Chapters 1 - U.S. Fish and Wildlife Service

Refuge Resources
Pellets WSP (EPA Registration No. 2724-448). Although methoprene is not used very often on the
Refuge, when needed, it is generally applied as Altosid® XR Briquets, which provides up to 150
days of control. This product is generally applied to an area prior to inundation by extreme high
tides. Methoprene is to be used on the Refuge only as a second line of defense.
The OCVCD recently requested that the Refuge allow the use of three new mosquito control
products on the Refuge: Natular, a larvicide with the active ingredient spinosad; Agnique®, a
larvicide and pupacide made from renewable plant oils; and AquaAnvil, a adulticide with the
active ingredients Sumithrin, a synthetic pyrethrin, and piperonyl butoxide.
Natular includes the active ingredient spinosad, a product of bacterial fermentation. Spinosad,
classified as a “reduced-risk” compound by the USEPA, triggers continuous involuntary nervous
stimulus in mosquito larvae that leads to paralysis and death. This product comes in several
formulation types including liquid, granule, and extended release tablet.
Agnique is an invisible monomolecular biodegradable film (MMF) made from renewable plant oils
that reduces surface tension on standing water. The presence of the film makes it difficult for
mosquito larvae and pupae to attach to the surface of the water and ultimate leads to drowning.
This product employs a physical, as opposed to toxic, mode of action to control mosquito and midge
larvae and pupae. This product can be applied using a backpack sprayer and is persistent for up to
22 days.
The adulticides AquaAnvil, a water-based formulation, and Anvil 10 +10 ULV, a mineral oilbased
formulation, include the active ingredient sumithrin (a combination of a synthetic phenothrin
and piperonyl butoxide [PBO]). Phenothrin is a synthetic pyrethroid made to mimic the
insecticidal properties of pyrethrins. It works upon physical contact with an insect or after
ingestion as a nerve stimulant that affects the nerve channels of insects and ultimately leads to
paralysis (USEPA 2008). These products are also formulated with piperonyl butoxide, a synergist,
to increase the effectiveness of phenothrin. AquaAnvil and Anvil 10 + 10 ULV can be applied with
all ultra-low volume (ULV) spray equipment, including non-thermal ULV portable backpack
sprayers and suitable truck-mounted thermal fogging equipment.
4.3.4.5 Marine Invertebrates
Surveys conducted in the 1970s identified at least 116 species of marine invertebrates in the salt
marsh area of Anaheim Bay (Reish et al. 1975). Of the species identified, polychaetes comprised
about 65 percent, crustaceans about 15 percent, and mollusks 13 percent. This and other studies
indicate that a diverse array of invertebrates inhabit the estuarine and marsh habitats on the
Refuge including polychaete worms, sea stars, sand dollars, crustaceans (especially penaeid and
palamonid shrimps, and portunid crabs), bivalves (i.e., clams) and gastropods. These creatures
fulfill many purposes within the Bay and the marsh, including scavenging, filter feeding, and
detritus feeding.
Survey data collected in the early 1990s at the Port of Long Beach mitigation ponds showed the
most abundant subtidal and intertidal species to be worms (polychaetes, oligochaetes, and
nematodes) and crustaceans (amphipods, ostracods, and copepods). Polychaetes are a class of
annelid worm and are primarily deposit feeders. They live in and on sediments and can reach high
densities. At the time of Reish’s 1975 survey, at least eight polychaete species occurring in the
area were unknown from any other bay or harbor in Southern California. Based on total survey
numbers, Cossura candida was the most common species in the marsh, comprising almost onethird
of all polychaetes in the area.
Draft Comprehensive Conservation Plan/Environmental Assessment 4-55