Role and consequences of fish diversity in the functioning of African freshwater ecosystems: a review

1995 ◽  
Vol 8 (1) ◽  
pp. 59-78 ◽  
Author(s):  
Christian Lévêque
2021 ◽  
Vol 16 (1) ◽  
pp. 123-133
Author(s):  
Shaista Manzoor ◽  
Harpreet Kaur ◽  
Rahul Singh

Wetlands are ecologically important and productive environments which help in several global processes. Microplastic pollution is an environmental issue of great concern. The studies related to this issue have been reported chiefly on the marine environment whereas freshwater ecosystems especially wetlands are receiving less consideration. Harike wetland is a northern largest wetland of India with area at present of 86km2. It is home to several migratory birds along with being rich in fish diversity. In this study the presence and type of microplastic in surface water of Harike wetland were investigated. Two types of microplastic are found in harike wetland namely nylon (Nylon 6) and high density polyethylene with size ranging from 4mm to 60µm. Results from the FTIR, RAMAN and GC-MS confirmed the presence of microplastic in Harike wetland. Rivers Sutlej and Beas could be a source of sewage input towards Harike wetland thereby being the reason of microplastic contamination in it. This study insights better understanding of microplastic pollution in wetlands giving way towards the threat that microplastic transfer could cause through the food chain and affect other organisms.


2012 ◽  
Vol 7 (2) ◽  
pp. 171
Author(s):  
Sudarto Sudarto ◽  
Emmanuel Paradis

Indonesia is one of the richest regions in the world in terms of biodiversity. However, recent evidence has shown that tropical forests destruction has maintained at a high rate over the last few years in this country. At the same time, living resources in Indonesian freshwater ecosystems are important: this country ranks at number seven in terms of production of inland capture fisheries with 323,150 tonnes in 2008. Freshwater fishes represent 42% of the total estimated ichthyofauna, concentrated in 0.01% of the total water covered environment. This environment is closer to human activities, making it critically vulnerable to adverse impacts. Furthermore, there has been some recent debates on the general sustainability of fisheries and aquaculture production systems. This research was focused on initiating a multi-scale study of fish biodiversity in freshwater environments. Two specific actions have been started. A review based on the analyses of the existing scientific literature and of databases on fish taxonomy and distributions. In parallel to this work, a global analysis of the distribution of fish diversity in Indonesia was undertaken. This work aims at identifying the major features of this resource as well as its current and future threats.


Oryx ◽  
2012 ◽  
Vol 46 (4) ◽  
pp. 544-553 ◽  
Author(s):  
Robin Kurian Abraham ◽  
Nachiket Kelkar

AbstractTerrestrial protected areas are often designated in inaccessible high elevation regions, and usually targeted towards conservation of charismatic large mammals and birds. It has been suggested that such protected areas, with partial coverage of riverine habitats, may not be adequate for conservation of freshwater taxa such as fishes. Also, protected areas are often designated in upstream catchments of dam reservoirs, and conservation of freshwater biodiversity is usually not a priority. We investigated the importance of existing protected areas for conservation of stream fishes within and across three dammed and two undammed rivers in the southern Western Ghats, India (a global biodiversity hotspot). Comparisons of stream sites in protected and unprotected areas were restricted to mid elevations because of confounding factors of dams, elevation and stream order. For dammed rivers, endemic and total species richness was significantly higher inside protected areas than unprotected areas. Total fish species richness increased with decreasing elevation and endemic species richness peaked at mid elevations. Species found in comparable stream orders across dammed and undammed midland river reaches were similar. Intensity of threats such as sand mining, dynamite fishing, pollution and introduced invasive fishes was higher in unprotected than in protected areas. Lack of awareness among managers has also led to the occurrence of some threats within protected areas. However, existing protected areas are vital for conservation of endemic fishes. Our results support the need for extending the scope of terrestrial protected areas towards better representation of freshwater ecosystems and biodiversity.


2007 ◽  
Vol 15 (NA) ◽  
pp. 15-41 ◽  
Author(s):  
K.E. Smokorowski ◽  
T.C. Pratt

Aquatic resource managers are continually faced with construction or site development proposals which, if allowed to proceed, would ultimately alter the physical structure and cover of fish habitat. In the absence of clear quantitative guidelines linking the change in habitat to fish, resource managers often use the change in habitat area as a basis for decisions. To assess the weight of scientific evidence in support of management decisions, we summarized both the observational and experimental freshwater fish-habitat literature. We then extracted data from experimental studies (where possible) for inclusion in a meta-analysis, to provide a more rigorous assessment of the published results of experimental habitat manipulations. We found relatively strong and consistent correlational evidence linking fish and physical habitat features, yet inconsistent evidence when narratively reviewing the experimental literature. On the whole, decreases in structural habitat complexity are detrimental to fish diversity and can change species composition. Increases in structural complexity showed increases, decreases, or no measurable changes in species and (or) communities. The majority of our meta-analyses resulted in supporting a direct link between habitat and fish abundance or biomass, with fish biomass responding most strongly to habitat change. Habitat alterations are most likely to affect individual species or community structure, and thus evaluating the extent of the effect on a biological basis depends on management objectives.


BioScience ◽  
2020 ◽  
Vol 70 (5) ◽  
pp. 404-414 ◽  
Author(s):  
Michaela Lo ◽  
James Reed ◽  
Leandro Castello ◽  
E Ashley Steel ◽  
Emmanuel A Frimpong ◽  
...  

