Large rivers in the United States support popular recreational and commercial fisheries despite being among the most heavily anthropogenically modified habitats due to the construction of dams and levees, agricultural and industrial pollution, and channel modification, all of which can disrupt aquatic ecosystem function and affect fish community composition and abundance. However, despite their relative importance, riverine fisheries research tends to lag behind that of lakes and reservoirs due to the complexity of habitats and difficulties in reliably sampling dynamic waterbodies. Many fisheries biologists, researchers, and managers have implemented long-term resource monitoring programs on large rivers to collect and aggregate data on fish assemblage, population demographics, and vital rates. Nonetheless, much is still unknown about many riverine sport and non-game fish populations and how the design and implementation of these monitoring programs affects the data collected. This study aimed to fill the knowledge gap around Smithland Pool, Ohio River Black Crappie (Pomoxis nigromaculatus) and White Crappie (Pomoxis annularis) populations, as well as use fish community data from the random site selection long-term electrofishing program (LTEF) in the Smithland Pool Ohio River and fixed site IDNR annual community sampling programs in the mainstem Smithland Pool (OHR) and Illinois tributaries (OHT) from 2012-2021 to compare measures of fish assemblage structure and relative abundance and size for select sportfish populations between concurrent fixed and random site selection sampling programs in Smithland Pool, with broader implications of the relative strengths of different site selection methods in the implementation of long-term large river fish monitoring programs. Crappie are infrequently encountered in the mainstem Smithland Pool and so were sampled in the lower reaches of seven tributaries in the fall and spring of 2020 and 2021. IDNR provided additional specimens through their annual fall tributary fish community monitoring efforts. Crappies were aged using whole sagittal otoliths and population demographics and vital rates were calculated for each species. Year-class strength was represented by catch curve residuals and correlational relationships with a variety of environmental factors were established. LASSO regression models were also used to eliminate unimportant variables. Smithland Pool tributary Black Crappie and White Crappie size structure, condition, growth rates, and mortality rates were consistent with other regional fisheries. White Crappie exhibited relatively lower mortality rates, faster growth rates, and a higher proportion of larger fish in the population, though 1.7x more Black Crappie were captured than White Crappie. Strong Black Crappie year-classes were positively associated with post-spawn (June-September) Ohio River discharge while strong White Crappie year-classes were positively associated with fall (October-December) air temperature, a proxy for water temperature. The findings of this study suggest that Smithland Pool Ohio River tributary crappie population structure and vital rates are such that they can support current levels of angler harvest and highlight the differential effects of environmental variables on either crappie species’ reproductive success. Rates of Smithland Pool tributary crappie fishing mortality are currently unknown and verification of vital rates, size structure, and environmental variable-recruitment relationships is needed to ensure proper management of these species into the future. ANOSIM and NMDS analysis indicated clear significant differences between fish assemblages observed through different programs, largely driven by centrarchid species, among others, who associated more with relatively structure rich tributary and fixed site mainstem habitats. Differences in CPUE and size structure of Bluegill (Lepomis macrochirus), Largemouth Bass (Micropterus salmoides), Longear Sunfish (Lepomis megalotis), Redear Sunfish (Lepomis microlophus), and Spotted Bass (Micropterus punctulatus) between programs were inconsistent among species but generally, fixed site tributary sampling caught experienced the highest CPUE, followed by fixed site river sampling and finally random site mainstem sampling. Observed size structure was most similar between fixed and random site river sampling programs, while fixed site tributary sampling generally yielded the smallest size structure, suggesting differential habitat use by fishes of different sizes/ages. These results help to inform the effects of site selection protocols and sampling location on data collected through long-term large river monitoring programs, provide guidelines regarding proper application of data from such programs, as well identify complementary relationships between concurrently implemented sampling designs.

