Influence of Thermal Pollution on the Physiological Conditions and Bioaccumulation of Metals, Metalloids, and Trace Metals in Whitefish (Coregonus lavaretus L.).

Natalia A Gashkina,Tatyana I Moiseenko

doi:10.3390/ijms21124343

Natalia A Gashkina, Tatyana I Moiseenko

Open Access

https://doi.org/10.3390/ijms21124343

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Abstract

The Kola nuclear power plant, which discharges warm water into one of the bays of subarctic Lake Imandra, significantly changes fish habitats. The temperature gradient of the lake is between 2 and 8 °C, which makes it significantly different from the natural temperature of the lake water. The stenothermal cold-water native species (lake whitefish (Coregonus lavaretus L.)), living for more than 40 years under conditions of thermal pollution, has adapted to this stressor. Moreover, this population differs favorably from the population in the natural-temperature environment in terms of its physiological state. Firstly, the hemoglobin concentrations in the fish blood are in the range of the ecological optimum, and secondly, it has a higher somatic growth, as estimated by Fulton’s condition factor. One of its main adaptive mechanisms of ion regulation is an intense metabolism of Na due to the high respiratory activity of the whitefish in warmer water. An increased accumulation of Rb and excretion of Se, Mo, and Si are associated more or less with that feature. Under conditions of an increased water temperature, the main metabolic need is due to a deficiency of Se in fish. The intensive metabolism of selenoproteins may involve risks of toxic effects and the bioaccumulation of Hg, As, and Cu in cases of increased existing stressors or the appearance of new ones.

Highlights

Power plants that discharge heated water into basins significantly affect the coastal ecosystems of cooling ponds
Thermal pollution did not influence the bioaccumulation of Pb and As, unlike Cu, Zn, Hg and Cd, by concentrators, such as oysters, in a coastal area affected by the thermal water discharge of the Houshi Power Plant, China [15]
Whitefish living in the thermal pollution area of subarctic Lake Imandra differ favorably from whitefish in the natural temperature environment in terms of their physiological state

Summary

Introduction

Power plants that discharge heated water into basins significantly affect the coastal ecosystems of cooling ponds. The Kola nuclear power plant (KNPP), built in 1973, provides about 50% of the electricity to the Murmansk region. Passing through the cooling system, the wastewater enters the Molochnaya Bay of subarctic Lake Imandra, with an amount of 1218 million m3 per year [1]. A thermal pollution area of up to 25 km was formed in the lake, with a temperature gradient from 8 ◦C, near the mouth of the discharge channel, and a gradual decrease as the heat flux spreads [2]. The secondary impacts of climate warming [3,4] or thermal pollution [5] include changes in nutrient cycling, primary productivity, and feeding relationships in food webs

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