Editing Rotenone (section)

==== Rotenone degradation and ecosystem impact ====
Rotenone primarily affects gilled organisms such as fish and aquatic invertebrates. Terrestrial animals such as birds, mammals, and amphibians (except tadpoles/larvae) are much less affected by rotenone.<ref>{{cite web |last1=Skaar |first1=Donald R. |display-authors=etal |title=Effects of Rotenone on Amphibians and Macroinvertebrates in Yellowstone |url=https://www.nps.gov/articles/effects-of-rotenone-on-amphibians-and-macroinvertebrates-in-yellowstone.htm |publisher=U.S. National Park Service |access-date=29 September 2024 |language=en}}</ref> When applied in freshwater systems, the treatment dose kills the target fish and usually other gilled species like tadpoles and zooplankton are affected, depending on dosage. However, timing treatments in the fall or winter, when many species are less active, can reduce these impacts. Some taxa may also recover through natural life cycles, such as resting eggs. Its use is more benign for the environment (as compared to drying ponds, or using other piscicides), and studies show that most ecosystems naturally recover within one or two years after rotenone application- with aquatic invertebrates repopulating affected areas,<ref>{{Cite book |last=Kjærstad |first=Gaute |title=The eradication of invasive species using rotenone and its impact on freshwater macroinvertebrates |publisher=Doctoral theses at NTNU |year=2022 |isbn=978-82-326-6270-8 |location=Trondheim |pages=1–100 |language=English}}</ref><ref>{{Cite journal |last=Fjellheim |first=A. |year=2004 |title=Virkning av rotenonbehandling på bunndyrsamfunnene I et område ved Stigstu, Hardangervidda |url=http://hdl.handle.net/11250/2630458 |journal=Lfi-122 |language=Norwegian |publisher=LFI, University of Bergen |pages=1–60 |issn=0801-9576 |hdl=11250/2630458}}</ref><ref>{{Cite journal |last1=Vinson |first1=V |last2=Dinger |first2=EC |last3=Vinson |first3=DK |year=2010 |title=Piscicides and invertebrates: after 70 years, does anyone really know? |journal=Fisheries |volume=35 |issue=2 |pages=61–71 |bibcode=2010Fish...35...61V |doi=10.1577/1548-8446-35.2.61}}</ref> thus restoring initial local biodiversity to its status prior to the introduction of the invasive species.

Rotenone decays through [[metabolite]]s and its final product is reduced to [[water]] and [[carbon dioxide]].<ref name=":0" />  It oxidizes to rotenolone, which is about an order of magnitude less toxic than rotenone. In water, the rate of decomposition depends upon several factors, including temperature, pH, water hardness and sunlight. The half-life of rotenone in a pond of 1.1 mean depth ranged from half a day at 24&nbsp;°C to 3.5 days at 0&nbsp;°C,<ref>{{cite web |author=Kevin C. Ott |title=Rotenone. A Brief Review of its Chemistry, Environmental Fate, and the Toxicity of Rotenone Formulations |url=http://www.newmexicotu.org/Rotenone%20summary.pdf |url-status=dead |archive-url=https://web.archive.org/web/20120904171741/http://www.newmexicotu.org/Rotenone%20summary.pdf |archive-date=2012-09-04}}</ref> but in deeper oligotrophic systems (thus less degradation due to sunlight and organic content) the half-life may be considerably longer.