In Tomales Bay, 4-, 5-, and 6-yr-old herring, Clupea harengus pallasi, composed 70% by number of the 1985-86 season's catch.  In San Francisco Bay, 2-, 3-, and 4-yr-old herring composed 78% by number of the roundhaul catch, and 4- and 5-yr-old herring composed 64% by number of the gill net catch.

The percent of 4-yr-old herring in both the Tomales Bay catch (25% and San Francisco Bay gill net catch (39%) is at a high level for the second year in a row.

Recruitment of 2-yr-old herring into the San Francisco Bay

roundhaul fishery was about average, with 2-yr-old herring

composing 33% of the catch.

The mean length of herring in the San Francisco Bay roundhaul catch increased to 178 mm BL, while the mean length of the gill net catch remained 196 mm BL. The mean length of the Tomales Bay catch decreased to 198 mm BL due to the increased number of 3- and 4-yr-old herring in the catch.  (18pp.

Spratt, Jerome D.

English

Aquatic Commons

BIOLOGLC41, CHAKACTERLSTlCS  O F  THE CATCH 
FROM TIlE 1985-86 PAC1Ff.C HEKKIMG, 
CLUPEA HAKENCUS PALLASI,  ROE FISHERY I N  C A L I F O R N I A  
--- ---- - -- 
by 
Jerome D. S p r a t t  
MARINE RESOURCES D I V I S I O N  
A d m i n i s t r a t i v e  Repor t  No. 86-5 
1986 
BIOLOGICAL CHARACTERISTICS OF THE CATCH 
FROM THE 1985-86 PACIFIC HERRING, 11 CLUPEA HARENGUS PALLASI , ROE FISHERY *IN CALIFORNIA- 
2 I Jerome Do Spratt- 
ABSTRACT 
In  Tomales Bay, 4-, 5-, and 6-yr-old he r r ing ,  Clupea harengus , 
p a l l a s i ,  composed 70% by number of the  1985-86 season's  catch. 
In  San Francisco Bay, 2-, 3-, and 4-yr-old he r r ing  composed 782 
by number of the  roundhaul catch,  and 4- and 5-yr-old he r r ing  
composed 64% by number of the  g i l l  ne t  catch. 
The percent of 4-yr-old he r r ing  i n  both t h e  Tomales Bay ca tch  
(25% and San Francisco Bay g i l l  net  ca tch  (39%) is  a t  a high 
l e v e l  f o r  the  second year  i n  a row. 
Recruitment of 2-yr-old he r r ing  i n t o  the  San Francisco Bay 
roundhaul f i s h e r y  was about average, with 2-yr-old he r r ing  
composing 33% of t h e  catch. 
The mean length  of he r r ing  i n  t h e  San Francisco Bay roundhaul 
ca tch  Increased t o  178 mm BL, while the  mean length  of t h e  g i l l  
n e t  ca tch  remained 196 mm BL. The mean length  of the  Tomales 
Bay ca tch  decreased t o  198 mm BL due t o  the  increased number of 
3- and 4-yr-old he r r ing  i n  the  catch. 
/Marine Resources Administrative Report No. 86-5. 
21Marine Resources Division,  Marine Resources Laboratory, 2201 Garden 
Road, Monterey, Ca l i fo rn ia  93940. 
ACKNOWLEDGMENTS 
I wish to thank Alistair Lizaranzu, Reed Ridge, Martin Swift, and 
Keith Warren for collecting and processing herring during the season. 
INTRODUCTION 
The Department began monitoring the age, size, and sex composition 
of the Pacific herrhg, Cl.upea harengus pallasi, roe fishery catch in 
Tomales and San Francisco Bays in 1973. Spratt (1981, 1982, 1983, 1984, 
and 1985) reported on data collected by sampling the herring roe fishery 
from 1973 until 1985. This report complements previous data to provide a 
continuous seasonal series from 1973 through the 1985-86 season. 
METHODS 
Sampling 
In the Tomales Bay area, herring were collected at Marshall. In San 
Francisco Bay, herring were collected at Sausalito and San Francisco. Up 
to four samples were taken per day in each bay, when herring were 
available. A sample consisted of 2.3 kg ( 5  lb) collected after vessels 
