scholarly journals Decline in New Zealand's freshwater fish fauna: Effect of land use

2020 ◽  
Author(s):  
Michael Joy ◽  
KJ Foote ◽  
P McNie ◽  
M Piria

© 2019 CSIRO. The number of New Zealand's freshwater fish listed as threatened has increased since 1992 when the first New Zealand threat classification system list was compiled. In this study, temporal and land cover-related trends were analysed for data on freshwater fish distribution, comprising more than 20 000 records for the 47 years from January 1970 to January 2017 from the New Zealand Freshwater Fish Database. The analysis included individual species abundance and distribution trends, as well as an index of fish community integrity, namely the Index of Biotic Integrity (IBI). Of the 25 fish species that met the requirements for analysis to determine changes in the proportion of sites they occupied over time, 76% had negative trends (indicating declining occurrence). Of the 20 native species analysed for the proportion of sites occupied over time, 75% had negative trends; 65% of these were significant declines and more species were in decline at pasture sites than natural cover sites. The average IBI score also declined over the time period and, when analysed separately, the major land cover types revealed that the IBI declined at pasture catchment sites but not at sites with natural vegetation catchments.

2020 ◽  
Author(s):  
Michael Joy ◽  
KJ Foote ◽  
P McNie ◽  
M Piria

© 2019 CSIRO. The number of New Zealand's freshwater fish listed as threatened has increased since 1992 when the first New Zealand threat classification system list was compiled. In this study, temporal and land cover-related trends were analysed for data on freshwater fish distribution, comprising more than 20 000 records for the 47 years from January 1970 to January 2017 from the New Zealand Freshwater Fish Database. The analysis included individual species abundance and distribution trends, as well as an index of fish community integrity, namely the Index of Biotic Integrity (IBI). Of the 25 fish species that met the requirements for analysis to determine changes in the proportion of sites they occupied over time, 76% had negative trends (indicating declining occurrence). Of the 20 native species analysed for the proportion of sites occupied over time, 75% had negative trends; 65% of these were significant declines and more species were in decline at pasture sites than natural cover sites. The average IBI score also declined over the time period and, when analysed separately, the major land cover types revealed that the IBI declined at pasture catchment sites but not at sites with natural vegetation catchments.


2021 ◽  
Author(s):  
Michael Joy ◽  
KJ Foote ◽  
P McNie ◽  
M Piria

© 2019 CSIRO. The number of New Zealand's freshwater fish listed as threatened has increased since 1992 when the first New Zealand threat classification system list was compiled. In this study, temporal and land cover-related trends were analysed for data on freshwater fish distribution, comprising more than 20 000 records for the 47 years from January 1970 to January 2017 from the New Zealand Freshwater Fish Database. The analysis included individual species abundance and distribution trends, as well as an index of fish community integrity, namely the Index of Biotic Integrity (IBI). Of the 25 fish species that met the requirements for analysis to determine changes in the proportion of sites they occupied over time, 76% had negative trends (indicating declining occurrence). Of the 20 native species analysed for the proportion of sites occupied over time, 75% had negative trends; 65% of these were significant declines and more species were in decline at pasture sites than natural cover sites. The average IBI score also declined over the time period and, when analysed separately, the major land cover types revealed that the IBI declined at pasture catchment sites but not at sites with natural vegetation catchments.


2021 ◽  
Author(s):  
Michael Joy ◽  
KJ Foote ◽  
P McNie ◽  
M Piria

© 2019 CSIRO. The number of New Zealand's freshwater fish listed as threatened has increased since 1992 when the first New Zealand threat classification system list was compiled. In this study, temporal and land cover-related trends were analysed for data on freshwater fish distribution, comprising more than 20 000 records for the 47 years from January 1970 to January 2017 from the New Zealand Freshwater Fish Database. The analysis included individual species abundance and distribution trends, as well as an index of fish community integrity, namely the Index of Biotic Integrity (IBI). Of the 25 fish species that met the requirements for analysis to determine changes in the proportion of sites they occupied over time, 76% had negative trends (indicating declining occurrence). Of the 20 native species analysed for the proportion of sites occupied over time, 75% had negative trends; 65% of these were significant declines and more species were in decline at pasture sites than natural cover sites. The average IBI score also declined over the time period and, when analysed separately, the major land cover types revealed that the IBI declined at pasture catchment sites but not at sites with natural vegetation catchments.


2019 ◽  
Vol 70 (1) ◽  
pp. 114 ◽  
Author(s):  
Michael K. Joy ◽  
Kyleisha J. Foote ◽  
Pierce McNie ◽  
Marina Piria

The number of New Zealand’s freshwater fish listed as threatened has increased since 1992 when the first New Zealand threat classification system list was compiled. In this study, temporal and land cover-related trends were analysed for data on freshwater fish distribution, comprising more than 20000 records for the 47 years from January 1970 to January 2017 from the New Zealand Freshwater Fish Database. The analysis included individual species abundance and distribution trends, as well as an index of fish community integrity, namely the Index of Biotic Integrity (IBI). Of the 25 fish species that met the requirements for analysis to determine changes in the proportion of sites they occupied over time, 76% had negative trends (indicating declining occurrence). Of the 20 native species analysed for the proportion of sites occupied over time, 75% had negative trends; 65% of these were significant declines and more species were in decline at pasture sites than natural cover sites. The average IBI score also declined over the time period and, when analysed separately, the major land cover types revealed that the IBI declined at pasture catchment sites but not at sites with natural vegetation catchments.


