The U.S. Environmental Protection Agency (EPA) has implemented measures to protect 28 federally endangered and threatened (listed) Pacific salmon and steelhead species and their designated critical habitat from the effects of bromoxynil, prometryn, metolachlor, and 1,3-D (also known as telone). Bromoxynil, prometryn, and metolachlor are herbicides used to control grasses and broadleaf weeds, and 1,3-D is a pesticide used in pre-plant soil fumigation. 

Biological Opinions 

In June 2021, after receiving public comments, the National Marine Fisheries Service (NMFS) issued final biological opinions for bromoxynil, prometryn, metolachlor, and 1,3-D. NMFS’s biological opinions found that registered uses of these pesticides do not jeopardize listed salmon and steelhead species or adversely modify their critical habitats. Because use of these pesticides may result in “take” of individuals of listed salmon and steelhead species, the biological opinions also describe measures to minimize the potential for take and any impacts of take. “Take” includes (among other things) unintentionally harming or killing an individual of a listed species. 

Implementation 

EPA has implemented these biological opinions by issuing Endangered Species Protection Bulletins, available on the Bulletins Live! Two website, and approving label amendments to protect listed species, thereby fulfilling its obligations under the Endangered Species Act (ESA) for these pesticides for the listed salmon and steelhead species and their critical habitat.  

The Endangered Species Protection Bulletins for the four pesticides describe geographically specific use limitations to protect listed salmon and steelhead species and critical habitat. The Bulletins include mitigation measures such as no-spray buffers, retention ponds, and vegetated ditches to minimize potential take.  

The amended labeling for bromoxynil, prometryn, metolachlor, and 1,3-D products includes instructions for pesticide users to obtain Bulletins and follow their required mitigation measures. The labeling also includes guidance on how to report ecological incidents associated with pesticide applications, should users observe any. This work aligns with the goals outlined in EPA’s April 2022 ESA Workplan and its November 2022 ESA Workplan Update to provide practical, timely protections for listed species from pesticides. 

Background 

Before NMFS developed these final biological opinions, EPA and NMFS determined that the registered uses of these pesticides have the potential to adversely affect one or more individuals of listed Pacific salmon and steelhead species. The “likely to adversely affect” (LAA) determination means that the Agencies reasonably expect that at least one individual animal or plant, among a variety of listed species, may be exposed to bromoxynil, prometryn, metolachlor, and 1,3-D at a sufficient level to have an adverse effect.  An LAA determination does not necessarily mean that a pesticide registration action will jeopardize a listed species or adversely modify critical habitat. 

See the final biological opinion for 1,3-D and metolachlor and the final biological opinion for bromoxynil and prometryn.