scholarly journals The ichthyofauna of the Rio Carinhanha basin, one of the main tributaries of the Rio São Francisco

2020 ◽  
Vol 51 (4) ◽  
pp. 31-44
Author(s):  
Gilberto Nepomuceno Salvador ◽  
Ruanny Casarim ◽  
Gustavo Ribeiro Rosa ◽  
Yuri Malta Caldeira ◽  
Paulo Santos Pompeu
Keyword(s):  
Endangered Species ◽  
Native Species ◽  
Catchment Area ◽  
Entire Length ◽  
Fish Populations ◽  
Migratory Fish ◽  
River Channels ◽  
Middle Section ◽  
Long Distance ◽  
Main River

The ichthyofauna of the Rio São Francisco basin is relatively well-documented. However, most of this knowledge is concentrated at the upper stretch of its catchment area. In this study, we compile a list of species encompassing almost the entire length of the Rio Carinhanha, an important tributary from upper-middle section of the Rio São Francisco, including a comprehensive diversity of environments. A total of 99 species from 8 orders and 27 families were recorded. Five species are considered non-native, six classifieds as long distance migrants, and three as vulnerable. The orders with the greatest richness of native species were Characiformes and Siluriformes. Characidae was the most represented family, followed by Loricariidae. The main river channels were the richest environments sampled, followed by floodplain lagoons, veredas, and streams. The Carinhanha basin has important lotic remnants, thus it has several migratory fish populations as well as endangered species. This study demonstrates the importance of cataloguing the still poorly explored tributaries of the upper-middle section of the Rio São Francisco basin.

scholarly journals Biogeographic Distribution of Cedrela spp. Genus in Peru Using MaxEnt Modeling: A Conservation and Restoration Approach

Diversity ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 261
Author(s):  
Alexander Cotrina Sánchez ◽  
Nilton B. Rojas Briceño ◽  
Subhajit Bandopadhyay ◽  
Subhasis Ghosh ◽  
Cristóbal Torres Guzmán ◽  
...  
Keyword(s):  
Endangered Species ◽  
Protected Areas ◽  
Native Species ◽  
Timber Species ◽  
National Service ◽  
Natural Forests ◽  
Entropy Model ◽  
Probability Of Occurrence ◽  
Bioclimatic Variables ◽  
Population Sizes

The increasing demand for tropical timber from natural forests has reduced the population sizes of native species such as Cedrela spp. because of their high economic value. To prevent the decline of population sizes of the species, all Cedrela species have been incorporated into Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). The study presents information about the modeled distribution of the genus Cedrela in Peru that aims to identify potential habitat distribution of the genus, its availability in areas protected by national service of protected areas, and highlighted some areas because of their conservation relevance and the potential need for restoration. We modeled the distribution of the genus Cedrela in Peru using 947 occurrence records that included 10 species (C. odorata, C. montana, C. fissilis, C. longipetiolulata, C. angustifolia, C. nebulosa, C. kuelapensis, C. saltensis, C. weberbaueri, and C. molinensis). We aim to identify areas environmentally suitable for the occurrence of Cedrela that are legally protected by the National Service of Protected Areas (PAs) and those that are ideal for research and restoration projects. We used various environmental variables (19 bioclimatic variables, 3 topographic factors, 9 edaphic factors, solar radiation, and relative humidity) and the maximum entropy model (MaxEnt) to predict the probability of occurrence. We observed that 6.7% (86,916.2 km2) of Peru presents a high distribution probability of occurrence of Cedrela, distributed in 17 departments, with 4.4% (10,171.03 km2) of the area protected by PAs mainly under the category of protection forests. Another 11.65% (21,345.16 km2) of distribution covers areas highly prone to degradation, distributed mainly in the departments Ucayali, Loreto, and Madre de Dios, and needs immediate attention for its protection and restoration. We believe that the study will contribute significantly to conserve Cedrela and other endangered species, as well as to promote the sustainable use and management of timber species as a whole.

Neolecanium cornuparvum (Magnolia scale).

