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1.
Landscape Determinants of Nonindigenous Fish Invasions 总被引:2,自引:0,他引:2
Robert M. Ross William A. Lellis Randy M. Bennett Connie S. Johnson 《Biological invasions》2001,3(4):347-361
Much has been written about the influence of exotic or nonindigenous species on natural habitats and communities of organisms, but little is known of the physical or biological conditions that lead to successful invasion of native habitats and communities by exotics. We studied invasivity factors in headwater streams of the Susquehanna River West Branch, which drains portions of the northern Appalachian Plateau. A replicated (two major tributaries) 3 × 3 factorial design was used to determine landscape effects of size (stream order) and quality (land use) on abiotic (physical and chemical) and biotic (fish community structure and function) stream attributes. Seven (21%) of thirty-four fish species (brown trout, common carp, mimic shiner, bluegill, smallmouth bass, fantail darter, and banded darter) collected in the eighteen streams sampled were nonindigenous to the basin. Watershed size (stream orders 1, 3, and 5) significantly affected stream geomorphologic and habitat variables (gradient, width, depth, current velocity, diel water temperature, bank overhang, canopy cover, and woody debris density) but not water-quality variables, while land use in watersheds (conservation, mining, and agriculture) significantly affected measured water-quality variables (alkalinity and concentrations of manganese, calcium, chloride, nitrate, and total dissolved solids) but not stream physical or habitat quality. Both watershed size and land use affected fish-community variables such as presence of particular species, species density, species diversity, tolerance diversity, and mean fish size, but in both cases the effect was transparent to native-origin status of fish species. No relationships were found between occurrence of nonindigenous species in watersheds and trophic structure or functional diversity. Therefore, the hypothesis that reduced species diversity increases vulnerability to nonindigenous species was not supported. However, the spatial variation associated with both water-quality and habitat-quality factors was greater in streams with mixed (those with nonindigenous species) than with exclusively native assemblages. These findings suggest that the mechanism for successful invasion by nonindigenous or exotic species is through change in water or habitat quality associated with human or natural disturbances, such as agriculture and mining activities in watersheds. Biotic factors appear to play no or a lesser role in the invasibility of northern Appalachian lotic systems. 相似文献
2.
David P. Gillette Allison M. Fortner Nathan R. Franssen Sara Cartwright Courtney M. Tobler Jeff S. Wesner Paulette C. Reneau Franz H. Reneau Ingo Schlupp Edie C. Marsh‐Matthews William J. Matthews Richard E. Broughton Corey W. Lee 《Ecography》2012,35(9):855-864
Rivers and streams are among the most threatened ecosystems worldwide, and their fish assemblages have been modified by anthropogenic habitat alteration and introductions of non‐native species. Consequently, two frequently observed patterns of assemblage change over time are species loss and biotic homogenization. In the present study, we compared contemporary (2006–2007) and historical (1948–1955) assemblages of darters, a group of small benthic fishes of the family Percidae, in the Arkansas River drainage of northeastern Oklahoma, USA. Results showed species loss between the two sampling periods, with historical estimates of overall species diversity across the study area exceeding contemporary estimates by five to eight species. Assemblages showed a low degree of darter similarity based on species presence and absence, with pairwise site comparisons (Jaccard's similarity index) between historical and contemporary samples averaging < 0.35. No significant homogenization or differentiation of assemblages occurred. Range expansion of widespread species, one of the primary mechanisms of biotic homogenization, was not observed; rather, all species occurred at a smaller proportion of sites in contemporary samples. Our results highlight the threat posed by anthropogenic habitat alteration to taxonomic groups such as darters, most of which are habitat specialists. However, our results suggest that biotic homogenization is unlikely to occur in the absence of immigration, especially if assemblages are subjected to ‘novel disturbances’ such as dam construction and watershed‐scale habitat degradation which negatively affect all components of the assemblage. 相似文献
3.
Christopher M. Bunt Steven J. Cooke R. Scott McKinley 《Environmental Biology of Fishes》1998,51(3):297-308
The biology, microhabitat use and migratory behaviour of the greenside darter, Etheostoma blennioides, was studied at the
Mannheim Weir on the Grand River, Ontario during the summer of 1995 and 1996. Officially listed as vulnerable in Canada, greenside
darters reached maturity at age 1 and lived up to 4 years. They were found in riffle habitats that consisted of cobble and
loose boulders, with large mats of Cladophora. This type of unembedded substrate is uncommon in the Grand River watershed.
