Freshwater Fish Species Richness Research Articles

Drivers of contemporary lacustrine fish species richness in the glacial Lake Agassiz basin

AbstractAimBiological communities are the result of a stepwise spatiotemporal filtering process, driven by large‐scale historical and local contemporary determinants. The biogeographical pattern and species richness of North American fishes are predominantly determined by historical processes of past glaciations and postglacial dispersal and by contemporary environmental and ecological processes. We evaluated the effects of postglacial dispersal through glacial Lake Agassiz and habitat heterogeneity, represented by lake surface area, on contemporary freshwater fish species richness patterns of northwestern Ontario lakes.LocationNorthwestern Ontario, Canada.TaxonFreshwater fishes.MethodsApplying the theory of island biogeography and species–area curves, we examined the effects of isolation from the past dispersal corridor of glacial Lake Agassiz and habitat heterogeneity on species richness across 264 contemporary lakes. While controlling for correlations among the predictor variables, generalized linear models were constructed between species richness, as the response variable and the explanatory variables of lake elevation and surface area, and connection to the dispersal corridor.ResultsDifferential cover by glacial Lake Agassiz led to variation in fish species richness across contemporary lakes and it is higher in lakes that were covered by Lake Agassiz relative to basins remaining outside of the boundaries of the glacial lake. Lake surface area is the strongest predictor of species richness, while lake elevation is the strongest factor predicting isolation.Main ConclusionsHabitat heterogeneity and postglacial colonization have led to differences in fish richness within the same geographical region, which increases with lake surface area and decreases with elevation. These are likely driven by greater niche diversity facilitating the assembly of more diverse communities and isostatic rebound and fluctuating levels of Lake Agassiz isolating lakes at high elevations from the dispersal route earlier during the colonization process, respectively. These patterns underscore the importance of incorporating historical and environmental community determinants in biodiversity studies.

Fish Assemblage and In-Stream Habitat Variation in Relation to Dam Structures on the Withlacoochee River, Florida, with Notes on Historical Records

The Withlacoochee River in central Florida is a large blackwater river lacking substantive data on fish assemblage and has undergone extensive hydrological modification since the early 1900s. We compared fish assemblages in river segments above and below 2 major dams by conducting electrofishing surveys between April 2016 and June 2018. We also compiled historical records to assess temporal changes in species occurrence. We found that fish assemblages were significantly different in the lower segment than in the middle and upper segments. The lower segment had the lowest total catch-per-unit-distance and freshwater-fish species richness. Fish assemblage patterns were most highly correlated with Secchi depth, specific conductance, and percent of non-vegetative habitat cover. Much of the variation in fish assemblages among segments was consistent with that observed in undammed coastal rivers, but the lack of estuarine species in upper reaches of our study area suggests that the Inglis Dam may restrict upstream dispersal of these taxa. Comparison of species composition with historical records did not reveal any potential extirpations since 1931, but we recorded 8 marine species and 3 non-native species that were not present in historical records.

Freshwater fish diversity in three tributary streams in Serayu Basin, Central Java, Indonesia

Abstract. Suryaningsih S, Bhagawati D, Sukmaningrum S, Sugiharto, Puspitasari IGAAR. 2020. Freshwater fish diversity in three tributary streams in Serayu Basin, Central Java, Indonesia. Biodiversitas 21: 5811-5817. Determining the diversity of freshwater fish species in Central Java, Indonesia has been confounded by temporal and spatial limitations in past studies. The Serayu Basin is a large watershed in Central Java that is believed to have high freshwater fish diversity. We aimed to determine the diversity and community structure of freshwater fish species in three tributaries of the Serayu, elucidate the factors influencing this diversity, and determine the extent to which these tributaries contribute to the total freshwater fish species richness for southwest Central Java. We conducted gill net sampling from May to August 2018 on the Tulis, Mrawu, and Kali Sapi Rivers located at Banjanegara district Sampling followed a random group technique in upstream, midstream, and downstream river sections of each tributary. In total, we observed 21 freshwater fish species. Broadly, fish species diversity was relatively low in the study area, and water temperature and dissolved oxygen were important in maintaining fish diversity. These three tributaries house 27–46% of the freshwater fish species reported for southern Central Java.

