Abstract

Jordan’s fish culture sector, primarily centered on Nile tilapia (Oreochromis niloticus) and common carp (Cyprinus carpio), faces critical challenges including high feed costs driven by imported fish meal (FM) dependency, water quality degradation due to arid climatic conditions, disease prevalence linked to intensive farming, and economic inefficiencies in smallholder systems. This review synthesizes 50 peer-reviewed studies, theses, and institutional reports (2002–2024) to analyze these challenges. Key findings highlight plant-based and agricultural by-product alternatives (e.g., Moringa leaf meal, tomato pomace, earthworm meal) as potential feed cost reducers, though their lower apparent digestibility coefficients (ADC) for protein and energy necessitate processing (e.g., extrusion, phytase supplementation) to match FM efficacy. Water quality parameters such as dissolved oxygen (DO), ammonia (NH₃-N), and pH are frequently suboptimal, correlating with reduced growth and increased disease risk. Antibiotic usage, while declining, remains a concern, with natural alternatives like Mentha piperita powder and Nelumbo-derived zinc oxide nanoparticles showing promise but requiring standardized testing. Irrigation pond systems demonstrate economic viability but are constrained by limited water management infrastructure. Recommendations emphasize integrated strategies for feed innovation, climate-smart water management, antibiotic reduction, and policy support to enhance sector resilience. 

Keywords

Fish Culture, Jordan, Aquaculture Challenges, Nile Tilapia, Feed Sustainability, Water Quality Management, Antibiotic Use. 

Abbreviations

ADC: Apparent Digestibility Coefficient; FM: Fish Meal; SGR: Specific Growth Rate (%); FCR: Feed Conversion Ratio; DO: Dissolved Oxygen (mg/L); NH₃-N: Ammonia (as Nitrogen, mg/L); NO₂⁻-N: Nitrite (as Nitrogen, mg/L); ANFs: Antinutritional Factors; IMTA: Integrated Multi-Trophic Aquaculture.

Introduction

Aquaculture has emerged as a cornerstone of global food security, contributing over 50% of fish for human consumption.¹ In Jordan, a nation characterized by acute water scarcity (mean annual rainfall: 100–300 mm) and arid climate, fish culture plays a pivotal role in diversifying protein sources and supporting rural livelihoods.² The sector is dominated by Nile tilapia and common carp, reared in earthen ponds and cages across regions like Karak Governorate.³ These species are valued for their adaptability to local conditions, rapid growth, and market demand, making them central to Jordan’s aquaculture development.⁴

Despite its potential, Jordanian fish culture confronts multifaceted challenges. Feed costs, accounting for 50–70% of total production expenses, are exacerbating due to reliance on imported FM, a premium protein source.^2,5 Concurrently, water quality degradation—driven by high temperatures (28–35°C), limited water exchange, and organic waste accumulation—threatens fish health and productivity.^6,7 Disease outbreaks, particularly bacterial infections (e.g., Vibrio alginolyticus, Clostridium perfringes), further strain production, often managed through prophylactic antibiotic use that raises concerns about resistance and environmental contamination.^8,9 Smallholder farmers, who dominate the sector, struggle with economic viability, constrained by high input costs and limited access to optimized technologies.^3,10

This review aims to synthesize existing literature and empirical data to examine these challenges, evaluate the efficacy of local solutions (e.g., alternative feedstuffs, irrigation pond systems), and provide evidence-based recommendations for sustainable development. By integrating quantitative metrics (ADC, growth performance, antibiotic use) and qualitative insights (farmer constraints), the review underscores the urgency of addressing interconnected barriers to enhance Jordan’s fish culture resilience. 

Materials and Methods

A systematic review approach was employed to analyze challenges in Jordanian fish culture.

Literature Search 

Relevant studies were identified via searches in Web of Science, Scopus, and Google Scholar using keywords: “fish culture Jordan,” “Nile tilapia aquaculture challenges,” “Jordan carp farming,” “aquaculture feed alternatives Jordan,” “water quality Jordan fish ponds,” “antibiotic use tilapia Jordan,” and “irrigation pond aquaculture.” Inclusion criteria focused on publications between 2002 and 2024 that addressed: (1) feed resource management and alternative ingredients; (2) water quality parameters and their impacts; (3) disease control and antibiotic use; (4) economic viability of production systems; and (5) species-specific (tilapia/carp) challenges in Jordan or regions with similar climatic/ecological conditions. 

 

Data Extraction and Analysis 

Data extraction prioritized quantitative metrics (e.g., ADC, weight gain [WG], SGR, FCR, antibiotic dosage) and qualitative findings (e.g., farmer-reported constraints). For feed studies, ADC values for protein, energy, and crude fiber were compiled. Growth performance metrics (WG, SGR, FCR, survival rate) were extracted for diets containing alternative ingredients. Water quality data included DO, pH, NH₃-N, NO₂⁻-N, and temperature ranges, alongside their reported impacts on fish health. Antibiotic usage trends (prevalence, dosage, shifts in class) and efficacy of natural alternatives (e.g., Mentha piperita, zinc oxide nanoparticles) were synthesized. Economic metrics (feed cost, revenue, net profit) from irrigation pond studies were analyzed.

Statistical software¹¹ organized extracted data into comparative tables. Qualitative themes (e.g., infrastructure gaps, knowledge limitations) were synthesized to highlight recurring challenges.

Results

Feed Resource Challenges and Alternative Ingredients 

Jordan’s fish culture sector heavily relies on FM, which accounts for 40–50% of dietary protein in tilapia diets.² Imported FM’s price volatility⁵ and logistical constraints (e.g., customs delays) strain smallholder economics, driving interest in local, low-cost alternatives. 

 

Nutrient Digestibility of Conventional vs. Alternative Feedstuffs 

Digestibility, measured via ADC, is critical for optimizing feed efficiency. Conventional FM exhibits high ADC for protein (92.1 ± 1.3%) and energy (89.5 ± 2.1%), aligning with global standards for teleost diets.¹² However, plant-based and agricultural by-products often have lower ADC due to ANFs (e.g., trypsin inhibitors, tannins), which reduce nutrient availability.¹³
 

Table 1 summarizes ADC values for protein, energy, and crude fiber across conventional and alternative ingredients, along with key ANFs and source studies. FM’s superior digestibility contrasts with plant-based alternatives like processed jackbean meal (protein ADC: 72.3 ± 2.4%) and Citrullus lanatus (watermelon) meal (68.7 ± 1.9%). Agricultural residues, such as tomato pomace (TP), show the lowest protein ADC (65.8 ± 2.0%) but comparable energy ADC (72.5 ± 2.5%) to some plant meals.¹⁴

 

Feedstuff	Protein ADC (%)	Energy ADC (%)	Crude Fiber ADC (%)	Key ANFs	Study (Year)
Fish Meal (Conventional)	92.1 ± 1.3	89.5 ± 2.1	12.4 ± 0.8	None significant	Al Khraisat (2014)2
Processed Jackbean Meal	72.3 ± 2.4	78.9 ± 3.1	28.5 ± 2.1	Trypsin inhibitors	Jimoh et al. (2010)15
Citrullus lanatus Meal	68.7 ± 1.9	74.1 ± 2.3	32.0 ± 2.5	Tannins, lignin	Jimoh et al. (2015)16
Jatropha curcas Meal	75.2 ± 2.1	79.8 ± 2.7	29.3 ± 1.8	Phytic acid, glucosinolates	Jimoh & Shittu (2020)17
Moringa Leaf Meal	70.4 ± 1.5	76.3 ± 2.0	30.1 ± 1.9	Cyanogenic glycosides	Kasiga & Lochmann (2014)18
Leucaena Leaf Meal	68.1 ± 1.7	74.9 ± 2.2	33.2 ± 2.0	Tannins, saponins	Kasiga & Lochmann (2014)18
Tomato Pomace	65.8 ± 2.0	72.5 ± 2.5	35.4 ± 2.3	High fiber, low protein	Al Khraisat (2015a)14
Earthworm Meal	85.0 ± 2.5	82.0 ± 1.9	20.0 ± 1.5	None reported	Siddik et al. (2024)19

 

Growth Performance of Tilapia Fed Alternative Diets 

Substituting FM with alternatives impacts growth metrics (WG, SGR, FCR, survival). Table 2 presents growth performance indicators for tilapia diets containing various alternatives, compared to FM-based controls. While FM diets yield optimal WG (350 ± 12 g) and SGR (2.0 ± 0.1%), plant-based alternatives generally reduce these metrics. For example, diets with Citrullus lanatus meal lower WG by 17% (290 ± 11 g) and SGR by 20% (1.6 ± 0.09%). 

Notably, earthworm meal (Siddik et al., 2024) and Moringa leaf meal (Kasiga & Lochmann, 2014) show minimal performance reduction, with WG (345 ± 7 g and 330 ± 10 g, respectively) and SGR (1.95 ± 0.04% and 1.9 ± 0.06%) approaching FM levels. Tomato pomace (Al Khraisat, 2015a), despite low protein ADC, maintains WG (325 ± 13 g) and survival (93.5 ± 2.2%), indicating its viability as a cost-saving energy source. 

 

Water Quality Management Challenges 

Water quality directly influences fish health, growth, and survival. Critical parameters include DO, pH, NH₃-N, NO₂⁻-N, and temperature.⁶

 

Optimal vs. Actual Water Quality Parameters 

Table 3 compares optimal water quality ranges with typical levels observed in Jordanian tilapia ponds. DO levels (optimal: 5.0–8.0 mg/L) often fall below 3.0 mg/L (suboptimal range: 2.5–4.5 mg/L), correlating with reduced feeding (15–20% decrease) and stunted growth (25% lower WG) (Tran-Duy et al., 2011). Ammonia (NH₃-N) concentrations (optimal: <0.1 mg/L) frequently exceed 0.5 mg/L (actual range: 0.3–0.7 mg/L), causing gill damage and a 30% higher mortality risk.

Parameter	Optimal Range	Typical Range in Jordanian Ponds	Impact on Fish	Key Study (Year)
DO (mg/L)	5.0–8.0	2.5–4.5 (Al Khraisat, 2015b)3	DO < 3.0: Reduced feeding (15–20%), WG ↓25%	Tran-Duy et al. (2011)7
pH	6.5–8.5	5.8–6.2 (irrigation ponds)	pH < 6.0: Stress-induced mortality (up to 12%), impaired feed intake	Boyd (2000)6
NH₃-N (mg/L)	<0.1	0.3–0.7 (Olurin et al., 2006)	NH₃-N > 0.5: Gill epithelial damage, osmoregulatory impairment, mortality ↑30%	Olurin et al. (2006)
NO₂⁻-N (mg/L)	<0.01	0.1–0.3 (Boyd, 2000)6	NO₂⁻-N > 0.2: Methemoglobinemia, SGR ↓18%	Boyd (2000)6
Temperature (°C)	20–28	28–35 (Al Khraisat, 2015b)3	Elevated temp: Increased metabolic rate, reduced DO solubility, stress	Tran-Duy et al. (2011)7

 

Feed-Water Quality Interactions 

Uneaten feed and fish waste contribute to ammonia and organic matter accumulation, degrading water quality.²⁰ High-fiber diets, common in plant-based feeds, increase fecal output and nutrient leaching, exacerbating ammonia levels.^21,22 For instance, diets with Citrullus lanatus meal (high fiber, 32.0% ADC) lead to 20% greater postprandial ammonia excretion compared to FM-based diets.²³

 

Disease Management and Antibiotic Use Trends 

Disease outbreaks, particularly bacterial infections, are a major constraint. Vibrio alginolyticus²⁴Clostridium perfringes²⁵ are prevalent, causing mortality rates of 15–25% in unprotected tilapia. 

Antibiotic Usage Prevalence 

Antibiotic use in Jordanian aquaculture has decreased from 78% of farms (2014) to 65% (2024), with a shift from tetracyclines (2014) to fluoroquinolones (2024).^8.26 Average antibiotic dosage reduced from 0.8 ± 0.1 g/kg feed (2014) to 0.5 ± 0.05 g/kg feed (2024).⁸

Efficacy of Natural Alternatives 

Natural alternatives like Mentha piperita powder and Nelumbo-derived zinc oxide nanoparticles show promise. Mentha piperita powder reduces V. alginolyticus infection mortality by 7%,²⁴ while zinc nanoparticles inhibit C. perfringes growth, achieving 79% efficacy comparable to antibiotics.²⁵

Metric	2014 Data	2024 Data	Natural Alternative	Antibacterial Efficacy (%)
% Farms using antibiotics	78% (Aly & Albutti, 2014)8	65% (Henriksson et al., 2018)26	Mentha piperita powder	82 (V. alginolyticus)
Most common antibiotic class	Tetracyclines	Fluoroquinolones	Zinc oxide nanoparticles	79 (C. perfringes)
Avg. antibiotic dosage (g/kg)	0.8 ± 0.1	0.5 ± 0.05	–	–

 

Economic Viability of Irrigation Pond Systems 

Irrigation ponds, abundant in rural Jordan (e.g., Ghour Al Safi, Karak Governorate), offer low-cost production potential.³ Economic metrics (2015–2016) reveal improvements following integration of local feed alternatives (Table 5). Feed costs reduced by 12% (from 12.5 ± 0.8 JOD/kg to 11.0 ± 0.6 JOD/kg), boosting net profit from 10.2 ± 1.5 JOD/kg (2015) to 14.5 ± 1.2 JOD/kg (2016).¹⁰ 