However, local abundance of greenside darters immediately downstream from the Mannheim Weir was likely due to high water velocities
from weir discharge, freshets and ice scour which help maintain unembedded riffle areas. Trap data indicated that greenside
darters temporally partition this habitat with the stonecat, Noturus flavus. Other darter species were not commonly found
in areas with greenside darters, whose depth selection and habitat choices were influenced by predators and morphology. Denil
fishways at the Mannheim Weir rarely passed greenside darters due to prohibitively high water velocities and exclusion by
larger fish.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
4.
Influences of low-head dams on the fish assemblages in the headwater streams of the Qingyi watershed, China 总被引:1,自引:0,他引:1
Yunzhi Yan Hong Wang Ren Zhu Ling Chu Yifeng Chen 《Environmental Biology of Fishes》2013,96(4):495-506
The influences of low-head dams on the fish assemblages were examined in this study, using fish data collected in six treatment and five reference sites at three low-head dams in the headwater streams of the Qingyi watershed, China. Comparing with those in the reference sites, local habitat variables were significantly altered by low-head dams in the treatment sites, involving wider channel (only in the impoundment area), deeper water and slower flow. Fish species richness varied significantly across seasons, not across site categories, suggesting that these low-head dams did not alter species richness. However, significant decreases in fish abundance and density were observed in the impoundment areas immediately upstream of dams, but not in the plunge areas downstream. Fish assemblage structures kept relative stability across seasons, and their significant difference between-site was only observed between the impoundment areas and the sites far from dams upstream. This variation in assemblage structures was due to the differing relative abundance of some co-occurring species; more lentic but less lotic fish was observed in the impoundment areas. The spatial and temporal patterns of fish assemblages were correlated with local habitat in this study area. Wetted width had negative correlation with fish species richness, abundance and density, respectively. Water temperature also positively affected species richness. In addition, wetted width, water depth, current velocity and substrate were the important habitat variables influencing assemblage structures. Our results suggested that, by modifying local habitat characteristics, low-head dams altered fish abundance and density in the impoundment areas immediately upstream of dam, not in the plunge areas immediately downstream, and thereby influenced fish assemblage structures in these stream segments. 相似文献
5.
VICTOR F. V. PAZIN WILLIAM E. MAGNUSSON JANSEN ZUANON FERNANDO P. MENDONÇA 《Freshwater Biology》2006,51(6):1025-1037
1. The effect of habitat structural features and physicochemical characteristics of the water on the composition and richness of fish assemblages in temporary ponds near streams were examined at three spatial scales: among ponds, among streams and between drainage basins, in a ‘terra‐firme’ (not subject to long‐term flooding) forest reserve in Central Amazonia. 2. The fish assemblage in temporary ponds was composed of subsets of 18 small‐bodied species widely distributed in the reserve. The assemblages had a nested subset structure, where smaller ponds contained subgroups of the species found in larger ponds. 3. Species composition and richness in temporary ponds were similar between drainage basins, although the fish assemblages in streams differed between basins. 4. Fish assemblage structure was influenced by local factors related to habitat structure, such as pond area and depth, canopy cover and hydroperiod. Physicochemical characteristics of the water in the ponds were similar between drainage basins and had little detectable effect on the structure of pond fish assemblages. 5. No correspondence was found between the composition, richness or abundance of fishes in the ponds and in stretches of the streams adjacent to the ponds. Therefore, it is not possible to predict the composition of these temporary pond fish assemblages from the fish assemblages found in adjacent streams. 相似文献
6.
