(DRAFT) - Taxonomy
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

TAXONOMY

NAME - herring, Pacific

OTHER COMMON NAMES - herring, California herring, Ches-Pechora herring, eastern herring, Kara herring, Pacific Ocean herring, seld and white sea herring

ELEMENT CODE -

CATEGORY - Fish

PHYLUM AND SUBPHYLUM - Chordata,

CLASS AND SUBCLASS - Osteichthyes,

ORDER AND SUBORDER - Clupeiformes,

FAMILY AND SUBFAMILY - Clupeidae,

GENUS AND SUBGENUS - Clupea,

SPECIES AND SSP - harengus, pallasi

SCIENTIFIC NAME - Clupea harengus pallasi

AUTHORITY - Valenciennes

TAXONOMY REFERENCES - 4, 209, 232 and 253

COMMENTS ON TAXONOMY -
Other common names include: California herring, Ches-Pechora herring,
eastern herring Kara herring, Pacific Ocean herring, seld, white sea
herring, herring.*4*, *253*

Taxonomy - 1 (DRAFT) - Status
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

STATUS

Coded Status
Commercial
Commercial/consumption
Sport Fish
Migrant

REFERENCES FOR STATUS - 4 and 232

COMMENTS ON STATUS -
The herring is a much prized and widely and fully used commercial species.
No major herring stock along the Pacific coast of the United States or
Canada has a harvestable surplus that exceeds the harvesting capacity of the
fishing fleet seeking it. In the Pacific Southwest, herring spawn primarily
in bays and estuaries, and are sensitive to changes in habitat induced by
man.*4*
Some sport fishing occurs for herring, primarily in San Francisco Bay, when
the herring move into shallow waters in large numbers to spawn.*4*

Migrational patterns are specific to each area and population *232*.

Herring are managed within the 3-mi limit by the State of Alaska, Department
of Fish and Game, and in the Fisheries Conservation Zone (3 to 200-mi limit)
by the U.S. Department of Commerce, National Marine Fisheries Service, as
directed by the joint policy of the State of Alaska's Board of Fisheries and
the North Pacific Fisheries Management Council *232*.

Status - 1 (DRAFT) - Distribution
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

DISTRIBUTION

Distribution - 1 HABITAT ASSOCIATIONS

HABITAT - MARINE

REFERENCES FOR HABITAT - 232

LAND USE -
Water
Bays and Estuaries

REFERENCES FOR LAND USE - 232

NATIONAL WETLAND INVENTORY CODES

NWI NWICLS NWIMOD NWISPEC

Estuarine OW0
Marine OW0

REFERENCES FOR NWI - 4

COMMENTS ON HABITAT ASSOCIATIONS -
Surveys indicate that the abundance of Pacific herring larvae was highest
in San Francisco Bay and second highest in Humboldt Bay. The larvae were
captured only during winter, and only small numbers of juveniles were taken
in spring. However, researchers reported that herring were caught in otter
trawls in South Humboldt Bay in every month except December. In 1968,
juvenile Pacific herring were caught in North Humboldt Bay with an otter
trawl from March to July and in October and November. Researchers noted
that large numbers of juvenile herring were seen near the surface in August
and September but that they were mostly uncatchable by bottom trawl.
Juvenile Pacific herring were netted with a lampara bait seine in Humboldt
Bay from April to October and with a midwater trawl from January to October
in many locations in San Francisco Bay. Most juvenile herring congregate
in deeper water in fall.*4*

Except for spawning habits and related behavior, little is known about
adult herring along the coast in the Pacific Southwest. The offshore
distribution is largely unknown, although there is a summer fishery for
adults in Monterey Bay. Fishermen have also reported fairly large schools
of herring offshore from the Farallon Islands in summer, but no samples
have been obtained. Pacific herring have a homing instinct that brings
them back to a certain area of the coast to spawn each year; consequently
researchers speculated that along the coast of California there may be
four to eight or more stocks. However, researchers stated that no evidence
has been shown to indicate separate California stocks.*4*

In the Bering Sea, spawning occurs on rocky headlands or in shallow lagoons
and bays. Herring north of Norton Sound may spawn in brackish bays and
estuaries *232*.

ANIMAL/PLANT SPECIES ASSOCIATIONS -
Sea birds
Flatfish
Bering cisco
Saffron cod
Sculpin
snail (Littiorina planaxis)
Comb jelly
Jellyfish
Habitat Associations - 1 Arrow worm
Salmon
Amphipod
Pacific herring
Dogfish
Marine mammals
Groundfish
Northern pike
Sheefish

REFERENCES FOR SPECIES ASSOCIATIONS - 232

COMMENTS ON SPECIES ASSOCIATIONS -
Sea birds have been documented as major predators of herring eggs in the
intertidal area. Predation by flatfish upon eggs has also been documented.
In Norton Sound, Bering cisco, saffron cod, sculpins, and snails (Littiorina
planaxis) were found to consume herring eggs *232*.

Predation upon larvae is intense. Predators may include comb jellies,
jellyfish, arrow worms, small salmon, and amphipods. Cannibalism of adult
herring upon larval herring has been documented when older herring have been
present on the spawning grounds during the egg-hatch period *232*.

Mature herring are most susceptible to predation by marine mammals, dogfish,
and seabirds on the spawning grounds and during migration to their offshore
feeding grounds. Herring are a very important staple in food webs, and in
the Bering Sea they serve as a dietary staple for marine mammals, birds,
salmon, and groundfish. Predation upon herring by northern pike captured in
Hotham Inlet in Kotzebue Sound has been documented. Herring have been found
to be a major food item for sheefish in northern Kotzebue Sound during
November *232*.

Habitat Associations - 2 (DRAFT) - Food Habits
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

FOOD HABITS

TROPHIC LEVEL -
OMNIVORE

REFERENCES FOR TROPHIC LEVEL - 4 and 232

LIFESTAGE FOOD FOOD PART
Adult Crustaceans Not Specified
Adult Osteichthyes Juvenile stage
Larva Crustaceans Larva stage
Larva Molluscs Larva stage
Larva Bryozoans Larva stage
Larva Rotiferans Larva stage
Larva Osteichthyes Larva stage
Larva Copepods Egg/Fetus stage
Larva See Comments; Food See Comments
Larva Crustaceans See Comments
Larva Ostracods See Comments
Larva Copepods See Comments
Larva Osteichthyes Larva stage
Larva Chrysophyta See Comments
Larva Copepods Egg/Fetus stage
Larva Copepods Larva stage
Important Copepods Larva stage
Larva Cirripeds Larva stage
Important Cirripeds Larva stage
Larva Plankton Not Specified
Juvenile Crustaceans Not Specified
Juvenile Copepods Not Specified
Juvenile Branchiopods Not Specified
Juvenile Malacostraca Not Specified
Juvenile Cirripeds Larva stage
Juvenile Osteichthyes See Comments
Juvenile Worms Not Specified
Juvenile Molluscs See Comments
Juvenile Bivalve Molluscs Larva stage
Juvenile Zooplankton Not Specified
Juvenile Sea Squirts Not Specified
Adult Crustaceans Not Specified
Adult Copepods Not Specified
Adult Clupeiformes Egg/Fetus stage
Adult Crustaceans Not Specified
Adult Osteichthyes Larva stage
Adult Gadiformes Larva stage
Adult Perciformes Larva stage
Adult Salmoniformes Larva stage
Adult Arrow worms Not Specified
Adult Annelids Not Specified
Adult Polychaetes Not Specified
Adult Molluscs Not Specified
Adult Polychaetes Not Specified
Adult Molluscs Not Specified
Food Habits - 1 (DRAFT) - Food Habits
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