unloaded. 
All samples were processed in a fresh condition and laboratory 
procedures have remained unchanged since the fishery began in 1973 
(Spratt 1981). Every fish in the sample was weighed to the nearest 0.1 g, 
daeasured in millimeters body length (mm BL) , and sex and maturity were 
determined. Body length was used as the unit of measurement because the 
fleshy caudal peduncle of herring makes the hypural plate difficult to 
locate. Body length was measured from the tip of the snout to the end of 
the silvery part of the body. Otoliths were removed for age 
determination and stored in gelatin capsules. Ages were assigned by the 
author using previously determined criteria (Spratt 1981), and otoliths ' 
were read twice before final age determinations were made. 
- 2 - 
RESULTS 
Tomales Bay 
A total of 34 samples was collected this season and 287 individual 
fish were processed. 
Age Composition 
The Tomales Bay fishery was restricted to gill nets in 1977. From 
the 1977-78 through 1984-85 seasons, the catch was dominated by 5-, 6-, 
and 7-yr-old herring. 
Normally, 5-, 6-, and 7-yr-old herring are the dominant age classes 
in Tomales Bay. However, in the 1985-86 season the percent of 4-yr olds 
in the catch increased to 25% by number, while the percent of 7-yr olds 
decreased to 10% by number. And for the first time, the three dominant 
age groups were 4-, 5-, and 6-yr olds composing 70% by number of the 
catch (Figure 1). 
The percent of 3-yr-old herring (14%) and 4-yr-old herring (25%) in 
the catch is at its highest level since the fishery was restricted to 
gill nets in 19.77. 
Length Composition 
The average length of herring in the Tomales Bay catch during the 
1985-86 season declined to 198 mm BL (Table 1). The combined average 
length of 5-, 6-, and 7-yr-old herring (Table 2) did not change from the 
1984-85 season (Spratt 1985). However, the record high number of 3- and 
4-yr-old herring in the catch, reduced the overall mean length. The 1982 
and 1983 yr classes are relatively strong in San Francisco Bay (Spratt 
1985). This recruitment pattern is also becoming evident in Tomales Bay, 
and the overall seasonal mean length should begin to increase when these 
'! 
two year classes are fully recruited. 
'ihe timing of the fishery in relation to spawning was not a factor 
this season. Our samples were taken throughout the season and not biased 
toward early or late season spawning runs, which have very different age 
and size compositions. 
Weight Composition 
The mean weight at age of Tomales Bay herring declined dramatically 
in the 1983-84 season, when weight at age of all exploited year classes 
was below normal (Spratt 1984). In the 1984-85 season, the mean we-ight 
at age increased, but this season the mean weight at age decreased 
slightly and the average weight of the dominant year classes remains 
below the long-term mean (Table 3). 
Sex Ratio 
The female to male number and biomass (weight) ratios of the 1985-86 
Tomales Bay catch were nearly equal (Table 4). The percent of females in 
the catch, 52% by number and S4I by weight, is less than expected. From 
the 1982-83 to 1984-85 season females have averaged more than 60% of the 
catch by number. 
--\ . San Francisco Bay 
A total of 56 samples was collected this season and 551 individual 
herring were processed. In San Francisco Bay both the roundhaul and gill 
net catches are sampled, but sample data is analyzed separately. 