Synopsis We documented species' distributions, size structure of populations, abundance in mainstem and tributary streams, habitat use, and diets of prickly sculpin, Cottus asper, and coastrange sculpin, C. aleuticus, in the Eel River drainage of California, to determine the processes allowing coexistence of these very similar fishes. We observed prickly sculpins at 43 sites and coastrange sculpins at 34. The species co-occurred at 26 sites. Young-of-year coastrange sculpins were only observed within 42 km of the ocean, but young-of-year prickly sculpins were present throughout the species range. Mean, maximum, and minimum lengths of coastrange sculpins were positively correlated with distance from the ocean but no significant relationships were found for prickly sculpins. Absolute abundance of both species was highest in mainstem habitat (prickly sculpins = 0.6 sculpins m–2 and coastrange sculpins = 0.4 sculpins m–2) . Tributary densities of both species tended to be less than 0.1 sculpins m–2. The species inhabited very similar habitats and had very similar diets. Coastrange sculpin populations in upstream areas were maintained by immigration from downstream areas in contrast with prickly sculpin populations that produced young-of-year fish throughout their range. Densities were probably not high enough for interspecific interactions to be important. The factors limiting the upstream distribution of the species may include high water temperatures, stability of the stream bed, and behavior of the fish. In the past, the range of sculpins within the Eel River drainage probably fluctuated with changing physical conditions. Recent introductions of exotic species that compete with and prey upon sculpins, and ongoing human activities in the drainage could result in major reductions in the distribution and abundance of one or both species. 相似文献
7.
Stormwater ponds are increasingly common aquatic habitats whose biotic communities are largely unexplored. As anthropogenic
development continues to alter the landscape, watershed land use is gaining recognition for its potential to predict species
compositions in aquatic systems. This study reports species composition of five aquatic hemipteran families (Notonectidae,
Corixidae, Belostomatidae, Nepidae, Pleidae) in 28 permanent, artificial stormwater ponds in watersheds with different land
covers and associated contaminant input. We hypothesized that land cover variables would be significant drivers of aquatic
hemipteran community structure in ponds, and that ponds with a high percentage of agricultural and lawn cover in the watershed
would be characterized by the absence of species intolerant of the chemical, physical, and ultimately biotic changes associated
with these watersheds. Non-metric multi-dimensional scaling (NMS) was used to identify dominant gradients of species composition
and environmental variables. Pond morphology variables, watershed lawn, watershed agriculture, and predatory fish abundance
were each found to have statistically significant correlations with hemipteran community structure. The abundance of Notonecta undulata, the species responsible for creating the largest (ranked) distance in species structure among ponds, was positively correlated
with shallow, fishless ponds and independent of land use variables. The abundances of four species of corixids were negatively
correlated with watershed agriculture, and hemipteran richness was positively correlated with watershed lawn and negatively
correlated with pond surface area. Heirarchical cluster analysis revealed non-random hemipteran species assemblages in which
congeneric corixid species tended to co-occur, contradicting traditional niche theory. Since artificial stormwater ponds are
chemically different from natural-pond habitat and rapidly increasing in number, knowledge of which insect species are capable
of thriving in this environment and their relationship to land use in the watershed is of both environmental and evolutionary
interest.
Handling editor: D. Dudgeon 相似文献
8.
Kirk O. Winemiller Hernán López-Fernández Donald C. Taphorn Leo G. Nico Aniello Barbarino Duque 《Journal of Biogeography》2008,35(9):1551-1563
Aim The aim of this study was to determine whether the Casiquiare River functions as a free dispersal corridor or as a partial barrier (i.e. filter) for the interchange of fish species of the Orinoco and Negro/Amazon basins using species assemblage patterns according to geographical location and environmental features. Location The Casiquiare, Upper Orinoco and Upper Negro rivers in southern Venezuela, South America. Methods Our study was based on an analysis of species presence/absence data and environmental information (11 habitat characteristics) collected by the authors and colleagues between the years 1984 and 1999. The data set consisted of 269 sampled sites and 452 fish species (> 50,000 specimens). A wide range of habitat types was included in the samples, and the collection sites were located at various points along the entire length of the Casiquiare main channel, at multiple sites on its tributary streams, as well as at various nearby sites outside the Casiquiare drainage, within the Upper Orinoco and Upper Rio