There are serious problems with the water of Lake Balaton and Lake Venice

Temperature Increase and Its Effects

The rising water temperature of lakes affects wildlife on multiple levels. Tamás K. Felföldi, a scientific associate at the Institute of Aquatic Ecology, HUN-REN Centre for Ecological Research, explained on InfoRádió that the increased evaporation particularly affects shallow lakes, making them even shallower and thus more sensitive to environmental impacts.

Oxygen Depletion and Biological Processes

With rising water temperatures, the solubility of oxygen decreases, which is critical for aquatic organisms that rely on dissolved oxygen for respiration. Additionally, higher temperatures accelerate biological processes, including the proliferation of algae. Algae play a crucial role in lake ecosystems as primary producers of biomass and organic matter.

Eutrophication and Algal Blooms

Algae need sunlight and nutrients to grow. As water warms, they receive more sunlight and potentially more nutrients, leading to algal blooms, a process known as eutrophication. Eutrophication adversely affects aquatic ecosystems by disrupting normal biological functions and altering food webs.

Oxygen Depletion and Toxin Production

The mass of proliferating algae eventually decomposes, consuming large amounts of oxygen and creating hypoxic (low oxygen) conditions. During such conditions, anaerobic processes dominate, potentially leading to foul-smelling water due to hydrogen sulfide production. Certain algae can also produce toxins, and eutrophication-related hypoxia can result in fish kills.

Refuge Areas for Fish

When asked where fish can find refuge during these conditions, Tamás K. Felföldi noted that the western part of Lake Velence contains a protected area, a reedbed known as a bird reserve. This less disturbed and well-watered area can effectively protect biodiversity under changing conditions.

Summary

The rising water temperatures in lakes pose significant challenges to aquatic life. Oxygen depletion, accelerated biological processes, and algal blooms contribute to changes in lake ecosystems. Maintaining protected areas and implementing measures to mitigate environmental impacts are crucial for preserving aquatic biodiversity.