25
Oct
(Beyond Pesticides, October 25, 2024) To better understand synergistic interactions between multiple stressors, researchers from the Helmholtz Centre for Environmental Research in Leipzig, Germany, analyze exposure to the pyrethroid insecticide esfenvalerate with two nonchemical environmental factors: elevated temperature and food limitation. In their recent publication in Environmental Pollution, the authors find the greatest synergistic effects when Daphnia magna (D. magna) are subjected to esfenvalerate under conditions experienced with climate change including lower food availability and increased temperature. D. magna, also known as daphnids or water fleas, are small planktonic crustaceans that represent an essential part of the food web in lakes and ponds. Impacts on populations of daphnids can lead to effects throughout multiple trophic levels that impact overall biodiversity. As the researchers state, “Global biodiversity is declining at an unprecedented rate in response to multiple environmental stressors… A key challenge is understanding synergistic interactions between multiple stressors and predicting their combined effects.†To study this, a Stress Addition Model (SAM), which predicts the cumulative effects of interacting stressors, was utilized and compared to laboratory data using 24-hour-old neonates of D. magna. The organisms were subjected to various conditions, singularly and in combination, including increased temperature, lower quantities of food, […]
Posted in Aquatic Organisms, Biodiversity, Climate Change, Ecosystem Services, Environmental Protection Agency (EPA), esfenvalerate, synergistic effects, Synthetic Pyrethroid, Synthetic Pyrethroids, United Nations, Water, Wildlife/Endangered Sp. | No Comments »
22
Oct
(Beyond Pesticides, October 22, 2024) A recent study, published through the American Chemical Society, analyzes pesticide contamination in riparian soil and plants as a result of flooding from streams in Germany. The authors hypothesize, and then prove, that frequently flooded sites have higher levels of pesticides present due to the pesticides in surface waters contaminating the soil. Results show that the plant vegetation in the contaminated soil then takes up the pesticides, which bioaccumulate and lead to higher contamination that can further cascade throughout the ecosystem and affect terrestrial food webs. “[O]ur study provides evidence from the field that nontarget plant species typical for riparian stream sites receive considerable pesticide exposure via flooding events,†the authors share. This exposure, and subsequent bioaccumulation in plants, threatens the food web, as many riparian plants are a vital food source for insects. According to the authors, flooding events, and their impact on pesticide contamination within soil and plants, are rarely investigated. This study, “measur[ing] 98 pesticides and metabolites in plants and root-zone soils sampled at five streams situated in an area in Southwest Germany characterized by intensive agricultural land use,†highlights the differences in contamination between frequently flooded and rarely flooded areas and […]
Posted in Azoxystrobin, Biodiversity, boscalid, Climate Change, Pendimethalin, Pollinators, soil health, Soil microbiome, United Nations, Water, Wildlife/Endangered Sp. | No Comments »
22
May
(Beyond Pesticides, May 22, 2024) A study in the journal of Environmental Science and Technology Letters, funded by the National Oceanic and Atmospheric Administration, is the first to find halogenated organic compounds (HOCs) in deep ocean sediment and biota off the coast of California. The test area, known as the Southern California Bight (SCB), is home to historic offshore DDT waste dumping, with part of the SCB designated as a U.S. Environmental Protection Agency (EPA) Superfund site. 49 HOCs were detected in the sediment and biota, many of which are DDT-related and not previously screened for. The presence of these “unmonitored compounds can significantly contribute to the contaminant body burden across a range of marine taxa,†the study states, which leads to impacts on critical food webs and biodiversity. While this study is the first to specifically analyze previously overlooked DDT+ compounds, the results are nothing new. There is a body of science around the bioaccumulation and biomagnification of harmful pollutants that continue to lead to a decline in biodiversity, negative impacts on water and soil, and detrimental human health effects.      To assess the bioavailability of DDT+ and HOCs in the deep ocean food web, this study focused on […]
Posted in Aquatic Organisms, Body Burden, California, DDT, Montrose, Mosquitoes, Oceans, Superfund, Wildlife/Endangered Sp. | No Comments »