Quantifying regional biodiversity in the tropics: A case study of freshwater fish in Trinidad and Tobago

AbstractExtinction rates are predicted to accelerate during the Anthropocene. Quantifying and mitigating these extinctions demands robust data on distributions of species and the diversity of taxa in regional biotas. However, many assemblages, particularly those in the tropics, are poorly characterized. Targeted surveys and historical museum collections are increasingly being used to meet the urgent need for accurate information, but the extent to which these contrasting data sources support meaningful inferences about biodiversity change in regional assemblages remains unclear. Here, we seek to elucidate uncertainty surrounding regional biodiversity estimates by evaluating the performance of these alternative methods in estimating the species richness and assemblage composition of the freshwater fish of Trinidad & Tobago. We compared estimates of regional species richness derived from two freshwater fish datasets: a targeted two year survey of Trinidad & Tobago rivers and historical museum collection records submitted to The University of the West Indies Zoology Museum. Richness was estimated using rarefaction and extrapolation, and assemblage composition was benchmarked against a recent literature review. Both datasets provided similar estimates of regional freshwater fish species richness (50 and 46 species, respectively), with a large overlap (85%) in species identities. Regional species richness estimates based on survey and museum data are thus comparable, and consistent in the species they include. Our results suggest that museum collection data are a viable option for setting reliable baselines in many tropical systems, thereby widening options for meaningful monitoring and evaluation of temporal trends.Abstract in Spanish is available with online material.

Biogeographic freshwater fish pattern legacy revealed despite rapid socio‐economic changes in China

AbstractUnderstanding drivers of freshwater fish assemblages is critically important for biodiversity conservation strategies, especially in rapidly developing countries, which often have environmental protections lagging behind economic development. The influences of natural and human factors in structuring fish assemblages and their relative contributions are likely to change given the increasing magnitude of human activities. To discriminate natural and human drivers of fish diversity and assemblage patterns in developing countries with rapid socio‐economic development, a dataset of 908 freshwater fish species and 13 metrics including three categories of both natural (i.e., biogeographic) and human drivers (i.e., economic growth, inland fisheries) in China were analysed with machine learning algorithms (i.e., self‐organizing map, random forest). Here, we found that biogeographic drivers explained 21.8% of the observed fish assemblage patterns in China and remained stronger predictors when compared to human drivers (i.e., 15.6%, respectively). Freshwater fish species richness was positively correlated to rainfall, air temperature, surface water area and inland fisheries production but negatively correlated with urbanization. In addition, the strong structuring effects of climatic variables on Chinese fish richness patterns suggested that the fish assemblages could be particularly vulnerable to climate change. Our results showed that natural biogeographic factors still dominate in driving freshwater fish assemblage patterns despite increased human disturbances on aquatic ecosystems in a rapidly developing country. These findings consequently suggested that we should consider both natural (e.g., climate) and human (e.g., urbanization, inland fisheries) factors when establishing aquatic conservation strategies and priorities for developing countries that are experiencing rapid socio‐economic changes.

Why does freshwater fish species richness differ between Pacific and Atlantic drainages of the Americas?

AbstractAimTo identify the contributions of geomorphological and hydrological/climatic factors to differences in total and endemic freshwater fish species richness between Atlantic and Pacific drainages.LocationGlaciated and unglaciated catchments draining to the Atlantic and Pacific Oceans in North (NA) and South America (SA).TaxonFish.MethodsA database of native freshwater fish species richnesses in drainage basins was compiled from published information, and the contributions of temperature, rainfall, catchment area, river length, channel gradient, discharge and geographic location in accounting for variation in total and endemic species richness were assessed using boosted regression trees.ResultsAtlantic drainages have larger catchments, with longer rivers, lower channel gradients, greater discharges and lower flow variability than Pacific ones of the same size. Unglaciated Atlantic drainages in bothNAandSAhave more species than Pacific drainages, but glaciated PacificNAhad significantly more species than the other Pacific areas. Geographic location had the greatest influence on total richness, but catchment area, river length and temperature were more important for endemic species. Pacific drainages had proportionally more endemics than Atlantic drainages.Main conclusionsTectonically driven topographic change, by altering relief, affects catchment size, slopes and connectivity, with the latter also affected by climatic changes in ice cover and aridity. These geomorphic and long‐term climatic changes, by influencing speciation, extinction and dispersal, govern freshwater fish species richness in Atlantic and Pacific catchments.

