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Lopez-Carr, D.

Publications and source records attributed to Lopez-Carr, D..

2 recordsLinked to original sources

Rice-Fish Co-Culturing for Sustainability, Food Security, and Disease and Poverty Reduction

Over 140 million households cultivate rice worldwide. However, rice production contributes to exceedances of planetary boundaries, such as freshwater use and biogeochemical flows. Additionally, rice-farming families may face increased risk of acquiring schistosomiasis, a parasitic disease transmitted by freshwater snails that contributes to reinforcing cycles of poverty and disease. Using data from 405 households in rural Senegal, we show that children in rice-farming households had higher Schistosoma mansoni prevalence and S. haematobium intensities than non-farming peers. To address this environmental-health challenge, we integrated native Nile Tilapia (Oreochromis niloticus) and African Bonytongue (Heterotis niloticus) into rice fields. The fish thrived, suppressed insects and snail pests, improved soil nutrients, and boosted rice yields by >25% with a net benefit of 1,805-3,415 USD/ha/year (benefit-to-cost ratio = 7.42). Hence, low-input rice-fish co-culturing offers a scalable planetary health solution that simultaneously advances sustainability, nutrition, health, and rural livelihoods. ResumePlus de 140 millions de foyers a travers le monde cultivent du riz. Cependant, cette production exerce une pression importante sur les ressources naturelles, notamment les reserves deau douce. Par ailleurs, les menages pratiquant la riziculture peuvent etre plus exposes au risq ue de bilharziose, une maladie parasitaire transmise par des escargots deau douce, qui contribue au cycle de pauvrete. A partir de donnees collectees aupres de 405 menages dans des villages senegalais, nous montrons que les enfants issus de familles pratiquant la riziculture presentent une prevalence plus elevee dinfection a Shistosoma mansoni et des intensites dinfection a S. haematobium plus importantes que ceux issues de familles ne cultivant pas le riz. Pour remedier a cela, nous avons integre deux especes locales de poissons, le tilapia du Nil (Oreochromis niloticus) et lHeterotis (Heterotis niloticus), dans les rizieres, afin de reduire les population descargots hotes, ameliorer les rendements agricoles et augmenter les revenus. Ces poissons ont montre une bonne croissance, ont contribue a la regulation des insectes et des escargots nuisibles, ont enrichi le sol en nutriments, et accru les rendements rizicoles de plus de 25%, avec un benefice net estime entre 1 805 et 3 415 USD/ha/an (ratio benefice-cout = 7,42). Ainsi, la co-culture riz-poisson a faibles intrants constitue une solution reproductible en faveur de la sante publique, permettant de concilier durabilite, nutrition et amelioration des moyens de subsistance en milieu rural.

ecology↗

Identifying low risk insecticides to address both food shortages and the biocontrol of human schistosomiasis

Use of agrochemicals, including insecticides, is vital to food production and predicted to increase 2-5 fold by 2050. Previous studies have shown a positive association between agriculture and the human infectious disease schistosomiasis, which is problematic as this parasitic disease infects approximately 250 million people worldwide. Certain insecticides might runoff fields and be highly toxic to invertebrates, such as prawns in the genus Macrobrachium, that are biocontrol agents for snails that transmit the parasites causing schistosomiasis. We used a laboratory dose-response experiment and an observational field study to determine the relative toxicities of three pyrethroid (esfenvalerate, {lambda}-cyhalothrin, and permethrin) and three organophosphate (chlorpyrifos, malathion, and terbufos) insecticides to Macrobrachium prawns. In the lab, pyrethroids were consistently several orders of magnitude more toxic than organophosphate insecticides, and more likely to runoff fields at lethal levels according to modeling data. In the field, we found that Macrobrachium prawn survival at 31 water contact sites in the lower basin of the Senegal River where schistosomiasis is endemic was predicted by pyrethroid application rates to nearby crop fields after controlling for abiotic and prawn-level factors. Our findings suggest that widely used pyrethroid insecticides can have strong non-target effects on Macrobrachium prawns that are biocontrol agents where 400 million people are at risk of human schistosomiasis. Understanding the ecotoxicology of high-risk insecticides may help improve human health in schistosomiasis-endemic regions undergoing agricultural expansion.

ecology↗