(Except for pesticides, October 1, 2019) According to a study published in the “Chemosphere”, commonly used fungicides can cause a trophic cascade reaction, which leads to the overgrowth of algae. Although the current pesticide control procedures in the United States focus on the acute toxicity of pesticides and may consider some chronic effects, the real-world complexity described in this study has not been reviewed. The gaps in our assessment will not only bring serious adverse effects to individual species, but also to the entire ecosystem.
Researchers investigated how fungal parasites called chytrids control the growth of phytoplankton. Although some chytrid strains are notorious for their effects on frog species, some actually provide important stopping points in the ecosystem.
IGB researcher Dr. Ramsy Agha said: “By infecting cyanobacteria, parasitic fungi will limit their growth, thereby reducing the occurrence and intensity of toxic algal blooms.” “Although we usually think of disease as a negative phenomenon, parasites are important to aquatic ecology The proper functioning of the system is very important, and in this case may also have a positive effect. The researchers added that the pollution caused by the fungicide can interfere with this natural process.
In a laboratory environment, the agricultural fungicides penbutaconazole and azoxystrobin were tested against cyanobacteria that were infected with chyle and toxic blooms. A control group was also established to compare the effects. At concentrations that may occur in the real world, the contact of the two fungicides will result in a significant reduction in filarial parasite infections.
These results indicate that the use of fungicides may promote the growth of harmful algae by inhibiting fungal pathogens, and fungal pathogens may control their growth.
This is not the first time that pesticides have participated in the reproduction of harmful algae. A study published in the journal Nature in 2008 found that the herbicide attriazine can directly kill free planktonic algae, thereby causing the attached algae to grow out of control. In this study, the researchers found other impacts on the ecosystem level. The growth of attached algae leads to an increase in the population of snails, which can infect amphibian parasites. As a result, more snails and a higher parasite load lead to a higher infection rate in the local frog population, which leads to a decline in the population.
Beyond Pesticides is working to raise awareness of the incomprehensible but critical ecosystem-level effects of pesticide use. As we pointed out in the study published last week, the study estimated that 3 billion birds have been lost since 1970, accounting for 30% of the total U.S. population. The report is not just a report on birds, it’s about , Hookworms and cad decline reports, creating food web-based species.
As the study’s co-author Dr. Justyna Wolinska pointed out: “As the cultivation and identification of aquatic fungi in scientific laboratories continues to improve, risk assessment should consider the impact of fungicides on aquatic fungi.” It is not only necessary to consider the issues raised by current research. , But also need to consider the widespread indirect impact of pesticide use.
For more information on how pesticide causes affect the entire food web and ecosystem, see Beyond Pesticides. The use of pesticides endangers the main species in the entire ecosystem.