Age Composition 
The percent of 2-yr-old herring in the roundhaul catch is normally a 
good indicator of year class strength. This season, recruitment of the 
1984 yr class (2-yr olds) into the 1985-86 fishery was about average. 
- 4 -  
The 1984 pr class follows two exceptionally strong year classes and all 
three are affecting the relative age composition (Figure I), which is 
heavily weighted toward younger age classes. The spawning season and 
fishery both came to an abrupt end on February 7th due to a series of 
winter storms that hit California. Late season spawning runs did not 
materialize, and it is these late runs that have the highest percentage 
of recruits or 2-yr olds. Therefore, the 1984 yr class may be stronger 
than samples indicate. 
The roundhaul fishery in San Francisco Bay was again confined to the 
later half of the spawning season, when older herring are less available 
. 
to the fishery. As a result there was only one 8-yr-old,.and no 9-yr-old 
herring in the samples, but in 7 out of 13 seasons, 8- and 9-yr-old 
herring have composed 1% or less of the'catch. 
Prior to the 1984-85 season, the San Francisco Bay gill net fishery 
was dominated by 5-, 6-, and 7-yr-old herring. In San Francisco Bay, the 
1984-85 season was the first full season with a minimum mesh size of 
2 118 in. Since then, the relative number of 7-yr olds in the catch has 
1 
decreased while the relative number of 4-yr olds in the catch has 
increased. In the 1985-86 season 4-, 5-, and 6-yr olds accounted for 77% 
of the catch by number and by weight (Figure 1). 
Length Composition 
The mean length of the San Francisco Bay roundhaul catch declined to 
an all-time low of 165 mm BL in the 1983-84 season (Spratt 1984). Since 
then, themean length of the catch has been increasing and reached 178 mm 
BL (Table 1) in the 1985-86 season. Good growth characteristics are 
again a factor in the overall increase in mean length of the catch this 
season, because all age groups increased in mean length from 1 to 4 mm 
(Table 5) from the 1984-85 season. 
- 5 -  
The mean l eng th  of t h e  g i l l  ne t  ca t ch  i n  San Francisco Bay i s  below 
200 mm BL f o r  t h e  second t ime (Table 1).  The average l eng th  a t  age 
(Table 6)  of h e r r i n g  i n  t h e  g i l l  ne t  ca tch  increased  over t h e  1984-85 
season,  b u t  t h e  reduced mesh s i z e  has r e s u l t e d  i n  an  i n c r e a s e  i n  t h e  
number of 3- and 4-yr-old he r r ing  i n  t h e  ca t ch  and a dec rease  i n  t h e  
o v e r a l l  mean l ength  of the  ca tch .  
Weight Composition 
The o v e r a l l  weight composition of t h e  San Francisco Bay roundhaul 
and g i l l  n e t  ca tches  (F igure  1) p a r a l l e l s  t h a t  of t h e  age composition. 
The roundhaul ca tch  w a s  dominated by 2- and 3-yr-old h e r r i n g ,  while  t h e  
g i l l  n e t  c a t c h  w'as composed mainly of 4- and 5-yr-old he r r ing .  
1 Samples from t h e  roundhaul ca t ch  i n  t h e  1985-86 season i n d i c a t e  t h a t  
growth w a s  above average dur ing  1985. Weight of a l l  age c l a s s e s  except  
7-yr o l d s  (Table 7 )  was above long-term averages.  
Sex Rat io  
The s e x  and biomass (weight)  r a t i o s  of t he  San Francisco Bay g i l l  
~ 
n e t  and roundhaul f icsheries  were s i m i l a r  t h i s  season. Females composed 
- 52% of t h e  g i l l  ne t  c a t c h  and 50X of t h e  roundhaul c a t c h  (Table 4). This 