LIFESTAGE FOOD FOOD PART
Adult Bivalve Molluscs Not Specified
Adult Osteichthyes Juvenile stage
Adult Detritus Not Specified
Adult Branchiopods Not Specified
Adult Platyhelminthes Not Specified
Adult Cirripeds Not Specified
Adult Salmoniformes Larva stage
Adult See Comments; Food See Comments
Juvenile See Comments; Food See Comments
Larva See Comments; Food See Comments
Important See Comments; Food See Comments

REFERENCES FOR GENERAL FOOD - 4

REFERENCES FOR IMPORTANT FOOD - 232

REFERENCES FOR ADULT FOOD - 4 and 232

REFERENCES FOR JUVENILE FOOD - 232

REFERENCES FOR LARVAE FOOD - 4 and 232

COMMENTS ON FOOD -
Feeding Locations: Feeding occurs primarily in coastal waters of the inner
continental shelf. In British Columbia, large aggregations of herring may
be scattered along 100 mi of coastline off the mouth of Juan de Fuca Strait.
These aggregations may move many miles north or south during the summer,
presuambly following their food supply. Herring remain in coastal waters
during the summer because of the concentration of zooplankton food items and
feeding conditions. Herring may remain in coastal waters during the summer
because heavy phytoplankton blooms and because poor feeding conditions exist
on the outer shelf. Herring may avoid areas of heavy phytoplankton bloom
because of its low nutritional value. Gills may become clogged by certain
species of phytoplankton, and respiration of the fish may be affected *232*.

Factors Limiting Availability of Food: Climatic conditions and ocean
currents may affect the availability of food. On the rearing grounds, for
instance, in larval-rearing areas, unfavorarable weather conditions, such as
lack of sunshine, may delay the spring bloom of phytoplankton and therefore
the subsequent development of zooplankton on which herring larvae feed. The
result could be an insufficient food supply available to meet the energy
needs of the arvae. Currents may carry herring larvae to places where the
food supply is inadequate. In British Columbia in years where freshwater
runoff is greater than normal or wind-driven water transport offshore has a
net southward direction, larvae will be carried offshore away from the more
abundant food supplies and be exposed to additional sources of predation
*232*.

Feeding Behavior: A day or so after yolk sac absorption, Atlantic herring
larvae instinctively snap at and try to capture bite-size particles and if
unsuccessful will give up the attempt. Adult herring generally feed heavily
Food Habits - 2 (DRAFT) - Food Habits
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

in summer and very little during winter months. Feeding in the Bering Sea
declines during early winter, ceasing completely in late winter. Juvenile
herring were found to feed during November and December in the Kamchatka
waters of the western Bering Sea. Examination of herring captured during
spring months from Bristol Bay to Norton Sound revealed that about 95% of
the stomachs were empty or contained traces of food items *232*.

COMMENTS ON ADULT FOOD -
Adult herring eat various crustaceans (preferring the larger forms), and
juvenile stages of smelt, herring, sandlance, hake, and rockfish.*4*

Adult herring captured in British Columbia fed primarily upon euphausiids,
copepods, and occasionally herring eggs. In the eastern Bering Sea, August
diets of adults were comprised of 84% euphausiids, 8% fish fry, 6% calanoid
copepods, 2% gammarid amphipods; fish fry, in order of importance, were
walleye pollock, sandlance, capelin, and smelt. During spring months, food
items were mainly Themisto (amphipoda) and Sagitta (chaetognath). After
spawning (eastern Bering Sea), adults ingested euphausiids, copepods
(Calanus spp.), and arrow worms (Sagitta spp.). Stomach contents of herring
found in demersal areas included polychaete worms, bivalve molluscs,
amphipods, copepods, juvenile fish, and detritus. Cladocerans, flatworms
(Platyhelminthes), copepods, and cirripeds were found in herring captured
during spring months. In Southeast Alaska, adult herring feeding during
spring months have preyed upon both pink salmon larvae, pink salmon fry, and
herring eggs. Rather than exhibiting a preference for certain food items,
adult herring feed opportunistically on any large organisms prevalent among
the zooplankton in a given area *232*.

COMMENTS ON JUVENILE FOOD -
Juveniles consume mostly crustaceans such as copepods, amphipods,
cladocerans, decapods, barnacle larvae, and euphausiids. Consumption of
some small fish, marine worms, and larval clams has also been documented.
In the western Bering Sea and Kamchatka area in November and December, the
diet of juveniles consists of medium-sized forms of zooplankton
(Chaetognaths, mysids, copepods, and tunicates) *232*.

COMMENTS ON LARVAE FOOD -
As soon as the yolk is exhausted herring larvae must begin exogenous
feeding. This "critical period" at the onset of feeding generally results
in high mortality because the margin between sufficient nutrition and
starvation is exceedingly narrow. The first food consists mainly of
invertebrate eggs, copepod nauplii, and diatoms. Within 2 months, young
herring are 2.5-4.0 cm long and the diet has broadened to include larvae of
barnacles, mollusks, bryozoans, rotifers, and fish -- though copepod nauplii
and adults are the most important food. Since larval feeding is sight
dependent, it occurs primarily during daylight.*4*

Herring larvae and postlarvae feed on ostracods, small copepods and
nauplii, small fish larvae, and diatoms. Studies of food habits of herring
captured in southern British Columbia noted that the food was present in
stomachs of herring larvae less than 9 mm in length. Larvae, however, were
found to feed before the yolk sac was absorbed. At the earliest feeding
stages, eggs, diatoms, and small copepod nauplii were eaten. Postlarvae and
Food Habits - 3 (DRAFT) - Food Habits
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

fry ingested a large variety of organisms, with copepod and cirripid larvae
being the most important items. The first food eaten by larval herring may
be limited to microscopic plankton organisms the larvae practically need to
run into to notice and capture. Early food items may be comprised of more
than 50% microscopic eggs *232*.

