Tick and other spraying within wetland resource areas, their buffer zones, and the Riverfront Area
Emails and Materials received for discussion on May 7, 2026 attached below (scroll down to the bottom of the page)
The Vineyard Gazette - Martha's Vineyard News | Tick Sprays Kill More Than Ticks
Board of Health letters to sprayers are attached below at the bottom of the page.
Ingredient | Best located primary literature / case studies | Aquatic / wetland relevance | Likely concern level near ponds |
Soaps / water; fatty-acid salts | A 2023 primary study tested fatty acid salts/soap toxicity to Daphnia magna and found toxicity varies with water hardness, which is important for ponds because hardness differs widely by watershed. (J-STAGE) A 2025 case study of a soap/detergent factory discharge into the Werabo River reported poor to very poor water quality and ecological/socioeconomic impacts downstream. (ScienceDirect) Older fish bioassays found soaps and synthetic detergents can be toxic to fathead minnows, with toxicity modified by soft vs. hard water. (JSTOR) | Directly relevant to runoff and wash-water pathways into ponds/wetlands. Daphnia and fish data are useful proxies for pond food webs. | Moderate to high if discharged directly; lower if small incidental residues are diluted/degraded. Avoid equipment washing or disposal into drains, swales, wetlands, or pond margins. |
Monolaurin / glycerol monolaurate, CAS 27215-38-9 | A primary study evaluated glycerol monolaurate nanocapsules ecotoxicity, noting GML’s antimicrobial potential and poor water solubility. (ScienceDirect) Several aquaculture feeding trials in fish and shrimp examine dietary GML as a feed additive, generally as a health/growth supplement rather than an environmental contaminant. (Frontiers) SDS-type sources often report no aquatic endpoint data or “not classified” for aquatic hazard, which is weaker than primary evidence. (Chemos GmbH&Co.KG) | Sparse direct pond/wetland data. Antimicrobial activity raises a theoretical concern for microbial processes in wetlands, but I did not find strong pond field studies. | Uncertain / probably lower than SLS for dissolved exposure, but formulations that increase solubility or nanoencapsulate it may change exposure and toxicity. |
Geraniol, CAS 106-24-1 | Aquaculture research found geraniol killed juvenile Nile tilapia and white snook within minutes at 300 mg/L and 150 mg/L during antiparasitic trials, leading authors to caution against its use for fish treatment. (OUP Academic) Zebrafish embryo/larval work reports developmental toxicity and inhibited nutrient utilization. (Wiley Online Library) Guideline/SDS-derived aquatic endpoints commonly report ~22 mg/L 96-h LC50 for zebrafish, 10.8 mg/L 48-h EC50 for Daphnia magna, and 13.1 mg/L 72-h algal EC50. (MilliporeSigma) | Strong lab relevance to fish, invertebrates, and algae; little whole-pond evidence. | Moderate to high for direct aquatic exposure, especially because it is bioactive and can affect fish at mg/L levels. Avoid application over water or at pond edges where spray drift/runoff can enter. |
Sodium lauryl sulfate / sodium dodecyl sulfate, CAS 151-21-3 | A 2023 systematic review found empirical evidence of environmental toxicity across a wide concentration range and concluded aquatic organisms are at higher exposure risk. (ScienceDirect) A 2024 primary study tested SLS on early life stages of common carp, zebrafish, and Xenopus laevis embryos. (Springer) Primary/field-relevant work on threatened and endangered freshwater mussels evaluated SDS toxicity and described contaminated waters, sediments, or soils as exposure routes. (Mollusk Conservation Society) Chronic Ceriodaphnia dubia tests showed reproducible survival/reproduction endpoints for SLS. (Springer) | This is one of the best-supported aquatic hazards on the list. It is directly relevant to ponds, wetlands, fish, amphibians, zooplankton, mussels/shellfish analogs, and algae. | High concern for direct or repeated runoff, especially near small ponds, shellfish waters, amphibian breeding areas, or low-flow wetlands. |