2021 ◽  
Author(s):  
Angela Whittaker
Keyword(s):  
Endangered Species ◽  
Adverse Effects ◽  
Native Species ◽  
Scale Insect ◽  
Scale Insects ◽  
Southern Ontario ◽  
Eastern Usa

Abstract Magnolia scale, Neolecanium cornuparvum, is a scale insect that is native to the eastern USA, where it is a widely distributed pest of wild and ornamental Magnolia in landscapes and nurseries. In general, non-native species of Magnolia tend to be more susceptible to attack than native US species. N. cornuparvum has also been reported on Wisteria in Connecticut. The genus and species were first reported from Canada from a specimen of N. cornuparvum collected in 1998 in southern Ontario, where the insect is now an established pest of Magnolia, having probably been spread via the plant trade. An infestation of scale insects believed to be N. cornuparvum was first observed in Hawaii on Sesbania tomentosa on Kauai in August 2004; it had significant adverse effects on this endangered species.

scholarly journals Assessment of the water pollution level and the environmental status of rivers in the Siverskyi Donets basin by BOD5

2020 ◽  
pp. 91-101
Author(s):  
N. S. Loboda ◽  
І. V. Katynska ◽  
О. V. Smalii
Keyword(s):  
Water Quality ◽  
River Water ◽  
Catchment Area ◽  
Donets Basin ◽  
Pollution Level ◽  
Early 21St Century ◽  
Main River ◽  
Environmental Status ◽  
The City ◽  
Hydrochemical Index

The paper topicality consists in the necessity for determination of the environmental status of the rivers in the Siverskyi Donets Basin and assessment of the possibilities for them to achieve ‘good environmental status’ under the modern climatic conditions and the anthropogenic load. Siverskyi Donets is the main river in the Eastern Ukraine. There are large industrial zones at the water catchment area. Among them, there are the Donetsk Coal Basin and the industrial complexes within the City of Kharkiv, which have exerted influence on surface water quality for decades. A method for assessment of the pollution level and the environmental status of waters by the hydrochemical index of BOD5 (biochemical oxygen demand for 5 days) is used in the paper. The paper is aimed at identification of the main trends in water quality changes by hydrochemical index of BOD5. The object of research is a pollution of the rivers at the Siverskyi Donets Basin by industrial, municipal and mine wastewaters. The subject of research is an assessment of water qualitative status by BOD5. The hydrochemical observation data for 7 gauges at the main river and 7 tributaries for the period of 1990-2015 were used in the paper. The major attention is focused on the most polluted rivers in the Eastern Ukraine: the Udy and the Kryvyi Torets. The quality of the Udy River water is largely determined by the municipal wastewater from Kharkiv. The Kryvyi Torets River belongs to the Donbas rivers, where pollution by mine water and wastewater from industrial enterprises is significant. Pollution levels, environmental status and saprobity were determined by the average annual indices of BOD5. Empirical probabilities for occurrence of a certain pollution parameter at various gauges were calculated for comparative analysis. It is found that a BOD5 downward trend has been prevalent on the rivers at the Siverskyi Donets catchment area in the early 21st century. The highest BOD5 values were observed on the Donbas tributaries and the Udy River (downstream from the City of Kharkiv), as well as upstream and downstream from Lysychansk, and the lowest ones were observed on the Oskil River. It is also revealed that in the early 21st century, the main river water has a ‘threshold’ environmental status (β-mesosaprobic zone), except for the Lysychansk gauge, where the status is ‘irreversibly altered’ owing to the inflow of polluted water from Donbas rivers into the Siverskyi Donets. Research into the Udy River water quality upstream and downstream from the industrial city of Kharkiv has shown that the water in the upper reaches of this river is classified as ‘clean’ and ‘moderately polluted’, and the environmental status may become ‘good’ in the future. Downstream from the city, the water is mostly ‘dirty’, and the environmental status is ‘irreversibly altered’, which corresponds to the α-mesosaprobic zone. For the Kryvyi Torets River (the Donbas Region), owing to the impact of organic pollution, the environmental status is defined as ‘threshold’, ‘irreversibly altered’ and it has begun to deteriorate in recent years. To improve the environmental status of the Donbas rivers, the reduction in discharges of untreated municipal and industrial wastewater into surface watercourses, as well as the construction of state-of-the-art sewage treatment plants are necessary.

