Effects of Urbanization on Stream Ecosystems

<em>Abstract.</em>—We examined fish assemblage responses to urban intensity gradients in two contrasting metropolitan areas: Birmingham, Alabama (BIR) and Boston, Massachusetts (BOS). Urbanization was quantified by using an urban intensity index (UII) that included multiple stream buffers and basin land uses, human population density, and road density variables. We evaluated fish assemblage responses by using species richness metrics and detrended correspondence analyses (DCA). Fish species richness metrics included total fish species richness, and percentages of endemic species richness, alien species, and fluvial specialist species. Fish species richness decreased significantly with increasing urbanization in BIR (<em>r </em>= –0.82, <EM>P </EM>= 0.001) and BOS (<em>r </em>= –0.48, <EM>P </EM>= 0.008). Percentages of endemic species richness decreased significantly with increasing urbanization only in BIR (<em>r </em>= – 0.71, <EM>P </EM>= 0.001), whereas percentages of fluvial specialist species decreased significantly with increasing urbanization only in BOS (<em>r </em>= –0.56, <EM>P </EM>= 0.002). Our DCA results for BIR indicate that highly urbanized fish assemblages are composed primarily of largescale stoneroller <em>Campostoma oligolepis</em>, largemouth bass <em>Micropterus salmoides</em>, and creek chub <em>Semotilus atromaculatus</em>, whereas the highly urbanized fish assemblages in BOS are dominated by yellow perch <em>Perca flavescens</em>, bluegill <em>Lepomis macrochirus</em>, yellow bullhead <em>Ameiurus natalis</em>, largemouth bass, pumpkinseed <em>L. gibbosus</em>, brown bullhead <em>A. nebulosus</em>, and redfin pickerel <em>Esox americanus</em>. Differences in fish assemblage responses to urbanization between the two areas appear to be related to differences in nutrient enrichment, habitat alterations, and invasive species. Because species richness can increase or decrease with increasing urbanization, a general response model is not applicable. Instead, response models based on species’ life histories, behavior, and autecologies offer greater potential for understanding fish assemblage responses to urbanization.

2011 ◽  
Vol 23 (2) ◽  
pp. 177-188 ◽  
Author(s):  
Yzel Rondon Súarez ◽  
Marcelo Maldonado de Souza ◽  
Fabiane Silva Ferreira ◽  
Maiane Jardim Pereira ◽  
Ediléia Amancio da Silva ◽  
...  

AIM: The present study analyzed the spatial variation in fish species richness and composition in streams of the Ivinhema River basin, Upper Paraná basin, determining the relationship between local and regional descriptors of the fish assemblage organization; METHOD: From 2001 to 2011 we sampled 200 stream stretches, using different sampling methods. Local species richness and composition were analyzed using univariate and multivariate methods to detect patterns of variation in the fish assemblage organization; RESULTS: We identified 111 fish species in the streams, and estimated the occurrence of 117 fish species (CIα0.05 = 111 to 123) with lower species richness in headwater streams compared to the lower parts of the basin. The fish species recorded were predominantly of small size, and the mean size increased from the headwaters to the river mouth. The four most common species are widely distributed in the basin. However, 24 species are allocthonous to the Upper Paraná basin, and two species (Chaetobranchopsis australis and Apistogramma commbrae) are recorded here for the first time in the Upper Paraná basin. Altitude was the main determinant of local fish species richness and composition, and a discontinuity in assemblage organization (richness, composition, fish size) was detected at approximately 430 m a.s.l.; CONCLUSION: Streams of the Ivinhema River basin are inhabited mainly by small-sized fishes; and longitudinal variation, interacting with local characteristics, determines the fish assemblage patterns.


<em>Abstract.</em>—An investigation of historical fisheries information for pools 4–13 of the upper Mississippi River (UMR) was conducted to 1) determine the pre-1938 relative abundance and distribution of bluegill <em>Lepomis macrochirus </em>and largemouth bass <em>Micropterus salmoides, </em>2) determine the composition and relative abundance of the preimpoundment fish assemblage, and 3) determine if a shift in frequency of occurrence and relative abundance has occurred due to impoundment.


