In the last 50 years, eutrophication in inland waters has increased drastically around the world (Padedda et al. 2022). Eutrophication, which has become the subject of both academic and public debate, is fed by nutrients in the form of widespread agricultural loading and point sources of industrial and municipal wastewater (Bonsdorff 2021). Eutrophication of aquatic ecosystems results from high concentrations of nutrients, particularly phosphates and nitrates. Coastal water bodies are exposed to pollution from agriculture, industrial facilities, sewage systems, and water treatment plants. Agricultural activities, which are the source of more than 40% of all pollution, gradually upset the balance of water quality (EAA 2015). Fertilizer consumption (N, P, and K) in all countries of the world is predicted to increase from 166 million tons to 263 million in the forty-five-year period from 2005 to 2050, (Alexandratos & Bruinsma 2012). Biologically usable in inland waters can disrupt the balance of the ecosystem, especially phosphorus and nitrogen loads.
Köyceğiz Lake reaches the Mediterranean Sea via the Dalyan Lagoon canal system. Agriculture, tourism, forestry, and fishing are the main sources of economic income in the area of the Lagoon. Fertilization is a common practice in agricultural lands (Gürel 2000). It is calculated that approximately 108 thousand kg of nitrogen and 9.7 thousand kg of phosphorus enter Dalyan Lagoon annually, even if fertilization is undertaken conscientiously and in accordance with good agricultural practices (Ekdal 2008).
Conventional treatment technologies to remove wastewater pollutants from the receiving aquatic environment are both costly and time-consuming. In contrast, phytoremediation is a cost-effective, green emerging technology with long-term viability (Ali et al. 2020).
Aquatic phytoremediation has the potential to be used both as a management strategy for the removal of pollutants from surface waters and for the recovery of nutrients. Macrophytes in particular are used for aquatic phytoremediation. Macrophytes take up N mainly in the form of nitrate (NO3) and ammonium (NH4), while P is taken as phosphate (PO3).
The total world fishery production in 2020 was 178 million tonnes, of which 87.5 million tons was obtained from aquaculture. The aquaculture sector is considered to be the fastest-growing sector among the food production sectors. The common carp is one of the most widely-cultured species of freshwater fish in the world (FAO 2022). World aquaculture production of common carp was close to 4.3 million tonnes in 2020, representing 8.6% of total inland aquaculture production of fish and 4.8% of total aquaculture production. Macro algae (generally known as seaweed) provide a novel and value-added dietary ingredient in fish diets (Wan et al. 2018). The total production of aquatic algae was 35.01 million tonnes (USD 16.5 billion) in 2020 (FAO 2022). Mustafa et al. (1995) stated that a small amount of algae added to the fish diet significantly improves growth, lipid metabolism, body composition, and disease resistance. Also, Chopin & Tacon (2021) revealed that the use of different seaweed raw materials in the diets of fish, crustaceans, mollusks, sea urchins, and sea cucumbers generally positively affects the growth of aquatic organisms at the level of 5–15%. Therefore, the production of algae is being developed. Algae meals, which are used as alternatives in fish diets at different rates, can significantly reduce feed prices when considered economically (Saleh 2020).
The first study on the effect of aquatic weeds on the growth performance of fish was carried out by Venkatesh & Shetty (1978). In their study
This study aims to demonstrate the effects of
Four isonitrogenous (38% crude protein), isolipidic (8% crude lipid), and isoenergetic (18 kJ g−1) diets were formulated to meet the nutritional needs of common carp. The feed experiment included a control group with no
Proximate composition and essential amino acid profile of feed ingredients in test diets
Proximate Analysis | CDM* | SBM | FM | WM | WGM |
---|---|---|---|---|---|
Dry matter (% in an original matter) | 89.57 | 89 | 92 | 88 | 89 |
Crude Protein | 15.78 | 44 | 65.4 | 11.7 | 80.7 |
Crude Lipid | 1.80 | 1.5 | 7.6 | 1.2 | 1.5 |
Crude Fibre | 18.61 | 7.3 | 1.0 | 1.3 | 0.5 |
Ash | 18.96 | 6.3 | 14.3 | 0.4 | 0.7 |
NFE1 | 34.42 | 29.90 | 3.70 | 73.40 | 5.60 |
Gross Energy (kJ g−1)2 | 10.22 | 15.83 | 18.58 | 15.74 | 20.10 |
Calcium | 0.22 | 0.03 | 0.63 | 0.03 | 0.14 |
Phosphorus | 0.38 | 0.07 | 0.39 | 0.34 | 0.26 |
EAA (DM %)3,4 | |||||
Arginine | 0.45 | 3.23 | 3.68 | 0.86 | 3.80 |
Histidine | 0.04 | 1.17 | 1.56 | 0.39 | 2.00 |
Isoleucine | 0.70 | 1.99 | 3.06 | 0.51 | 3.70 |
Leucine | 1.09 | 3.42 | 5.00 | 0.92 | 6.30 |
Lysine | 0.95 | 2.83 | 5.11 | 0.58 | 4.90 |
Methionine | 0.18 | 0.61 | 1.95 | 0.19 | 1.60 |
Phenylalanine | 0.64 | 2.18 | 2.66 | 0.55 | 4.50 |
Threonine | 0.70 | 1.73 | 2.82 | 0.46 | 1.60 |
Tryptophan | — | 0.61 | 0.76 | 0.25 | 1.05 |
Valine | 0.76 | 2.40 | 3.51 | 0.69 | 4.00 |
CDM -
Nitrogen-free extracts (NFE) = Dry matter % – (lipid (%) + protein (%) + fiber (%) + ash (%)
Calculated using the factors: carbohydrates, 4.1 kcal g−1; protein, 5.5 kcal g−1; lipid, 9.1 kcal g−1 (New 1987), and use a factor of 4.184 to convert to kJ.
Essential amino acids values of soybean meal, fish meal, and wheat meal were obtained from NRC (2011).
Essential amino acids values of
CDM crude protein, crude lipid, crude fibre, ash, and dry matter values analysed in our study; SBM, FM, and WM values obtained from NRC (2011).
Ingredients and proximate composition of the four experimental diets
Ingredients (%) | Diets | ||||
---|---|---|---|---|---|
Control | CM5 | CM10 | CM15 | ||
Fish Meal | 300 | 305 | 305 | 305 | |
Soybean Meal | 360 | 342 | 324 | 306 | |
Wheat Meal | 205 | 200 | 200 | 190 | |
Fish Oil | 100 | 100 | 100 | 100 | |
0 | 18 | 36 | 54 | ||
Wheat Gluten | 20 | 20 | 20 | 30 | |
Vit-Min Mix | 10 | 10 | 10 | 10 | |
Antioxidant | 5 | 5 | 5 | 5 | |
Proximate analysis (% DM) | |||||
Dry matter | 90.55 | 90.92 | 90.91 | 91.02 | |
Crude protein | 37.99 | 37.90 | 37.54 | 37.87 | |
Crude lipid | 8.00 | 8.06 | 8.06 | 8.06 | |
Crude Fibre | 1.19 | 1.94 | 2.63 | 3.79 | |
Ash | 5.71 | 6.64 | 7.76 | 8.40 | |
NFE1 | 36.66 | 36.38 | 34.92 | 32.90 | |
Calcium | 0.33 | 0.34 | 0.35 | 0.36 | |
Phosphorus | 0.3 | 0.3 | 0.28 | 0.26 | |
Gross Energy (kJ g−1)2 | 18.46 | 18.03 | 17.70 | 17.43 | |
EAA (g 100 g−1 DM) | |||||
Amino Acids | Carp3 | Control | CM5 | CM10 | CM15 |
Arginine | 1.7 | 2.52 | 2.48 | 2.43 | 2.41 |
Histidine | 0.8 | 1.01 | 0.99 | 0.97 | 0.97 |
Isoleucine | 1.0 | 1.81 | 1.80 | 1.78 | 1.79 |
Leucine | 1.5 | 3,05 | 3,02 | 2,98 | 2,99 |
Lysine | 2.2 | 2.77 | 2.76 | 2.72 | 2.73 |
Methionine | 0.3 | 0.88 | 0.88 | 0.87 | 0.88 |
Phenylalanine | 1.3 | 1.79 | 1.77 | 1.74 | 1.75 |
Threonine | 1.5 | 1.60 | 1.59 | 1.57 | 1.56 |
Tryptophan | 0.3 | 0.52 | 0.51 | 0.50 | 0.50 |
Valine | 1.4 | 2.14 | 2.12 | 2.09 | 2.10 |
Nitrogen-free extracts (NFE) = Dry matter % – (lipid (%) + protein (%) + fibre (%) + ash (%)
Calculated using the factors: carbohydrates, 4.1 kcal g−1; protein, 5.5 kcal g−1; lipid, 9.1 kcal g−1 (New 1987), and use a factor of 4.184 to convert to kJ.
Requirements according to NRC (2011).
Dry ingredients were mixed according to weight and homogenized for 16 minutes. Fish oil and water were added to the mixture which was then pulped and converted to a 2mm diameter pellet after being passed through a pelletizer. The pellets were prepared using a constant temperature (about 70°C) feed-making machine. Prepared feeds were crumbled into a dried material and maintained at 4°C for three days until use.
Common carp (
Dissolved oxygen, temperature and pH in the water system were measured daily using the Hach-Lange HQ40 D model multiparameter device. The N-NO2- and N-NO3 content of water were measured weekly using Noratex test kits. The mean values were as follows: mean water temperature 20.5°C ± 2, 8.68 mg l−1 ± 1 dissolved oxygen, 8.3 ± 0.2 pH, 0.1 ppm N-NO2, and 0.5 ppm N-NO3.
All experimental feeds and fish samples were analyzed for the chemical composition according to the Association of Official Analytical Chemistry (AOAC 2002; AOAC 2002b). Dry mass was determined by oven drying at 105°C for 24 hours to constant weight; ash content was determined by firing in a muffle furnace at 550°C for 4 hours; Crude protein was determined by Kjeldahl protein unit. Crude lipid was determined by the ether extraction method. Before starting the experiment, 5 fish from the first batch were chosen to be subjected to hypothermia in the refrigerator, stored in polyethylene bags, and frozen (−20°C) for subsequent body composition analysis. At the end of the feeding trial, 5 fish were randomly removed from each tank (15 fish per treatment), killed as described above, and stored for analysis. Samples were prepared by homogenizing whole fish in a blender prior to analysis. All analyses were performed in triplicate.
