Irrigation, and especially farmer-led irrigation, is considered to be a promising option for enhancing agricultural productivity in Sub-Saharan Africa. However, there is a lack of thorough understanding of the impacts of irrigation development on environment. Past discussions are mainly limited to the water depletion and hydrological regime change effect of irrigation. This paper presents a study to narrow the knowledge gap by assessing nutrient water pollution risk induced by the expansion of farmer-led irrigation in Ethiopia. Using household survey data collected from four woredas in Ethiopia where irrigated crop production currently concentrates, we first evaluate the impact of irrigation on cropping intensity and annual consumption level of fertilizers and then use the findings of the household survey data analysis to support conceptualization of a modeling framework for assessing agricultural nutrient water pollution risk from farmer-led irrigation development in Ethiopia at national scale. We project that overall farmer-led irrigation development in Ethiopia will lead to a gentle increase in national total of agricultural nutrient loadings. This result helps justify the endeavor of promoting farmer-led irrigation in Ethiopia. On the other hand, the projected nutrient flow and nutrient loading growth rate related to the farmer-led irrigation expansion are highly heterogeneous spatially, and risk of local water quality deterioration exists. There is still need to make investment to ensure the environmental sustainability of farmer-led irrigation development.

Irrigation, and especially farmer-led irrigation, is considered to be a promising option for enhancing agricultural productivity in Sub-Saharan Africa. However, there is a lack of thorough understanding of the impacts of irrigation development on environment. Past discussions are mainly limited to the water depletion and hydrological regime change effect of irrigation. This paper presents a study to narrow the knowledge gap by assessing nutrient water pollution risk induced by the expansion of farmer-led irrigation in Ethiopia. Using household survey data collected from four woredas in Ethiopia where irrigated crop production currently concentrates, we first evaluate the impact of irrigation on cropping intensity and annual consumption level of fertilizers and then use the findings of the household survey data analysis to support conceptualization of a modeling framework for assessing agricultural nutrient water pollution risk from farmer-led irrigation development in Ethiopia at national scale. We project that overall farmer-led irrigation development in Ethiopia will lead to a gentle increase in national total of agricultural nutrient loadings. This result helps justify the endeavor of promoting farmer-led irrigation in Ethiopia. On the other hand, the projected nutrient flow and nutrient loading growth rate related to the farmer-led irrigation expansion are highly heterogeneous spatially, and risk of local water quality deterioration exists. There is still need to make investment to ensure the environmental sustainability of farmer-led irrigation development. | PR | IFPRI3; 1 Fostering Climate-Resilient and Sustainable Food Supply; 4 Transforming Agricultural and Rural Economies | Natural Resources and Resilience (NRR); Transformation Strategies

As an important part of marine litter at the seafloor “Abandoned, lost, discarded or otherwise lost fishing gear” (ALDFG) is gaining increasing attention in environmental assessments. Within this study marine litter at the seafloor of the Baltic Sea was quantified and characterized with special regard to fishery as source. Litter items (LI) were collected within fishery catches by bottom trawling during three cruises in 2020 and 2021. The resulting mean litter abundance was 9.2 LI/km2. Approximately 56 % of all LI were plastic, with PE as the most frequently identified polymer. ALDFG was present in considerable amounts with a mean value of 2.2 LI/km2 (22.2 %). However, the absolute counts of fishery nets were low (0.4 LI/km2; 4.2 %). Regarding weight, fishery nets are the dominant part of litter at the Baltic seafloor. Threshold values for marine litter at the seafloor are missing and might be developed using quantitative data on ALDFG.

Marine litter at the seafloor comprises different materials. Plastic is the most frequent material of marine litter found at the seafloor of the Baltic Sea (55,6%). "Abandoned, lost, discarded or otherwise lost fishing gear" (ALDFG) is a subgroup of plastic litter with special importance for environmental assessment because it has a defined source and may pose a health risk to animals. With the data provided, marine litter at the seafloor of the Baltic Sea was quantified and characterized with special regard to fishery as source. 72 litter items (LI) were collected within fishery catches by bottom trawling during three cruises in 2020 and 2021. The data were used to quantify litter at the seafloor of the Baltic Sea (9.2 LI/km²) including 2.2 LI/km² ALDFG and 0.4 LI/km² fishery nets. We conclude that fishery is an important source of litter and ALDFG represent a considerable share of marine litter with 22.2%.

Marine litter at the seafloor comprises different materials. Plastic is the most frequent material of marine litter found at the seafloor of the Baltic Sea (55,6%). "Abandoned, lost, discarded or otherwise lost fishing gear" (ALDFG) is a subgroup of plastic litter with special importance for environmental assessment because it has a defined source and may pose a health risk to animals. With the data provided, marine litter at the seafloor of the Baltic Sea was quantified and characterized with special regard to fishery as source. 72 litter items (LI) were collected within fishery catches by bottom trawling during three cruises in 2020 and 2021. The data were used to quantify litter at the seafloor of the Baltic Sea (9.2 LI/km²) including 2.2 LI/km² ALDFG and 0.4 LI/km² fishery nets. We conclude that fishery is an important source of litter and ALDFG represent a considerable share of marine litter with 22.2%.