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

of alkylphenol polyethoxylates in carbaryl- or carbofuran- containing formulations. Adjuvants
are frequently mixed with formulations prior to applications, so although they may not be present
in the formulations they could still be co-applied. Below we discuss NP’s toxicity as an example
of potential adjuvant toxicity, as we received no information on adjuvant use or toxicity within
the BEs.
We queried EPA’s ECOTOX online database and retrieved 707 records of nonylphenol’s (NP)
acute toxicity to freshwater and saltwater species. The lowest reported LC50 for a salmonid was
130 μg/L for Atlantic salmon. Aquatic invertebrates, particularly crustaceans, were killed at low
concentrations of NP, with the lowest reported LC50 = 1 μg/L for H. azteca. These data indicate
that a wide array of aquatic species are killed by NP at μg/L concentrations. We also queried
EPA’s ECOTOX database for sublethal toxicity and retrieved 689 records of freshwater and
saltwater species tested in chronic experiments. The lowest fish LOEC reported was 0.15 μg/L
for fathead minnow reproduction. Numerous fish studies reported LOECs at or below 10 μg/L.
Additionally, salmonid prey species are sensitive to sublethal effects of NP at low μg/L
concentrations. The amphipod, Corophium volutator, grew less and had disrupted sexual
differentiation (Brown, Conradi et al. 1999). Multiple studies with fish indicated that NP
disrupts fish endocrine systems by mimicking the female hormone 17β-estradiol (Brown and
Fairchild 2003; Arsenault, Fairchild et al. 2004; Madsen, Skovbolling et al. 2004; Jardine,
MacLatchy et al. 2005; Luo, Ban et al. 2005; McCormick, O'Dea et al. 2005; Segner 2005;
Hutchinson, Ankley et al. 2006; Lerner, Bjornsson et al. 2007; Lerner, Bjornsson et al. 2007).
NP induced the production of vitellogenin in fish at concentrations ranging from 5-100 μg/L
(Hemmer, Bowman et al. 2002; Ishibashi, Hirano et al. 2006; Arukwe and Roe 2008;
Schoenfuss, Bartell et al. 2008). Vitellogenin is an egg yolk protein produced by mature females
in response to 17-β estradiol, however immature male fish have the capacity to produce
vitellogenin if exposed to estrogenic compounds. As such, vitellogenin is a robust biomarker of
exposure. A retrospective analysis of an Atlantic salmon population crash suggested the crash
was due to NP applied as an adjuvant in a series of pesticide applications in Canada (Fairchild,
Swansburg et al. 1999; Brown and Fairchild 2003). Additionally, processes involved in sea
water adaptation of salmonid smolts are impaired by NP (Madsen, Skovbolling et al. 2004;
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