Global evidence of positive impacts of freshwater biodiversity on fishery yields.

AimAn often‐invoked benefit of high biodiversity is the provision of ecosystem services. However, evidence for this is largely based on data from small‐scale experimental studies of relationships between biodiversity and ecosystem function that may have little relevance to real‐world systems. Here, large‐scale biodiversity datasets are used to test the relationship between the yield of inland capture fisheries and species richness from 100 countries.LocationInland waters of Africa, Europe and parts of Asia.MethodsA multimodel inference approach was used to assess inland fishery yields at the country level against species richness, waterside human population, area, elevation and various climatic variables, to determine the relative importance of species richness to fisheries yields compared with other major large‐scale drivers. Secondly, the mean decadal variation in fishery yields at the country level for 1981–2010 was regressed against species richness to assess if greater diversity reduces the variability in yields over time.ResultsDespite a widespread reliance on targeting just a few species of fish, freshwater fish species richness is highly correlated with yield (R 2 = 0.55) and remains an important and statistically significant predictor of yield once other macroecological drivers are controlled for. Freshwater richness also has a significant negative relationship with variability of yield over time in Africa (R 2 = 0.16) but no effect in Europe.Main conclusionsThe management of inland waters should incorporate the protection of freshwater biodiversity, particularly in countries with the highest‐yielding inland fisheries as these also tend to have high freshwater biodiversity. As these results suggest a link between biodiversity and stable, high‐yielding fisheries, an important win–win outcome may be possible for food security and conservation of freshwater ecosystems. However, findings also highlight the urgent need for more data to fully understand and monitor the contribution of biodiversity to inland fisheries globally.

Freshwater fish species richness and conservation of mountain streams in the Jinggangshan National Nature Reserve, China

Jinggangshan National Nature Reserve is located in the middle reach of the Luoxiao Mountains in the south-western Jiangxi Province. The fish fauna of mountain streams in the nature reserve was investigated seasonally during 2011. A total of 553 samples were collected and classified into 12 families and 38 species. The samples collected in the nature reserve did not include any exotic species. The most abundant fish species collected was Pseudogastromyzon changtingensis tungpeiensis, followed by Acrossocheilus parallens, Rhinogobius cliffordpopei and Rhinogobius giurinus. A total of 16 species were found to be endemic to China. Current threats to the conservation of fishes in the nature reserve were reviewed and management solutions were suggested.

A scenario for impacts of water availability loss due to climate change on riverine fish extinction rates

Summary Current models estimating impact of habitat loss on biodiversity in the face of global climate change usually project only percentages of species ‘committed to extinction’ on an uncertain time‐scale. Here, we show that this limitation can be overcome using an empirically derived ‘background extinction rate–area’ curve to estimate natural rates and project future rates of freshwater fish extinction following variations in river drainage area resulting from global climate change. Based on future climatic projections, we quantify future active drainage basin area losses and combine them with the extinction rate–area curve to estimate the future change in extinction rate for each river basin. We then project the number of extinct species in each river basin using a global data base of freshwater fish species richness. The median projected extinction rate owing to climate change conditions is c. 7% higher than the median background extinction rate. A closer look at the pattern reveals great geographical variations highlighting an amplification of aridity by 2090 and subsequent increase in extinction rates in presently semi‐arid and Mediterranean regions. Among the 10% most‐impacted drainage basins, water availability loss will increase background extinction rates by 18·2 times (median value). Projected numbers of extinct species by 2090 show that only 20 river basins among the 1010 analysed would experience fish species extinctions attributable to water availability loss from climate change. Predicted numbers of extinct species for these rivers range from 1 to 5. Synthesis and applications. Our results strongly contrast with previous alarming predictions of huge surface‐dependent climate change–driven extinctions for riverine fishes and other taxonomic groups. Furthermore, based on well‐documented fish extinctions from Central and North American drainages over the last century, we also show that recent extinction rates are, on average, 130 times greater than our projected extinction rates from climate change. This last result implies that current anthropogenic threats generate extinction rates in rivers far greater than the ones expected from future water availability loss. We thus argue that conservation actions should be preferentially focused on reducing the impacts of present‐day anthropogenic drivers of riverine fish extinctions.

