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

Status and Trends
S-CCC steelhead were listed as threatened in 1997. Their classification was retained
following a status review on January 5, 2006 (71 FR 834). Historical data on the S-C CC
steelhead DPS are limited. In the mid-1960s, the CDFG estimated the adult population at
about 18,000. We know of no recent estimates of the total DPS. However, five river
systems, the Pajaro, Salinas, Carmel, Little Sur, and Big Sur, indicate that runs are
currently less than 500 adults. Past estimates for these basins were almost 5,000 fish.
Carmel River time series data indicate that the population declined by about 22% per year
between 1963 and 1993 (Good, Waples et al. 2005). From 1991 the population increased
from one adult, to 775 adults at San Clemente Dam. Good et al. (2005) thought that this
recent increase seemed too great to attribute simply to improved reproduction and
survival of the local steelhead population. Other possibilities were considered including
that the substantial immigration or transplantation occurred, or that resident trout
production increased as a result of improved environmental conditions within the basin.
Nevertheless, the majority (68%) of BRT votes were for “likely to become endangered,”
and another 25% were for “in danger of extinction”.
Critical Habitat
Critical habitat was designated for this species on September 2, 2005 (70 FR 52488).
The critical habitat designation for this DPS identifies PCEs that include sites necessary
to support one or more steelhead life stages. Specific sites include: (1) freshwater
spawning, (2) freshwater rearing, (3) freshwater migration, (4) estuarine areas free of
obstruction, (5) nearshore marine areas free of obstructions, and (6) offshore marine areas
with good water quality. The physical or biological features that characterize these sites
include water quality and quantity, natural cover, and adequate forage.
Southern California Steelhead
Distribution
Southern California (SC) steelhead occupy rivers from the Santa Maria River to the U.S.
–Mexico border (Figure 32).
174