appendix b final 2008 biological surveys of los angeles and long ...

3.0 Adult and Juvenile Fishes
croaker had a bimodal size distribution, with the majority of fish between 2 and 12 cm and 16 to
22 cm (Figure 3.4-3). The small size classes (2-12 cm) likely represents young-of-year and new
recruits while the larger size distribution (16-22 cm) represents adult fish. No significant spatial
or temporal differences were found for average white croaker sizes.
Queenfish had the third highest abundance, representing 6.7% of the total trawl catch and
10.6% of the total biomass (Table 3.4-1). Similar to white croaker, this species was collected
during every sampling quarter and at every station, with the highest numbers observed during
night sampling. Queenfish also had a bimodal size distribution, with the majority of fish between
5 and 9 cm and 14 to 17 cm, representing distributions of juveniles (small sizes) and adults
(larger sizes) (Figure 3.4-3). No significant spatial or temporal differences were found for
average queenfish sizes.
Shiner surfperch accounted for 6.7% of the abundance and 1.4% of the trawl biomass (Table
3.4-1). This species was collected during every quarter, but was not caught at all stations.
Shiner surfperch were generally collected more extensively at POLA stations compared to
POLB. For example, this species was collected at 6 of 10 POLA stations and only 3 of 9 POLB
stations during winter surveys. In April, shiner surfperch were collected at 7 of 10 POLA and 2
of 9 POLB stations. In summer, this species was captured at 8 of 10 POLA and 2 of 9 POLB
stations. Shiner surfperch sizes ranged from 3 to 15 cm, with the greatest number of individuals
in the 5 cm size class and likely represent new recruitment of young fish (Figure 3.4-3).
Commercially and/or recreationally important species, including California halibut and barred
sand bass, had relatively low total abundance and biomass. California halibut ranked tenth in
total abundance (192 individuals) and fourth in total biomass (nearly 70 kg) over all stations and
surveys (Tables 3.4-1). Halibuts ranged in size from 4 to 74 cm, and had a bimodal distribution.
The most abundant small individuals of this species ranged from 7 to 15 cm and the most
abundant larger fish were from 24 to 34 cm. Since this species matures at relatively larger sizes
(males at 23 to 33 cm and females at 48 to 58 cm; Emmett et al. 1991), most of the fish caught
in the current study were likely juveniles and/or young adults.
Barred sand bass ranked twelfth in total abundance and fifteenth in biomass (Table 3.4-1), with
only 130 individuals captured over all stations and surveys. The size class distribution for this
species was bimodal, as shown in Figure 3.4-3. The most abundant small individuals ranged
from 3 to 6 cm, while the larger individuals were from 15 to 19 cm. Although spatial patterns
were generally not evident, barred sand bass were commonly collected at shallow-water
stations such as Stations LA2, LA3, and LB2.
The size distributions of other species commonly collected by otter trawl are shown on Figure
3.4-3, including California tonguefish and speckled sanddab (Citharichys stigmaeus). California
tonguefish ranged in size between 4 and 20 cm, with adults ranging upwards from 8 cm and the
majority of the adults in the 8 to 11 cm range. Speckled sanddab were most abundant at 8 to 9
cm and mostly were comprised of adult fish.
3.4.3 Summary of Spatial and Temporal Variations
There were no statistically significant differences in trawl catch between day and night. Almost
the same abundance was caught using trawls during the day (49.7% of total catch) compared to
night (50.3% of total catch). Similarly, no significant seasonal differences in trawl catch were
found, even though more fish were collected in the summer than all other seasons. In addition,
no apparent spatial patterns were found in fish abundances.
Spatial and temporal patterns in biomass were generally similar to the patterns in abundance.
However, substantially higher total biomass was observed in spring (April) compared to all other
2008 Biological Surveys of Los Angeles and Long Beach Harbors 3–11
April 2010