Using remote underwater video to estimate freshwater fish species richness

Species richness records from replicated deployments of baited remote underwater video stations (BRUVS) and unbaited remote underwater video stations (UBRUVS) in shallow (<1 m) and deep (>1 m) water were compared with those obtained from using fyke nets, gillnets and beach seines. Maximum species richness (14 species) was achieved through a combination of conventional netting and camera-based techniques. Chanos chanos was the only species not recorded on camera, whereas Lutjanus argentimaculatus, Selenotoca multifasciata and Gerres filamentosus were recorded on camera in all three waterholes but were not detected by netting. BRUVSs and UBRUVSs provided versatile techniques that were effective at a range of depths and microhabitats. It is concluded that cameras warrant application in aquatic areas of high conservation value with high visibility. Non-extractive video methods are particularly desirable where threatened species are a focus of monitoring or might be encountered as by-catch in net meshes.

Fish-SPRICH: a database of freshwater fish species richness throughout the World

There is growing interest in large-scale approaches to ecology, for both plants and animals. In particular, macroecological studies enable examination of the patterns and determinants of species richness of a variety of groups of organism throughout the world, which might have important implications for prediction and mitigation of the consequences of global change. Here, we provide richness data for freshwater fishes, which, with more than 13,000 described species, comprise a quarter of all vertebrate species. We conducted an extensive literature survey of native, non-native (exotic), and endemic freshwater fish species richness. The resulting database, called Fish-SPRICH, contains data from more than 400 bibliographic sources including published papers, books, and grey literature sources. Fish-SPRICH contains richness values at the river basin grain for 1,054 river basins covering more than 80% of the earth’s continental surface. This database is currently the most comprehensive global database of native, non-native and endemic freshwater fish richness available at the river basin grain.

Pattern and process in the distribution of North American freshwater fish

Published species lists were analysed to determine the contributions of dispersal, habitat preference, river channel size, body size, and glacial history to large-scale patterns in freshwater fish species richness in North America, north of central Mexico. Total species richness declines to the north and west but the pattern for endemics differs from that of widespread species. Mississippi Basin regions are more species rich than more isolated, coastal, regions. Richness declines more rapidly with increasing latitude in riverine specialist than in habitat generalist species. Levels of endemism are greatest in species found in small- to medium-sized river channels. The strong Rapoport effect, more marked in migratory than resident species, is correlated with habitat preference, channel size, and glacial history. Body size increases with latitude, largely as a result of a trend from small resident to large migrant species. In unglaciated regions, ancestral species survived in large habitats because these are longer-lived, more extensive, less isolated and more stable than headwaters, permitting larger populations and lower extinction levels. Reduced levels of gene flow in small, peripheral, channels isolated by larger downstream habitats have resulted in the production of many, small range, small-bodied species. The latitudinal richness gradient is a consequence of speciation and extinction events in unglaciated faunas and an increasing domination of faunas by generalist, large bodied, large channel, recolonizing species in more northern regions. (C) 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100, 46-61.