Constructed reefs are used successfully in marine systems to enhance spawning habitat; this study examines the effectiveness of constructed reefs in a tidal-freshwater river. Fish abundance, species diversity and richness, residency, water column position, reproductive guilds, and feeding guilds were analyzed on two constructed reefs in the tidal-freshwater James River and compared to silted regions representing the primary substrate in the river. Reefs were sampled using hydroacoustics, electroshocking, gillnetting, trawling, and egg mats. The constructed reefs had a greater proportion of fish that broadcast spawn over hard substrate and a trend of more overall individual, residential, and demersal fish. The results suggest that the reefs may be attracting a different fish community than their respective comparison sites, though additional research on the effectiveness of constructed reefs in tidal-freshwater rivers is recommended.

Bioassessment can be performed through several methods and with different bioindicators. In Canadian Areas of Concern (AOC), fishes are used as a proxy for site condition. The Index of Biotic Integrity (IBI), a multimetric index for biological assessment, has been applied to fish data across Canadian AOCs to detect recovery. Previous studies, however, have indicated the IBI is not sensitive to assemblage changes characteristic of later stages of recovery. In this study, the IBI and multivariate methods were applied to data from two AOCs, the Detroit and St. Clair rivers. The results revealed that the IBI is susceptible to species substitutions within metric categories. The substitutions produced high variability within narrative ranks and rendered the IBI insensitive to changes, detected by multivariate methods, in the fish assemblage. In the absence of reference sites, the multivariate analyses were supplemented with the development of a reference condition based on best professional judgment.

Bioassessment can be performed through several methods and with different bioindicators. In Canadian Areas of Concern (AOC), fishes are used as a proxy for site condition. The Index of Biotic Integrity (IBI), a multimetric index for biological assessment, has been applied to fish data across Canadian AOCs to detect recovery. Previous studies, however, have indicated the IBI is not sensitive to assemblage changes characteristic of later stages of recovery. In this study, the IBI and multivariate methods were applied to data from two AOCs, the Detroit and St. Clair rivers. The results revealed that the IBI is susceptible to species substitutions within metric categories. The substitutions produced high variability within narrative ranks and rendered the IBI insensitive to changes, detected by multivariate methods, in the fish assemblage. In the absence of reference sites, the multivariate analyses were supplemented with the development of a reference condition based on best professional judgment.

Patterns of fish spatial distribution were studied in two Czech canyon-shaped reservoirs and in three Dutch basin-shaped reservoirs. Effects of environmental variables like habitat depth, slope, distance from the shore and distance from the dam were evaluated using multivariate statistics. Gillnet selectivity was also studied as fish were sampled using gillnets.

Anthropogenic development is altering watersheds and threatening freshwater ecosystems and the resources therein. Direct impacts of industry including conversion of land cover and increased water withdrawals from rivers, compounded with indirect influences such as climate change, collectively affect the health and sustainability of freshwater ecosystems. Many studies have indicated a suite of ecological impacts that large-scale anthropogenic land use and development impose on the structure and function of riverine systems. The overarching goal of this thesis was to examine the potential impacts associated with land use disturbance and Oil Sands (OS) mining operations on fish community composition patterns in three rivers located in the Athabasca Oil Sands Region (AOSR). Using historical data sets, this thesis attempted to evaluate disturbance-related patterns in fish community composition. Fish community-environmental relationships were investigated on a temporal scale, across which community composition could be constrained or altered by development. Structural and trait-based changes in fish community composition were analyzed to determine whether significant variation between levels of