Food Habits - 4 (DRAFT) - Environment Associations
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

ENVIRONMENTAL ASSOCIATIONS

G = General A = Adult
LIM = Limiting RA = Resting Adult
J = Juvenile FA = Feeding Adult
RJ = Resting Juvenile BA = Breeding Adult
FJ = Feeding Juvenile P = Pupae
L = Larvae E = Egg
RL = Resting Larvae
FL = Feeding Larvae

LIFESTAGE ENVIRONMENTAL ASSOCIATIONS
A Water Temperature: Below 15 degrees C
A Water Temperature: Specified in Comments
E Water Temperature: Below 15 degrees C
E Water Temperature: Specified in Comments
L Water Temperature: Below 15 degrees C
L Water Temperature: Specified in Comments
L
L
L Bottom Type [Aquatic]: Mud or silt
A Turbidity: Clear water
A Turbidity: Specified in Comments
E Turbidity: Clear water
E Currents: specified in comments
A Water Temperature: Below 15 degrees C
A Water Temperature: Specified in Comments
J
J
J
E
L
E
L
BA Water Temperature: Specified in Comments
BA Water Temperature: Below 15 degrees C
A Water Temperature: Specified in Comments
A Water Temperature: Below 15 degrees C
J Water Temperature: Between 15-21 degrees C
J Water Temperature: Specified in Comments
E Water Temperature: Below 15 degrees C
E Water Temperature: Specified in Comments
A Water Depth Preference: 200-500 ft.
A Water Depth Preference: Specified in Comments
G Water Depth Preference: Specified in Comments
G Coastal Wetlands: Specified in Comments
G Coastal Wetlands: Sounds and bays
G Water Depth Preference: 50-100 ft.
BA Water Depth Preference: 25-50 ft.
BA Water Depth Preference: Specified in Comments
G Water Depth Preference: 500-1000 ft.
FA Coastal Wetlands: Specified in Comments
Environment Associations - 1 (DRAFT) - Environment Associations
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

LIFESTAGE ENVIRONMENTAL ASSOCIATIONS
BA Substrate: Rocks
BA Substrate: Specified in Comments
BA Coastal Wetlands: Sounds and bays
BA Coastal Wetlands: Specified in Comments
E Substrate: Plants
E Substrate: Specified in Comments
E Substrate: Rocks
E Substrate: Sand
E Water Temperature: Specified in Comments
E Water Temperature: Below 15 degrees C
A
A Water Temperature: Specified in Comments

REFERENCES FOR ENVIRONMENTAL ASSOC_ - 253 and 232

REFERENCES FOR ADULT ENVIRONMENTAL ASSOC_ - 4 and 232

REFERENCES FOR FEEDING ADULT ENVIRONMENTAL ASSOC_ - 232

REFERENCES FOR BREEDING ADULT ENVIRONMENTAL ASSOC_ - 4 and 232

REFERENCES FOR JUVENILE ENVIRONMENTAL ASSOC_ - 232

REFERENCES FOR LARVAE ENVIRONMENTAL ASSOC_ - 4, 253 and 232

REFERENCES FOR RESTING LARVAE ENVIRONMENTAL ASSOC_ - 4

REFERENCES FOR EGG ENVIRONMENTAL ASSOC_ - 4 and 232

COMMENTS ON ENVIRONMENTAL ASSOCIATIONS -
Populations show wide fluctuations in abundance, which is apparently
related to environmental conditions, and are affected by alterations of
bays and estuaries.*253*

In the Bering Sea, temperature may have the greatest influence on the
seasonal distribution of herring. Herring moving from the overwintering
grounds in the Bering Sea to spawning ground shave passed through water at
subzero (centigrade) temperatures. Herring appear to remain in shallower
coastal waters after spring spawning in the Bering Sea, as few are taken in
offshore trawl surveys. In Southeast Alaska, herring overwinter in
protected bays that are usually close to respective spawning area.
Overwintering herring have been reported at depths of 90 fathoms but are
more commonly found at depths of 23 m or less *232*.

COMMENTS ON ADULT ENVIRONMENTAL ASSOC_ -
Dense schools of overwintering adult herring have been found at
temperatures of from 2 to 3.5 oC in the Bering Sea. Herring moving from
the overwintering grounds in the Bering Sea to spawning grounds have passed
through water at subzero (centigrade) temperatures. In the Kotzebue
Sound-Chukchi Sea area, adult herring were captured in areas where water
twmperatures ranged from 2 to 14 oC. Adults were found to overwinter at
Environment Associations - 2 (DRAFT) - Environment Associations
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

depths from 107 to 137 m in the Bering Sea. Herring appear to remain in
shallower coastal waters after spring spawning in the Bering Sea, as few
are taken in offshore trawl surveys *232*.

Immature herring may typically occupy shallower, less saline waters than
adults. Immature fish in the Bering Sea exhibit greater tolerance for
colder, less saline areas in their overwintering grounds on the continental
shelf than do adult fish *232*.

COMMENTS ON FEEDING ADULT ENVIRONTAL ASSOC_ -
Feeding occurs primarily in coastal waters of the inner continental shelf
*232*.

COMMENTS ON BREEDING ADULT ENVIRONMENTAL ASSOC_ -
In California, spawning temperatures are normally above 9 C. Salinity
tolerances of larvae are affected by salinity and temperature during egg
incubation.*253*
The Pacific herring generally lives at water temperatures of 0-10 degrees C
throughout its distribution during the maturation and spawning of adults.
For North American stocks these events tend to occur in the upper half of
the temperature range; usually 8-10 degrees C for California waters.
Within the optimal ranges, maximum incubation success accompanies lower
salinities coupled with lower water temperatures or higher salinities with
higher temperatures.

Excessive turbidity resulting in settling out of sediments may hinder the
spawning of herring. The spawning female tests the substrate with her
genital papilla before depositing eggs, and researchers stated that
sediment on the substrate may inhibit spawning.*4*

The timing of spawning in the western Bering Sea is related to winter and
spring water temperatures, with early maturation occuring in warm years and
delayed development in colder years. In Bristol Bay, herring appear on the
spawning grounds when water temperatures reach 4 oC, and spawning has been
osberved to occur at 5 oC. A water temperature of 10 oC has been
documented in Bristol Bay during the spawning season. Water temperatures
occurring on Bering Sea spawning grounds between Norton Sound and Bristol
Bay have ranged between 5.6 and 11.7 oC. Alaskan herring move inshore to
spawn in both subtidal and intertidal areas in the spring. Spawning in
Southeast Alaska has been documented from the intertidal area to depths of
11.5 m. Major spawning activity occurs in the subtidal area in Southeast
Alaska *232*.

In the Bering Sea, spawning occurs on rocky headlands or in shallow lagoons
and bays. Substrate on which herring spawn in southeast Alaska includes
Fucus, Agarum, Zostera, Alaria, Laminaria, and rock surfaces. The
vegetative type used most frequetly, however, is Desmarestia. Spawning
activity is related to water temperatuers and occurs soon after water has
become ice-free. Recorded water temperatures in which spawning activity has
been documented are approximately 3 to 5.5 oC; 5 to 9.4 oC in Southeast
Alaska; 6 to 10 oC in Bristol Bay; and 5.6 to 11.7 oC on the spawning
grounds between Norton Sound and Bristol Bay. Herring north of Norton Sound
may spawn in brackish bays and estuaries *232*.
Environment Associations - 3 (DRAFT) - Environment Associations
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

COMMENTS ON JUVENILE ENVIRONMENTAL ASSOC_ -
Juveniles are found in a wide range of salinities in British Columbia, with
concentrations documented at 25 ppt. Juvenile herring were caught in
Krusenstern Lagoon in mid August in water temperatures measured to 18.3 oC
*232*.