Negro river systems. Most specimens and field data used in this analysis are archived in the Museo de Ciencias Naturales in Guanare, Venezuela. We performed canonical correspondence analysis (CCA) based on species presence/absence using two versions of the data set: one that eliminated sites having < 5 species and species occurring at < 5 sites; and another that eliminated sites having < 10 species and species occurring at < 10 sites. Cluster analysis was performed on sites based on species assemblage similarity, and a separate analysis was performed on species based on CCA loadings. Results The CCA results for the two versions of the data set were qualitatively the same. The dominant environmental axis contrasted assemblages and sites associated with blackwater vs. clearwater conditions. Longitudinal position on the Casiquiare River was correlated (r2 = 0.33) with CCA axis‐1 scores, reflecting clearwater conditions nearer to its origin (bifurcation of the Orinoco) and blackwater conditions nearer to its mouth (junction with the Rio Negro). The second CCA axis was most strongly associated with habitat size and structural complexity. Species associations derived from the unweighted pair‐group average clustering method and pair‐wise squared Euclidean distances calculated from species loadings on CCA axes 1 and 2 showed seven ecological groupings. Cluster analysis of species assemblages according to watershed revealed a stronger influence of local environmental conditions than of geographical proximity. Main conclusions Fish assemblage composition is more consistently associated with local environmental conditions than with geographical position within the river drainages. Nonetheless, the results support the hypothesis that the mainstem Casiquiare represents a hydrochemical gradient between clearwaters at its origin and blackwaters at its mouth, and as such appears to function as a semi‐permeable barrier (environmental filter) to dispersal and faunal exchanges between the partially vicariant fish faunas of the Upper Orinoco and Upper Negro rivers. 相似文献
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Biogeography,ecoregions, and geomorphology affect fish species composition in streams of eastern Oklahoma,USA 总被引:1,自引:0,他引:1
Daniel C. Dauwalter Dale K. Splinter William L. Fisher Richard A. Marston 《Environmental Biology of Fishes》2008,82(3):237-249
Stream fish assemblages are structured by biogeographical, physical and biological factors acting on different spatial scales.
We determined how physical factors, geomorphology and stream habitat, influenced fish species composition (presence–absence)
in eastern Oklahoma, USA relative to the ecoregion and biogeographic effects previously reported. We sampled fish assemblages
and surveyed geomorphology and habitat at 107 stream sites in the Boston Mountains, Ouachita Mountains, and Ozark Highlands
ecoregions in eastern Oklahoma. Partial canonical correspondence analyses (pCCAs) and variance partitioning showed that patterns
of endemism related to drainage basins and ecoregions explained important variation in fish species composition in all streams,
but stream size and local channel morphology explained more variation overall. Stream size effects were most important in
explaining variability in fish species composition in both northeastern and southeastern Oklahoma streams. Local channel morphology
and substrate characteristics were secondarily important. Variables typically considered important as fish habitat (aquatic
vegetation, etc.) had little effect on fish species composition. 相似文献
12.
Detailed analyses of habitat associations with rare species are typically constrained by limited sample size and the availability
of habitat data. The dense spatial coverage of stream sampling by the Maryland Biological Stream Survey provides ample data
to quantitatively examine correlations between habitat and rare species distributions. The shield darter, Percina peltata, has a widespread distribution on the Atlantic Slope of the United States, but is uncommon throughout its range in Maryland.
Associations of in situ physical habitat, water chemistry, and alterations in landscape with shield darter presence in the
Eastern Piedmont physiographic province in Maryland were examined. Shield darter occurrence was associated with larger sized
streams in concordance with the species’ known ecology. Shield darter distribution was further associated with stream segments
with deep riffle habitats with diverse velocities, low concentrations of chloride and sulfate, low levels of urbanization
in upstream catchments, and several pollution intolerant fish species. Although the exact mechanism of the effects is not
clear, results indicate that the shield darter is sensitive to urban development and habitat and water quality alteration
that typically accompanies urbanization. Shield darter conservation in Maryland necessitates the protection and restoration
of minimally urbanized watersheds where they are known to occur. The results from this study indicate that habitat information
on rare species may be important in elucidating important habitat associations that are not evident via examination of community
level data. 相似文献
13.
