Natural regenerations of endangered fish populations in the Pilica drainage basin after reducing human impacts

1996 ◽  
pp. 121-133 ◽  
Author(s):  
T. Penczak
Keyword(s):  
Drainage Basin ◽  
Human Impacts ◽  
Fish Populations ◽  
Endangered Fish

An inventory of riverine biodiversity in monsoonal Asia: present status and conservation challenges

2002 ◽  
Vol 45 (11) ◽  
pp. 11-19 ◽  
Author(s):  
D. Dudgeon
Keyword(s):  
Drainage Basin ◽  
Human Impacts ◽  
Flow Regulation ◽  
Freshwater Ecosystems ◽  
Ecosystem Goods And Services ◽  
Knowledge To Action ◽  
Goods And Services ◽  
Floods And Droughts ◽  
Essential Prerequisite ◽  
Concomitant Species

There are few parts of the planet where human impacts on riverine biodiversity are more apparent than in monsoonal Asia. Flow regulation, drainage-basin degradation and conversion of riverine wetlands to agriculture have been occurring for centuries, while pollution and over-harvesting have become important in recent decades. Concomitant species loss appears both ongoing and rampant. Uncertainty over rates of loss is imposed by the fact that the extremely rich biodiversity of Asian rivers has not been inventoried adequately. It is nevertheless evident that some taxa are gravely threatened. Specialist riverine birds have declined, turtles are highly endangered, and over-harvesting has severely impacted fishes - an effect that is exacerbated by pollution and flow regulation. A particular conflict that constrains biodiversity conservation is the tendency for dam construction, which damages river ecosystems, to produce tangible benefits for humans through hydropower generation and relief from floods and droughts. Resolution of such conflicts requires changes in perception: for instance, realistic economic valuations of the ecosystem goods and services provided by rivers, and promotion of flagship species as conservation icons to increase citizen awareness. Translation of awareness and knowledge to action, however, remains the essential prerequisite for societal commitment to the conservation of freshwater ecosystems.

Estimating the probability of exceeding elevated pH values critical to fish populations in a hypereutrophic lake

1999 ◽  
Vol 56 (12) ◽  
pp. 2262-2270 ◽  
Author(s):  
Jacob Kann ◽  
Val H Smith
Keyword(s):  
Chlorophyll A ◽  
Fish Growth ◽  
Fish Populations ◽  
Fish Kills ◽  
Endangered Fish ◽  
Growth And Survival ◽  
Nonparametric Models ◽  
Ph Values ◽  
Algal Photosynthesis ◽  
Critical Ph

Current eutrophication models typically are used to predict seasonal mean conditions. However, the risk of summer fish kills in hypereutrophic lakes is likely to be more closely dependent on periodic extreme events, such as potentially lethal peaks in pH driven by algal photosynthesis. In hypereutrophic Upper Klamath and Agency lakes, Oregon, peak summertime pH values frequently exceed critical levels that can reduce fish growth and survival (pH > 9.50, a likely sublethal tolerance limit for two resident endangered fish species). We developed two empirical models, one parametric and one nonparametric, that predict the likelihood of exceeding user-defined critical values of pH from concentrations of chlorophyll a in these lakes. Separate models were derived to incorporate seasonal dynamics and differences between the two lakes, and the behavior of these models was tested under four different critical pH scenarios. Both parametric and nonparametric models performed similarly, suggesting that management efforts to reduce chlorophyll a in these lakes from 200 to 100 µg·L-1 should decrease the probability of exceeding pH 9.5 by 45%. We suggest that this general approach potentially can be applied to the management of fish populations in other hypereutrophic lakes as well.

Conservation Genetics of Endangered Fish Populations in Arizona

Science ◽  
1985 ◽  
Vol 229 (4711) ◽  
pp. 400-402 ◽  
Author(s):  
R. C. VRIJENHOEK ◽  
M. E. DOUGLAS ◽  
G. K. MEFFE
Keyword(s):  
Conservation Genetics ◽  
Fish Populations ◽  
Endangered Fish

A biometric study of three populations of the European grayling, Thymallus thymallus (L.), from the French Jura Mountains

1986 ◽  
Vol 64 (11) ◽  
pp. 2430-2438 ◽  
Author(s):  
C. Surre ◽  
H. Persat ◽  
J. M. Gaillard
Keyword(s):  
Discriminant Analysis ◽  
Drainage Basin ◽  
Fish Populations ◽  
Morphometric Characteristics ◽  
Jura Mountains ◽  
Thymallus Thymallus ◽  
European Grayling ◽  
French Jura