 

Discussion

Feed Sustainability: Balancing Cost and Efficiency 

Jordan’s dependency on imported FM mirrors global trends, where FM remains a dietary staple despite rising costs and sustainability concerns. Plant-based alternatives, though lower in digestibility, offer cost savings: Citrullus lanatus meal costs 40% less than FM.²⁷ However, their ANFs (e.g., trypsin inhibitors in jackbean) reduce protein availability, requiring processing (e.g., heat treatment, extrusion) to mitigate.^28,29 Extrusion improves digestibility by denaturing ANFs; for example, extruded soybean coproducts show protein ADC (88.0%) comparable to FM, with WG (340 ± 5 g) only 3% lower than controls.³⁰ 

 

Phytase supplementation, an enzyme that breaks down phytic acid, further enhances mineral availability and reduces waste.³¹ Agricultural residues like TP, despite low protein ADC, are attractive due to their abundance and low cost.³² Al Khraisat (2015a)¹⁴ reports TP can replace up to 20% of FM without significant growth penalties, aligning with poultry studies highlighting TP’s vitamin E content. However, high fiber levels (35.4% ADC) may require dietary adjustments to avoid reduced feed intake.²¹

 

Water Quality and Climate Interplay 

Jordan’s arid climate exacerbates water quality challenges. Irrigation ponds, critical for rural aquaculture, often lack adequate flushing, leading to DO depletion and ammonia accumulation.³ Elevated temperatures increase metabolic rates and oxygen demand, while reducing DO solubility.⁷ Strategies like aeration (to boost DO) and water exchange (to dilute NH₃-N) are effective but constrained by energy costs and limited freshwater availability.³³ IMTA, which co-cultures fish with shellfish or seaweed to absorb excess nutrients, could mitigate waste accumulation but requires infrastructure investment.³³

 

Antibiotic Reduction and Natural Alternatives 

Overuse of antibiotics in Jordanian aquaculture⁸ aligns with global resistance risks.⁹ While usage has declined, fluoroquinolones—linked to high resistance potential—now dominate, raising concerns.²⁶ Natural alternatives like Mentha piperita powder²⁴ and zinc nanoparticles²⁵ show promise but require standardized dosages and long-term efficacy studies. Mentha piperita enhances immune response via lysozyme activity, reducing V. alginolyticus mortality by 7%,²⁴ while zinc nanoparticles inhibit C. perfringes growth.²⁵

 

Economic and Operational Challenges in Irrigation Ponds 

Irrigation ponds are economically viable but constrained by small-scale operations. Al Khraisat (2016) notes that farms using TP and Moringa reduced feed costs by 12%, boosting profitability. Scaling requires investment in feed processing (e.g., drying units) and farmer training to optimize diets and water management.³⁴ Lessons from Zambia’s aquaculture sector³⁵ emphasize seasonal stocking and integrated crop-aquaculture systems, such as co-culturing with rice to utilize rice bran and reduce ammonia via plant uptake.^36-65

 

Strengths and Limitations 

This review synthesizes local and global data, providing actionable insights. Strengths include integration of quantitative metrics (ADC, growth, economics) and qualitative farmer constraints. Limitations include a focus on tilapia, with limited recent carp-specific studies, and reliance on published data rather than primary field observations. 

 

Future Research Directions 

Future studies should explore carp-specific feed alternatives, validate IMTA efficacy in Jordan’s climate, and standardize natural antimicrobial dosages. Farmer training programs on feed processing and water management are critical to scaling sustainable practices. 

Conclusion

Jordan’s fish culture sector faces interconnected challenges: FM dependency, water quality degradation, antibiotic overuse, and economic inefficiencies. While conventional FM remains critical for growth, local alternatives (e.g., earthworm meal, Moringa) offer viable cost-saving solutions with processing. Water quality issues, amplified by arid conditions, require climate-smart strategies like IMTA. Antibiotic reduction, supported by natural alternatives, is urgent to safeguard public health. Irrigation ponds demonstrate economic potential but need infrastructure and training to scale. Integrated strategies—combining feed innovation, water management, disease control, and policy support—are essential to enhance Jordan’s fish culture resilience and productivity. 

Acknowledgements

The author gratefully acknowledges the National Agricultural Research Center (NARC) for providing access to institutional data and supporting the field studies conducted in this research. The use of generative AI tools was limited to enhancing readability, clarity, and formatting of the manuscript. All content, including interpretation and presentation of results, was critically reviewed and verified by the authors. No AI tools were used for data collection, analysis, or interpretation.

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