Chapters 1 - U.S. Fish and Wildlife Service

Chapter 4
Mollusk communities in southern California salt marshes are typically dominated by Cerithidea
californica, Melampus olivaceous, and Assiminea californica, which are all epifaunal surface
feeders (USFWS and U.S. Navy 1990). Most mollusks are detritus and filter feeders or grazers,
and to a lesser extent, predators. The California hornsnail (Cerithidia californica), which serves
as food for species such as crabs and birds, is widespread in the Refuge.
Eighteen species of crustaceans have been documented in Anaheim Bay. In their larval form they
are an important food source for birds and fish. Crabs are conspicuous as they forage on mudflats.
Amphipods, ostracods and copepods are abundant in subtidal and intertidal areas. Amphipods
(Orchestia traskiana and O. californica) and isopods are found under debris near the upper
margins of the marsh and ghost shrimp (Callianassa californiensis) live in muddy sediments. Also
found on the Refuge is the California brackish water snail (Tryonia imitator), a species that has
been identified by the State of California as imperiled (USFWS and U.S. Navy 1990). This
species, which inhabits coastal lagoons, estuaries, and salt marshes, is found only in permanently
submerged areas and can tolerate a wide range of salinities and inhabit a variety of sediment types
(Kellogg 1980).
4.3.4.6 Fishes
The earliest available information regarding fish populations in Anaheim Bay is from a paper
published in 1916 by Carl Hubbs, who collected fish in the Bay in 1913. Additional collections were
made by Hubbs and the California State Fisheries Laboratory between 1919 and 1928 (Lane 1975).
No attempts to record the diversity of fish fauna in Anaheim Bay were made again until 1969,
when a four year effort to describe the biology of the bay was undertaken by faculty and staff at
California State University, Long Beach. Surveys to establish fish diversity in the Bay were
conducted between 1969 and 1971. A full account of the fish and other resources in the Bay as a
result of undertaking are provided in Fish Bulletin #165, “The Marine Resources of Anaheim Bay”
(CDFG 1975). Additional data were collected in the 1990s as part of the Port of Long Beach’s
mitigation and monitoring program.
The surveys conducted in the early 1970s identified 45 fish in the Refuge portion of Anaheim Bay,
the most common of which was topsmelt (Atherinop affinis). Other common species included the
round stingray (Urobatis halleria), California killifish (Fundulus parvipinnis), and California
halibut (Paralichthys californicus). California halibut, as well as diamond turbot (Hypsopsetta
guttulata), another commercially and recreationally important fish, use the bay as juveniles, but
move out to the open ocean as they approach maturity. Topsmelt, shiner perch (Cymatogaster
aggregata), Pacific staghorn sculpin (Leptocottus armatus), California killifish (Fundulus
parvipinnis), Pacific anchovy (Engraulis moradx), white seabass (Atractoscion nobilis), and
California corbina (Menticirrhus undulatus) all spawn in the bay (CDFG and USFWS 1976). The
results of these studies also indicated that total numbers of fish were relatively higher in spring
and summer months and species diversity was greatest in winter and spring (Reish et al. 1975).
In comparing the results of the collections made in the 1920s with those of the early 1970s, one can
find several significant differences between the two collections. It should be noted that the
collection made in the 1920s preceded the dredging of the outer harbor and construction of the
jetties at the western end of Anaheim Bay, which may account for some of these differences.
Several species collected in the 1920s were not collected in the early 1970s including California
butterfly ray (Gymnura marmorata), Señorita (Oxyjulis californica), and California scorpionfish
(Scorpaena guttata). California butterfly ray was however recently collected on the Refuge during
stingray research conducted by Kate Jirick.
4-56 Seal Beach National Wildlife Refuge