Abstract Tropical forests influence freshwater fish through multiple pathways, only some of which are well documented. We systematically reviewed the literature to assess the current state of knowledge on forests and freshwater fish in the tropics. The existing evidence is mostly concentrated in the neotropics. The majority of studies provided evidence that fish diversity was higher where there was more forest cover; this was related to the greater heterogeneity of resources in forested environments that could support a wider range of species. Studies quantifying fish abundance (or biomass) showed mixed relationships with forest cover, depending on species-specific habitat preferences. We identify the key challenges limiting our current understanding of the forest–fish nexus and provide recommendations for future research to address these knowledge gaps. A clear understanding of the functional pathways in forest–freshwater ecosystems can improve evidence-based policy development concerned with deforestation, biodiversity conservation, and food insecurity in the tropics.


2021 ◽  
Vol 9 ◽  
Author(s):  
Elena Arboleya ◽  
Sara Fernández ◽  
Laura Clusa ◽  
Eduardo Dopico ◽  
Eva Garcia-Vazquez

The social value of natural aquatic ecosystems is very important to set management priorities. River connectivity is essential for the conservation of freshwater ecosystems because barriers alter both abiotic conditions and the biotic communities, compromising biodiversity; however, the appreciation of this river feature has been insufficiently considered in socio-environmental studies that are mainly focused on the acceptance of new dams. Here we used a willingness to pay approach to estimate the value of connectivity, native species, fish diversity (measured as functional diversity or as species richness), fish abundance and environmental quality in three groups of students of different educational background in Asturias (NW of Spain). As in other studies where they are more sensitive to environmental issues, educational sciences students would pay more to conserve and improve river conditions than students of other disciplines. Connectivity was the least valued river feature by students of educational and natural sciences, and the third (before biodiversity and fish abundance) by engineering students. We measured the same features on lowland reaches of four coastal rivers in the Bay of Biscay, and applied declared will amounts to model their appreciation. Differences between the river ranks obtained from functional diversity (that changes with non-native species) and species richness, and small differences between students of different disciplines in the gap between most and least preferred rivers arise from the model. This indicates the importance to involve diverse stakeholder sectors in decisions about rivers. The importance of river connectivity in the conservation of local biodiversity should be explained to general public, perhaps through environmental campaigns.


2019 ◽  
Vol 34 (1-2) ◽  
pp. 81-93
Author(s):  
D. D. BHUTEKAR ◽  
◽  
S. B. AHER ◽  
M. G. BABARE ◽  
◽  
...  

2013 ◽  
Vol 25 (1-2) ◽  
pp. 136-148
Author(s):  
I. V. Gryb

The concept of an explosion in freshwater ecosystems as a result of the release of accumulated energy, accompanied by the destruction of the steady climax successions of hydrocenoses is presented. The typification of local explosions as well as methods for assessing their risk during the development of river basins are shown. The change in atmospheric circulation, impaired phases of the hydrological regime of rivers, increasing the average temperature of the planet, including in Polesie to 0,6 ºC, deforestation leads to concentration and release of huge amounts of unmanaged terrestrial energy, which manifests itself in the form of disasters and emergencies. Hydroecological explosion is formed as a result of multifactorial external influence (natural and anthropogenic) on the water body in a certain period of time. Moreover, its level at wastewater discharge depends on the mass of recycled impurities and behaved processing capacity of the reservoir, and the mass of dumped on biocides and the possibility of the water flow to their dilution and to the utilization of non-toxic concentrations. In all these cases the preservation of "centers of life" in the tributaries of the first order – local fish reproduction areas contributed to ecosystem recovery, and the entire ecosystem has evolved from equilibrium to non-equilibrium with further restructuring after the explosion and environmental transition to a new trophic level. It means that hydroecological explosion can be researched as the logical course of development of living matter in abiotic environmental conditions, ending abruptly with the formation of new species composition cenoses and new bio-productivity. The buffer capacity of the water environment is reduced due to re-development and anthropic transformation of geobiocenoses of river basins, which leads to a weakening of life resistance. This applies particularly to the southern industrial regions of Ukraine, located in the arid zone that is even more relevant in the context of increased average temperature due to the greenhouse effect, as well as to Polesie (Western, Central and Chernihiv), had been exposed to large-scale drainage of 60-80th years, which contributed to the degradation of peatlands and fitostroma. Imposing the western trace of emissions from the Chernobyl accident to these areas had created the conditions of prolonged hydroecological explosion in an intense process of aging water bodies, especially lakes, change in species composition of fish fauna and the occurrence of neoplasms at the organismal level. Under these conditions, for the existence of man and the environment the vitaukta should be strengthened, i.e. buffer resistance and capacitance the aquatic environment, bioefficiency on the one hand and balanced using the energy deposited - on the other. This will restore the functioning of ecosystems "channel-floodplain", "riverbed-lake", reducing the energy load on the aquatic environment. Hydroecological explosions of natural origin can not be considered a pathology – it is a jump process of natural selection of species of biota. Another thing, if they are of anthropogenic origin and if the magnitude of such an impact is on the power of geological factors. Hydroecological explosions can be regarded as a manifestation of environmental wars that consciously or unconsciously, human society is waging against themselves and their kind in the river basins, so prevention of entropy increase in the aquatic environment and the prevention of hydroecological explosions is a matter of human survival. While the man - is not the final link in the development of living matter, it can develop without him, as matter is eternal, and the forms of its existence are different.


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