scholarly journals Broad and fine-scale threats on threatened Brazilian freshwater fish: variability across hydrographic regions and taxonomic groups

2021 ◽  
Vol 21 (2) ◽  
Author(s):  
Murilo Luiz e Castro Santana ◽  
Fernando Rogério Carvalho ◽  
Fabrício Barreto Teresa
Keyword(s):  
Freshwater Fish ◽  
Habitat Loss ◽  
Fish Species ◽  
Threatened Species ◽  
Environmental Changes ◽  
Anthropogenic Impacts ◽  
Conservation Status ◽  
Fine Scale ◽  
Hydrographic Regions ◽  
Taxonomic Groups

Abstract: Anthropogenic environmental changes are the main cause of species extinction during the Holocene. Species have been exposed to major source of threats, such as habitat loss and fragmentation, pollution, introduced species, and harvesting, many of which are derived from specific anthropogenic activities, such as urbanization, agriculture, and damming (i.e. fine-scale threats). However, the importance of these threats on the species conservation status in a given region depends on the type of impacts they are exposed to and the susceptibility of species to these impacts. In this study, we used a database of threatened Brazilian freshwater fish species to test whether the major source of threats and the specific anthropogenic impacts to species vary across hydrographic regions and taxonomic groups. Our results showed that habitat loss is a ubiquitous major threat jeopardizing the conservation status of the Brazilian fish species. However, different fine-scale threats mediate this process across hydrographic regions and taxonomic groups. The combination of impacts from agriculture, deforestation, and urbanization affects most of the threatened species in the basins of the Northeast, South, and Southeast, including the species of the most threatened order, the Cyprinodontiformes. Damming is the main human activity affecting threatened species of Siluriformes, Characiformes, Gymnotiformes, and Cichliformes, especially in northern basins (Amazon and Tocantins-Araguaia). Therefore, we found that specific fine-scale threats influencing threatened species vary across hydrographic regions and taxonomic groups, probably due to geographic variability in the incidence of human activities and differential niche requirements and vulnerability of species to these activities.

scholarly journals Conservation Status of Marine Biodiversity in Oceania: An Analysis of Marine Species on the IUCN Red List of Threatened Species

2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Beth A. Polidoro ◽  
Cristiane T. Elfes ◽  
Jonnell C. Sanciangco ◽  
Helen Pippard ◽  
Kent E. Carpenter
Keyword(s):  
Threatened Species ◽  
Environmental Changes ◽  
Extinction Risk ◽  
Conservation Status ◽  
Marine Species ◽  
Iucn Red List ◽  
Red List ◽  
Marine Biodiversity ◽  
Conservation Priorities ◽  
Conservation Action

Given the economic and cultural dependence on the marine environment in Oceania and a rapidly expanding human population, many marine species populations are in decline and may be vulnerable to extinction from a number of local and regional threats. IUCN Red List assessments, a widely used system for quantifying threats to species and assessing species extinction risk, have been completed for 1190 marine species in Oceania to date, including all known species of corals, mangroves, seagrasses, sea snakes, marine mammals, sea birds, sea turtles, sharks, and rays present in Oceania, plus all species in five important perciform fish groups. Many of the species in these groups are threatened by the modification or destruction of coastal habitats, overfishing from direct or indirect exploitation, pollution, and other ecological or environmental changes associated with climate change. Spatial analyses of threatened species highlight priority areas for both site- and species-specific conservation action. Although increased knowledge and use of newly available IUCN Red List assessments for marine species can greatly improve conservation priorities for marine species in Oceania, many important fish groups are still in urgent need of assessment.

scholarly journals A review of length-weight relationships of freshwater fishes in Malaysia

2018 ◽  
Vol 20 (1) ◽  
pp. 55-68 ◽  
Author(s):  
Amonodin Mohamad Radhi ◽  
Mohd-Fadzil Nurul Fazlinda ◽  
Mohammad Noor Azmai Amal ◽  
Hashim Rohasliney
Keyword(s):  
Freshwater Fish ◽  
Fish Species ◽  
Environmental Changes ◽  
Meta Analysis ◽  
Freshwater Fishes ◽  
Clarias Batrachus ◽  
Ecological Health ◽  
Allometric Growth ◽  
Freshwater Fish Species

Abstract This manuscript reviews the length-weight relationships (LWRs) of freshwater fishes in Malaysia. A total of 102 LWRs of fishes gathered from literature pertaining to 64 freshwater fish species were analysed. A meta-analysis from 13 previous reports showed that the b values was ranged from 2.19 (Clarias batrachus) to 4.106 (Barbodes binotatus). Out of 64 observed species, 47 species (11 families) experienced positive allometric growth, while another 23 species (eight families) and 31 species (12 families) were recorded under isometric and negative allometric growth, respectively. The fish LWRs observed can be used as an indicator of environmental changes and fish ecological health for freshwater fishes in Malaysia.

