scholarly journals Spatiotemporal Dynamics of Stream Fish Assemblages Over Four Decades

2019 ◽  
Author(s):  
Zachery D. Zbinden

ABSTRACTFish assemblage structure was compared between 1974 and 2014 at 33 sampling locations in the Muddy Boggy River drainage, OK. The two main objectives for this comparison were to first quantify change in assemblage structure, and, second, to test for a relationship between compositional change and spatial scale. Spatial scale was manipulated by pooling assemblage data into groups ranging from K=33 pairs (i.e., local scale) to K=1 pair (i.e., global scale). Local assemblages varied in the degree of assemblage change over 4 decades (range=10-99% dissimilarity; mean=66%). The global assemblage remained quantitatively and qualitatively similar: most species persisted through time and those that did not were rare, and several diversity measures were not significantly different between time periods. Pooling assemblage data into consecutively larger groups and assessing the resultant compositional change revealed interesting patterns indicative of domains of spatial scaling. A discontinuity in the relationship between compositional change and spatial scale occurred at K=15, and this grouping is roughly the size of the headwater/tributary drainages of the Muddy Boggy system. This result suggests assemblages are more predictable when defined at scales larger than a stream reach, and a domain of higher predictability exists at a scale smaller than the entire drainage.

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Paulo Ilha ◽  
Sergio Rosso ◽  
Luis Schiesari

ABSTRACT The expansion of the Amazonian agricultural frontier represents the most extensive land cover change in the world, detrimentally affecting stream ecosystems which collectively harbor the greatest diversity of freshwater fish on the planet. Our goal was to test the hypotheses that deforestation affects the abundance, richness, and taxonomic structure of headwater stream fish assemblages in the Upper Xingu River Basin, in Southeastern Amazonia. Standardized sampling surveys in replicated first order streams demonstrated that deforestation strongly influences fish assemblage structure. Deforested stream reaches had twice the fish abundance than reference stream reaches in primary forests. These differences in assemblage structure were largely driven by increases in the abundance of a handful of species, as no influence of deforestation on species richness was observed. Stream canopy cover was the strongest predictor of assemblage structure, possibly by a combination of direct and indirect effects on the provision of forest detritus, food resources, channel morphology, and micro-climate regulation. Given the dynamic nature of change in land cover and use in the region, this article is an important contribution to the understanding of the effects of deforestation on Amazonian stream fish, and their conservation.


2010 ◽  
Vol 67 (1) ◽  
pp. 143-156 ◽  
Author(s):  
Darren J. Thornbrugh ◽  
Keith B. Gido

We found that riverine confluences had localized effects (within 20 km) on stream fish assemblages of the Kansas River basin. The majority of variation in fish assemblages occurred from east to west and along a stream size gradient. After controlling for the influences of longitude and stream size, distance of sample sites from streams ≥ 5th order accounted for a small proportion of taxonomic variability. However, species richness was significantly higher and assemblage structure was different in tributary stream segments directly connected to larger-ordered streams, suggesting that the effects of spatial position within this stream network were greatest in close proximity to tributary–mainstem confluences. Fish collections from three intensively sampled tributaries also indicated an abrupt change in species assemblages between mainstem river sites and tributary sample sites above confluences, followed by a gradual taxonomic change with increasing distance up to 20 km from the confluence. Changes in fish assemblages were associated with the reduced abundance of adult stream species near the confluence with the mainstem, rather than the occurrences of riverine species in the tributary.


2005 ◽  
Vol 62 (6) ◽  
pp. 1254-1270 ◽  
Author(s):  
John C Brazner ◽  
Danny K Tanner ◽  
Naomi E Detenbeck ◽  
Sharon L Batterman ◽  
Stacey L Stark ◽  
...  

The relative importance of regional, watershed, and in-stream environmental factors on fish assemblage structure and function was investigated in western Lake Superior tributaries. We selected 48 second- and third-order watersheds from two hydrogeomorphic regions to examine fish assemblage response to differences in forest fragmentation, watershed storage, and a number of other watershed, riparian, and in-stream habitat conditions. Although a variety of regional, fragmentation, and storage-related factors had significant influences on the fish assemblages, water temperature appeared to be the single most important environmental factor. We found lower water temperatures and trout–sculpin assemblages at lower fragmentation sites and higher temperatures and minnow–sucker–darter assemblages as storage increased. Factors related to riparian shading and flow separated brook trout streams from brown trout (Salmo trutta) – rainbow trout (Oncorhynchus mykiss) streams. Functionally, fish assemblages at lower fragmentation sites were dominated by cold-water fishes that had low silt tolerance and preferred moderate current speeds, while fishes with higher silt tolerances, warmer temperature preferences, and weaker sustained swimming capabilities were most common at higher storage sites. Our results suggest that site-specific environmental conditions are highly dependent on regional- and watershed-scale characters and that a combination of these factors operates in concert to influence the structure and function of stream fish assemblages.