I season t h e  percentage of females i n  t h e  roundhaul ca t ch  was normal, bu t  
1 the  percentage of females i n  t h e  g i l l  ne t  ca t ch  was l e s s  than  expected. 
1 The t r end  toward sma l l e r  mesh i n  t h e  g i l l  n e t  f i s h e r y  is  a f f e c t i n g  t h e  
I sex r a t i o  of t h e  ca t ch ,  because sma l l e r  mesh n e t s  ca tch  a lower 
1 percentage of females  t han  l a r g e r  mesh n e t s  ( R e i l l y  an$ Moore 1986). 
DISCUSSION 
The age composition of t h e  Tomales Bay ca t ch  has  been composed 
pr imaf i ly  of 5-, 6-, and 7-yr-old he r r ing  every season s i n c e  t h e  f i s h e r y  
was l i m i t e d  t o  g i l l  n e t s  only i n  1977. These age groups comprised 
! 
- 6 -  
between 72% and 82% of the catch until this season, when the percentage 
of 5-, 6-, and 7-yr-old herring dropped to 55%. This is due to initial 
recruitment of the strong 1982 and 1983 yr classes (3- and 4-yr olds). 
Those two year classes have good growth charactistics and are expected to 
have a positive impact as they move through the fishery. 
The strength of the 1984 yr class appears to be average in San 
Francisco Bay, but could be weak in Tomales Bay because of low spawning 
escapement in 1984 (Spratt 1985b). This year class will not be fully 
recruited in Tomales Bay until the 1988-89 season. 
The age and size composition of the San Francisco Bay roundhaul 
1 .  catch changed lirtle from 1973 to 1984-85, with 2- and 3-yr-old herring 
dominating the catch (Spratt 1985). Recruitment of the 1984 yr class 
into the roundhaul fishery is about average, accounting for 33% of the 
Catch by number. Good recruitment is one factor contributing to the 
modest increase in spawning biomass this season (Spratt 1986). 
CONCLUSION 
The biological characteristics of the Tomales Bay catch are normal, 
with indications that the strength of the two year classes entering the 
fishery may be better than average. 
In San Francisco Bay, the biological characteristics of the catch 
indicate that relative recruitment of the 1984 yr class was about 
average, causing the population growth rate to slow (Spratt 1986). 
Recruitment of the 1985 yr class next year will be a major factor in 
determining population size. 
Based on the biological characteristics of the catch, the condition 
of the herring stocks in both bays remains good, and major changes in the 
population's size are not expected next year. Therefore, no change is 
recommended for the roe fishery quotas in Tomales Bay or San Francisco 
Bay of 1000 tons and 7500 tons, respectively. 
REFERENCES 
Reilly, P.N. and T.O. Moore. 1986. Pacific herring, Clupea harengus 
pallasi, studies in San Francisco Bay, and central and northern 
California, and Washington March 1985 to May 1986. Calif. Dept. 
Fish and Game, Mar. Resources Admin. Rept. 86-6. 
Spratt, J.D. 1981. Status of the Pacific herring Clupea harengus 
pallasi, in California to 1980. Calif. Fish and Game, Fish Bull. 
171: 1-104. 
------ . 1982. Biological characteristics of the catch from the 1980-81 
and 1981-82 Pacific herring, Clupea harengus pallasi, roe fishery in 
California. Calif. Dept. Fish and Game, Mar. Resources Admin. Rept. 
----- . 1983. Biological characteristics of the catch from the 1982-83 
Pacific herring, Clupea harengus pallasi, roe fishery in California. 
Calif. Dept. Fish and Game, Mar. Resources Admin. Rept 83-4: 1-11. 