Management of Chrysanthemoides monilifera subsp. rotundata in Western Australia

2014 ◽  
Vol 7 (1) ◽  
pp. 190-196 ◽  
Author(s):  
John K. Scott ◽  
Kathryn L. Batchelor
Keyword(s):  
Western Australia ◽  
Native Species ◽  
Initial Step ◽  
Buffer Zone ◽  
Industrial Area ◽  
Long Distance ◽  
Awareness Campaign ◽  
First Time ◽  
Established Population ◽  
Bitou Bush

AbstractOne of Australia's most serious weeds, Chrysanthemoides monilifera subsp. rotundata (bitou bush) was recently found for the first time in Western Australia as a well established population in Kwinana, a major port and industrial area south of Perth, the State's capital. This population is remote from other bitou bush infestations in Australia and had escaped detection despite extensive surveys in the same State for the other subspecies that is present in Australia, Chrysanthemoides monilifera subsp. monilifera (boneseed). The main reasons it went undetected are thought to be the tightly controlled access to this area because of mineral processing and port activities, the unusual invasion route via a heavy industrial area and the morphological similarity to a native species when it is not flowering. Two surveys defined the core population of 1038 plants that are spread along the coast over a 25-ha semi-circle with about a 500-m (1640 ft) diameter. Subsequent surveys of first a 500 m buffer zone and later a 1-km (0.621 mi) buffer found four additional plants, indicating that there is considerable potential for dispersal. We concluded that the survey has not delimited the distribution because of the potential and evidence for long distance dispersal. Cooperation by the various land managers has led to all plants being killed, as an initial step to management of this species. Other steps to be undertaken include an awareness campaign in the area that would need to be surveyed for delimitation of the spatial distribution and seed bank assessment to measure potential dispersal both in space and through time. It remains to be determined what is the best strategic response: eradication or containment.

Round goby movement patterns in a non-navigable river

2020 ◽  
Vol 77 (3) ◽  
pp. 475-483
Author(s):  
Luděk Šlapanský ◽  
Michal Janáč ◽  
Kevin Roche ◽  
Pavel Jurajda
Keyword(s):  
Native Species ◽  
Field Experiments ◽  
Round Goby ◽  
Neogobius Melanostomus ◽  
Species Dispersal ◽  
Dispersal Patterns ◽  
Long Distance ◽  
Movement Rates ◽  
Established Population ◽  
Future Management

Understanding non-native species dispersal is vital for their future management. The round goby (Neogobius melanostomus) has greatly extended its range since the 1990s, with commercial shipping being the main vector. However, our knowledge regarding their secondary dispersal from points of introduction is surprisingly limited. In this study, a series of field experiments were undertaken on a mid-sized river to assess goby dispersal patterns within an established population, following a simulated release of a large number of propagules, or at a simulated invasion front. Most of the established population remained stationary and just a few individuals undertook long-distance dispersal (principally upstream). Mean distance travelled was 1.1 m·day−1 (max. 29.6 m·day−1). While site fidelity appeared to last for most of the year (including winter), it was surprisingly relaxed during the spawning season. Concentrated release of a large number of propagules resulted in appreciably greater movement rates than in the established population, with upstream movement again dominating. In general, smaller, mostly male fish tended to move further and appeared as first colonizers in uninvaded areas.