development (pre versus post) in the AOSR could be attributed to observed changes in fish community metrics. No significant difference in community composition patterns was observed between levels of development; however, there was a significant decline in fish species richness on a regional scale. The lack of significant results could be attributed to the limitations of the collected data, including temporal gaps, inconsistent sampling methods, and seasonal sampling inconsistencies. Furthermore, the scale of interpretation between individual tributaries and the regional datasets, demonstrates that studies of fish communities on a regional scale can elucidate different states of community change, implying that local controls can play a role in species presence/absence. An assessment of the features and patterns of the hydrograph that could explain variation in fish communities was constrained due to dataset and subsequent methodological limitations. Currently, there is an inability to link changes (historical) to hydrologic regimes, land use or development within these systems, and how they have impacted fish communities therein due to inconsistencies in the methods and sampling during most of the pre-development and for a portion of post- development time span (until 2009). Long-term, standardized community monitoring will be critical to gain a greater understanding of how land management practices affect fish communities and what kind of ecosystem management can mitigate impacts to streams, rivers and the biota therein. Further recommendations were made from synthesizing these findings in conjunction with relevant literature and are intended to provide an improved understanding of the long-term cumulative changes within these systems and to help guide and improve future monitoring plans in the AOSR. / Graduate

I examined the abundance, composition, and distribution of fish communities in the lower Roanoke River, a hydropeaking system in North Carolina. Fishes were sampled at before and after peaking events over three years; 2007 to 2009. I evaluated trends in species richness, diversity, and assemblage composition. There were no significant differences in either richness or diversity suggesting consistent trends in richness and diversity throughout the study. I used non-metric multidimensional scaling (NMDS) to create a community composition model. Fish composition was noticeably greater post-peaking and changed minimally across time and event. There were no statistically significant differences in species composition among pre or post peaking samples, sites, or years (ANOSIM p < 0.05). I concluded that the small amount of fish community variation observed supports the possibility that the present assemblage has adapted to a regulated flow regime, however a direct relationship between peaking and community composition cannot be established. Additionally, fishes were sampled at three longitudinal sites during summer months of 2007 to 2009. I examined fish community composition to assess longitudinal gradients away from the source of peaking. Differences among fish species within each longitudinal site were examined by use of trophic and habitat/reproductive guilds. Statistically significant differences were detected between both trophic and reproductive guilds among sites and therefore aided in creating a pattern of longitudinal separation in community structure. The fish community of the Roanoke River between Roanoke Rapids and Hamilton does not appear to show signs of variation that may be attributed exclusively to hydropeaking. Changes in hydrology, river morphometry and topography, and habitat structure may account for the longitudinal variation observed in the community structure analyses. The Roanoke River has been regulated for over 50 years. It is possible that the existing fish community has adapted to fluctuating flows created by seasonal hydropeaking. I concluded that in order to develop an appropriate community model and evaluate the full extent of changes in fish community characteristics over time long-term monitoring is needed in the Roanoke River.

Orientador: Miguel Petrere Júnior / Resumo: Com o objetivo de descrever os principais padrões de organização das comunidades de peixes realizamos amostragens trimestrais em diferentes ambientes da bacia do rio Iguatemi. Os dados de abundância e ocorrência das espécies foram submetidos a métodos uni e multivariados procurando verificar a existência de um padrão longitudinal e sazonal para essas comunidades. Encontramos 72 espécies de peixes em toda a bacia, constatamos que existe variação longitudinal estatisticamente significativa na composição de espécies para os rios Jogui e Iguatemi, mas não existe variação sazonal. A diversidade de espécies não variou longitudinalmente no rio Iguatemi, mas sim no rio Jogui. As espécies apresentam um padrão determinístico de associação, com clara diferenciação ente espécies de riachos de cabeceira e de rios de maior volume. Existem diferenças significativas na composição de espécies entre os ambientes estudados. Contudo estas diferenças não foram relacionadas às características selecionadas dos ambientes estudados. / Abstract: This paper aims to describe the main patterns of fish communities organization. Tree-monthly samples were realized in different environments of Iguatemi River basin. The abundance and occurrence of species were submitted to uni and multivariate statistical methods in order to verify the existence of a longitudinal and seasonal pattern in fish communities. Seventy two fish species were collected in all basin. We observed longitudinal differences in species composition for Jogui and Iguatemi Rivers. However we did not detect any seasonal variation. The species diversity did not show statistically significant longitudinal variation in Iguatemi River, contrary to Jogui River. Fish species presented a deterministic association pattern in both rivers, with a clear differentiation between headwaters and downstream. Albeit we detected a significant difference in species composition in the whole basin it is not correlated to selected environmental characteristics. / Doutor

Cette étude a pour objectif principal dinventorier les espèces de poissons de la partie congolaise de lInkisi et de contribuer à la connaissance de leur structure de peuplements. A partir des pêches expérimentales et artisanales effectuées entre octobre 2005 et octobre 2008 et des spécimens déposés antérieurement dans les musées, 61 espèces appartenant à 38 genres et 15 familles ont été répertoriées. Trente-sept de ces espèces nétaient pas encore connues du bassin de lInkisi ; huit espèces sont endémiques et sont localisées en amont de la chute de Zongo : Barbus vanderysti, Labeobarbus sp. inkisi, Varicorhinus robertsi (Cyprinidae), Nannopetersius mutambuei (Alestidae), Schilbe zairensis (Schilbeidae) Aphyosemion labarrei (Nothobranchiidae) et Haplochromis sp. snoeksi et Chetia sp. inkisi (Cichlidae). Deux nouvelles espèces ont été décrites, Nannopetersius mutambuei et Haplochromis sp. snoeksi et les descriptions de deux autres sont en préparation. En ce qui concerne les proportions, la famille des Cyprinidae est la plus diversifiée (15 espèces soit 24,6 %); puis viennent les Mormyridae (11 espèces soit 18,0 %), les Cichlidae (9 espèces soit 7,1 %), les Clariidae (7 espèces soit 11,5 %), les Schilbeidae (4 espèces soit 6,6 %), les Mochokidae et les Amphilidae (3 espèces chacune soit 4,9 %) et les Nothobranchiidae (2 espèces soit 3,3 %). La somme des autres familles, représentées par une seule espèce, vaut 6,4 %. Les peuplements des poissons ont été échantillonnés aux filets maillants dans dix stations en prenant en compte 21 variables environnementales. Des analyses canoniques de redondance ont permis de mettre en évidence cinq variables environnementales (la couverture de la canopée, la présence de gros blocs de roches, la largeur de la rivière, le plancher rocheux et le substrat vaseux) qui influent sur la distribution des poissons et un plan spatial de peuplement de cinq types dhabitats : trois sur les affluents (Nsoni, Ngeba et Nua-Luidi-Bongolo-Wungu) et deux sur le cours principal (amont de la chute de Zongo et aval de la chute de Zongo). Les espèces qui caractérisent Nsoni, habitat à canopée sont Parauchenoglanis balayi, en terme dabondance et Barbus vanderysti, en terme de présence. Dans Ngeba, habitat à substrat boueux, les espèces caractéristiques en terme de présence sont Parachanna obscura et Ctenopoma nigropannosum. Dans le complexe Nua-Luidi-Bongolo-Wungu il y a, en terme dabondance, Varicorhinus latirostris, Raiamas kheeli et Garra congensis. Sur le cours principal, en amont de chute Zongo, habitats larges à fond rocheux, on retrouve, en terme dabondance Varicorhinus macrolepidotus, Labeo macrostomus, Doumea alula, Barbus cf. argenteus, et Chetia sp. inkisi. Finalement, en aval de la chute Zongo, habitat à gros blocs de roches, il y a 14 espèces caractéristiques en terme de présence dont les plus abondantes sont Labeo