Thirty years of environmental change reduces local, but not regional, diversity of riverine fish assemblages in a Himalayan biodiversity hotspot

The aim of the present study was to determine whether boat-based deployment of remote underwater video cameras is effective for surveying fish assemblages in the deepest reaches of two large tropical rivers in north-eastern Australia. In addition, we compared fish assemblages recorded on baited versus unbaited cameras, and evaluated the sampling effort (duration of recording) required to estimate fish assemblages using remote underwater videos. We found that fish assemblages differed according to the depth, with statistically significant differences largely attributable to the prevalence of small-bodied species (Ambassis sp., Melanotaenia sp. and Pseudomugil signifer recorded in shallow (0.4–2.0m) and intermediate (2.1–4.9m) depths, and larger-bodied fish species (>10cm TL), such as Lutjanus argentimaculatus, Mesopristes argenteus and Caranx sexfasciatus, in deep water (>5.0m). Estimates of fish assemblage attributes generally stabilised after 60min recording duration, suggesting that interrogation of video footage beyond this duration may not be cost-effective. We conclude that depth is an important consideration when surveying large and deep river fish assemblages and that where water clarity is favourable, underwater video provides one of the means by which an assemblage can be investigated across the entire depth profile.

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Highβ-diversity maintains regional diversity in Brazilian tropical coastal stream fish assemblages

Fisheries Management and Ecology ◽

10.1111/fme.12194 ◽

2016 ◽

Vol 23 (6) ◽

pp. 531-539 ◽

Cited By ~ 2

Author(s):

F. A. Teshima ◽

B. J. G. Mello ◽

F. C. Ferreira ◽

M. Cetra

Keyword(s):

Fish Assemblages ◽

Stream Fish ◽

Regional Diversity ◽

Stream Fish Assemblages

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Persistence of Stream Fish Assemblages: Effects of Environmental Change

The American Naturalist ◽

10.1086/284393 ◽

1985 ◽

Vol 126 (1) ◽

pp. 24-40 ◽

Cited By ~ 123

Author(s):

Stephen T. Ross ◽

William J. Matthews ◽

Anthony A. Echelle

Keyword(s):

Environmental Change ◽

Fish Assemblages ◽

Stream Fish ◽

Stream Fish Assemblages

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Factors influencing riverine fish assemblages in Massachusetts

Scientific Investigations Report ◽

10.3133/sir20115193 ◽

2011 ◽

Cited By ~ 15

Author(s):

David S. Armstrong ◽

Todd A. Richards ◽

Sara B. Levin

Keyword(s):

Fish Assemblages ◽

Factors Influencing ◽

Riverine Fish

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Predicting New Zealand riverine fish reference assemblages

10.7287/peerj.preprints.26479v1 ◽

2018 ◽

Author(s):

Adam D Canning

Keyword(s):

New Zealand ◽

Freshwater Fish ◽

Riparian Vegetation ◽

Fish Assemblages ◽

Reference Conditions ◽

Native Fish ◽

River Reach ◽

Riverine Fish ◽

Insight Into

Biomonitoring is a common method to monitor environmental change in river ecosystems, a key advantage of biomonitoring over snap-shot physicochemical monitoring is that it provides a more stable, long-term. insight into change that is also effects-based. In New Zealand, the main biomonitoring method is a macroinvertebrate sensitivity scoring index, with little established methods available for biomonitoring of fish. This study models the contemporary distribution of common freshwater fish and then uses those models to predict freshwater fish assemblages for each river reach under reference conditions. Comparison of current fish assemblages with those predicted in reference conditions (as observed/expected ratios) may provide a suitable option for freshwater fish biomonitoring. Most of the fish communities throughout the central North Island and lower reaches show substantial deviation from the modelled reference community. Most of this deviation is explained by nutrient enrichment, followed by downstream barriers (i.e., dams) and loss of riparian vegetation. The presence of modelled introduced species had relatively little on the presence of the modelled native fish. The maps of observed/expected fish assemblage may provide a rapid way to identify potential restoration sites.

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Community Ecology of Stream Fishes: Concepts, Approaches, and Techniques

Community Ecology of Stream Fishes: Concepts, Approaches, and Techniques ◽

10.47886/9781934874141.ch5 ◽

2010 ◽

Keyword(s):

United States ◽

Life History ◽

Environmental Change ◽

Fish Assemblages ◽

Spatial Scales ◽

The United States ◽

Life History Strategies ◽

Population Responses ◽

Hydrologic Variability ◽

Reproductive Life

<em>Abstract</em>.—The flow regime is considered the primary driver of physical processes in riverine ecosystems; thus we expect that the trait composition of fish assemblages might respond similarly to hydrologic variability, even at broad spatial scales. Here, we test the hypothesis that freshwater fish life history strategies on two continents (southern United States and eastern Australia) converge along gradients of hydrologic variability and primary productivity at the drainage scale. Our results show that the fishes of the United States and Australia conform to the three-dimensional adaptive space arising from the trade-offs among three basic demographic parameters of survival, fecundity, and onset and duration of reproductive life. Species from both continents represent the endpoints in adaptive space defining the periodic (19% versus 33% for the United States and Australia, respectively), opportunistic (69% versus 52%), and equilibrium life history strategies (12% versus 15%). We found evidence that fish life history composition of drainage basins in the two continents have converged across similar gradients of hydrologic variability and productivity despite phylogenetic and historical differences. Moreover, these relationships were largely consistent with predictions from life history theory. Increasing hydrologic variability has promoted the greater prevalence of opportunistic strategists (a strategy that should maximize fitness in environmental settings dominated by unpredictable environmental change) while concurrently minimizing the persistence of periodic-type species (a strategy typically inhabits seasonal, periodically suitable environments). Our study provides a conceptual framework of management options for species in regulated rivers because life history strategies are the underlying determinants for population responses to environmental change and therefore can be used to classify typical population responses to flow alteration or mitigation via environmental flow prescriptions.

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