Scott M. Reid Nicholas E. Mandrak Leon M. Carl Chris C. Wilson 《Environmental Biology of Fishes》2008,81(1):111-125
Redhorse, Moxostoma spp., are considered to be negatively affected by dams although this assertion is untested for Canadian populations. One
hundred and fifty-one sites in the Grand River watershed were sampled to identify factors influencing the distribution of
redhorse species. Individual species of redhorse were captured from 3 to 32% of sites. The most widespread species were golden
redhorse, M. erythrurum (30%) and greater redhorse, M. valenciennesi (32%), while river redhorse, M. carinatum, was only found along the lower Grand River. Redhorse were absent from the highly fragmented Speed River sub-watershed and
upper reaches of the Conestogo River and the Grand River. Redhorse species richness was positively correlated to river fragment
size and upstream drainage area. Generalized additive models (GAMs) were applied to evaluate the influence of river fragment
length, connectivity and habitat on species distribution. Principal component analysis reduced habitat data to three axes
representing: channel structure, substrate, and pool, riffle and run habitats (PC1); gradient and drainage area (PC2); and
cover (PC3). GAMs indicate that PC2 was important for predicting black redhorse and greater redhorse site occupancy and PC1
was important for golden redhorse. River fragment length was important for predicting site occupancy for shorthead redhorse,
but not other species. 相似文献
14.
Synopsis The tolerance of fantail, rainbow, and greenside darters to low oxygen was determined by exposing fish to conditions of progressively
decreasing oxygen levels and recording the oxygen concentration at which loss of equilibrium occurred. The greenside darter
was least tolerant to low oxygen levels in summer, with loss of equilibrium occurring at a mean O2 concentration of 3.39 mg l−1. Tolerances then increased through spring. A similar trend was observed for the fantail darter, with the lowest tolerance
occurring in summer (2.36 mg −1). and greatest tolerance in spring (2.03 mg l−1). The rainbow darter exhibited its greatest tolerance to low oxygen in summer and spring (1.64 and 1.93 mg l−1, respectively). Interspecific differences were greatest in summer, with greenside darters being the least tolerant to low
oxygen levels and the rainbow darter being the most tolerant. No differences in tolerance among the species were noted in
winter. The low oxygen tolerance exhibited in summer by the greenside darter may be due to a higher metabolic cost and a higher
critical oxygen tension at maximal stream temperatures (>25° C). The observed differences in oxygen tolerance may influence
the longitudinal distribution and habitat selection of darters, especially in the summer months. 相似文献
15.
Genetic diversity and species diversity are expected to covary according to area and isolation, but may not always covary
with environmental heterogeneity. In this study, we examined how patterns of genetic and species diversity in stream fishes
correspond to local and regional environmental conditions. To do so, we compared population size, genetic diversity and divergence
in central stonerollers (Campostoma anomalum) to measures of species diversity and turnover in stream fish assemblages among similarly sized watersheds across an agriculture–forest
land-use gradient in the Little Miami River basin (Ohio, USA). Significant correlations were found in many, but not all, pair-wise
comparisons. Allelic richness and species richness were strongly correlated, for example, but diversity measures based on
allele frequencies and assemblage structure were not. In-stream conditions related to agricultural land use were identified
as significant predictors of genetic diversity and species diversity. Comparisons to population size indicate, however, that
genetic diversity and species diversity are not necessarily independent and that variation also corresponds to watershed location
and glaciation history in the drainage basin. Our findings demonstrate that genetic diversity and species diversity can covary
in stream fish assemblages, and illustrate the potential importance of scaling observations to capture responses to hierarchical
environmental variation. More comparisons according to life history variation could further improve understanding of conditions
that give rise to parallel variation in genetic diversity and species diversity, which in turn could improve diagnosis of
anthropogenic influences on aquatic ecosystems. 相似文献
16.