scholarly journals On the freshwater fish fauna of Krishna River, Sangli District, Maharashtra, India

2021 ◽  
Vol 13 (8) ◽  
pp. 19093-19101
Author(s):  
Suresh M. Kumbar ◽  
Shrikant S. Jadhav ◽  
Swapnali B. Lad ◽  
Abhijit Ghadage ◽  
Satyawan S. Patil ◽  
...  
Keyword(s):  
Freshwater Fish ◽  
Threatened Species ◽  
Conservation Status ◽  
Fish Fauna ◽  
River System ◽  
Iucn Red List ◽  
Cauvery River ◽  
Freshwater Fish Fauna ◽  
Data Deficient ◽  
First Time

Freshwater fish fauna of Krishna River, Sangli district was studied from 2013 to 2017. A total of 73 species belonging to 10 orders, 22 families, and 49 genera were recorded, of which, 29 species are endemic to the Western Ghats and 11 species endemic to the Krishna River system. Labeo kontius, an endemic barb of the Cauvery River System was recorded for the first time from the Krishna River, Maharashtra. As per the IUCN Red List of Threatened Species, 54 species are assessed as ‘Least Concern’, four species as ‘Near Threatened’, three species as ‘Vulnerable’, five as ‘Endangered’, and two as ‘Data Deficient’. The conservation status of two species has not yet been assessed. Fish fauna of the Krishna River within the study area is threatened as a result of alien species, and several anthropogenic stressors such as pollution from industrial as well as agricultural sources, human settlements, and overfishing.  Since, this small study area harbours 28 endemic and eight threatened species, their conservation should be given high priority.

scholarly journals Indigenous Freshwater Ichthyofauna in the Dhanu River and Surrounding Wetlands of Bangladesh: Species Diversity, Availability, and Conservation Perspectives

Conservation ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 241-257
Author(s):  
Debasish Pandit ◽  
Shuva Saha ◽  
Mrityunjoy Kunda ◽  
Ahmed Harun-Al-Rashid
Keyword(s):  
Fish Species ◽  
Anthropogenic Impacts ◽  
Public Awareness ◽  
Conservation Status ◽  
Habitat Preferences ◽  
National Level ◽  
Fish Population ◽  
Population Trends ◽  
Fish Diversity ◽  
Wallago Attu

A checklist of the native fishes of the Dhanu River and adjacent waters at Mithamain Upazila under the Kishoreganj district of Bangladesh is prepared with details on their availability, conservation status, habitat preferences, population trends, and threats. Data were collected monthly by field survey, focus group discussions, and personal interviews by using a semi-structured questionnaire and a pictorial check list of fish species. A total of 91 indigenous fish species of 59 genera belonging to 29 families under 11 orders were documented where 17.6%, 27.5%, 31.9%, and 23.1% species were abundantly available, commonly available, moderately available, and rarely available, respectively. Among those, 24 fish species (26.4%) were under the threatened category (3 critically endangered, 11 endangered, and 10 vulnerable) according to the IUCN Bangladesh. Notably, the globally threatened Cirrhinus cirrhosus, Channa orientalis, and Wallago attu were available in the study area. Fish population trends of 24.2% and 59.3% of the entire fish species were found in decreasing trends at the global and national level, respectively. The leading threats to the fish diversity were indiscriminate overfishing followed by fishing by dewatering of wetlands, the katha fishing method, the use of deprecated fishing gears, etc. Minimizing anthropogenic impacts, enacting fishing laws, installing and managing fish sanctuaries, and raising public awareness can be effective for the conservation of existing fisheries resources.

scholarly journals Fish species transshipped at sea (Saiko fish) in Ghana with a note on implications for marine conservation

2020 ◽  
Author(s):  
Denis Worlanyo Aheto ◽  
Isaac Okyere ◽  
Noble Kwame Asare ◽  
Jennifer Eshilley ◽  
Justice Odoiquaye Odoi
Keyword(s):  
Fish Species ◽  
Threatened Species ◽  
Conservation Status ◽  
Marine Ecosystem ◽  
Policy Formulation ◽  
Iucn Red List ◽  
Marine Conservation ◽  
Small Scale ◽  
Regulatory Enforcement ◽  
Fish Samples