2005 ◽  
Vol 15 (03n04) ◽  
pp. 95-101 ◽  
Author(s):  
B. J. HICKS ◽  
D. W. WEST ◽  
B. J. BARRY ◽  
A. MARKWITZ ◽  
C. F. BAKER ◽  
...  

Half of the freshwater fish fauna in New Zealand is diadromous (i.e., migrates between the sea and freshwater); unimpeded access to and from the sea is important for the conservation of diadromous fish. The genus Galaxias (Galaxiidae: Osmeriformes) contains five diadromous species that spawn in freshwater, migrate to sea as larvae, and then migrate back into freshwater as 50-55-mm juveniles. Microchemistry of the otolith, a calcified structure in the fish's head, allows an independent test of assumptions about these migrations. Concentric layers of CaCO 3 with some Sr as SrCO 3 comprise the otolith, creating a chronosequence that reflects a fish's migratory history. More Sr accumulates in the otolith when a fish is in seawater than when it is in freshwater. High-resolution nuclear microscopy was used to measure the molar ratios of Sr/Ca in two galaxiid species. Otoliths of inanga (G. maculatus) caught in freshwater all showed a central zone of 100-200 μm in radius with Sr/Ca of 0.008-0.012, indicating early rearing in the sea. Sr/Ca values decreased to 0.001-0.002 as the fish moved into freshwater. Of six adult koaro (G. brevipinnis) caught in a river with sea access and no lakes, five had migrated to sea but one had not, raising questions about the generalized assumptions of migration.


Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1534
Author(s):  
Daniela Giannetto ◽  
Deniz Innal

Due to its peculiar geographical position and its environmental heterogeneity, Turkey represents an important biodiversity hotspot for freshwater fish fauna. Unfortunately, native fish communities of Turkey, mainly from lentic ecosystems, have been massively altered in the past decades. Furthermore, these species, especially the endemic species, are now threatened by several human activities in addition to the global issue of climatic changes. The aim of this paper is to provide an updated review on the current status of endemic fish species from main lakes of Turkey including major threats affecting fish assemblages. By gathering data from the literature and authors’ personal observations, 62 endemic fish species were reported to occur in the considered 37 Turkish Lakes. The presence of non-native species, agriculture activities, climatic drought, and decreasing water level were found to be the threats that most affect the fish communities of the considered Turkish Lakes.


Author(s):  
Wen Xiong ◽  
Qiang Wang ◽  
Dong Xie ◽  
David H Fletcher ◽  
Dekui He

Hainan Island is located within the Indo-Burma global biodiversity hotspot, however, the freshwater fish fauna on this island is poorly understood. Based on field investigations and literature review, we compiled a list of 154 freshwater fish species (138 native and 16 non-native) belonging to 10 orders, 31 families and 104 genera found on Hainan Island. Of these, 31 species are endemic to China. The native freshwater fish fauna in Hainan Island is affiliated to South China sub-region of the Oriental Region. Current knowledge suggests that overexploitation, water pollution, flow modification, habitat degradation, and non-native species have severely reduced the freshwater fish biodiversity in Hainan Island. To protect freshwater fish biodiversity and fisheries in Hainan Island, some new measures should be adopted and current measures better enforced. This study constitutes an important resource for conservation management of freshwater fishes in Hainan Island.


2017 ◽  
Author(s):  
Anbu Aravazhi Arunkumar ◽  
Arunachalam Manimekalan

Abstract. We studied the freshwater fish fauna of Rivers of Southern Western Ghats for a period of three years from 2010 to 2013. We recorded 64 species belonging to 6 orders, 14 families and 31 genera. Alteration in the micro and macro habitats in the system severely affects the aquatic life especially fishes and also complicates the fish taxonomy. In the present study a total of 31 sites of six river systems of Southern Western Ghats were studied in which a total of 64 species belonging to 6 orders, 14 families and 31 genera were recorded. Among the 64 species Cyprinidae was the dominant family with 3 family 18 genus and 49 species (76.6 %) compared to other order and families, further the data analyses suggested that species belonging to the order Cypriniformes were found to be the dominant species in the locations considered in the present survey. Interestingly, among the 31 sites Thunakadavu stream, Gulithuraipatti, Athirappalli, Naduthotam, Nadathittu, Mullaithodu, Thonanthikla, Noolpuzha and Sinnaru exhibited high variations in species abundance and as well species richness. Fifteen out of the 64 fish species endangered to the Western Ghats. Garra periyarensis and Cirrhinus cirrhosus are known to be vulnerable and Hemibagrus punctatus is Critically Endangered because of various anthropogenic activities. The significances of the study and timely measures needed to protect the species have also been concisely discussed. https://doi.org/10.1594/PANGAEA.882214


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