Macroecology of a host-parasite relationship 总被引:3,自引:0,他引:3
The larvae of freshwater mussels are obligate ectoparasites on fishes while adults are sedentary and benthic. Dispersal of mussels is dependent on the movement of fish hosts, a regional process, but growth and reproduction should be governed by local processes. Thus, mussel assemblage attributes should be predictable from the regional distribution and abundance of fishes. At a broad spatial scale in the Red River drainage, USA, mussel species richness and fish species richness were positively associated; maximum mussel richness was limited by fish richness, but was variable beneath that constraint. Measured environmental variables and the associated local fish assemblages each significantly accounted for the regional variation in mussel assemblages. Furthermore, mussel assemblages showed strong spatial autocorrelation. Variation partitioning revealed that pure fish effects accounted for 15.4% of the variation in mussel assemblages; pure spatial and environmental effects accounted for 16.1% and 7.8%, respectively. Shared variation among fish, space and environmental variables totaled 40%. Of this shared variation, 36.8% was associated with the fish matrix. Thus, the variation in mussel assemblages that was associated with the distribution and abundance of fishes was substantial (> 50%), indicating that fish community structure is an important determinant of mussel community structure. Although animals commonly disperse plants and, thus, influence the structure of plant communities, our results show a strong macroecological association between two disparate animal groups with one strongly affecting the assemblage structure of the other. 相似文献
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Genetic, demographic, and environmental processes affect natural populations synergistically, and understanding their interplay is crucial for the conservation of biodiversity. Stream fishes in metapopulations are particularly sensitive to habitat fragmentation because persistence depends on dispersal and colonization of new habitat but dispersal is constrained to stream networks. Great Plains streams are increasingly fragmented by water diversion and climate change, threatening connectivity of fish populations in this ecosystem. We used seven microsatellite loci to describe population and landscape genetic patterns across 614 individuals from 12 remaining populations of Arkansas darter (Etheostoma cragini) in Colorado, a candidate species for listing under the U.S. Endangered Species Act. We found small effective population sizes, low levels of genetic diversity within populations, and high levels of genetic structure, especially among basins. Both at- and between-site landscape features were associated with genetic diversity and connectivity, respectively. Available stream habitat and amount of continuous wetted area were positively associated with genetic diversity within a site, while stream distance and intermittency were the best predictors of genetic divergence among sites. We found little genetic contribution from historic supplementation efforts, and we provide a set of management recommendations for this species that incorporate a conservation genetics perspective. 相似文献
20.
Peter B. Moyle Patrick K. Crain Keith Whitener Jeffrey F. Mount 《Environmental Biology of Fishes》2003,68(2):143-162
The Cosumnes River is the largest stream without a major dam on its mainstem in the Sacramento–San Joaquin drainage, central California, U.S.A. We studied its fishes over a 3-year period to answer the following questions: (1) Was the native fish fauna still present? (2) Why were alien fishes so abundant in a river system with a 'natural' flow regime, which elsewhere has been shown to favor native fishes? (3) Were there assemblages of fishes that reflected environmental differences created by the underlying geology? (4) Were there features of the watershed that consistently favored native fishes or that could be managed to favor native fishes? Of the 25 species collected, 17 were alien species; 14 species (five native) were abundant or widely distributed enough to use in detailed analyses. Of the native species, only rainbow trout, Oncorhynchus mykiss, still occupied much of its native range in headwater streams. Other native species have been extirpated or persisted mainly above barriers to alien invasions. The most widely distributed alien species was redeye bass, Micropterus coosae, previously unknown from the river, whose abundance was associated with low-numbers of native species. Other aliens were found primarily in low-land habitats on the valley floor or foothills. Canonical Correspondence Analysis indicated that both native and alien species located on environmental gradients determined largely by elevation, temperature, flow, and emergent vegetation, but the associations with these variables were not strong. While most alien fishes were found in lowland sections of river flowing through agricultural regions, the general relationships between species abundance and landscape-level variables were weak. Assemblages of fishes were poorly defined mixtures of native and alien species. The strikingly distinct geological regions of the basin no longer supported distinct fish assemblages. Species distributions were highly individualistic, reflecting dynamic patterns of introductions, invasions, and local extinctions, as well as physiological tolerances and life history patterns. Most native fishes are likely to persist in the Cosumnes River only if summer flows are increased and if populations above natural barriers are protected from further invasions by alien species, especially redeye bass. General conclusions from this study include: (1) altered habitats can support native species under some circumstances; (2) new fish assemblages with characteristics of 'natural' communities are likely to develop in invaded systems; (3) restoring flow regimes to favor native fishes may require restoring minimum summer flows as well as high channel-forming flows. However, reversing or even reducing, the impact of the predatory redeye bass, pre-adapted for California streams, is probably not possible. 相似文献