{"id":42106,"date":"2026-07-23T00:01:01","date_gmt":"2026-07-23T04:01:01","guid":{"rendered":"https:\/\/beyondpesticides.org\/dailynewsblog\/?p=42106"},"modified":"2026-07-21T13:08:17","modified_gmt":"2026-07-21T17:08:17","slug":"popular-mosquito-insecticide-undermines-aquatic-organism-health-according-to-study","status":"publish","type":"post","link":"https:\/\/beyondpesticides.org\/dailynewsblog\/2026\/07\/popular-mosquito-insecticide-undermines-aquatic-organism-health-according-to-study\/","title":{"rendered":"Popular Mosquito Insecticide Undermines Aquatic Organism Health, According to Study"},"content":{"rendered":"

(Beyond Pesticides<\/em>, July 23, 2026) The unintended consequences of pesticide dependency once again emerge as new research out of University of California, Davis finds sublethal adverse effects to sturgeon fish exposed to the widely used insecticide bifenthrin<\/a> in their natural habitats. A study published in Environmental Research<\/em><\/a> concludes that \u201csublethal bifenthrin exposure impairs locomotion and motor coordination\u201d in Green and White Sturgeon populations. These findings are important given that bifenthrin, a synthetic pyrethroid, is one of the most popular mosquito control pesticides, and it is broadly used for insects in homes, gardens, and agriculture. The preponderance of scientific evidence\u2014in addition to lax chemical company accountability for hazard warnings resulting from the Monsanto v. Durnell<\/a> <\/em>Supreme Court ruling in June\u2014continues to galvanize concerned individuals, including decisionmakers, researchers, and organizations nationwide who are advocating for alternatives to the chemical-intensive practices.<\/p>\n

Because of acute toxicity to fish and aquatic organisms, the bifenthrin label <\/a>contains a strict warning: \u201cThis pesticide is extremely toxic to fish and aquatic invertebrates. To protect the environment, do not allow pesticide to enter or run off into storm drains, drainage ditches, gutters or surface waters.\u201d Because pesticides applied for mosquito control and others are used to move off of the target site, these findings raise significant policy issues associated with their use. Regarding mosquito control, Penn State University<\/a> writes, \u201cDespite careful application, sometimes pesticides move from the target and contaminate adjacent areas, including creeks, streams, and other water bodies. Unfortunately, pyrethroids break down more slowly in water, especially where there is less sunlight, and persist for much longer in aquatic sediments. This increases harmful impacts on non-target organisms when residue enters waterways.\u201d<\/p>\n

Methodology and Main Findings<\/strong><\/h2>\n

The researchers of this study build on a previous study published in 2025 (see here<\/a>) by including temperature as a variable. The goal was to determine whether two closely related sturgeon species interact similarly under cumulative environmental stressors (heat and pesticides) or whether their physiology drives differentiated vulnerability. Three days after hatching, larvae were exposed to four increasing degrees of bifenthrin (0\/control, 10 nanograms\/liter, 100 ng\/L, and 500 ng\/L) as well as three temperatures (12, 15, and 18 degrees centigrade), followed by a 28 percent recovery period. The study includes two replicate tanks per treatment, with 65 Green or 100 White Sturgeon larvae per tank to assess survival, growth, and mortality; separately, there were individual exposures on 12 dishes per treatment (one larva per plate) to assess potential neurobehavioral impacts. To assess neurobehavioral health, the researchers tested for the enzyme acetylcholinesterase (AChE) activity.<\/p>\n

The two additional main findings include:<\/p>\n