2010 ◽  
Vol 61 (11) ◽  
pp. 1298 ◽  
Author(s):  
Brenton P. Zampatti ◽  
Christopher M. Bice ◽  
Paul R. Jennings

River regulation can diminish freshwater flows to estuaries and compromise estuarine functionality. Understanding biotic responses to altered flow regimes is imperative to effectively manage aquatic ecosystems. The present study investigated temporal variation in fish assemblage structure and the recruitment of catadromous fish in the Coorong estuary at the terminus of the Murray River, in south-eastern Australia. Over the three-year study period, freshwater inflows to the estuary diminished and ultimately ceased, disconnecting freshwater and estuarine environments. It was hypothesised that these conditions would lead to (1) increases in estuarine salinities and concomitant changes in fish assemblage structure and abundance, and (2) decreased recruitment of catadromous fish. As freshwater inflow decreased, salinities immediately downstream of a series of tidal barrages increased from brackish to marine–hypersaline, species richness and diversity decreased, freshwater and diadromous species became less abundant and assemblages were increasingly characterised by marine species. Furthermore, the abundance of young-of-year catadromous fish decreased dramatically. Excessive regulation of freshwater inflows is resulting in the Coorong estuary resembling a marine embayment, leading to a loss in species diversity. We suggest, however, that even small volumes of freshwater may promote diversity in estuarine fish assemblages and some recruitment of catadromous species.


Diversity ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 430
Author(s):  
Atsuko Fukunaga ◽  
Randall K. Kosaki ◽  
Kailey H. Pascoe ◽  
John H. R. Burns

The architectural complexity of coral-reef habitat plays an important role in determining the assemblage structure of reef fish. We investigated associations between the reef habitats and fish assemblages in the Northwestern Hawaiian Islands (NWHI) using in situ fish counts and data on habitat metrics and benthic community composition that were obtained from three-dimensional (3D) photogrammetric reconstructions of the surveyed sites. The structure of fish assemblage as a whole on the basis of Bray–Curtis dissimilarity, species richness and the abundances of herbivores and piscivores were associated with habitat metrics, with higher levels of architectural complexity generally supporting greater numbers of fish species and individuals. Benthic cover did not explain additional variation in these variables after the effects of habitat metrics were taken into account. Corallivorous fish was the only group that showed positive associations with both habitat metrics and benthic cover (Acropora and Pocillopora corals). The total fish abundance and the abundances of planktivores and invertivores did not show associations with either habitat metrics or benthic cover. This study suggests that an appropriate combination of habitat metrics can be used to account sufficiently for the effects of habitat architecture on fish assemblages in reef monitoring efforts in the NWHI.


2004 ◽  
Vol 82 (10) ◽  
pp. 1554-1565 ◽  
Author(s):  
Michael C Quist ◽  
Wayne A Hubert ◽  
Daniel J Isaak

Fish and habitat were sampled from 110 reaches in the Salt River basin (Idaho and Wyoming) during 1996 and 1997 to assess patterns in fish assemblage structure across a Rocky Mountain watershed. We identified four distinct fish assemblages using cluster analysis: (1) allopatric cutthroat trout (Oncorhynchus clarki (Richardson, 1836)); (2) cutthroat trout – brook trout (Salvelinus fontinalis (Mitchell, 1814)) – Paiute sculpin (Cottus beldingi Eigenmann and Eigenmann, 1891); (3) cutthroat trout – brown trout (Salmo trutta L., 1758) – mottled sculpin (Cottus bairdi Girard, 1850); and (4) Cyprinidae–Catostomidae. The distribution of fish assemblages was explained by thermal characteristics, stream geomorphology, and local habitat features. Reaches with allopatric cutthroat trout and the cutthroat trout – brook trout – Paiute sculpin assemblage were located in high-elevation, high-gradient streams. The other two fish assemblages were generally located in low-elevation streams. Associations between habitat gradients, locations of reaches in the watershed, and occurrence of species were further examined using canonical correspondence analysis. The results suggest that stream geomorphology, thermal conditions, and local habitat characteristics influence fish assemblage structure across a Rocky Mountain watershed, and they provide information on the ecology of individual species that can guide conservation activities.


2009 ◽  
Vol 66 (6) ◽  
pp. 933-948 ◽  
Author(s):  
Lynn D. Bouvier ◽  
Karl Cottenie ◽  
Susan E. Doka

Although many local and regional variables structure fish assemblage composition, few studies have assessed the effects of aquatic connectivity on fish assemblages in wetlands. Fish and habitat surveys were conducted in 12 wetlands across the lower Great Lakes basin in the spring and fall of 2003 and 2004. Spatial and temporal connectivity were classified into four connectivity classes to evaluate the interaction between aquatic connectivity and fish assemblage structure. Sequential, nested analysis of covariance was used to model the effect of habitat area and connectivity at long- and short-term time scales on aggregate descriptors of assemblage structure (i.e., species richness, piscivore richness, abundance, and diversity). Although no species–area relationship was detected, increases in connectivity were shown to positively affect species richness and piscivore richness. A variation decomposition method indicated that a combination of aquatic connectivity, followed by environmental and area variables, was most influential in structuring fish assemblages at short-term time scales. Connectivity thus influences both the local species pool present, as well as the abundance of these species within a wetland. Future fundamental and applied studies (e.g., climate change predictions, impact of humans on water budget, wetland management) on wetland fish assemblages should include connectivity as an important structuring process.


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