COMMENTS ON LARVAE ENVIRONMENTAL ASSOC_ -
Larvae are tolerant of salinities ranging from 2-28 ppt. Salinity
tolerances of larvae are affected by salinity and temperature during egg
incubation. Turbidity in estuaries may increase larval survival.*253*

Fry were found in Imuruk Basin near Port Clarence, Alaska, in water of 4
ppt salinity *232*.

COMMENTS ON RESTING LARVAE ENVIRONMENTAL ASSOC_ -
Early larvae appear to be euryplastic. Length at hatching, larval growth
rate, and growth efficiency on yolk appear to be enhanced at salinities of
13-21 ppt at temepratures of 5.5-12 degrees. Researchers concluded that
survival of Pacific herring larvae passively transported into the open
waters of the Pacific Ocean might be limited by their inability to
tolerate high offshore salinities.*4*

COMMENTS ON EGG ENVIRONMENTAL ASSOC_ -
The Pacific herring generally lives at water temperatures of 0-10 degrees C
throughout its distribution during the maturation and spawning of adults.
For North American stocks these events tend to occur in the upper half of
the temperature range; usually 8-10 degrees C for California waters.
Within the optimal ranges, maximum incubation success accompanies lower
salinities coupled with lower water temperatures or higher salinities with
higher temperatures.
Excessive turbidity resulting in settling out of sediments may hinder the
spawning of herring. The spawning female tests the substrate with her
genital papilla before depositing eggs, and researchers stated that
sediment on the substrate may inhibit spawning. Researchers stated that
the delivery of oxygen to, and the removal of metabolites from, herring
eggs incubating under layered conditions is pertinent to survival --
particularly for occluded eggs in the interior of an egg mass. The
researchers assumed that substantial movement of water through the
interstices between eggs in a mass is required to provide for respiratory
exchange. Excess fine sediment settling on egg masses can block the
interstices and prohibit adequate circulation of water.*4*

Herring eggs were found in Imuruk Basin near Port Clarence, Alaska, in
water of 4 ppt salinity. The optimum temperature for egg development was
found in the laboratory in southern British Columbia to range from 5 to 9
oC. At continuous exposures below 5 oC, the eggs die. Eggs are deposited
both subtidally and intertidally on aquatic vegetation, rock, and sand.
Predominant vegetation types along the Bering Sea coastline are eelgrass
(Zostera spp.), rockweed (Fucus spp.), and ribbon kelp (Laminaria spp.). In
Prince William sound, broad leaf kelp, Agarum, and Laminaria are the
primary vegetation types. Substrate on which herring spawn in southeast
Alaska includes Fucus, Agarum, Zostera, Alaria, Laminaria, and rock
surfaces. The vegetative type used most frequetly, however, is Desmarestia
Environment Associations - 4 (DRAFT) - Environment Associations
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

*232*.

Eggs take 10 to 21 days to hatch, depending on the water temperature. In
Bristol Bay, at temperatures of 8 to 11 oC, 13 to 14 days are required for
hatching. The optimum temperature reported for egg development is from 5
to 9 oC *232*. Eggs can tolerate temperatures of 5-14 C and salinities of
3-33 ppt.*253*

Environment Associations - 5 (DRAFT) - Life History
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

LIFE HISTORY

PHYSICAL DESCRIPTION:

Pacific herring are moderately compressed silvery fish with unspined fins,
including a short dorsal near middle of back and abdominal pelvic fins
beneath the dorsal. The caudal fin is deeply forked. Keeled scales
(scutes) along the ventral midline are only moderately developed. Compared
to other clupeid species there are no scales or striations on the head or
gill cover, no spots on the sides, no lateral line canal, no modified scales
or flaps on the side of the tail fin, no teeth on the jaw (although the
are fine teeth on the vomer), and the last dorsal fin ray is not elongate.

Dorsal fin rays 15-21; anal 13-20; pectorals about 17; pelvics about 9, each
with a fleshy scale above its insertion; vertebrae 46-55; large cycloid
scales 38-54 midlaterally. Color dark bluish green to olive on dorsal
surface, shading to silver on side and belly. Length usually less than 30
cm but occasionally to 46 cm standard length (SL).*4*

REPRODUCTION:
Pacific herring spawn in many intertidal and subtidal locations along
Califoinia's coast, but Tomales Bay and San Francisco Bay have the largest
spawning populations. Other known spawning areas are San Diego Bay, San
Luis River, Morro Bay, Elkhorn Slough, Bodea Bay, Russian River, Noyo River,
Shelter Cove, Humboldt Bay, and Crescent City Harbor. In California,
herring spawn from November to June but primarily from December to February.

Adult herring typically congregate near the spawning grounds several weeks
to months before spawning. In California, the first spawners gradually
enter the bays, and build up into large aggregations for several weeks
before spawning; later spawners move in just before they spawn. Maturing
adults enter San Francisco, Tomales, and Humboldt Bays often several weeks
before spawning, remaining in loosely aggregated schools in deep channels.

The stimuli that initiate spawning are not well understood. In northern
latitudes spawning times are apparently synchronized with water
temperatures, and spawning does not begin until incubation temperatures
exceed 6 degrees C. However, in California water temperatures are above 9
degrees C throughout the winter-spring spawning season and the initiation of
spawning is apparently not temperature related. When the right conditions
prevail, schools of herring move into intertidal shallows and some subtidal
areas, and spawn on any suitable substrate. However, herring appear to have
substrate preferences: in San Francisco Bay they choose algae and grass
first, then prominent rocks, and lastly flat surfaces. The principal
substrate used n Tomales and Humboldt Bays is common eelgrass (Zostera
marina), although in some years the areas with the lushest beds of eelgrass
are not used for spawning. In Humboldt Bay, which generally exceeds 28 ppt
salinity, researchers suggested that the location of fresh water inflows
probably influenced the location of herring spawning. Researchers found that
low-salinity water stimulated herring to spawn while in captivity.
Researchers reported that hatching success decreased with increasing
salinity. However, researchers believed that extended periods of salinities
below 20 ppt in San Francisco Bay inhibited herring spawning.
Life History - 1 (DRAFT) - Life History
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

Both the male and female herring interact closely with the vegetation on
which the highly adhesive eggs are laid. The ventral surface and genital
papilla contact the spawning substrate and the fish deposit tracts of eggs
and milt along its surface. The texture and rigidity of the substrate are
tested by the fish using the tips of the pelvic and pectoral fins before
they spawn, and sediment on the substrate may inhibit spawning. Extrusion
of eggs appears to be impeded unless the vent is in contact with the
substrate. Researchers suggested that male herring probably initiate the
spawning act by releasing milt that triggers the actual spawning process.
In large mass spawnings the water often appears "milky" over the entire
spawning areas due to the presence of milt. Herring sperm remain fertile
for at least 3 hours in seawater at 8 degrees C. The eggs are deposited in
layers of one to two eggs thick in light intensity spawns to many egg layers
in heavy spawns. Researchers reported a herring spawn in San Francisco Bay
in January 1975 with some egg layers nearly 10 cm thick, calculated
to be about 6 million eggs/m(squared). Mass spawnings in San Francisco and
Tomales Bays may take place in a few hours of one night or may continue as
long as a week. Frequently two or more spawnings occur in the same
location, separated roughly by 10-15 days. In California adult herring
return to sea immediately after spawning.

