PUBLICATION

Potash mining effluents induce moderate effects on histopathological and physiological endpoints of adult zebrafish (Danio rerio)

Authors
Irob, K., Wagler, M., Baberschke, N., Meinelt, T., Kloas, W.
ID
ZDB-PUB-190811-10
Date
2019
Source
The Science of the total environment   694: 133471 (Journal)
Registered Authors
Meinelt, Thomas
Keywords
Freshwater fish, Ion imbalances, Osmoregulatory stress, Potash mining effluents, Secondary river salinisation
MeSH Terms
  • Animals
  • Complex Mixtures/toxicity*
  • Toxicity Tests
  • Water Pollutants, Chemical/toxicity*
  • Zebrafish/physiology*
PubMed
31400679 Full text @ Sci. Total Environ.
Abstract
Stress in fish can be caused by a variety of factors and has the potential to evoke stress responses leading to a reduction of physical condition and of health. The river Werra (Germany) presents a severe case of secondary salinisation caused by potash mining activities. The model organism Danio rerio was exposed to different ion-concentrations depicting current (HT) and future (LT) threshold values of the Werra, as well as to solutions with single-exceeding ions (Mg2+ + K+ (KMg), Mg2+ (Mg) and K+ (K)). After a six-week exposure period, cortisol levels, growth and weight were measured, gills and gonads were histologically analysed and mRNA expression of follicle stimulating hormone (FSH), luteinising hormone (LH), growth hormone (GH) and prolactin (PRL) were determined. Cortisol was still elevated in fish in the HT and K group, indicating moderate stress. However, gills revealed structural changes in zebrafish in all exposure groups, size of oocytes differed in the LT and K group, male FSH mRNA levels were elevated in the HT and LT group whereas PRL mRNA levels were lower in HT and LT for both, male and female fish. These results suggest that ion-stress induces moderate effects on a variety of biological parameters that mainly serve to adapt to elevated ion concentrations. For these reasons current and even future thresholds should be reconsidered, including thresholds for total as well as single ion concentrations. Future research looking at the effects on local fish species is needed, along with regular and long-term monitoring of environmental conditions, species abundance and diversity.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping