The Potential of Several Wild Invasive Fish Species as Fish-Based Organic Fertilizers on the Growth of Two Common Vegetables in Malaysia

Abstract

Three common invasive fish species in Malaysia, Peacock Bass (Cichla ocellaris), Nile Tilapia (Oreochromis niloticus) and Algae Suckermouth Catfish (Hypostomus plecostomus) were assessed for their efficacy as potential fish powder fertilizers. These invasive fish species were known to disturb the stability of lentic and lotic aquatic ecosystems in Malaysia, especially O. niloticus and H. plecostomus, altering aquatic habitats and food webs to be unsuitable for survival of indigenous fish species, while C. ocellaris becoming active aggressive predators on indigenous fish species, overall reducing indigenous fish species diversity. Plant primary macronutrient traces showed that C. ocellaris fish powder fertilizer recorded the highest Nitrogen (N) element percentage (15.81 ± 0.43 N %w/w) and trace Potassium (K) element (28,909.15 ± 32.56 K mg/kg), while H. plecostomus fish powder fertilizer recorded the highest trace Phosphorus (P) element (30,562.09 ± 197.11 P mg/kg). Plant secondary macronutrient traces showed that C. ocellaris fish powder fertilizer recorded the highest trace Magnesium (Mg) element (1496.66 ± 3.99 Mg mg/kg), while H. plecostomus fish powder fertilizer recorded the highest trace Calcium (Ca) element (6984.48 ± 26.20 Ca mg/kg). Two vegetable species tested for their growths, the water spinach (Ipomoea aquatica) and the spinach (Spinacia oleracea), showed that C. ocellaris fish powder fertilizer recorded the highest heights (263.74 ± 12.29 mm, 166.35 ± 9.46 mm), the widest leaf width (14.82 ± 0.66 mm, 21.08 ± 1.53 mm), and the widest stalk width (3.06 ± 0.10 mm, 2.89 ± 0.17 mm), respectively, comparable to the NPK 15:15:15 compound fertilizer, followed by H. plecostomus and O. niloticus fish powder fertilizers. C. ocellaris as predatory invasive fish species with the highest Mg concentration and moderate Ca concentrations, was especially suitable for the growth of both semi-aquatic and terrestrial vegetables grown on low Mg concentration soils.

Innovative Solution for Invasive Species and Water Pollution: Hydrochar Synthesis from Pleco Fish Biomass

“…A high 𝐻/𝐶 ratio indicates that the aromat tent in the samples is low, while a decrease in the 𝑂/𝐶 ratio implies that the mat undergoing decarboxylation reactions and chemical dehydration [36]. Figure 12 that with increasing temperature and/or hydrocarbonization time of the samples t a marked tendency towards dehydration and decarboxylation, which coincides wi reported by [6,9]. In this study, the carbon content ranges from 26 to 73%, which is consistent with that reported by (Afolabi and Sohail, 2017;Huezo et al, 2021) [34].…”

“…The equation for this CCD is presented in Equation ( 6) (R 2 = 99.5). CV = 246.23 − 1.97B + 0.003A 2 + 0.005B 2 (6) This equation provides information to understand the effects of the variables in the CV, where the negative coefficients indicate that bigger temperature values reduce the CV. The quadratic model was optimized using the Microsoft Excel 2023 Solver add-in program, maximizing the CV of the quadratic model with the upper and lower levels of the variables as constraints.…”

“…In response to this situation, some research has been conducted to address the issue of plecos, directing the findings to its use as food for the general population or to obtain by-products as fertilizers, fish silage as a feed supplement for livestock, as well as fishmeal for fish feed. The most promoted option among fishing communities is fish consumption as part of the diet, although without much acceptance so far [6].…”