Fecundity. Fecundity is positively correlated with the size of the female.
The number of eggs per gram of body weight is a useful measure of relative
fucundity, particularly for herring spawn surveys used to estimate total
biomass of spawning fish. Mean fecundity of females was 227 eggs per gram
in Tomales Bay and San Francisco Bay and 220 eggs per gram in Humboldt Bay.
Thus a gravid female herring weighing 100 g would be expected to contain
about 22,000 eggs. For Humboldt Bay herring, researchers calculated a
linear relation between body length and egg production, showing that a
female herring about 177 mm long SL produced 22,000 eggs. Along the Pacific
coast the total size-specific fecundity is inversely related to
latitude.*4*

Egg Stage. The eyes of the Pacific herring egg become pigmented about
halfway through the incubation period. Incubation time was 6-10 days in
water temperatures of 8-10 degrees C in Tomales Bay and 10.5 degrees C in
San Francisco Bay. Survival is reduced where the eggs are deposited several
layers thick. Adequate respiration of eggs within an egg mass is assumed to
require continuous movement and replacement of interstitial water. Egg
mortality is occasionally high as a result of predation on deposited layers
of eggs by gulls, diving birds, and fish; also, erratic major storms
sometimes tear loose egg-laden vegetation and windrow it along beaches.

Fertilized Pacific herring eggs are spherical, 1.2-1.5 mm in diameter; they
have a yellowish granular yolk, no oil globule, a thick, tough, transparent
chorion, and a wide perivitelline space, equal to 20%-30% of the egg
diameter.*4*

Larval and Juvenile Stages. At hatching, herring larvae are 5.6-7.5 mm long
TL and have a small spherical, thoracic yolk sac that persists for a period
of time that varies in length with water temperature, but does not usually
Life History - 2 (DRAFT) - Life History
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

exceed 2 weeks. At completion of the yolk sac stage the larvae are 9-10 mm
long TL. Herring larvae have a long straight gut that becomes segmented in
the postlarval stage. Pacific herring have a total of 45-57 myomeres, of
which 37-44 are preanal. Herring larvae are characterized by having paired
melanophores along the gut that are dorsal to mid-body and then ventral to
the anus.

As soon as the yolk is exhausted herring larvae must begin exogenous
feeding. This "critical period" at the onset of feeding generally results
in high mortality because the margin between sufficient nutrition and
starvation is exceedingly narrow. The first food consists mainly of
invertebrate eggs, copepod nauplii, and diatoms. Within 2 months, young
herring are 2.5-4.0 cm long and the diet has broadened to include larva of
barnacles, mollusks, bryozoans, rotifers, and fish -- though copepod nauplii
and adults are the most important food. Since larval feeding is sight
dependent, it occurs primarily during daylight.

Most juvenile herring congregate in bays during summer and move into deeper
water in fall.*4*

Adult Stage. Except for spawning habits and related behavior, little is
known about adult herring along the coast in the Pacific Southwest. The
offshore distribution is largely unknown, although there is a summer fishery
for adults in Monterey Bay. Fishermen have also reported fairly large
schools of herring offshore from the Farallon Islands in summer, but no
samples have been obtained. Pacific herring have a homing instinct that
brings them back to a certain area of the coast to spawn each year;
consequently researchers speculated that along the coast of California there
may be four to eight or more stocks. However, researchers stated that no
evidence has been shown to indicate separate California stocks. In
California some herring spawn at 2 years of age and all are mature by age 3.
Herring up to 11 years old are taken each year in the various fisheries, but
fish of ages 2-6 are most common. The numerical ratio of females to males
among adult herring captured by gears that are relatively non-selective for
size does not differ significantly from 1:1 in Tomales, San Francisco, and
Humboldt Bays. Researchers stated that adult herring eat various
crustaceans (preferring the larger forms), and juvenile stages of smelt,
herring, sandlance, hake, and rockfish.*4*

LIMITING FACTORS:
Predators. Predators are attracted to herring spawn deposits and contribute
significantly to egg mortality. In Canada, researchers reported that major
egg depositions in the intertidal zone frequently were exploited by flocks
of gulls, which consumed 30%-55% of the exposed eggs, mostly within 3 days
after deposition. Researchers observed that the extent of predation varies
greatly. In Tomales Bay researchers speculated occasional predation rates
of 90-100%, 5-7 days after deposition. Bird predators observed include the
California gull Larus californicus, the mew gull L. canus, the
glaucous-winged gull L. glaucescens, the western gull L. occidentalis, the
American coot Fulica americana, and the surf scoter Melanitta perspicillata.
Divers collecting herring eggs reported that various fish and crabs ate
herring eggs: sturgeons Acipenser spp., smelts (Atherinidae), surfperches
(Embiotocidae), and crabs (probably Cancer spp.). In Tomales Bay diving
Life History - 3 (DRAFT) - Life History
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

birds greatly reduce the density of eelgrass in herring spawning beds. They
tear the leaves off and often pull whole plants out of the substrate. By
the end of the spawning season, many lush beds of eelgrass have been cropped
to within a few inches of the substrate.

Herring larvae are abundant in the ichthyoplankton of the bays where they
hatch and presumably are preyed upon by older stages of many fish species.
Researchers reported that predation and starvation are the two main causes
of larval mortality in many stocks of marine fish. Researchers stated that
years of high abundance of fish that prey on larvae often are also years of
rich food abundance for the fish larvae and that the food for larvae is
often also the main food of the planktonic predators. Although juvenile
herring are known to be eaten by other species, there is no evidence of
excessive predation at that stage. Researchers found that herring larvae
were eaten by several species of medusae and stated that if a species of
medusae reached peak abundance at the time of emergence of herring larvae,
the survival of the larvae might be reduced. Ctenophores (Pleurobrachia
spp.) and chaetognaths (Sagitta sp.) can also be important predators.
Laboratory rearing experiments showed that juvenle Pacific herring fed
extensively on newly hatched larvae of their own species when the two
occurred together and suggested that such cannibalism could add considerably
to the mortality of herring in early life. Sub-adult and adult herring in
schools appear to be one of the major fodder animals of the sea, providing
food for salmon, sharks, and lingcod (Ophiodon elongatus), as well as for
waterfowl, sea lions and whales.*4* They are also eaten by many species of
birds and marine mammals such as seals and sperm whales. *253*

Food supply. As soon as the yolk is exhausted herring larvae must begin
exogenous feeding. This "critical period" at the onset of feeding generally
results in high mortality because the margin between sufficient nutrition
and starvation is exceedingly narrow.*4*

Turbidity and Sedimentation. Researchers stated that the turbid waters of
estuaries and bay used by larval herring as nursery areas may offer survival
advantages. In experiments, feeding incidence and intensity of herring
larvae were significantly greater at levels of sedimentary suspension of 500
to 1000 mg/l than at the control level (0 mg/l). Feeding decreased at
greater concentrations. The suspended sediments may enhance feeding by
providng visual contrast of prey items on the small perceptive scale of
larvae. Larval residence in turbid environments such as estuaries may serve
to reduce predation from larger visual planktivores, while searching ability
in the small larval perceptive field is not decreased significantly.

