Details

Autor(en) / Beteiligte

• Santos, R.M.B.
• Monteiro, S.M.
• Cortes, R.M.V.
• Pacheco, F.A.L.
• Fernandes, L.F. Sanches

Titel

Seasonal effect of land use management on gill histopathology of Barbel and Douro Nase in a Portuguese watershed

Ist Teil von

• The Science of the total environment, 2021-04, Vol.764, p.142869, Article 142869

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2021

Quelle

MEDLINE

Beschreibungen/Notizen

• The Vilariça River (located in the northeast of Portugal) is inserted in an agricultural basin and it was chosen to replace the spawning grounds for fish, that was lost due to the construction of dams in the Sabor River. Thus, it is essential to study the effect of agricultural practices on water quality and in the health status of fish. The barbel (Luciobarbus bocagei) and Douro nase (Pseudochondrostoma duriense) were the selected species and the work was developed in two seasons (Summer 2016 and Winter 2017). For that, the histopathological changes of fish gill were used as biomarkers, through a semi-quantitative approach that considers the injuries severity. And the water quality assessment criteria followed the methodologies proposed for classifying the status of surface water bodies from Portugal. The current study showed severe histopathological changes in both species and both seasons, and the water was classified as polluted and extremely polluted in Summer and Winter respectively. The pollution in Summer was due to high temperatures, low dissolved oxygen and major concentration of As and Mn, and in Winter is due to the high concentration of Total Suspended Solids, nitrites and Cd. The increase of values of physico-chemical parameters on the water was caused by the less streamflow and excessive agricultural fertilization in Summer which arrive the river by irrigation, and by the erosion of soil particles with heavy metals associated in Winter. Also, the canonical analysis showed that physico-chemical parameters concentrations in Summer justify the major prevalence of aneurism in barbel and exudate in nase and Winter the major prevalence of hypertrophy in barbel. In conclusion, the study showed that the gill injuries of barbel and Douro nase was correlated with the water quality and it is influenced by seasonal agricultural practices and the flow regime. [Display omitted] •Gill histopathology of barbel and Douro nase was evaluated in Vilariça River.•Gill histopathological analysis showed severe changes in both species.•The water quality was classified as polluted and extremely polluted.•In Summer, the pollution is due to less streamflow and agricultural fertilization.•In Winter, the pollution is due to the erosion of soil particles with metals.