Carbaryl, Carbofuran, and Methomyl - National Marine Fisheries ...

• Unrelated (0): Conclusive evidence exists that a stressor other than exposure to the given
pesticide caused the incident.
NMFS reviewed several incident reports provided by EPA from OPP’s incident database. This
database is populated with reports received by EPA from registrants that are defined as
reportable under FIFRA 6(a)(2) and includes other information received from registrants and
other sources.
Relatively few incidents involving lethality to fish were documented in the database, considering
the length of time these products have been registered and their toxicity profiles. EPA provided
the following table summarizing known mortality incidents (Table 72). NMFS is uncertain as to
how representative this database is of known fish kills and the level of coordination that has
occurred with various state and federal agencies that investigate these incidents. The mortality
events discussed above for carbaryl applications in Willapa Bay and Grays Harbor were not
recorded in the database. Several of the incidents provided by EPA are discussed in more detail
below.
Table 72. EPA summary of field incident data with carbaryl, carbofuran, and methomyl;
highlighted incidents (*) are discussed.
Carbaryl Carbofuran Methomyl
Incident ID Certainty Incident ID Certainty Incident ID Certainty
B0000-246-01* Probable I000165-052 Possible B0000-216-19 Unlikely
B0000-501-92* Probable I000599-008* Probable B0000-501-36 Unlikely
I000799-003 Possible I001605-003 Probable I000108-001* Probable
I000910-001 Unlikely I005416-001
Highly
Probable 1
I007720-020 Probable I012265-001 Possible
I015419-644 Possible I012265-003 Probable
I018436-001 Possible I012265-004 Possible
I013436-001* I013436-001* Possible I013436-001* Possible
1 Waterfowl mortality incident in flooded rice
Incident I013436-001: A report of a large fish kill on October 16, 2001, was investigated by the
California Department of Fish and Game. The kill involved several thousand fish. Although
salmonids were not identified, it occurred in the San Joaquin River, which is used by listed
salmonids. EPA characterized this event as “possible” regarding its association with carbaryl,
carbofuran, and methomyl. Methomyl was detected in fish gills and several other pesticides
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