High prevalence of non-native fish species in a remote region of the Mamberamo River, Indonesia

2020 ◽  
Vol 26 (3) ◽  
pp. 293
Author(s):  
Arif Wibowo ◽  
Dwi Atminarso ◽  
Lee Baumgartner ◽  
Anti Vasemagi
Keyword(s):  
Native Species ◽  
River System ◽  
New Guinea ◽  
Current Status ◽  
Native Fish ◽  
Fish Diversity ◽  
Main River ◽  
Main River Channel ◽  
High Prevalence ◽  
Major River

Indonesian freshwater fish diversity is threatened by human activities such as logging, land clearing, pollution and introduction of non-native species. The latter may pose serious threats to endemic freshwater fauna even in relatively pristine and isolated habitats. One such area, West Papua in the island of New Guinea, is one of the least studied regions in the world and a biodiversity hotspot. The Mamberamo River contains the highest proportion of non-native fish compared to other major river systems in New Guinea. To document this, we conducted a field study to validate and further temporally characterise the fish biodiversity to ascertain its current status. Since the last ichthyological survey 15 years ago, we detected two additional non-native species (Leptobarbus melanopterus and Oreochromis niloticus) that have established in the river system. Moreover, our survey revealed that non-native fish are extremely common in the mid reaches of the Mamberamo River, comprising 74% of total catch, with non-native Barbonymus gonionotus (family Cyprinidae) now established as the dominant species. The biomass of non-native B. gonionotus now exceeds that of all native fish combined in the main river channel. These results highlight the serious threat of invasive species in remote regions that support high levels of endemic biodiversity. Plans for containment, prevention through education programmes, and management are urgently required.

scholarly journals Spawning of migratory fish species between two reservoirs of the upper Uruguay River, Brazil

2012 ◽  
Vol 10 (4) ◽  
pp. 829-835 ◽  
Author(s):  
David A. Reynalte-Tataje ◽  
Alex P. O. Nuñer ◽  
Michele C. Nunes ◽  
Valquíria Garcia ◽  
Carolina A. Lopes ◽  
...  
Keyword(s):  
Environmental Variables ◽  
Water Surface ◽  
High Water ◽  
Migratory Fish ◽  
Migratory Species ◽  
Prochilodus Lineatus ◽  
Main River ◽  
Fish Spawning ◽  
Uruguay River ◽  
Salminus Brasiliensis

This study investigated the migratory fish spawning within the reservoirs of the Machadinho and Itá dams (upper Uruguay River, Brazil) and its relationship to environmental variables. Sampling was conducted in the lotic region of the river in two sites between the dams' reservoirs: Uruguay (main river) and Ligeiro (tributary). Sampling included nine consecutive reproductive periods (RP) spanning the period from 2001 to 2010 and was conducted at night on the water surface using cylindrical-conical plankton nets (0.5 mm mesh); environmental variables were also recorded. The spawning of the migratory species Salminus brasiliensis, Prochilodus lineatus, and Steindachneridion scriptum was registered: S. brasiliensis and P. lineatus spawned in the tributary river at the end of spring/beginning of summer, during flooding and during periods of high water temperature. Steindachneridion scriptum spawned in the main river at the beginning of spring. The study showed that S. brasiliensis, P. lineatus, and S. scriptum are able to spawn in small lotic river stretches within two reservoirs, but only under very specific and not common environmental conditions.

Geological investigations and proposed development of the Colonia Soto district, Tegucigalpa, Honduras

1987 ◽  
Vol 4 (1) ◽  
pp. 475-484
Author(s):  
C. D. Warren ◽  
D. Blakeway
Keyword(s):  
Urban Area ◽  
Future Development ◽  
Twin Cities ◽  
River Channels ◽  
Drainage Systems ◽  
Main River ◽  
The Republic ◽  
The City ◽  
Physical Dimensions

AbstractThe twin cities of Tegucigalpa and Comayaguela, Honduras are located within an intermontaine basin. The urban area is dissected by several rivers which converge to form the main River Choluteca, flowing northwards. The river channels follow tortuous courses dictated principally by accidents of geology. As a consequence of the variable rainfalls and hurricanes that periodically lash the Republic, and the previous lack of management, the channel profiles have generally attained unacceptable physical dimensions inside the urban perimeter with some sections showing signs of instability. To add to this, the absence of appropriate stormwater drainage systems within certain areas of the City has given rise to foundation problems associated with collapse settlement. This paper summarizes the geological investigations carried out in the Colonia Soto district of the City with a view to eliminating the present hazardous conditions, as related to the underlying geology, with recommendations being made for future development of the hillside.

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