Abstract Increasing global seafood demand over the last couple of decades has resulted in overexploitation of certain fish species by both industrial and small-scale artisanal fishers. This phenomenon has threatened the livelihoods and food security of small-scale fishing communities especially in the West African sub-region. In Ghana, fish transshipment (locally referred to as saiko) has been catalogued as one more negative practice that is exacerbating an already dire situation. The goal of this study was to characterise transshipped fish species landed in Ghana on the basis of composition, habitat of origin, maturity and conservation status on the IUCN list of threatened species to enhance understanding of the ecological implications of the practice and inform regulatory enforcement and policy formulation. Using identification manuals, morphometric and gravimetric analyses among others, data on saiko fish samples landed at Elmina in the Central Region of Ghana were collected at bi-weekly intervals between November 2016 and June 2017. A total of sixty-eight (68) fish species from 44 families comprising finfish and shellfish of pelagic, demersal, benthopelagic, and reef-associated fishes were identified. The round scad (Decapterus punctatus), the mackerel scad (Caranx rhonchus), the round sardine (Sardinella aurita) and the red pandora (Pagellus bellottii) were the numerically dominant species recorded. By habitat classification, 44 species (65%) were demersals while 6 species (9%) were pelagic and 6 species (9%) were reef-associated. Majority of the demersal species were juveniles while composition of juveniles among the pelagic species ranged between 67% - 84%. In addition, 6 (10%) of the recorded species were either vulnerable or near threatened on the IUCN red list of threatened species. It could be deduced from these observations that the recruitment of juveniles into the small pelagic fish stocks may be compromised and possibly lead to the future collapse of such fishery. The practice is also inadvertently a clear threat to the marine ecosystem, and sustainable fish production in Ghana.

Classifying threatened species: means and ends

1994 ◽  
Vol 344 (1307) ◽  
pp. 91-97 ◽  
Keyword(s):  
Threatened Species ◽  
Extinction Risk ◽  
Conservation Status ◽  
Species Conservation ◽  
Conservation Priorities ◽  
Extinction Rate ◽  
Sources Of Information ◽  
Means And Ends ◽  
Species Area ◽  
Taxonomic Groups

Threatened species lists are widely consulted as sources of information on the conservation status of species. However, their application to planning for conservation is limited because they have not been developed systematically, and because the criteria used to judge extinction risk are subjective. Recently, new proposals have been made to increase the broader usefulness of these lists, and some elements of these proposals are reviewed here. Apart from indicating the geographical and taxonomic groups containing most threatened species, these lists can provide other kinds of information. Some data from threatened species classifications using quantitative criteria provide a new method for estimating extinction rates in a variety of vertebrate taxa. This analysis suggests that over the next 100 years, the extinction rate could be as high as 15-20% in these groups. These values are comparable to those based upon extrapolations from species-area curves. However, allocating threatened species categories is only a first step towards developing rational systems for setting conservation priorities. These systems will need to consider a quite different set of variables, including those for incorporating species conservation priorities in area-based planning

scholarly journals Rapid survey of ichthyofauna from rivers and streams of coastal hydrographic regions of Santa Catarina state, Brazil

Check List ◽  
2015 ◽  
Vol 11 (5) ◽  
pp. 1781
Author(s):  
Vitor Pimenta Abrahão ◽  
Alexander Claro-García ◽  
Lenice Souza-Shibatta ◽  
Oscar Akio Shibatta
Keyword(s):  
Freshwater Fish ◽  
Fish Species ◽  
Freshwater Fishes ◽  
Santa Catarina ◽  
Freshwater Fish Species ◽  
Rivers And Streams ◽  
Comprehensive Survey ◽  
Hydrographic Regions ◽  
Mimagoniates Microlepis ◽  
Santa Catarina State

The lack of knowledge on the distribution and taxonomy of ichthyofauna from coastal Atlantic Rainforest of Santa Catarina state, Brazil, is noteworthy. This study presents a rapid but comprehensive survey of fish species from the coastal hydrographic regions of Santa Catarina. The samples were conducted in October 2012, in 19 sampling sites of five hydrographic regions, using sieves, seine nets, and throw nets. A total of 1,878 individuals belonging to 51 species distributed in 16 families are reported; four freshwater fish species represent distribution novelties for the region. The families Characidae and Loricariidae were predominant, mainly due to the abundance of Astyanax sp., Mimagoniates microlepis, Epactionotus itaimbezinho, and Pareiorhaphis stomias. Therefore, this study provides important contributions to the knowledge of the freshwater fishes from the studied area.

scholarly journals Effective reassessments of freshwater fish species: a case study in a Mediterranean peninsula

Hydrobiologia ◽  
2021 ◽  
Author(s):  
Imanol Miqueleiz ◽  
Rafael Miranda ◽  
Arturo H. Ariño ◽  
Tommaso Cancellario
Keyword(s):  
Iberian Peninsula ◽  
Freshwater Fish ◽  
Fish Species ◽  
Conservation Status ◽  
Fish Fauna ◽  
Iucn Red List ◽  
Molecular Techniques ◽  
Red Lists ◽  
Freshwater Fish Species ◽  
Freshwater Fish Fauna