Identifying priority sites for the conservation of freshwater fish biodiversity in a Mediterranean basin with a high degree of threatened endemics

The Guadiana River basin’s freshwater fish species richness, endemicity and threatened status (92% of native species are threatened) highlight the need for a large-scale study to identify priority areas for their conservation. One of the most common problems in conservation planning is the assessment of a site’s relative value for the conservation of regional biodiversity. Here we used a two-tiered approach, which integrates an assessment of biodiversity loss and the evaluation of conservation value through site-specific measures. These measures based on the reference condition approach introduce the ability to make objective comparisons throughout the Guadiana River basin, thus avoiding a priori target areas. We identified a set of biodiversity priority areas of special conservation significance—which contain rare taxa as well as intact fish communities—because of their outstanding contribution to the basin’s biodiversity. The inclusion of complete sub-basins in these priority areas might guarantee an optimal solution in terms of spatial aggregation and connectivity. However, the high spatial fragmentation to which the Guadiana River basin is submitted due to river regulation highlights the necessity of a systematic approach to evaluate the capability of the identified priority areas to maintain the Guadiana’s freshwater fish biodiversity.

A spatial linkage between dams and non‐native fish species in Hokkaido, Japan

Abstract – The native and non‐native freshwater fish species richness as well as the proportion of native fish species to overall fish species were examined to test a hypothesis of a spatial linkage between the distributions of dams and non‐native fishes based on survey data collected in rivers and streams in Hokkaido, Japan. Non‐native fish species have steadily increased in Hokkaido since the mid 1970s, as indicated by the decreasing proportion of native fish species per fish survey. Non‐native species richness was significantly higher in areas above dams (i.e., reservoirs and their inlet streams) compared to areas without dams. As a result, the proportion of native fish species was lower above dams. This proportion was lower in developed and agricultural areas compared with forest areas, although both native and non‐native species richness were higher in areas with development and agriculture. Non‐native cyprinids, catfish and snakehead occurred primarily in a particular river basin with the largest drainage area, the longest history of reclamation and highest human population in the island. Non‐native salmonids on the other hand, occurred in forest areas at higher elevations and their occurrence was associated with the existence of dams. There was a spatial linkage between the distribution of dams and non‐native species, although it was applicable only to salmonids. The management of dams and reservoirs needs a strategy to prevent further expansion of exotic salmonids such as rainbow and brown trout. These species can be a significant threat to native Japanese salmonids as a result of various biological mechanisms.

Pattern and process in the ecological biogeography of European freshwater fish

1. Species lists for regions of Europe defined by Illies (1978, Limnofauna Europaea, 2nd edn. Gustav Fischer Verlag, Stuttgart), and augmented by information from Maitland (2000, Guide to Freshwater Fish of Britain and Europe. Hamlyn, London), are used to describe patterns in freshwater fish species richness and to examine the contribution of habitat preference, migration, body size and glacial history to these patterns. 2. The number of non-endemic species declines to the north and west, with increasing distance from the Ponto-Caspian region, the main source area, whereas endemic species richness declines only with latitude. 3. Habitat generalists tend to be migratory while riverine specialists are usually resident. Similar numbers of riverine species and generalists occur in Europe as a whole but generalists dominate in regional faunas and, to an increasing extent, in more isolated, formerly glaciated areas. Very few lacustrine specialists were found, reflecting the geologically ephemeral nature of lakes. Only 8% of riverine species have colonized glaciated areas, compared with more than half the generalist species, and the number declines rapidly with increasing distance from the source area. 4. Diadromous species show no geographical variation in species richness but potamodromous and resident species are affected by glaciation and by mountain and marine barriers. 5. The mean body size of regional faunas increases with latitude because there are relatively fewer small species in more distant, glaciated areas. 6. About half the species occurring in Europe are restricted to one region and the majority of these endemics occur in barrier regions with Mediterranean climates. Species in glaciated regions have much larger range sizes. Habitat preference and migration type, not body size, are the main determinants of range size. 7. Freshwater habitat availability varies across Europe with glaciated areas having more lakes of a given size than unglaciated areas. Catchment size is greatest at mid-latitudes. For a given catchment size rivers in glaciated areas are shorter. 8. The results support the notion that habitat variability, on both short and long time scales, favours colonization ability, which requires large body size. 9. As a result of their limited vagility northern fish faunas are depauperate, show high levels of plasticity and polymorphism and may show elevated speciation rates. The isolated southern faunas of the Iberian and Italian peninsulas and the Balkans are rich in endemic species but may be subject to extinctions because of the spread of the highly seasonal Mediterranean climate.