Carbon / activated carbon, CAS 7440-44-0 | Activated carbon is commonly studied as a treatment substraterather than a toxicant. A Salinas Valley case study monitored a constructed wetland plus granular activated carbon filter treating pesticide-contaminated irrigation runoff toxic to aquatic organisms. (Springer) A 2025 wetland-system study found activated carbon or biochar can improve nutrient removal in simulated sediment wetlands/constructed wetlands under some conditions. (PMC) A 2024 constructed wetland–microbial fuel-cell study used activated carbon as substrate/anode material and evaluated removal performance and microbial communities. (MDPI) | Most relevant as a mitigation medium for runoff or wetland treatment cells. Potential physical effects depend on particle size, dust, and sediment loading, but carbon itself is generally a sorbent. | Generally low direct toxicity; potentially beneficial when contained in filters or treatment media. Avoid loose fine carbon entering ponds where it could increase turbidity or smother benthic habitat. |
Castor oil, CAS 8001-79-4 | Direct pond/wetland primary studies are sparse. Regulatory/assessment summaries characterize castor oil as a triglyceride expected to biodegrade and generally low aquatic toxicity. (santos.com) ECHA dossiers for castor-oil derivatives report guideline fish studies for related materials, including no toxic effects up to solubility limits for some castor oil esters. (ECHA) Castor-oil-derived biodiesel has been tested with Daphnia magna, but that is a fuel product rather than castor oil pesticide use. (Springer) | Ingredient-level aquatic hazard appears lower than SLS/essential oils, but oil films can be physically harmful by affecting oxygen transfer, surface tension, and invertebrate/egg surfaces. | Low to moderate, but avoid direct water application; risk is more about formulation, oil sheen, emulsifiers, and volume released. |
Cedarwood oil / cedar oil, CAS 8000-27-9 | A primary study on Western juniper and Port Orford cedar essential oils evaluated acute toxicity to freshwater and marine organisms because these oils were being considered for repellents/cosmetics. (Springer) ECHA and SDS sources report Daphnia EL50 values in the low mg/L range for some cedarwood oils, with algae effects also in mg/L ranges. (ChemicalBook) Cornell’s cedarwood oil profile notes cedarwood oil has been applied to open water as a mosquito larvicide and is a minimum-risk pesticide active ingredient. (Cornell eCommons) | Relevant because some uses can be close to aquatic systems, including mosquito-control contexts. Essential-oil composition varies by source species, so toxicity can vary. | Moderate to high for direct aquatic exposure, especially to zooplankton, aquatic insects, larvae, and possibly fish early life stages. |
Oleic acid, CAS 112-80-1 | Direct oleic-acid aquatic toxicity literature is limited, but related oleic-acid surfactants have primary data: peroxy sulfonated oleic acids were tested under OECD methods with rainbow trout, Daphnia magna, algae, and activated sludge. (PMC) One thesis/library record reports oleic acid LC50 to Daphnia magnaof 338.38 ppm, classed as moderate toxicity, but this is not as strong as peer-reviewed primary literature. (Universitas Indonesia Library) Oleic acid is also a normal dietary/metabolic fatty acid in fish, and rainbow trout studies examine oleic acid sensing/metabolism rather than environmental toxicity. (PLOS) | Low direct pond evidence. Free fatty acids and oleate salts can behave like surfactants, and toxicity depends on pH, hardness, solubility, and formulation. | Low to moderate, higher if formulated as a soluble/emulsified surfactant or applied repeatedly near water. |
Lemongrass oil, CAS 8007-02-1 | A 2023 zebrafish embryo/larval study found lemongrass, thyme, and oregano essential oils reduced epiboly, affected development, and calculated a lemongrass oil LC50 of 3.7 µg/mL. (PMC) Other work evaluated essential oils including lemongrass oil in zebrafish toxicity screens. (Directory of Open Access Journals) A 2025 seabass feeding study found 2 mL/kg dietary lemongrass oil did not cause signs of disease, toxicity, or mortality, but that was dietary aquaculture exposure, not pond contamination. (Springer) | Strong lab evidence for fish early-life effects; limited pond/wetland case studies. Composition is usually citral-rich and can vary by plant source. | Moderate to high for direct water exposure, especially around fish spawning areas, amphibian breeding pools, and invertebrate-rich wetlands. |
