Limnological Review

16 pages, 7236 KiB

Open AccessArticle

Reconstructing the Relative Ice-Flow Chronology South of Lake Mistassini in Canada from New Ice-Flow Indicator Mapping

by Mohamed El Amrani, Khadija Diani, Mohamed Hafedh Hamza, Mohamed Elhag, Said Courba, Afaf Amine, Moulay Ahmed Ben Driss, Lahcen Ousaid, Nabil Mdiker, Youssef Hahou and Larbi Boudad

Limnol. Rev. 2024, 24(4), 450-465; https://doi.org/10.3390/limnolrev24040026 - 16 Oct 2024

Viewed by 230

Abstract

Understanding paleo-ice flow chronology is essential for reconstructing past ice mass dynamics, interpreting the current landscape, and identifying the sources of Quaternary sediments in deglaciated regions. A recent systematic mapping of striated bedrock and streamlined landforms south of Lake Mistassini in Canada reveals a complex sequence of five ice flows. The earliest flow was directed to the southeast (SE) and originated from a NE-SW ice divide located northwest of Lake Mistassini at the Last Glacial Maximum. A progressive clockwise rotation of this ice divide, likely triggered during the early deglaciation, appears to have generated ice flows toward the south–southeast (SSE) and then toward the south (S). During the later stages of deglaciation, the flow originated from the Québec–Labrador Dome, initially toward the south–southwest (SSW) and then toward the southwest (SW). This study presents new data on ice flows south of Lake Mistassini and shows that the southward and south–southeastward ice events occurred before the late stage of deglaciation. This interpretation contradicts some previous studies and will contribute to the discussion on the dynamics of the Laurentide Ice Sheet in the Mistassini area and support mineral exploration efforts in the region. Full article

► Show Figures

Figure 1

13 pages, 2023 KiB

Open AccessArticle

Dam Impact on Fish Assemblages Associated with Macrophytes in Natural and Regulated Floodplains of Pandeiros River Basin

by Ivo Gavião Prado, Marcela Alves de Souza, Flávia Freitas Coelho and Paulo Santos Pompeu

Limnol. Rev. 2024, 24(4), 437-449; https://doi.org/10.3390/limnolrev24040025 - 14 Oct 2024

Viewed by 260

Abstract

The impacts of hydropower plants and their reservoirs on floodplains can potentially create new environmental filters and reduce the exchange of organisms and access to habitats. In this study, we aimed to compare the fish assemblage associated with aquatic macrophytes between floodplain lakes under natural conditions and a regulated floodplain lake in the Environmental Protection Area of Rio Pandeiros, Brazil. We tested the hypothesis that in the regulated floodplain lake, there would be a lower richness and a greater of abundance of macrophytes and fish than is natural. We also verified the influence of the seasons, macrophyte bank richness, and biomass on the fish assemblage abundance. The fish assemblages differed between the regulated and natural floodplains due to the higher richness and abundance of fish in the natural floodplains. The presence of non-native and generalist species in the regulated floodplain influenced the dissimilarity between the floodplains. Migratory species have been found only in natural floodplains. Fish abundance was negatively related to macrophyte richness on the regulated lake. There was a lower fish abundance and macrophyte richness in the regulated lake. There was no evidence that macrophyte biomass affected the abundance and richness of fishes. Our results confirm that the Pandeiros small hydroelectric dam affects the fishes’ assemblage and the macrophyte community, since the regulated floodplain lake has a lower richness and abundance of fish. The regulated floodplain lake is connected to a reservoir created by a small hydroelectric dam, which will be removed in the coming years. The removal of this dam might change these dynamics, and this must be evaluated when the change is implemented. Full article

► Show Figures

Figure 1

31 pages, 642 KiB

Open AccessReview

Unveiling the Hydrochemical and Ecotoxicological Insights of Copper and Zinc: Impacts, Mechanisms, and Effective Remediation Approaches

by Halina Falfushynska, Kamila Lewicka and Piotr Rychter

Limnol. Rev. 2024, 24(4), 406-436; https://doi.org/10.3390/limnolrev24040024 - 12 Oct 2024

Viewed by 237

Abstract

Water pollution is a pressing global issue significantly affecting ecosystem health, biodiversity, and human well-being. While numerous studies have concentrated on toxic metals like cadmium, lead, and mercury, essential metals such as copper and zinc often receive less attention. This review focuses on the distribution and occurrence of copper and zinc in surface water, their accumulation in freshwater organisms, and potential strategies for mitigating the environmental pressure caused by these metals. Zinc concentrations in uncontaminated freshwater usually range from 3 to 12 μg∙L⁻¹ and form low-bioavailable hydroxo-complexes that are especially stable in weak alkaline water. The zinc concentration trend globally is Europe > Africa > Asia > South America > North America. Conversely, copper concentrations vary from 0.2 to 5.5 µg∙L⁻¹, with the order being Asia > Africa > South America > North America > Europe. Humic substances are the likely predominant ligands for copper in these environments. The accumulation of copper and especially zinc in freshwater animals may not be a reliable indicator of metal pollution due to potential metabolic regulation. Bioremediation approaches, including phytoremediation and biosorption using plants and microorganisms, show promise in addressing water contamination. Future research should emphasize advanced bioremediation methods, emission reduction strategies, and refined modeling techniques to predict pollution trends and evaluate remediation effectiveness. Full article

► Show Figures

Figure 1

Journal Menu

Journal Browser

Limnol. Rev., Volume 24, Issue 4 (December 2024) – 3 articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI