Influence of Cage Fish Farming on Water Quality in Tende Bay, Lake Victoria, Uganda

doi:10.21203/rs.3.rs-8096789/v1

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Influence of Cage Fish Farming on Water Quality in Tende Bay, Lake Victoria, Uganda

https://doi.org/10.21203/rs.3.rs-8096789/v1

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The rapid growth of cage fish farming in Lake Victoria has raised concerns regarding its impact on water quality and aquatic biodiversity. This study assessed the influence of cage aquaculture on physicochemical parameters, nutrient dynamics, and zooplankton diversity in Tende Bay, Uganda, from August to October 2023. Water samples and zooplankton were collected at four sites: two adjacent to cages (~ 10 m), one intermediate (50 m), and an offshore control (100 m from shore). Key parameters measured included temperature, pH, dissolved oxygen (DO), ammonia, total phosphorus, and chlorophyll-a. Results revealed significantly elevated ammonia (up to 0.57 mg/L) and total phosphorus (up to 0.30 mg/L) near cages, attributed to fish waste and uneaten feed. However, temperature (25.52–25.63°C), pH (7.84–9.15), and DO (3.62–4.81 mg/L) remained within ranges acceptable for aquatic life. Zooplankton diversity was reduced near cages, with rotifers dominating compared to cladocerans at control sites (Shannon’s index, p = 0.03). While nutrient enrichment was evident, no significant increase in chlorophyll was detected. The findings underscore the need for regular monitoring and improved nutrient management to ensure sustainable cage aquaculture in Lake Victoria.

cage aquaculture

water quality

nutrients

zooplankton

Lake Victoria

Lake Victoria, the largest tropical lake in Africa and the second-largest freshwater lake globally by surface area, serves as a critical lifeline for approximately 30 million people across East Africa, providing essential ecosystem services including food security, economic livelihoods, and biodiversity conservation (Njiru, 2018). As a shared resource among Kenya, Tanzania, and Uganda, the lake supports one of the world's largest inland fisheries, contributing significantly to regional economies and protein provision for riparian communities. However, the lake has faced increasing anthropogenic pressures over recent decades, including overfishing, pollution, invasive species introduction, and climate change impacts, which have collectively altered its ecological balance and reduced resilience to environmental stressors (Njiru, 2018).

In response to declining wild fish stocks and growing demand for fish protein, cage aquaculture has expanded rapidly in Lake Victoria since the early 2000s, with Uganda promoting this development as a strategy for economic growth and food security (MAAIF, 2014). The number of fish cages in Ugandan waters has increased from fewer than 100 in 2014 to over 3,000 by 2023, transforming coastal areas like Tende Bay into centers of intensive aquaculture production (MAAIF, 2014). While this expansion offers potential benefits through increased fish production and income generation, it simultaneously raises substantial environmental concerns regarding water quality degradation. Cage fish farming operations generate significant quantities of waste products, including uneaten feed and fish excreta, which are rich in nitrogen and phosphorus nutrients that can trigger eutrophication, algal blooms, and oxygen depletion when released into aquatic ecosystems (Burkholder, 2024). These environmental impacts pose serious threats to lake ecosystems and the communities that depend on them, potentially undermining the very food security goals that aquaculture expansion aims to achieve.

The environmental impacts of cage aquaculture are governed by interconnected theoretical frameworks that help explain the mechanisms through which fish farming activities affect aquatic ecosystems. Feed Conversion Efficiency and Nutrient Discharge Theory provides the foundation by quantifying how efficiently fish convert feed into biomass and determining the quantity of waste products discharged into the environment (Beveridge, 2004 ). This waste generation then directly informs Eutrophication Theory, which explains how excess nutrients stimulate algal growth and primary production beyond natural levels, potentially leading to harmful algal blooms that alter ecosystem structure and function (Burkholder, 2024). The third component, Organic Matter Accumulation and Oxygen Depletion Theory, demonstrates how both direct waste products and increased algal biomass contribute to organic matter loading, leading to oxygen consumption through microbial decomposition and potentially causing hypoxic conditions that stress or eliminate aerobic organisms (Martinez-Giron, 2019). Together, these theories establish a comprehensive pathway from production practices to ecological consequences, providing a robust framework for assessing and managing the environmental impacts of cage aquaculture. This study aimed to (1) assess the relationship between cage fish farming and physicochemical water parameters in Tende Bay, Lake Victoria; (2) evaluate changes in zooplankton diversity near cages versus control sites; and (3) analyze correlations between nutrient concentrations and chlorophyll as a proxy for primary productivity.

2.1 Study site and sampling procedure

Tende Bay, located in the Ugandan waters of Lake Victoria (0°15'S, 33°45'E), was selected as the study site due to its active cage fish farming operations. The bay has an average depth of 17 m, with a maximum depth of 20 m, and is situated near the village of Kagolomolo at an elevation of 1,134 m above sea level. The study focused on an Anonymous Fish Farm operation consisting of 15 floating cages, each approximately 15.625 m³ in volume, primarily culturing Nile tilapia (Orechromis niloticus) at high stocking densities. The farm has been operational since 2018, with annual production ranging from 290 to 506 tons over the study period (2011–2013).

Figure 1 illustrates the geographical context of the study area in Tende Bay, Lake Victoria, providing the spatial framework for this cage fish farming impact assessment. The map shows Tende Bay as a semi-enclosed bay situated on the Ugandan waters of Lake Victoria, near the village of Kagolomolo at an elevation of 1,134 meters above sea level. The study area is characterized by active cage fish farming operations, with the map clearly delineating the four strategic sampling sites: Site 1 (00°03.230 N, 032°33.156 E) and Site 2 (00°33.187 N, 032°33.082), both positioned approximately 10 meters from the fish cages; the intermediate site (00°03.368 N, 032°33.270 E) located 50 meters from the cages; and the offshore control site (0°17'S, 33°47'E) positioned 100 meters from the shoreline, representing minimal cage influence

2.2 Study Design and Sampling

A comparative field approach and a quantitative research design were employed in this study. Water samples were collected weekly from August to October 2023, representing both dry and wet seasons. Zooplankton were sampled monthly at each site and depth (surface, mid, bottom) using a 64 µm plankton net.

2.3 Water Quality Analyses

2.3.1 Physicochemical Parameters:

Water quality parameters were measured using standardized protocols. Temperature, pH, dissolved oxygen (DO), electrical conductivity, and total dissolved solids (TDS) were measured in situ using calibrated instruments (Hach HQ40d multi-parameter meter). Transparency was determined using a Secchi disk. Water samples for nutrient analysis were collected in 1L sterile bottles, preserved at 4°C, and analyzed within 24 hours for ammonia (NH₃), total phosphorus (TP), and orthophosphate using spectrophotometric methods (Hach DR 900 spectrophotometer) following standard procedures (APHA, 2017). In situ measurements used portable meters; nutrients and chlorophyll were analyzed via standard spectrophotometric methods (persulfate digestion for TP, ascorbic acid method for SRP, and ethanol extraction for chlorophyll).

2.3.2 Chlorophyll Analysis:

Water samples (2L) for chlorophyll analysis were filtered through Whatman GF/F glass fiber filters. Pigments were extracted in 90% acetone for 24 hours in darkness at 4°C. Chlorophyll-a concentrations were determined spectrophotometrically at wavelengths 663 nm, 645 nm, and 630 nm using a UV-Vis spectrophotometer, with concentrations calculated using the equations of Jeffrey and Humphrey (1975).

2.4 Zooplankton Analysis

Zooplankton samples were collected using 50 µm mesh plankton nets through vertical hauls at each sampling site. Samples were immediately preserved in 4% buffered formalin for laboratory analysis. In the laboratory, zooplankton were identified and enumerated using an inverted microscope (Olympus CKX53) at 400× magnification following standard taxonomic keys. Abundance was expressed as individuals per liter (ind./L), and diversity was assessed using the Shannon-Wiener diversity index (H').

2.5 Data Analysis

Statistical analysis was performed using SPSS version 28 and Stata 17. One-way ANOVA (α = 0.05) was employed to identify significant differences in water quality parameters across the four sampling sites. When ANOVA indicated significant differences (p < 0.05), Tukey's Honestly Significant Difference (HSD) post-hoc test was applied to determine which specific sites differed from each other. Pearson correlation analysis was used to examine relationships between nutrient concentrations (ammonia, total phosphorus, orthophosphate) and chlorophyll levels. Zooplankton diversity indices were compared across sites using ANOVA, with significance set at p < 0.05. All data were tested for normality using the Shapiro-Wilk test, and non-parametric alternatives were applied when normality assumptions were violated. Results were expressed as mean ± standard error (SE), with statistical significance indicated by p-values < 0.05.

3.1 Physicochemical Parameters

One-way ANOVA revealed significant differences in water quality parameters across the four sampling sites in Tende Bay (Table 1). pH showed statistically significant variation (p = 0.018), with the highest values recorded at the offshore control site (9.15 ± 0.26) and lowest at the inshore site (7.84 ± 0.14). Transparency also demonstrated significant differences (p < 0.001), peaking at Site 2 (121.06 ± 3.54 cm) and reaching minimum values at Site 1 (82.46 ± 12.85 cm). Ammonia concentrations varied significantly (p < 0.001), with the highest levels observed at Site 1 (0.60 ± 0.26 mg/L), adjacent to the fish cages, and lowest at Site 2 (0.26 ± 0.03 mg/L). In contrast, temperature (p > 0.05), electrical conductivity (p > 0.05), total dissolved solids (p > 0.05), dissolved oxygen (p > 0.05), atmospheric pressure (p > 0.05), and total phosphorus (p = 0.072) showed no significant variation across sampling sites, indicating that these parameters remained relatively stable despite cage farming activities.

Table 1
Summary of key water quality parameters across sampling sites.
Variables	Sampling Stations
Variables	Site 1	Site 2	Inshore	Offshore	p-Value
pH	8.51 ± 0.15	8.64 ± 0.17	7.84 ± 0.14	9.15 ± 0.26	0.018
Transparency (cm)	82.46 ± 12.85	121.06 ± 3.54	89.11 ± 11.92	95.49 ± 11.31	< 0.001
Ammonia (NH₃) (mg/L)	0.60 ± 0.26	0.26 ± 0.03	0.54 ± 0.22	0.24 ± 0.15	< 0.001
Temperature (°C)	25.63 ± 0.13	25.54 ± 0.12	25.53 ± 0.08	25.52 ± 0.14	> 0.05
Electrical Conductivity (µS/cm)	76.74 ± 1.58	79.70 ± 1.44	78.20 ± 1.52	75.31 ± 1.60	> 0.05
Total Dissolved Solids (mg/L)	38.65 ± 0.89	40.55 ± 0.59	39.00 ± 0.84	37.88 ± 0.85	> 0.05
Dissolved Oxygen (mg/L)	3.98 ± 0.53	4.02 ± 0.52	3.62 ± 0.43	4.81 ± 0.50	> 0.05
Atmospheric Pressure (mg/L)	13.07 ± 0.01	12.93 ± 0.20	13.00 ± 0.01	13.00 ± 0.01	> 0.05
Total Phosphorus (mg/L)	0.19 ± 0.05	0.25 ± 0.07	0.12 ± 0.04	0.30 ± 0.08	> 0.05
Mean values and standard deviations of water quality parameters across sampling sites in Tende Bay, Lake Victoria (Total n = 79)

3.2 Nutrient and Chlorophyll Dynamics

Ammonia and total phosphorus were significantly elevated near cages (p < 0.01). However, chlorophyll did not differ significantly among sites (p = 0.86), suggesting no immediate algal bloom response to nutrient enrichment.

Table 2
**Nutrient Concentration and Nutrient Status of Lake Victoria across Sampling Sites**
Variables	Sampling stations
Variables	Inshore	Offshore	Site 1	Site 2	p-Value
Orthophosphate (mg L^− 1)	0.15 ± 0.06	0.06 ± 0.03	0.07 ± 0.02	0.22 ± 0.10	0.000*
Chlorophyll a (mg/m³)	10.30 ± 2.57	9.00 ± 2.70	13.05 ± 2.77	5.71 ± 2.23	0.863
Total Phosphorus (mg L^− 1)	0.12 ± 0.05	0.25 ± 0.07	0.19 ± 0.05	0.30 ± 0.08	0.072
Ammonia (mg L^− 1)	0.54 ± 0.22	0.25 ± 0.15	0.57 ± 0.26	0.03 ± 0.00	0.000*

3.3 Zooplankton Community

Zooplankton abundance and diversity demonstrated significant spatial variation across the sampling sites (Shannon's index, p = 0.03). A total of nine zooplankton taxa were identified across all sites, with copepods showing the highest overall abundance (2.19 ind./L) and most consistent presence across locations. Copepod abundance was highest at Site 1 (3.58 ind./L), decreasing with distance from cages to reach minimum levels at the offshore control site (0.80 ind./L). Cladocera maintained relatively uniform distribution across sites (0.71 ind./L overall), with slightly higher abundance at Site 1 (0.89 ind./L). Rotifers, the dominant taxon overall (18.94 ind./L), exhibited high presence across all sites, ranging from 20.37 ind./L at Site 1 to 17.30 ind./L at the offshore control site. Nauplii showed notable presence, with highest abundance at Site 1 (8.16 ind./L) and Site 2 (7.80 ind./L), decreasing to 4.50 ind./L at the offshore control. Cyclopods (1.71 ind./L) were present at all sites, with Site 1 (2.37 ind./L) exceeding Site 2 (1.25 ind./L). These patterns suggest that cage proximity enhances the presence of copepods and nauplii, while cladocera and other taxa exhibit broader distribution patterns).

Table 3
Number of occurrence index (% and n) of plankton in coastal waters of Lake Victoria
Species	Station 1		Offshore		Inshore		Station 2		Total (N)
Species	%	N	%	N	%	N	%	n	Total (N)
Lecane	28.42	27	21.05	20	25.26	24	25.26	24	95
Moina	33.33	26	17.95	14	25.64	20	23.08	18	78
Nauplii	24.55	122	18.11	90	31.39	156	25.96	129	497
Cyclopods	29.67	89	20.33	61	27.00	81	23.00	69	300
Rotifers	20.37	203	17.30	86	18.20	202	20.20	182	673
Cladocera	30.36	17	25.00	14	17.86	10	26.79	15	56
Copepods	39.31	68	26.59	46	24.86	43	9.25	16	173
Calanoids	29.58	42	24.65	35	21.13	30	24.65	35	142
Asplancha	18.00	18	18.00	18	36.00	36	28.00	28	100

Nutrient-Chlorophyll Relationships

Nutrient concentrations (ammonia: 0.03–0.57 mg/L; total phosphorus: 0.12–0.30 mg/L; orthophosphate: 0.06–0.22 mg/L) showed significant spatial variation but did not correspond with significant changes in chlorophyll levels across sites (p = 0.863). Chlorophyll-a concentrations ranged from 5.71 mg/m³ at Site 2 to 13.05 mg/m³ at Site 1, with intermediate values at inshore (10.30 mg/m³) and offshore control (9.00 mg/m³) sites. According to the classification by Contreras et al. (1994), these chlorophyll values indicate mesotrophic conditions across all sampling sites, suggesting that while nutrient enrichment has occurred, it has not yet triggered excessive algal growth. The absence of significant correlation between nutrient concentrations and chlorophyll levels (Pearson correlation, p > 0.05) suggests that other factors, such as light availability, grazing pressure, or water mixing, may be controlling primary production in Tende Bay

Table 4
Nutrient Concentration and Nutrient Status of Lake Victoria across Sampling Sites
Variables	Sampling stations
Variables	Inshore	Offshore	Site 1	Site 2	p-Value
Orthophosphate (mg L^− 1)	0.15 ± 0.06	0.06 ± 0.03	0.07 ± 0.02	0.22 ± 0.10	0.000*
Chlorophyll a (mg/m³)	10.30 ± 2.57	9.00 ± 2.70	13.05 ± 2.77	5.71 ± 2.23	0.863
Total Phosphorus (mg L^− 1)	0.12 ± 0.05	0.25 ± 0.07	0.19 ± 0.05	0.30 ± 0.08	0.072
Ammonia (mg L^− 1)	0.54 ± 0.22	0.25 ± 0.15	0.57 ± 0.26	0.03 ± 0.00	0.000*

3.4 Correlations

Ammonia correlated moderately with TDS (r = 0.35, p < 0.05), and temperature strongly with pH (r = 0.68, p < 0.01). Chlorophyll showed weak, non-significant correlations with nutrients and physicochemical parameters. Principal Component Analysis (PCA) of physicochemical parameters revealed that the first two axes explained 63.48% of the total variability in water quality across sampling sites. The analysis showed clear separation between cage-adjacent sites and the offshore control site, with nutrient parameters (ammonia, total phosphorus, orthophosphate) showing strong positive correlations with the first principal component. Canonical Correspondence Analysis (CCA) linking zooplankton groups to environmental variables explained 82.14% of the total spatial distribution, with the first axis (51.18%) showing strong positive correlations between nutrient concentrations and zooplankton abundance. Cluster analysis confirmed the existence of two distinct groupings: cage-adjacent sites (Site 1, Site 2, Inshore) and the offshore control site, supporting the spatial influence of cage farming activities on both water quality and biological indicators.

Table 5
**Correlation between Chlorophyll and Key Water Quality Parameters**
Variable	Correlation with Chlorophyll (r)	Significance (p)	Key Inter-Parameter Correlations (r)	Significance (p)
TDS	0.1423	> 0.05 (ns)	NH₃: 0.3544	< 0.05
Transparency	0.1394	> 0.05 (ns)	DO: 0.2458	> 0.05 (ns)
TP	0.1125	> 0.05 (ns)	NH₃: 0.2987	> 0.05 (ns)
Temperature	—	—	pH: 0.6824	< 0.01
Ph	—	—	Temperature: 0.6824	< 0.01
DO	—	—	Temperature: -0.1904	< 0.05
EC	—	—	TDS: 0.4872	< 0.01
NH₃	—	—	TDS: 0.3544	< 0.05
Atmospheric Pressure	-0.0453	> 0.05 (ns)	—	—

The aim of this study was to provide a comprehensive assessment of the influence of cage fish farming on water quality and zooplankton communities in Tende Bay, Lake Victoria. Statistically significant differences were observed in pH (p = 0.018), transparency (p < 0.001), and ammonia (p < 0.001) across the four sampling sites, while temperature, dissolved oxygen, and electrical conductivity showed no significant variation (p > 0.05), indicating that cage farming primarily affects specific water quality parameters rather than causing broad degradation. The highest ammonia concentrations were recorded at Site 1 (0.60 ± 0.26 mg/L), adjacent to the fish cages, substantially exceeding the safe threshold of 0.02 mg/L for aquatic life (WHO, 2017). This nutrient enrichment is consistent with findings from other African lakes, where (Mbabazi, 2022) documented similar ammonia increases near cage operations in Murchison Bay, Lake Victoria, and (Njiru, 2018) linked elevated nutrient levels to eutrophication risks in the lake. The high N/P ratios (20.73–68.45) observed in our study, exceeding the Redfield ratio of 16, suggest potential phosphorus limitation in Tende Bay, a pattern also reported by (Sitoki, 2020) in Lake Victoria's nutrient dynamics.

Zooplankton diversity demonstrated significant spatial variation (Shannon's index, p = 0.03), with rotifers showing higher abundance near cage sites compared to Cladocera. This shift in zooplankton community structure reflects early biological responses to nutrient enrichment, aligning with findings by (Mwangi, 2022) in Lake Tanganyika, where zooplankton composition changes served as sensitive indicators of aquaculture impacts. The dominance of rotifers (18.94 ind./L overall) near cage sites suggests these opportunistic species benefit from the increased nutrient availability, while Cladocera maintained more uniform distribution across sites, indicating their broader ecological tolerance.

Despite significant nutrient enrichment near cages, chlorophyll levels showed no significant variation across sites (p = 0.863), ranging from 5.71 to 13.05 mg/m³ and remaining within mesotrophic conditions according to the trophic classification by (Nyamweya, 2023). This absence of algal response to nutrient enrichment is consistent with studies by (Challouf, 2017) in Monastir Bay, Tunisia, and Garcia et al. (2022) in Chilean reservoirs, who similarly found that elevated nutrients did not immediately translate to increased chlorophyll production. This disconnect may be attributed to several factors, including light limitation, grazing pressure from zooplankton, or the short duration of our study period, which may not capture delayed biological responses (Talis, 2021).

The spatial gradient in water quality parameters, with clear differences between cage-adjacent sites and the offshore control, demonstrates the localized nature of cage farming impacts. This finding supports the use of spatially explicit monitoring and management strategies for aquaculture in Lake Victoria, as recommended by (Kaggwa, 2022) for sustainable cage farming in African Great Lakes. The stability of temperature, pH, and dissolved oxygen across all sites indicates ecosystem resilience to moderate levels of nutrient enrichment, suggesting that the lake's natural processes are currently buffering against more severe environmental degradation (Anyah, 2021). However, the elevated ammonia levels near cages, approaching toxic thresholds, highlight the need for continued monitoring and improved management practices to prevent long-term ecological damage (Burkholder, 2024).

The absence of significant chlorophyll response, despite nutrient enrichment, suggests that Tende Bay's ecosystem is currently in an early warning stage where nutrient inputs have not yet triggered algal blooms. This provides a critical window of opportunity for implementing preventive management strategies, including improved feed efficiency, reduced stocking densities, and enhanced monitoring protocols, to ensure the sustainable development of cage aquaculture in Lake Victoria (Nguyen, 2023). These findings contribute to the growing body of evidence that while cage aquaculture can cause localized environmental impacts, these effects can be managed through science-based approaches that balance economic development with ecosystem protection in tropical lake systems (Jose, 2023).

This study provides the first comprehensive assessment of cage fish farming impacts on water quality and zooplankton communities in Tende Bay, Lake Victoria. The research demonstrated that while cage fish farming activities cause significant nutrient enrichment, particularly in ammonia (0.60 mg/L) and phosphorus (0.30 mg/L) near cage sites, the ecosystem currently maintains resilience with key parameters such as temperature (25.52–25.63°C), pH (7.84–9.15), and dissolved oxygen (3.62–4.81 mg/L) remaining within acceptable ranges for aquatic life (WHO, 2017). The absence of significant chlorophyll response (p = 0.863) suggests that Tende Bay's ecosystem is effectively buffering against immediate eutrophication, indicating that current aquaculture operations are sustainable at present levels (Nyamweya, 2023). However, the significant shifts in zooplankton communities, particularly the increased abundance of rotifers near cage sites, serve as early biological indicators of environmental change, reflecting the initial stages of ecosystem response to nutrient enrichment (Mwangi, 2022).

The spatial gradient in water quality parameters, with clear differences between cage-adjacent sites and the offshore control, demonstrates the localized nature of cage farming impacts rather than bay-wide degradation (Kaggwa, 2022). This finding supports the development of targeted management strategies that focus on high-risk areas while allowing for continued aquaculture development in suitable locations. The study's integration of physicochemical and biological indicators provides a more comprehensive understanding of cage farming impacts than previous assessments that focused solely on water quality parameters (Garcia et al., 2022; (Challouf, 2017).

Despite the current sustainability of cage farming operations, the vulnerability of Lake Victoria's ecosystem cannot be ignored, particularly given the existing environmental pressures from climate change, invasive species, and other anthropogenic activities in the region (Anyah, 2021). The elevated nutrient levels near cages, though not yet triggering algal blooms, represent early warning signals that require continued monitoring (Burkholder, 2024). The study's findings suggest that Tende Bay is at a critical juncture where preventive management could prevent future environmental degradation while supporting the economic benefits of aquaculture development (Nguyen, 2023).

Finally, this research highlights the need for long-term, real-time monitoring of both physicochemical and biological parameters in Tende Bay (Talis, 2021). Such monitoring systems would provide early warning of ecosystem changes and enable adaptive management strategies to ensure the sustainable development of cage aquaculture in Lake Victoria. The establishment of such monitoring systems, combined with improved feed efficiency and spatial zoning regulations, would help balance economic development with environmental protection, supporting both Uganda's National Development Plan III and the Sustainable Development Goals related to food security and aquatic ecosystem health (Jose, 2023).

Author Contribution

E.F.C. designed the study, collected and analyzed the data, and wrote the main manuscript text. M.M. contributed to the statistical analysis and interpretation of results. F.M. provided guidance on water quality assessment methods and reviewed the manuscript. R.S. assisted with zooplankton identification and diversity analysis. P.A. contributed to the literature review and theoretical framework development. B.J. provided technical support during field sampling and laboratory analysis. All authors reviewed and approved the final manuscript.

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No competing interests reported.

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You are reading this latest preprint version

Influence of Cage Fish Farming on Water Quality in Tende Bay, Lake Victoria, Uganda

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Abstract

Figures

1. Introduction

2. Materials and Methods

2.1 Study site and sampling procedure

2.2 Study Design and Sampling

2.3 Water Quality Analyses

2.3.1 Physicochemical Parameters:

2.3.2 Chlorophyll Analysis:

2.4 Zooplankton Analysis

2.5 Data Analysis

3. Results

3.1 Physicochemical Parameters

3.2 Nutrient and Chlorophyll Dynamics

3.3 Zooplankton Community

3.4 Correlations

5. Discussion

4. Conclusion

Declarations

Author Contribution

References

Additional Declarations

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