nasus, Steatocranus casuarius, Labeo greeni, Campylomormyrus rhynchophorus et Schilbe grenfelli. Dans la partie congolaise de lInkisi le gradient longitudinal de peuplement nest pas perceptible : laugmentation de la richesse spécifique amont-aval napparaît pas mais la composition spécifique amont-aval est différente. Les indices de diversités (richesse spécifique et équitabilité) variées en fonction des stations ; les plus élevés sont dans la station aval de la chute Zongo et les plus faibles dans la station Nsoni (pour la richesse spécifique) et la station Nua (pour léquitabilité). Les peuplements ichtyologiques semblent équilibrés dans la partie située en aval de la chute Zongo. Des affluents tel que Wungu ont été perturbés suite à lutilisation des techniques destructives (ichtyotoxique). Une planification et une gestion rationnelle des ressources halieutiques dans ce bassin doivent sopérer et être effectives pour préserver sa biodiversité. The present study aimed making a species inventory and contributing to the knowledge of the fish community structure of the Congolese part of Inkisi basin. Based on fishes collected between October 2005 and October 2008 using gill nets and local fishing gear, and specimens previously deposited in musea, a total of 61 species belonging to 38 genera and 15 families have been surveyed. Thirty seven of these species are new citations for the Inkisi basin; eight species are endemic and are only found upstream from the Zongo fall: Barbus vanderysti, Labeobarbus sp. inkisi, Varicorhinus robertsi (Cyprinidae), Nannopetersius mutambuei (Alestidae), Schilbe zairensis (Schilbeidae) Aphyosemion labarrei (Nothobranchiidae) and Haplochromis sp. snoeksi, Chetia sp. inkisi (Cichlidae). Two new species were described, Nannopetersius mutambuei and Haplochromis sp. snoeksi and two others are currently under preparation. The family Cyprinidae is the most diversified (15 species, 24.6 %), followed by Mormyridae (11 species, 18.0 %), Cichlidae (9 species, 7.1 %), Clariidae (7 species, 11.5 %), Schilbeidae (4 species, 6.6 %), Mochokidae and Amphilidae (with 3 species each one), and Nothobranchiidae (2 species, 3.3 %). The remaining families have only one species each and constitute 6.4 %. The fish communities were sampled using gill nets in ten stations taking into account 21 environmental variables. The canonical redundancy analysis retained five important environmental variables (canopy cover, presence of big rock blocs, river width, rocky bottom and muddy bottom) explaining the distribution of the fish species and revealed a spatial plan of five habitat types: three patterns for the affluents (i.e. Nsoni, Ngeba and Nua-Luid-Bongolo-Wungu) and two for the main channel (i.e. upstream of the Zongo fall and downstream of the Zongo fall). For the Nsoni, station with canopy, the typical species are Parauchenoglanis balayi and Barbus vanderysti, respectively, in abundance, and presence. In the Ngeba, station with muddy bottom, the typical species, in abundance, are Parachanna obscura and Ctenopoma nigropannosum. For the Nua-Luidi-Bongolo-Wungu complex, the typical species, in abundance, are Varicorhinus latirostris, Raiamas kheeli and Garra congensis. For the main channel of the Inkisi course upstream of the Zongo fall, wide habitats with rocky bottom, the typical species, in abundance, are Varicorhinus macrolepidotus, Labeo macrostomus, Doumea alula, Barbus cf. argenteus, and Chetia sp. inkisi. Finally, for the Inkisi main channel downstream of the Zongo fall, the station with big rock blocs, 14 species are typical in term of presence, among them the most common are Labeo nasus, Steatocranus casuarius, Labeo greeni, Campylomormyrus rhynchophorus, and Schilbe grenfelli. For the Congolese part of Inkisi no longitudinal gradient of the fish community assemblages was observed along the river. Species richness did not increase from upstream to downstream although the species composition between both is certainly different. Diversity index (species richness and equitability) vary according to station with the highest indexes observed downstream of the Zongo fall and the lower ones at Nua (for the equitability) and Nsoni (for the species richness). Fish communities seem equilibrated downstream of the Zongo fall. On the contrary affluents like the Wungu are being disturbed mainly by bad fishing practice (use of ichthyotoxin). A planification and sustainable use of the natural resources of the Inkisi River must be applied and executed to protect its fish diversity.