Fish-habitat relationships and fish conservation in small coastal streams in southern Spain

1. Studies dealing with the fish fauna of coastal streams are scarce in the scientific literature, particularly those from Mediterranean climates. Owing to their small size, these systems suffer extreme seasonal fluctuations, following the typical Mediterranean flood–drought cycle and leading to a high risk of extinction to freshwater fish. 2. This work analyses fish distribution in 14 stream stretches belonging to eight basins in the northern sector of the Strait of Gibraltar (southern Spain). Fish–habitat relationships were studied through multivariate ordination techniques at two scales: basin and stretch. 3. A principal components analysis clearly discriminated larger and more sinuous basins from smaller and steeper ones. This ordination was related to the non-migratory freshwater fish species richness and to the total number of fish species present in the middle reaches of each basin. 4. The main sources of variation in community composition and habitat characteristics in the different stretches were related to a clear upstream–downstream gradient, along which total species richness increased. 5. These small coastal basins are inhabited by two highly endangered species, Andalusian toothcarp (Aphanius baeticus) and Iberian chub (Squalius pyrenaicus), and have similar or higher overall freshwater species richness than larger adjacent basins. The near absences of flow regulation and introduced species make these streams one of the few types of Iberian aquatic system where unaltered fish–habitat relationships can be studied. Copyright © 2005 John Wiley & Sons, Ltd.

Spatiotemporal Variation in Shallow-Water Freshwater Fish Distribution and Abundance in a Large Subtropical Coastal Lagoon

Patos Lagoon is located off the southern Brazilian coast and represents one of the largest coastal lagoons in the world. We estimated hydrological and physicochemical conditions associated with spatial variation in the abundance and diversity of freshwater fishes along the lagoon, and inter-annual variability in abundances of freshwater fishes occurring in its estuarine zone. During our study, the region experienced two periods of average rainfall and two periods with above-average rainfall. The characids Astyanax eigenmaniorum and Oligosarcus jenynsii and the siluriform Parapimelodus nigribarbis were the most abundant freshwater fishes in the estuary during wet periods when water levels were higher and salinity was lower. Increases in abundance of these species in the estuarine area, all of which members of primary-division freshwater families, apparently were associated with pulses of reproduction and passive transport from freshwater habitats located near middle and upper lagoon reaches. Abundance of species from secondary freshwater families, such as poeciliids and cichlids, were less correlated with hydrological conditions, and their patterns of occurrence in the estuary suggest active migration from nearby freshwater habitats draining into this area. Findings indicate that freshwater discharge in the basin and expansion/retraction of freshwaters in the middle-upper lagoon determined patterns of freshwater fish abundance and species richness in the estuarine zone.

Is there an influence of historical events on contemporary fish species richness in rivers? Comparisons between Western Europe and North America

Freshwater fish species richness on 132 West European and North American rivers is analysed using eleven variables related to contemporary ecology (nine) and history (two). This is done in order to examine the relative and joint effects of both historical and ongoing processes on the contemporary richness of these two regional fish faunas. Relationships are quantified by simple and stepwise multiple regression procedures. Species‐area curves are presented for the fish faunas within both continents. We show that ecological factors statistically explain most of the variation in freshwater fish species richness for both continents. Effects of historical factors are shown to be statistically significant, but add only a little to the variance already explained by ecological factors. Our analyses further indicate that rivers (which flow directly into the ocean) support fewer species of fish than do similarly sized tributaries. The immigration‐extinction hypothesis appears to provide a plausible explanation for this observed pattern. The fact that in our final model, a continental effect is still highly significant, leads us not to exclude the possibility of some other historical influences in generating different overall species richness levels on the two continents.