Excessive turbidity resulting in settling out of sediments may hinder the
spawning and incubation of herring. The spawning female tests the substrate
with her genital papilla before depositing eggs, and researchers stated that
sediment on the substrate may inhibit spawning. The delivery of oxygen to,
and the removal of metabolites from, herring eggs incubating under layered
conditions is pertinent to survival -- particularly for occluded eggs in the
interior of an egg mass. It is assumed that substantial movement of water
through the interstices between eggs in a mass is required to provide for
respiratory exchange. Excess fine sediment settling on egg masses can block
the interstices and prohibit adequate circulation of water.*4*
Life History - 4 (DRAFT) - Life History
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

Pollutants: Estuaries, by their nature, are subject to the introduction of
many kinds of pollutants. Eggs and larvae are usually the life stages of
fish most sensitive to pollutants. Researchers found that sublethal
exposure to benzene, an aromatic component of crude oil, modified the
metabolic processes of Pacific herring embryos and larvae. Researchers
reported that herring embryo mortalities were significant after 180-hour
exposures to a copper concentration of 35 ug/l. A survey of six municipal
waste discharges along the southern California coast revealed concentrations
of copper ranging from 74 to 13,900 ug/l.*4*

POPULATION ATTRIBUTES:
Ecological Role. In terms of consistent contribution to worldwide fish
biomass, the herring has historically been extremely successful. The
herring is specially adapted in several respects. Pacific herring eggs can
withstand extremes of temperature for at least a short time, as well as
(presumably) some desiccation when the tide ebbs. This eurythermy, together
with euryhalinity, means that the herring egg has a formidable ability to
survive in harsh environments. The herring also has a complex camouflage
system based on silvery layers of guanine crytals in the skin which cause
the undersides of the fish, seen from below, to blend in with the surface (a
form of counter shading), a specialized retina for visual acuity, and a
complex acousticolateralis system linked to the swimbladder that endows the
herring with excellent hearing sensitivity independent of hydrostatic
pressure change. It is physostomous (allowing rapid vertical movements of
wide amplitude), strongly schooling in habit, and has the facility to switch
from particulate to filter feeding. Researchers concluded that the herring
could be considered a successful species in terms of its ability to recover
from drastic overfishing.

Researchers calculated that, for Canadian herring stocks, about 22% of the
total herring spawning stock biomass is released annually as milt and eggs.
Reseachers estimated that the carbon contribution of the products to the
ecosystem is high relative to primary production. This material is a source
of energy for secondary producers, particularly microzooplankton, such as
protozoa, copepod nauplii, or larvae of benthic animals, all of which could
serve as food for herring larvae.*4*

OTHER MISCELLANEOUS LIFE HISTORY INFORMATION:
The larval nematode Anisakis sp. (herring worm) is a stable part of the
parasitic fauna of herring. The importance of Anisakis larvae as a public
health problem became known when they were found to cause gastric
granulomata (herring worm disease) in man -- first reported in the United
States in 1975. Researchers stated that the presence of Anisakis makes
human consumption of brined or cold smoked Pacific herring a potential
health hazard.*4*

Reproductive Habitat: In the Bering Sea, spawning occurs on rocky headlands
or in shallow lagoons and bays. Eggs are deposited both subtidally and
intertidally on aquatic vegetation, rock, and sand. Predominant vegetation
types along the Bering Sea coastline are eelgrass (Zostera spp.), rockweed
(Fucus spp.), and ribbon kelp (Laminaria spp.). In Prince William sound,
broad leaf kelp, Agarum, and Laminaria are the primary vegetation types.
Life History - 5 (DRAFT) - Life History
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

Substrate on which herring spawn in southeast Alaska includes Fucus, Agarum,
Zostera, Alaria, Laminaria, and rock surfaces. The vegetative type used
most frequetly, however, is Desmarestia. Spawning activity is related to
water temperatuers and occurs soon after water has become ice-free. Recorded
water temperatures in which spawning activity has been documented are
approximately 3 to 5.5 oC; 5 to 9.4 oC in Southeast Alaska; 6 to 10 oC in
Bristol Bay; and 5.6 to 11.7 oC on the spawning grounds between Norton Sound
and Bristol Bay. Herring north of Norton Sound may spawn in brackish bays
and estuaries *232*.

Reproductive Seasonality: Alaskan herring are classed as spring spawners,
although spawning activity within the state may occur from March to August,
depending upon geographic location and environmental conditions. Peak
spawning activity is usually earliest in Southeast Alaska and becomes
progressively later for more northern areas. Herring in Southeast Alaska
spawn from March through May, with most activity occurring during the months
of April and May. In Prince William sound, spawning activity usually occurs
from early April through May, in Cook Inlet from May through mid June, and
in the Kodiak area from mid April to early August. In the Kodiak area,
timing of spawning usually ranges from early April in the Fox Bay, Paramanof
Bay areas, to late July in the Olga Narrows area, and early August in the
Deadman Bay area. On the Bering Sea coast, spawning activity extends from
late April through July in Bristol Bay and along the Alaska Peninsula,
becoming progressively later to the north and occurring from ice breakup
through mid August in Kotzebue Sound. Because spawning areas in the Chukchi
Sea retain their ice cover into July, spawning activity could be delayed
until August after ice cover is gone *232*.

