THE ABUNDANCE OF Lemina minor IN EARTHEN PONDS IN SELECTED FISH FARMS ALONG IKPOBA RIVER BENIN CITY, EDO STATE
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Abstract
The abundance of duckweeds in earthen fish ponds is a phenomenon that warrants detailed study due to its ecological, economic, and management implications. This study investigated the abundance, spatial distribution, and management of Lemna minor (duckweed) in earthen fish ponds along the Ikpoba River in Benin City, Edo State, focusing on Oredo and Ikpoba-Okha Local Government Areas. Structured questionnaires and field assessment were used to collect
data from 100 fish farmers, while descriptive and spatial analyses were performed to evaluate duckweed coverage, biomass, and management practices. Results showed that Lemna minor was relatively abundant, with mean coverage of 63.8% (40.8 g/m²) in Oredo and 66.2% (42.9 g/m²) in Ikpoba-Okha, particularly concentrated at pond inlets where nutrient inflow was greatest. Most farmers were educated (54.2%) males aged 30–39 years (56%), mainly culturing Clarias
gariepinus (60.2%) under intensive systems. About 63.2% of respondents reported duckweed presence, primarily during the rainy season (86.6%), with 28.3% perceiving it as beneficial for water shading and nutrient removal, while 17.2% considered it harmful due to oxygen depletion and feeding obstruction. Manual removal (54.3%) and biological control (21.7%) were the most common management practices, though only moderately effective. It concludes that L. minor
proliferation indicates nutrient-rich pond conditions and recommends integrated management through nutrient regulation, regular monitoring, and biological control to enhance sustainable aquaculture productivity
data from 100 fish farmers, while descriptive and spatial analyses were performed to evaluate duckweed coverage, biomass, and management practices. Results showed that Lemna minor was relatively abundant, with mean coverage of 63.8% (40.8 g/m²) in Oredo and 66.2% (42.9 g/m²) in Ikpoba-Okha, particularly concentrated at pond inlets where nutrient inflow was greatest. Most farmers were educated (54.2%) males aged 30–39 years (56%), mainly culturing Clarias
gariepinus (60.2%) under intensive systems. About 63.2% of respondents reported duckweed presence, primarily during the rainy season (86.6%), with 28.3% perceiving it as beneficial for water shading and nutrient removal, while 17.2% considered it harmful due to oxygen depletion and feeding obstruction. Manual removal (54.3%) and biological control (21.7%) were the most common management practices, though only moderately effective. It concludes that L. minor
proliferation indicates nutrient-rich pond conditions and recommends integrated management through nutrient regulation, regular monitoring, and biological control to enhance sustainable aquaculture productivity
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