Growth parameters and feed utilization protein efficiency were calculated with the following equations:
Ethics statement all animal care, welfare, and handling procedures in the present study protocol were approved (Protocol Number 64583101/127) by the Animal Experiments Local Ethics Committee of Aydın Adnan Menderes University of Türkiye. This manuscript was produced from
Statistical differences among the experimental groups were tested by one-way ANOVA followed by post hoc Tukey’s test (
The results of growth rates and survival percentages of fish fed on four different feeds (Basal diet, three coontail diets) are shown in Table 3. There was no statistical difference (
Growth performance and feed utilization parameters of Common Carp fed experimental diets
Parameters | Units | Control | CM5 | CM10 | CM15 |
---|---|---|---|---|---|
Initial Weight | g | 19.08 ± 0.13a | 18.88 ± 0.04a | 18.87 ± 0.06a | 18.73 ± 0.15a |
Final Weight | 33.83 ± 0.07a | 33.42 ± 0.38a | 29.43 ± 1.70b | 27.30 ± 0.55b | |
Weight Gain | 14.75 ± 0.12a | 14.54 ± 0.42a | 10.56 ± 1.65b | 8.56 ± 0.64b | |
Weight Gain | % | 77.31 ± 1.03a | 77.01 ± 2.38a | 55.96 ± 8.62b | 45.76 ± 3.69b |
SGR | 1.1 ± 0.00a | 1.09 ± 0.02a | 0.86 ± 0.09b | 0.71 ± 0.04b | |
Daily feed intake | g fish−1 day−1 | 0.472 ± 0.006a | 0.476 ± 0.007a | 0.475 ± 0.005a | 0.450 ± 0.004b |
FCR | 1.66 ± 0.03b | 1.70 ± 0.05b | 2.38 ± 0.25a | 2.75 ± 0.23a | |
Feed Efficiency Value | 0.60 ± 0.01b | 0.58 ± 0.02b | 0.44 ± 0.04a | 0.36 ± 0.03a | |
Protein efficiency rate | 1.75 ± 0.45 | 1.69 ± 0.61 | 1.22 ± 0.23 | 1.00 ± 0.35 | |
Survival Rate | % | 97.77 ± 3.14a | 95.55 ± 3.14a | 95.55 ± 4.44a | 97.77 ± 3.14a |
Values refer to mean ± standard deviation. Values expressed in different exponential letters in the same row are statistically different from each other (
The amount of feed consumption between the experimental groups was not significant (
The results of the dietary effect on the body chemistry of the
Carcass composition of common carp fed diets containing different levels of
Parameters | Units | Control | CM5 | CM10 | CM15 |
---|---|---|---|---|---|
Crude Protein | % | 16.55 ± 0.32b | 17.46 ± 0.25a | 17.21 ± 0.51a | 16.76 ± 0.25b |
Crude Lipid | 9.68 ± 0.62a | 8.46 ± 0.55a | 6.59 ± 0.76b | 6.75 ± 0.45b | |
Moisture | 71.86 ± 3.21 | 71.97 ± 1.55 | 74.19 ± 1.11 | 74.57 ± 2.25 | |
Crude Ash | 1.91 ± 0.11 | 2.11 ± 0.20 | 2.01 ± 0.10 | 1.98 ± 0.9 |
Values refer to mean ± standard deviation. Values expressed in different exponential letters in the same row are statistically different from each other (
The present study reports the first use of a natural phytoremediation
The findings of Balkhasher et al (2021) showed that the use of
Anti-nutrient factors can bind to nutrients and affect their usefulness. Examples of these substances are saponins, tannins, phytic acid, gossypol, lectins, protease inhibitors, and amylase inhibitor (Samtiya et al. 2020). Although most of the anti-nutrients in fish diets do not cause death, they may adversely affect biomass (Francis et. 2001). Norambuena et al. (2015) also stated that complex polysaccharides in algal products can adversely affect the digestibility of nutrients. Omnes et al. (2017) demonstrated that tannin supplementation of upwards of 10 g kg−1 in European sea bass diets reduces protein digestion, while growth performance above 20 g kg−1 significantly decreases. Although there are anti-nutrient substances such as lectin in marine algae, they are less common than in terrestrial plants (Rogers & Hori 1993). The main point here is that knowing the threshold level of these components can eliminate their harmful effects.
The whole-body composition of fish is often used as an indicator of fish health and meat quality (Ahmed 2018). In this study, the higher protein level results in increased body composition of fish due to the increase of aquatic macrophyte in the diets, whereas the rise in the
Throughout the experimental study, we did not detect a difference in longevity in all diet groups and there was no visual sign of disease or deformity. This research was the first attempt to supplement the diet of carp fish with the natural phytoremediation of