Reproductive Behavior: Herring in Lynn Canal in Southeast Alaska overwinter
in inshore waters, where maturation continues. About one to four weeks
before spawning, herring seem to move closer to the spawning grounds. In
British Columbia, herring travelled 160 km in 6 days from Barkley Sound to
Espenanze Inlet to spawn, and from Lambert Channel they travelled 350 km to
Juan de Fuca Canyon in 16 days. Both instances indicate a speed of one body
length per second. Some herring remain nearshore close to their spawning
grounds throughout the year. In the eastern Bering Sea, older herring may
move inshore first. In Southeast Alaska, however, adult herring do not
exhibit any correlation between the timing of spawning and the age of the
fish, although males have been reported arriving on the spawning grounds
prior to females. The herring's shore-spawning behavior may be due to the
low temperatures prevailing in deeper water. Spawning may last from a few
days to several weeks. Environmental or physical stimuli such as storms and
crowding may cause a few males to extrude milt, triggering a spawning
reaction by the entire herring school. It is unclear whether males or
females initiate spawning, although there is some evidence to indicate that
males start spawning activity before females and that females respond only
to the presence of milt. The texture and surface properties of the
vegetation are tested by the fish prior to spawning, and the sediment on
the substrate may inhibit spawning. In the presence of suitable substrate,
the fish rise to the surface and mill about, extending their genital
papillae. The herring then arch their backs and swim with short rapid body
movements against the substrate, making contact with their pectoral fins and
chins. Eggs or milt are extruded from the papillae, which also contact the
Life History - 6 (DRAFT) - Life History
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

substrate. The extrusion of eggs appears to be impeded unless the vent is
in contact with the substrate (eelgrass, kelp, rockweed, or other seaweed),
but eggs were found deposited in the water column. Females usually lay few
eggs in a single spawning act, but repetition of the act results in multiple
layers of eggs on the substrate. Eggs are fertilized by milt broadcast or
dissipated in the water by males *232*.

Age at Sexual Maturity: Sexual maturity of Alaskan herring varies by
geographic area, with some stocks entering the spawning population at age 2.
In the Gulf of Alaska and Bering Sea, most herring do not spawn until ages 3
and 4. By age 5, 95% of the populaton has matured. Herring may live up to
15 years in the Bering Sea. Though 15-year-old herring have been documented
in Southeast Alaska, herring appear to experience a heavy mortality after
age 7 *232*.

Fecundity: The number of eggs carried increases with increases in body
length and width. In some Atlantic herring population, egg size also
increases with fish size. Egg weights of recruit spawners were
significantly less than those of older, large, repeat spawners. In
comparisons of fecundity from different North American populations, a
decrease in fecundity at a particular body size was apparent with increasing
latitude. Herring of ages 4 to 8 in the Bering Sea produce 26.6 to 77.8
thousand eggs. The fecundity of herring from Bristol Bay ranged from 13.1
to 71.9 thousand eggs for herring ranging in size from 171 to 320 mm.
Fecundity for herring in southeast Alaska ranged from 14,000 to 36,000 eggs
for fish of standard lengths from 180 to 230 mm. More specifically,
fecundities of herring with standard lengths of 220 mm to 230 mm averaged
36,000 eggs; for standard lengths of 210 to 215 mm, fecundity averaged
24,000 eggs; for standard lengths of 200 to 205 mm, fecundity averaged
25,000 eggs; for lengths of 185 to 195 mm, fecundity averaged 23,000 eggs;
and for fish of about 180 mm in standard length, fecundity averaged 14,000
eggs *232*.

Frequency of Breeding: Pacific herring breed annually upon reaching
maturity *232*.

Incubation Period/Emergence: Eggs take 10 to 21 days to hatch, depending on
the water temperature. In Bristol Bay, at temperatures of 8 to 11 oC, 13 to
14 days are required for hatching. The optimum temperature reported for egg
development is from 5 to 9 oC. Newly hatched larvae are about 8 mm in size.
Larvae grow to 30 mm in 6 to 10 weeks and begin to metamorphose into
free-swimming juveniles *232*.

Movements Associated with Life Functions and Developmental Stages,
Juveniles: Larvae are at the mercy of water currents until they develop the
ability to swim. Larvae migrated downwards during the day and to the
surface at night, following their planktonic food supply. In British
Columbia, juveniles form schools that move out of bays as summer progresses
and they move from the spawning grounds to different rearing areas. In
British Columbia and Southeast Alaska, juveniles feed in coastal waters in
summer and move to deeper water in winter. Very little is known about
juvenile herring in the Bering Sea and other Alaskan waters *232*.

Life History - 7 (DRAFT) - Life History
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

Movements Associated with Life Functions and Developmental Stages, Adults:
Migrational patterns are specific to each area and population. Temperature
may have the greatest influence on seasonal distribution. Generally, mature
adult herring return to offshore feeding gounds after spawning inshore
during spring, and in August or September they move further offshore into
deeper water to overwinter. Tagging studies indicate that adult Pacific
herring return, or home, to approximately the same geographic spawning areas
each year. Some smaller herring populatons in British Columbia do not move
to offshore feeding grounds and are available throughout the year in the
same waters and later segregate as the spawning season approaches. The
migration of herring to wintering areas in Southeast Alaska coincided with
the breakdown of the thermocline in October. In the eastern Bering Sea,
populations that spawn in Bristol Bay and possibly in areas in the Kuskokwim
delta are believed to engage in a feeding migration south along the Alaska
Peninsual to the Unalaska Island area during May through August. THese fish
may then migrate along the ocntinental shelf to major wintering grounds
northwest of the Pribilof Islands. Migration from coastal waters to the
winter grounds occurs from mid August through September. Concentrations in
water from 2 to 4 oC on the overwintering grounds begins in October,
continuing into winter. Mature fish arrive at wintering areas before
immature herring. Concentrations of overwintering herring may shift
northwest in the Bering Sea in mild winters and southeast during severe
winters. Overwintering herring leave the wintering area for the spawning
grounds in late March. Prior to spawning, these large overwintering groups
of herring break apart, and the fish appear to travel closer to the spawning
grounds, where they may again hold for short periods of time before moving
into shallow areas. After spawning, adult herring remain in coastal waters
to feed. Concentrations of herring appear off Nunivak and Unimak islands
in the Bering Sea during August. Herring spawnings are restricted by depth,
temperature, substrate type, and other factors, such as high sediment loads
either in the water column or on the sea bottom *232*.

Natural Factors Influencing Populations, Egg Stage: Mortality of eggs of
British Columbia herring may reach 70 to 80% during incubation. Up to 80%
mortality has been obsrved in other areas in Alaska, such as Cape Romanzoff,
the major causes being wave actions, exposure to air, and bird predation.
Wave action can destroy both spawn and spawn substrates in intertidal areas.
Desiccation of eggs by high tidal fluctuation and low salinity caused by
freshwater runoff of melting snow and ice also contribute to mortality. Sea
birds have been documented as major predators of herring eggs in the
intertidal area. Predation by flatfish upon eggs has also been documented.
In Norton Sound, Bering cisco, saffron cod, sculpins, and snails (Littiorina
planaxis) were found to consume herring eggs. Egg survival decreases as the
layers of egg deposition increase and oxygen cannot reach the bottom layers.
The number of healthy larvae that will hatch from a deposition nine layers
thick will very likely be less than for eggs in the same area four layers
thick. Environmental stress during the egg stage also results in malformed
larvae and eventual death *232*.

Natural Factors Influencing Populations, Larval Stage: Mortality is high
for herring in the larval stage and may exceed 99%. It is possible that
year-class strength is determined at the larval stage. Proper sized food
items of adequate nutritional value must be available during the initial
Life History - 8 (DRAFT) - Life History
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

feeding of larvae to prevent starvation at the first stage of development.
Mortality of larvae may be attributed to environmental stress on the
organism during the egg stage, resulting in the hatching of incompletely
developed or malformed larvae that are not strong enough to cope with
predators or the environment. Changes in food supply as a result of
environmental conditions will also cause larval mortality. Predation upon
larvae is intense. Predators may include comb jellies, jellyfish, arrow
worms, small salmon, and amphipods. Cannibalism of adult herring upon larval
herring has been documented when older herring have been present on the
spawning grounds during the egg-hatch period *232*.

