might have modified a lot that the silted-up islands now not exist and thus now not have a habitat for the Baltic goldfish,” he explains.

What significantly horrified him throughout his last water evaluation: The salt content material within the Oder is sort of as excessive because it was in the course of the environmental catastrophe in August. Based on Wolter, that is proof that nutrient-rich waste water continues to be being discharged into the river. “If countermeasures aren't lastly taken, the water won't ever get better,” he makes clear.

Lars Dettmann, Managing Director of the Brandenburg State Fishing Affiliation, takes an analogous view. “These excessive salt ranges don't have any place in freshwater. Particularly when the water is low, these discharges aren't diluted and have devastating results,” he warns. Comparable issues to these within the Oder additionally exist in different German rivers such because the Saale or Werra, in accordance with Dettmann. “We have to deal with our waters in a different way,” he calls for. (dpa)