2007 ◽  
Vol 67 (2) ◽  
pp. 191-195 ◽  
Author(s):  
M. Cetra ◽  
M. Petrere JR.

This work intends to examine if there are associations between fish species and the state of conservation of the riparian forest in the Corumbataí River Basin. Four main rivers were chosen for this study with three sites on each. Collections were carried out from March to June and from September to December 2001. Multivariate techniques were applied to determine the correlation between species richness and the order of the rivers, preservation level of the riparian forest, shade level, presence or absence of Eucalyptus, sugar cane and pastures, and surrounding declivity stability of the sites. Species richness was highest at locations with greater vegetation cover and preserved riparian forest.


2019 ◽  
Vol 76 (4) ◽  
pp. 1131-1139 ◽  
Author(s):  
Ben L Gilby ◽  
Andrew D Olds ◽  
Christopher J Henderson ◽  
Nicholas L Ortodossi ◽  
Rod M Connolly ◽  
...  

Abstract The seascape context of coastal ecosystems plays a pivotal role in shaping patterns in fish recruitment, abundance, and diversity. It might also be a principal determinant in structuring the recruitment of fish assemblages to restored habitats, but the trajectories of these relationships require further testing. In this study, we surveyed fish assemblages from 14 restored oyster reefs and 14 control sites in the Noosa River, Queensland, Australia, that differed in the presence or absence of seagrass within 500 m, over four periods using baited cameras. Fish assemblages at oyster reefs differed from those at control sites, with higher species richness (1.4 times) and more individuals of taxa that are harvested by fishers (1.8 times). The presence or absence of seagrass nearby affected the abundance of a key harvestable fish species (yellowfin bream Acanthopagrus australis) on oyster reefs, but not the overall composition of fish assemblages, species richness, or the total abundance of harvestable fishes overall. These findings highlight the importance of considering species-specific patterns in seascape utilization when selecting restoration sites and setting restoration goals, and suggest that the effects of restoration on fish assemblages might be optimized by focusing efforts in prime positions in coastal seascapes.


2020 ◽  
Vol 100 (7) ◽  
pp. 1171-1179
Author(s):  
Okan Akyol ◽  
Aytaç Özgül ◽  
F. Ozan Düzbastılar ◽  
Halil Şen ◽  
José M. Ortiz de Urbina ◽  
...  

AbstractThis study aims to determine the relationship between physico-chemical variables on a seasonal basis and wild fish assemblages beneath sea-cage fish farms. Assemblages of wild fish were counted monthly on two separate days at each of six fish farms between August 2015 and July 2017, by six rapid visual counts (RVC) in 5 minutes with scuba by two divers. Seawater samples were simultaneously taken by a Nansen bottle during the RVC from the fish farm barge. SST (°C), salinity (ppm), dissolved oxygen (mg l−1) and pH were measured by YSI multiparameter, while Secchi disk was also used for light transmittance. Wild fish species richness went up with increasing temperature and salinity in the Izmir region, however, this stopped at about 26°C and about 39 ppm. Wild fish richness increased when the DO was at a level of 7 mg l−1 and the pH at about 7.9 in Izmir. Between 10 and 20 m, light transmittance showed greater wild fish species richness in Izmir region. In contrast, the wild fish species richness of the Muğla region fluctuated more. In terms of wild fish species richness, these fluctuations increased with salinity and DO, while they decreased with SST, pH and light transmittance. However, the range of variation of the recorded physico-chemical variables is rather narrow. The results of the correlation matrix indicate that the relationship between wild fish species richness and pH and SST was statistically significant in Izmir region (P < 0.05).