Natural Factors Influencing Populations, Adult Stage: The natural mortality
rate of adult herring is highly variable but averages about 30%. The
probability of mortality increases with age, particularly for males.
Mortality rates increase at age 5 as a consequence of senility, disease, and
spawning mortality. Increased mortality, selective for male herring with
age, is not characteristic for herring in Southeast Alaska. Mature herring
are most susceptible to predation by marine mammals, dogfish, and seabirds
on the spawning grounds and during migration to their offshore feeding
grounds. Herring are a very important staple in food webs, and in the
Bering Sea they serve as a dietary staple for marine mammals, birds, salmon,
and groundfish. Predation upon herring by northern pike captured in Hotham
Inlet in Kotzebue Sound has been documented. Herring have been found to be
a major food item for sheefish in northern Kotzebue Sound during November.
Natural mortality of herring through all life stages in the Bering Sea has
been estimated to be 47% and in Southeast Alaska, about 40% *232*.

Human-related Factors Influencing Populations: A summary of possible
impacts on herring abundance and distribution from human-related activities
includes the following: alteration of preferred water temperature, pH,
dissovled oxygen, and chemical composition; alteration of preferred spawning
substrate; alteration of intertidal areas; increase in suspended organic or
mineral material; reduction in food supply; reduction in spawn substrate
(e.g., seaweed beds); obstruction of migration routes; shock waves from
explosions in the aquatic environment; and human harvest *232*.

LIFE HISTORY CODES -
Periodicity: Active in day
Average Number of Offspring/Reproductive Effort: Grea
Dispersion: Clumped
Periodicity: Most active in early summer
Periodicity: Most active in late summer
Breeding/Spawning Season: March
Breeding Spawning Season: April
Breeding/Spawning Season: May
Breeding/Spawning Season: June
Breeding/Spawning Season: July
Breeding/Spawning Season: August
Spawning Site: Rocks
Spawning Site: Aquatic Vegetation
Average Number of Offspring/Reproductive Effort: Grea
Number of Broods/Litters (Reproductive Efforts) Per Ye
Gestation/Incubation Period: 1-2 weeks
Life History - 9 (DRAFT) - Life History
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

LIFE HISTORY CODES -
Gestation/Incubation Period: 3-4 weeks

COMMENTS ON LIFE HISTORY -
Eggs are adhesive after fertilization and attach to benthic substrates.
Larvae, juveniles, and adults are schooling, pelagic, and nektonic.*253*

REFERENCES FOR LIFE HISTORY- 4 and 232

Life History - 10 (DRAFT) - Management Practices
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

MANAGEMENT PRACTICES

RESULT MANAGEMENT PRACTICE

Existing Regulating harvest of species being described
Beneficial Developing/maintaining suitable pH
Beneficial Maintaining natural vegetation [native]
Adverse Migration barriers
Adverse Underwater explosions
Beneficial Regulating harvest of species being described
Adverse Other management practices [specified in comments]
Beneficial Other management practices [specified in comments]

REFERENCES FOR BENEFICIAL MANAGEMENT PRACTICES - 232

REFERENCES FOR ADVERSE MANAGEMENT PRACTICES - 232

REFERENCES FOR EXISTING MANAGEMENT PRACTICES - 4

COMMENTS ON MANAGEMENT PRACTICES -
In the Pacific Southwest, herring spawn primarily in bays and estuaries, and
are sensitive to changes in habitat induced by man.*4*

To prevent the overfishing of California's herring stocks, the State
establishes quotas each year. Although there is not good evidence that
separate stocks exist in California, herring at each major spawning area are
managed separately. Each year the California Department of Fish and Game
conducts spawning surveys in San Francisco and Tomales Bays. The total
number of eggs spawned during the season is estimated, and the biomass of
adult spawning herring is estimated on the basis of average fecundity.
These estimates are then used to establish harvest quotas for the following
season. Researchers calculated that Pacific herring can sustain an
exploitation rate of about 30%. Researchers recommended, however, that
herring fishery managers opt for a conservative harvesting policy. The
California Department of Fish and Game sets quotas to harvet about 15%-16%
of the spawning population. The 1985-86 quotas were 6,800 mt for San
Francisco Bay, 900 mt for Tomales Bay, 54 mt for Humboldt Bay, and 27 mt for
Crescent City. The San Francisco Bay fishery involves about 390 gill net
permittees and 40 round haul vessles fishing purse or lampara seines. To
distribute the catch gill-netters are divided into 3 groups of about 130
Management Practices - 1 (DRAFT) - Management Practices
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

boats each and each group has a harvest quota; seiners have individual
quotas. For 1985-86 round haul vesseles were allotted 54 mt each and
gill-netters 1,437-1,526 mt each, depending on which period or day of the
season they fished.

In San Francisco Bay the commercial harvest of herring eggs on seaweed is
set at a quota of 4.5 mt (the total weight of the seaweed with eggs
attached). The divers who harvest the eggs on seaweed usually do not
attain this quota. Pacific herring taken in a small round haul summer
fishery in Monterey Bay are processed primarily for animal food.

The possession limit is 23 kg for sport-caught herring and 11 kg for eggs on
seaweed.*4*

Pollutants. Estuaries, by their nature, are subject to the introduction of
many kinds of pollutants. Eggs and larvae are usually the life stages of
fish most sensitive to pollutants. Researchers found that sublethal
exposure to benzene, an aromatic component of crude oil, modified the
metabolic processes of Pacific herring embryos and larvae. Researchers
reported that herring embryo mortalities were singnificant after 180-hour
exposures to a copper concentration of 35 ug/l. A survey of six municipal
waste discharges along the southern California coast revealed concentrations
of copper ranging from 74 to 13,900 ug/l.*4*

Management Practices - 2 (DRAFT) - References
Species herring, Pacific
Species Id M010012
Date 27 AUG 96

References

4* Barnhart, R. 1988. Species Profiles: Life Histories and
Environmental Requirements of Coastal Fishes and Invertebrates
(Pacific Southwest)--Pacific Herring. U.S. Fish and Wildlife
Service Biol. Rep. 82(11.79) pp 14.

209 * Grosse, D. and D. Hay. 1988. Species Synopses: Life Histories of
Selected Fish and Shellfish of the Northeast Pacific and Bering
Sea. Wilimovsky, N. J., L. S. Incze, S. J. Westrheim (eds.).
University of Washington:8311.

232 * State of Alaska Department of Fish, and Game. 1986. Alaska
Habitat Management Guide: Life Histories and Habitat
Requirements of Fish and Wildlife. (ed.). Alaska Department of
Fish and Game Juneau, Alaska:763.

References - 1