Made available in DSpace on 2016-06-02T20:36:14Z (GMT). No. of bitstreams: 1 1921.pdf: 3522049 bytes, checksum: e4749783eaadb07bb9283371ac311531 (MD5) Previous issue date: 2007-05-12 / Universidade Federal de Sao Carlos / The increasing public recognition of environmental degradation and inequitable use of natural resources drives the search for environmentally sustainable and socially equitable resource utilization. In this search context is recognized the necessarily considers different spheres that make up a complex environmental problem including environmental, social, economic and cultural questions. This recent change in perspective and paradigm allows scientific knowledge to authoritatively trump other types of knowledge, such as traditional knowledge developed from the culture and way of life of traditional extractive communities. To develop a scientific research project that considers popular knowledge was used the action-based research perspective on the metal contamination evaluation in the Sao Francisco River trough the water, sediment and muscle fish metals evaluation. The results were compared with the specific environment quality criteria and indicated that the waters of the Sao Francisco River in the area influenced by VM are primarily contaminated by zinc and manganese, at levels that violate the resolution 357/05 of the Brazilian National Environment Committee (CONAMA) in two points during the dry season. In the rainy season, contamination is more serious, as more violations of the CONAMA Resolution 357/05 are found for a variety of metals (Cd, Mn, Pb, Zn, Cu e Fe). This is probably due to run-off from soils with residual deposits, increased percolation from retention ponds, and increased quantity of suspended material in the water with potential to aggregate metal contaminants. For sediments in the study area, there are worrisome metal concentrations that exceed this tabulated Severe Effect Limits (SEL) by up to 16 times, indicating a strong probability that the sediments are causing an adverse effect on the biota and contributing significantly to the degradation of water quality. With respect to contamination of fish, of the 54 fish analyzed, only one showed concentrations of metals above the limits for human consumption established by decree 685/98 of the National Agency for Health Vigilance (ANVISA). Another results were multi-stakeholder involvement in an environmental problem through participative tools, promoting the exchange of different types of knowledge, fosters dialogue between different actors involved in the same socio-environmental context, and promotes the insertion of research into the context of the complexity in which the demand for it developed. Science is thus applied in favor of the community in search of sustainable livelihoods and environments. / A atualidade dos problemas ambientais nos remete a um aumento gradativo na busca de modos de vida e de produção ambientalmente sustentáveis em resposta ao estado atual de degradação e utilização desigual dos recursos naturais. Nesta busca há um reconhecimento da necessidade de se considerar as diferentes esferas que compõem um problema ambiental na sua complexidade, passando por questões econômicas, sociais, ecológicas e culturais. Esta perspectiva recente implica na mudança de alguns paradigmas da ciência que se coloca de forma autoritária como detentora de um saber que prevalece sobre os demais saberes. Com o intuito de desenvolver um projeto de pesquisa cientifica que considerasse saberes populares é que se desenvolveu o presente trabalho dentro da perspectiva da pesquisa-ação, implementando-se, a partir da demanda comunitária, um diagnóstico de contaminação ambiental por metais e metalóides no Rio São Francisco, região de Três Marias MG, através da análise das concentrações de metais em amostras de água, sedimentos e peixes, sendo os resultados comparados com os critérios de qualidade pertinentes a cada compartimento ambiental. Este diagnóstico confirmou a contaminação por metais nas águas, caracterizada pela violação dos limites estabelecidos na Resolução CONAMA n° 357/05 para corpos de água de Classe 2 (classe atribuída a esse trecho do rio), pelos metais Zn e Mn no período da seca (1ª coleta) em pontos amostrais próximos ao lançamento de efluentes da Votorantim Metais, e por uma maior diversidade de metais no período da chuva (Cd, Mn, Pb, Zn, Cu e Fe), que foi atribuída principalmente ao aumento de partículas suspensas na água, já que essas partículas (sólidos totais suspensos) possuem um elevado potencial de concentrar contaminantes, como os metais e metalóides. Para os sedimentos, as concentrações determinadas mostram altos valores nos pontos mais próximos à fonte pontual (VM), violando, várias vezes, os valores guia de qualidade TEL (Threshold Effect Level) e PEL (Probable Effect Level) e, inclusive, o SEL (Severe Effect Level), o que representa sério risco de impacto ambiental (ecológico), pois representa a violação de um valor guia de qualidade que prevê a ocorrência de efeitos biológicos negativos severos. Outras análises realizadas para indicar o potencial tóxico desses sedimentos apontam como ponto mais crítico a foz do córrego Consciência e o ponto de lançamento de efluentes tratados da VM. Para peixes, os dados indicam que os níveis de metais não comprometem o consumo do filé, mas deve-se levar em conta que análises foram feitas para três espécies (curimba-pacu, mandi e trairão) e que o número de amostras não foram muito grande. Além do diagnóstico da contaminação ambiental, o que se obteve foi o estabelecimento de espaços de diálogo nos quais a comunidade de pescadores tiveram voz quando se apropriaram do conhecimento e informação fruto da pesquisa-ação, colocando a ciência em favor desses atores, possibilitando a esses alcançarem alguns avanços no caminho da sustentabilidade de seu modo de vida e cultura.