2014 ◽  
Vol 59 (No. 1) ◽  
pp. 35-44 ◽  
Author(s):  
Z. Valová ◽  
M. Janáč ◽  
J. Švanyga ◽  
P. Jurajda

In August 2007, the 0+ juvenile fish assemblage of the upper River Elbe was surveyed using electrofishing. Thirty-six localities were sampled along a 177 km long section between the towns of Verdek and Brand&yacute;s nad Labem (river km (RKM) 136&ndash;313). Four localities with natural riverbeds, 14 channelized stretches, nine beaches, and nine backwaters were sampled. Altogether, 4521 0+ juvenile fishes were caught, belonging to 26 species. A decrease in species richness and abundance was evident near Hradec Kr&aacute;lov&eacute;, while decreased species abundance was noted along the navigated stretch below Přelouč. The highest catch-per-unit-effort (CPUE), species richness, and Shannon index values were observed at beach habitats, the lowest in channelized habitats, and intermediate values in backwaters. Generally, rare beach habitats had significantly more rheophilic species than other habitats, while backwaters had significantly more eurytopic species and higher CPUE for limnophilic species. Backwaters and channel habitats, however, did not differ in any other 0+&nbsp;fish assemblage parameter studied. The study demonstrated the importance of beaches for fish assemblages along navigable channels. Surprisingly, however, backwaters were not confirmed as important nursery habitats.


<em>Abstract.</em>—Iowa leads the nation in percentage of land area converted to cropland, with a resulting negative impact on streams. We examined physical habitat, land use, and fish assemblage data from 37 second- to sixth-order stream sites, representing 7 of the 10 ecoregions within Iowa. Physical habitat conditions varied widely among sites, with sand dominating substrate composition. A nonmetric multidimensional scaling ordination of physical habitat variables suggested a pattern of among-site similarities defined by a stream size axis, an axis contrasting sites dominated by either woody or rocky fish cover, and an axis characterizing degree of riparian canopy coverage. Bluntnose minnow <em>Pimephales notatus </em>and sand shiner <em>Notropis stramineus </em>were the most abundant fish species, followed by green sunfish <em>Lepomis cyanellus </em>and common carp <em>Cyprinus carpio</em>. These four species were collected in more than 80% of the sites. Fish species richness at sites averaged 22, ranging from 6 to 38, and fish index of biotic integrity (IBI) at sites averaged 47 (fair), ranging from 21 (poor) to 96 (excellent). Species richness and IBI were highest at sites characterized by rocky fish cover and relatively coarse substrates. Values for several physical habitat and land use variables were significantly different between sites with IBI ≤ 30 (fair) and sites with IBI ≥ 50 (good). We found a general pattern of IBI, species richness, total fish abundance, and width-to-depth ratio decreasing from the northeast to the southwest ecoregions, and percentage of unvegetated banks and bank slope increasing from northeast to southwest. Stable and vegetated banks, wide stream channels with coarse substrates, and rocky fish cover were associated with high biotic condition; while unvegetated and eroding banks, and deep channels with predominantly fine substrates were associated with lower biotic condition. Land use was calculated at three spatial scales: catchment, network riparian buffer, and local riparian buffer. We found few relationships of fish assemblages with land use, potentially due to sampling design and the pervasiveness of agriculture across Iowa. There is substantial variation among physical habitat, land use, and fish assemblage conditions across Iowa, due to a combination of geology, climate, zoogeography, and human alteration.


2016 ◽  
Vol 76 (4) ◽  
pp. 851-863 ◽  
Author(s):  
J. C. Silva ◽  
É. A. Gubiani ◽  
P. A. Piana ◽  
R. L. Delariva

Abstract Geographical barriers influence species distribution and play an important role in the segregation of fish assemblages. The present study aims to test the influence of a small natural barrier on the spatial distribution of fish species in the Verde River, Upper Paraná River Basin, Brazil, considering two biotopes: upstream and downstream of the Branca Waterfall. We observed the highest species richness downstream of the Branca Waterfall, which also had the highest number of exclusive species. Richness, evenness, and abundance varied significantly among biotopes. The composition and structure of the fish assemblage differed between biotopes, which were characterized by different indicator species, mainly downstream of the Branca Waterfall. Physical and chemical variables and geographical distance between sites were not responsible for the differences observed. Hence, the present study shows that small barriers can also be crucial in structuring fish fauna and play a key role in the segregation of fish assemblages.