AbstractIUCN Red List assessments for fish species can quickly become out of date. In recent years molecular techniques have added new ways of obtaining information about species distribution or populations. In this work, we propose the Iberian Peninsula as an example of reassessment needs in its endangered freshwater fish fauna. We compiled the list of freshwater fish species occurring in continental Spain and Portugal and examined their conservation status in global and national Red Lists. We retrieved records for these species in the Iberian Peninsula and calculated several biological indexes (richness and vulnerability indexes). Our results showed a patchy data coverage of fish records in the Iberian Peninsula. Threat levels reported within national Red Lists are higher than their global counterparts, reinforcing the necessity of improving and maintaining up to date national Red Lists. Iberian watersheds have moderate levels of threat and high levels of out of date assessments. The nearly fully completed genetic databases for Iberian fish species, along with the limited distribution of many endangered species and the necessity of update their assessments constitute an excellent opportunity to use data obtained from eDNA to improve species monitoring practices and their conservation status.

scholarly journals Water Quality and Conservation Status of Fish Fauna of Main Outfall Drain, Al-Diwaniya City, Iraq

2021 ◽  
Vol 910 (1) ◽  
pp. 012062
Author(s):  
Kadhim J.L. Al-Zaidy
Keyword(s):  
Water Quality ◽  
Freshwater Fish ◽  
Fish Species ◽  
Lower Risk ◽  
Fish Community ◽  
Conservation Status ◽  
Fish Fauna ◽  
Fish Diversity ◽  
Ecological Indices ◽  
The Third

Abstract Freshwater fish diversity, abundance, the ecological indices, and water quality from Main Outfall Drain (MOD) in Al-Diwaniya City/middle Iraq were studied monthly from January to December 2017 in two sites. The present study has shown that the third river (MOD) supported 15 fish species belonging to 7 families. As far as biodiversity status in fish community (IUCN-2019) is concerned, out of 15 species, eleven fish species are categorized into Lower risk least concern (LC or LR/lc), four Vulnerable (VU). Eight species were sensitive to salinity; seven species were tolerance. The results were concluded that the properties of water were tolerable for the fish community. Ultimately, it can be concluded that the sector of MOD supported the fish community. But it needs constant monitoring for the conserve and development of the diversity and the case of the healthy fish.

scholarly journals ’n Vergelyking van die Mollusca-diversiteit in die Mooirivier (Noordwes-Provinsie) soos gevind met opnames wat gemaak is in 1963 en weer 50 jaar later

2015 ◽  
Vol 34 (1) ◽  
Author(s):  
Cornelius T. Wolmarans ◽  
Victor Wepener ◽  
Uané Pretorius ◽  
Johannes H. Erasmus ◽  
Kenné N. De Kock
Keyword(s):  
Environmental Changes ◽  
Anthropogenic Impacts ◽  
Abiotic Factors ◽  
Conservation Status ◽  
Habitat Destruction ◽  
Low Flow ◽  
Current Status ◽  
Adjacent Area ◽  
Freshwater Molluscs ◽  
Mollusc Species

The highest number ofdocumented extinctions of any major taxonomic group is ascribed to the Mollusca. Factorsmainly responsible for this include environmental changes and anthropogenic impacts whichresult in habitat destruction. Furthermore, the conservation status of less than 2% of the moreor less 7000 mollusc species, known worldwide, is still not properly assessed. The aim ofthe study done in 2014 was to assess the current status of the mollusc diversity in the MooiRiver and to compare the results to the study done in 1963. The eight sites selected for thissurvey correspond with sites surveyed during the 1963 study, with surveys conducted duringboth an early and late low-flow period. The pH, electrical conductivity (EC) and temperaturewere also measured at each locality. Of the 15 mollusc species collected in 2014, altogether14 were the same as in the 1963 survey. However, an alien invasive species Physa acuta wasadditionally collected during the current survey, which is probably due to an increase inorganic enrichment. During the 1963 survey Burnupia mooiensis and Pisidium langlyanum werepresent at most of the sites, while Gyraulus connollyi and Ferrissia cawstoni were found at sixof the eight sites during the 2014 survey. Most of the molluscs previously recorded, were stillpresent in 2014. With regard to the abiotic factors, the pH values recorded in 2014 showed amoderate to large decrease as compared to the 1963 survey. This acidification is ascribed tothe development of gold mines in the adjacent area and apparently had little influence on themollusc diversity. The increase in EC measured in 2014 did not have any influence on thediversity of the molluscs, probably due to their wide tolerance for this factor. As expected,the temperature measured in 2014 was markedly higher during the late low-flow period ascompared to the early low-flow period. In conclusion, the differences discussed above revealedno obvious influence on the diversity of the freshwater molluscs over a 50 year period, despiteincreased anthropogenic impacts.

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