------ . 1984. Biological characteristics of the catch from the 1983-84 
- 
Pacific herring, Clupea harengus pallasi, roe fishery in California. 
Calif. Dept. Fish and Game, Mar. Resources Admin. Rept. 84-4: 1-18. 
----- . 1985a. Biological characteristics of the catch from the 1984-85 
Pacific herring, Clupea harengus pallasi, roe fishery in California. 
Calif. Dept. Fish and Game, Mar. Resources Admin. Rept. 85-3: 1-20. 
------ . 1985 b. Biomass estimates of Pacific herring, Clupea harengus 
-- 
- \ 
- .  
pallasi, in California from the 1984-85 spawning-ground surveys. 
Calif. Dept. Fish and Game, Mar. Resources Admin. Rept. 85-2: 1-27. 
----- . 1986. Biomass estimates of Pacific herring, Clupea harengus 
pallasi, in California from the 1985-86 spawning-ground surveys. 
Calif. Dept. Fish and Game, Mar. Resources Admin. Rept. 86-3. 
TmLE 1. Mean Length of 
Bay Roe Fisher  
P a c i f i c  Herring from 
ies, 1972-73 through 
Tomales Bay 
Tomale4 and San Francisco 
1985-86 Seasons. 
San Francisco Bav 
Gill ne t  Roundhaul 
Mean Mean Mean 
length  Size  length  Size  length  Size  
Season mm BL range mm BL range mm BL range 
1976-77 169 140-2 16 212 192-236 181 142-228 
1977-78 217 ' 194-248 211 178-236 178 144-232 
1978-79 No Samples 203 164-234 183 146-222 
1979-80 214 196-236 208 184-230 180 148-220 
mte: Tomales Bay has been r e s t r i c t e d  t o  g i l l  n e t s  only s ince  1977, and 
minimum mesh r e s t r i c t i o n s  were lowered t o  2 118 in.  from 2 114 in .  
- 1 . f o r  t h e  San Francisco Bay g i l l  ne t  f i s h e r y  i n  1984. 
TABLE 2. Length Frequency of the Tomales Bay Gill Net Catch in the 
1985-86 Season. 
St. dev. - 8.3 7 2 6.6 5.7 6.8 4.5 8.5 
TABLE 3. Mean Weight in Grams at  Age of Herring in  the Tomales Bay Gill Net 
Catch By Season. 
Age 
Unwted. 
Season 2 3 4 5 6 7 8 9 mean *' 
1978-7 9 No Samples 
1982-83 - - 100 120 132 150 169 172 140 , 
1983-84 - - 9 1 106 114 131 141 150 117 
1984-85 76 102 109 117 135 151 161 172 135 
1985-86 73 94 106 121 137 150 148 162 132 * 
Unwted . 
average 74 9 3 113 124 137 149 162 170 137 
-- \ft%lculated from ages 4 through 8 only, because they comprise over 95% of the samples.. 
TABLE 4. Female to Male Sex and Biomass (Weight) Ratios 
of the Catch for the 1985-86 Season by Area. 
Tomales Bay 
Sex ratio 1 :0.9 
Biomass ratio 1 :0.8 
San Francisco Bay Gill Net 
Sex ratio 1 :0.9 
Biomass ratio 1 :0.9 
San Francisco Bay Roundhaul 
Sex ratio 1: 1.0 
Biomass ratio 1 ~0.9 
TdBLE 5 .  Length Frequency of the  San Francisco Bay Roundhaul Catch i n  the 
1985-86 Season. 
ZlLbLE 6. Length Frequency of the San Francisco Bay G i l l  Net Catch i n  the  
1985-86 Season. 
I66 1 1 
H 1 38 114 7 1 3 7 19 9 - 
ikan 166 188 193 199 20 2 207 215 - 
St, dev. - 7.9 5.8 5.7 5.2 4 . 9 7 3 - 
TABLE 7. Mean Weight i n  Grams a t  Age of Herring i n  the San Francisco bay 
Roundhaul Catch. 
Age Seasonal 
unwted . 
Season 2 3 4 5 6 7 8 9 mean * 
average 61 ' 80 9 7 113 125 138 161 164 95 
*Computed from age 2 through 6 only, because these age c lasses  comprise over 
90% of the catch. 
PERCENT PERCENT PERCENT 


Biological characteristics of the catch from the 1985-86 Pacific herring, Clupea harengus pallasi, roe fishery in California

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Biological characteristics of the catch from the 1985-86 Pacific herring, Clupea harengus pallasi, roe fishery in California

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