Chapters 1 - U.S. Fish and Wildlife Service

Chapter 5
moderately toxic to fish. Intertidal habitat extends almost to the edges of the Refuge; therefore,
the use of this product even in the areas currently designated for mosquito control could adversely
affect the marine organisms present in these estuarine habitats.
Agnique is considered to be “practically nontoxic.” Studies show no effects on the various life
stages of long-nose killifish, fiddler crab, snail, or marine plants. This product is however
potentially lethal to any aquatic insect that lives on the water surface or requires contact with the
air-water interface. As a result, its use on the Refuge could have adverse indirect effects on the
food base of fish species that prey on aquatic insects, but these effects are considered minimal.
Synthetic pyrethrin/piperonyl butoxide products, such as AquaAnvil and Anvil 10 +10 ULV,
used to control adult mosquitoes, are moderately toxic (LC50 = 3.94 ppm) to estuarine and marine
fish and highly toxic to estuarine invertebrates (LC50 = 0.49 ppm) (USEPA 2006b). The Material
Safety Data Sheet (August 2006) for AquaAnvil states that this product is toxic to aquatic
organisms, including fish and aquatic invertebrates, and according to the product label should not
be applied to “bodies of water (lakes, rivers, permanent streams, natural ponds, commercial fish
ponds, swamps, marshes or estuaries), except when necessary to target areas where adult
mosquitoes are present, and weather conditions will facilitate movement of applied material away
from the water in order to minimize incidental deposition into the water body.” The active
ingredient piperonyl butoxide is considered by the USEPA to be moderately toxic (LC50 = 3.94
ppm) to estuarine and marine fish and highly toxic to estuarine invertebrates (LC50 = 0.49 ppm)
(USEPA 2006b). The marine organisms supported in the Refuge’s estuarine habitats would likely
be adversely affected if this product is applied in a manner that would result in measurable drift of
the product over sensitive wetland areas.
To minimize the adverse effects to marine and estuarine organisms and the species that forage on
these organisms, the use of sumithrin products (adulticides) on the Refuge would only be
permitted when pathogen activity is documented in mosquito pool(s) on the Refuge and a public
health emergency has been declared by the appropriate health authority servicing the area in
which the Refuge is located. Additional measures to minimize the potential impacts to fish and
other marine organisms involve spatial and temporal separation of aerosol applications in
proximity to sensitive wetland areas and pre-application evaluation of wind speed, direction, and
presence or absence of a temperature inversion to ensure that product drift can be managed to
avoid entering wetland areas or other areas that may support sensitive non-target organisms.
Implementation of these measures, as well as the BMPs outlined in Appendix D, the stipulations in
the Compatibility Determination for Mosquito Management, and the conditions included in annual
SUPs would ensure that impacts to fish and other marine organisms are minimized and temporary
in nature.
Public Use
As no new public use opportunities are proposed under Alternative B, the effects to fish and other
marine organisms would be the same as those described for Alternative A.
5.4.2.4 Effects to Terrestrial Invertebrates, Amphibians, and Reptiles
Wildlife and Habitat Management
Reptiles and amphibians are generally not well represented within salt marshes and marine
habitats, and the limited amount of upland area on the Refuge generally supports low quality
nonnative habitat. As a result, species diversity of these organisms on the Refuge is low. The
Refuge management activities described in Alternative A would also be implemented in
5-48 Seal Beach National Wildlife Refuge