Three populations of grayling (Thymallus thymallus L.) from the Jura Mountains (Rhône drainage basin, France) were compared using 8 meristic and 10 morphometric characteristics; discriminant analysis clearly distinguished these populations. This result raises a number of questions about the specificity of fish populations inhabiting any given river and the usefulness of stocking that has been carried out up to now without any controls.

scholarly journals Effects of landscape features on population genetic variation of a tropical stream fish, Stone lapping minnow, Garra cambodgiensis, in the upper Nan River drainage basin, northern Thailand

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4487 ◽  
Author(s):  
Chaowalee Jaisuk ◽  
Wansuk Senanan
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Population Genetic ◽  
Allelic Richness ◽  
Drainage Basin ◽  
Fish Populations ◽  
Tropical Stream ◽  
Genetic Clusters ◽  
Spatial Genetic Variation ◽  
River Drainage Basin

Spatial genetic variation of river-dwelling freshwater fishes is typically affected by the historical and contemporary river landscape as well as life-history traits. Tropical river and stream landscapes have endured extended geological change, shaping the existing pattern of genetic diversity, but were not directly affected by glaciation. Thus, spatial genetic variation of tropical fish populations should look very different from the pattern observed in temperate fish populations. These data are becoming important for designing appropriate management and conservation plans, as these aquatic systems are undergoing intense development and exploitation. This study evaluated the effects of landscape features on population genetic diversity of Garra cambodgiensis, a stream cyprinid, in eight tributary streams in the upper Nan River drainage basin (n = 30–100 individuals/location), Nan Province, Thailand. These populations are under intense fishing pressure from local communities. Based on 11 microsatellite loci, we detected moderate genetic diversity within eight population samples (average number of alleles per locus = 10.99 ± 3.00; allelic richness = 10.12 ± 2.44). Allelic richness within samples and stream order of the sampling location were negatively correlated (P < 0.05). We did not detect recent bottleneck events in these populations, but we did detect genetic divergence among populations (Global FST = 0.022, P < 0.01). The Bayesian clustering algorithms (TESS and STRUCTURE) suggested that four to five genetic clusters roughly coincide with sub-basins: (1) headwater streams/main stem of the Nan River, (2) a middle tributary, (3) a southeastern tributary and (4) a southwestern tributary. We observed positive correlation between geographic distance and linearized FST (P < 0.05), and the genetic differentiation pattern can be moderately explained by the contemporary stream network (STREAMTREE analysis, R2 = 0.75). The MEMGENE analysis suggested genetic division between northern (genetic clusters 1 and 2) and southern (clusters 3 and 4) sub-basins. We observed a high degree of genetic admixture in each location, highlighting the importance of natural flooding patterns and possible genetic impacts of supplementary stocking. Insights obtained from this research advance our knowledge of the complexity of a tropical stream system, and guide current conservation and restoration efforts for this species in Thailand.

Human Impacts on Drainages of the Mesa Central, Mexico, and Its Genetic Effects on an Endangered Fish, Zoogoneticus quitzeoensis

2007 ◽  
Vol 21 (1) ◽  
pp. 168-180 ◽  
Author(s):  
OMAR DOMÍNGUEZ-DOMÍNGUEZ ◽  
LUIS BOTO ◽  
FERNANDO ALDA ◽  
GERARDO PÉREZ-PONCE DE LEÓN ◽  
IGNACIO DOADRIO
Keyword(s):  
Human Impacts ◽  
Genetic Effects ◽  
Central Mexico ◽  
Endangered Fish

Enumeration and Identification of Asbestos Fibres in Water

1974 ◽  
Vol 32 ◽  
pp. 526-527 ◽  
Author(s):  
O. Mudroch ◽  
J. R. Kramer
Keyword(s):  
Water Supply ◽  
Water Samples ◽  
Drainage Basin ◽  
Lake Superior ◽  
Research Work ◽  
List Type ◽  
The West ◽  
Asbestos Fibre ◽  
Amphibole Asbestos

Approximately 60,000 tons per day of waste from taconite mining, tailing, are added to the west arm of Lake Superior at Silver Bay. Tailings contain nearly the same amount of quartz and amphibole asbestos, cummingtonite and actinolite in fibrous form. Cummingtonite fibres from 0.01μm in length have been found in the water supply for Minnesota municipalities.The purpose of the research work was to develop a method for asbestos fibre counts and identification in water and apply it for the enumeration of fibres in water samples collected(a) at various stations in Lake Superior at two depth: lm and at the bottom.(b) from various rivers in Lake Superior Drainage Basin.

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