2010 ◽  
Vol 55 (No. 3) ◽  
pp. 123-136 ◽  
Author(s):  
P. Jurajda ◽  
Z. Adámek ◽  
M. Janáč ◽  
Z. Valová

The aim of this study was to provide the first account of fish and macroinvertebrate communities in a heavily degraded river basin in the Czech Republic. Fish and macrozoobenthos were surveyed at 18 sites in the Bílina River and 11 sites in tributary streams during June–July 2007. Fish were sampled by electrofishing and macrozoobenthos were collected by kick-sampling using a sweep net. The composition of macroinvertebrate assemblages in headwater and reference sites in the upper Bílina River indicated clean water with saprobic index (SI) 1.31–1.43 followed by a transitional stretch downstream the Kyjická reservoir (SI 2.05–2.32) and dramatic decline of water quality to SI 3.18 in the river stretch downstream of industrial and municipal pollution at Litvínov-Záluží. Despite several minor pollution sources on the subsequent downstream river stretch until its mouth into the Elbe River, the water quality indicators fluctuated in the range of lower betamesosaprobity (SI 2.06–2.58). Species richness and biodiversity indices followed a similar pattern as river saprobity. Twenty-three fish species were documented in the Bílina River basin. Chub (<I>Leuciscus cephalus</I>), gudgeon (<I>Gobio gobio</I>) and roach (<I>Rutilus rutilus</I>) were the most frequent species at the Bílina sites. Chub was the most numerous fish in the tributaries. Fish species richness in the longitudinal profile did not increase downstream in the Bílina mainstem, most likely because the presence of reservoirs and water pollution interrupted the river continuum pattern. Qualitative data on fish assemblages corresponded to the course of environmental stress. A sustainable fish community was documented only in the lowermost site in Ústí nad&nbsp;Labem near the confluence with the Elbe River. The Bílina River tributaries constitute potential refuges for fish in this basin.


Author(s):  
Y. Letourneur ◽  
S. Ruitton ◽  
S. Sartoretto

Patterns of distribution of a Mediterranean fish assemblage, with special attention to juvenile labrids, were studied at different depths on the basis of their relationships with environmental and benthic habitat features on a rocky coast at Marseille, south-eastern France. Fish species were distributed according to depth, with juveniles and small individuals being found in shallow waters, whereas larger individuals were found in deeper waters. However, depth by itself was not a significant factor in explaining fish species pattern, whereas sandy bottom habitat was significant. The most significant factors explaining fish species distribution were small and large blocks, and rock cover. Juvenile labrids, such as the most abundant ones Coris julis and Symphodus ocellatus, were only rarely observed deeper than 10 m, and the distribution of these juveniles was mainly correlated with a cover of macroalgae, rubble and small blocks. Fish density and fish biomass were higher in shallow than in deeper waters, although some species displayed an opposite pattern, such as the adult of C. julis and Diplodus sargus. The most significant factors explaining the fish density pattern found were the presence of macroalgae, Posidonia oceanica sea grass and sand cover. Among environmental factors assessed in this study, exposure to dominant winds was never significant, either for the whole fish assemblage or for juvenile labrids, or for the communities at any of the depth strata investigated. Depth was a significant factor influencing the distribution of juvenile labrids, whereas its significance in explaining fish density was lower. Bottom slope was generally more significant than depth, and thus constituted the most significant environmental factor. Benthic habitat characteristics were all significant, except for rubble cover, in explaining both fish species and fish density distributions. However, the amplitude of the relationships between substrate variables and fish assemblages was dependent on the descriptor studied (i.e. species distribution, including considerations of fish sizes, and fish density), suggesting that extrapolation of a particular relationship to other components of a fish assemblage would most likely be unfounded. Our results as a whole indicate that benthic habitat use by fish on Mediterranean rocky infralittoral coast is clearly non-random, and suggest that differences in habitat and/or environmental characteristics have significant effects at a small spatial scale on these fish assemblages.


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