Some fish species endangered due to low water levels, heat

Ljubljana – Fish in Slovenian rivers are generally doing well, but certain species are highly affected by low water levels and overheating and some areas have seen fish kills in recent weeks. Water levels are extremely low in the Primorska and Notranjska regions, including Lake Cerknica, as well as in the Savinja and most small tributaries of large rivers.

Particularly threatened are species of the Salmonidae family, such as brown trout, grayling and Danube salmon, as well as certain warm-blooded species in areas where there is a lack of water or oxygen, the Slovenian Fishermen’s Association has told the STA.

The last three summers have been somehow manageable in terms of water levels and similar conditions were seen in 2017 but not for such a long period as this year.

The federation thus banned angling clubs from organising competitions and recommended them to ban fishing in the most affected rivers.

It would also like activities such as swimming or other sport activities in rivers to be banned because this “puts even more pressure on the fish”.

The association would also like to see the Agriculture Ministry as the regulator in charge of introducing obligatory measures play a more active role.

“We would like supervisory bodies, such as inspection services, to be more active. It is also totally unacceptable that watercourses are being encroached on.”

Here the association criticised a plan to pump water out of the Rižana river to fill the water supply system reservoirs as the coast has been hit by the worst drought in 35 years.

It believes this would “lower the water level below the ecologically permissible and acceptable flow. This simply means that some people don’t care about fish.”

The association monitors the situation through the fisheries service and staff at angling clubs, also cooperating with the country’s public Fisheries Research Institute.

On a more positive note, Slovenia has made progress in terms of cleanness of waters, with a number of rivers being in the first quality class and most of the remaining ones in the second quality class.

Slovenia also has pristine nature, especially in the areas of the Alpine rivers, which attracts fishing tourists, the association said, adding that fish stock is also good.

What worries the fishermen is a constant and reckless encroachment on watercourses, the cutting of riparian vegetation and the warming of the water during the summer months, which forces the grayling and trout to move upstream, which means that certain fish species are disappearing in certain areas.

Slovenia remains an attractive destination for foreign fishermen, but the association is worried about the impact global warming will have on rivers and lakes and on fishing tourism.

It has been also pushing against regulation of watercourses and for considering bringing rivers back to their original state, giving them space and planting a lot of vegetation along their banks to return the fish to their natural habitat and help them survive.