(DRAFT) - Taxonomy
Species cisco, least
Species Id M010059
Date 27 AUG 96
TAXONOMY
NAME - cisco, least
OTHER COMMON NAMES - lake herring
ELEMENT CODE -
CATEGORY - Fish
PHYLUM AND SUBPHYLUM - ,
CLASS AND SUBCLASS - ,
ORDER AND SUBORDER - ,
FAMILY AND SUBFAMILY - Salmonidae, Coregoninae
GENUS AND SUBGENUS - Coregonus,
SPECIES AND SSP - sardinella,
SCIENTIFIC NAME - Coregonus sardinella
AUTHORITY - Valenciennes
TAXONOMY REFERENCES - 232
COMMENTS ON TAXONOMY -
Common names include least cisco and lake herring *232*.
The least cisco is a member of the family Salmonidae, subfamily Coregoninae,
the whitefishes. Whitefishes are common throughout the north, inhabiting
both lakes and rivers, and some species exhibit anadromous characteristics.
There are many species of whitefish and cisco recognized, but because of
extensive intraspecific variation and interspecific similarities the
taxonomic structure of this group of fishes has changed often. The least
cisco Coregonus sardinella is known to occur in several forms with uncertain
relationships and has been referred to as a "species complex." Various
distribution and local population characteristics have contributed to
changes in classification of least cisco in past years *232*.
Taxonomy - 1 (DRAFT) - Status
Species cisco, least
Species Id M010059
Date 27 AUG 96
STATUS
Coded Status
Migrant
Commercial/consumption
Subsistence
Sport Fish
See Comments
REFERENCES FOR STATUS - 232
COMMENTS ON STATUS -
THe Board of Fisheries develops regulations governing the harvest of least
cisco throughout its freshwater and coastal marine range. Because only
localized harvesting by commercial, subsistence, and sport fishermen occurs,
no statewide management plan has been formulated *232*.
Status - 1 (DRAFT) - Distribution
Species cisco, least
Species Id M010059
Date 27 AUG 96
DISTRIBUTION
Distribution - 1 HABITAT ASSOCIATIONS
HABITAT - MARINE
AQUATIC
REFERENCES FOR HABITAT - 232
LAND USE -
Water
Streams and Canals
Lakes
REFERENCES FOR LAND USE - 232
NATIONAL WETLAND INVENTORY CODES
NWI NWICLS NWIMOD NWISPEC
Marine
Riverine
Lacustrine
REFERENCES FOR NWI - 232
COMMENTS ON HABITAT ASSOCIATIONS -
The least cisco is a resident of many inland water throughout Interior
Alaska and is anadromous in streams and rivers draining into the Bering,
Chukchi, and Beaufort seas. Least cisco are present in most streams and
lakes north of the Alaska Range and in the nearshore zone of the marine
coastal environment. Anadromous least cisco inhabit brackish waters
throughout the summer. In fall, least cisco migrate back into freshwater
rivers and lakes to spawn and overwinter. Least cisco inhabit a wide
varietyy of habitats: shallow, slow-moving lakes and sloughs; large, deep,
fast-moving rivers; and shallow tributary streams. Migratory forms of least
cisco spend the winter in freshwater rivers and river deltas and the summer
and early fall in coastal regions immediately adjacent to the shoreline.
Least cisco have been found abundant in the nearshore brackish-water zone
*232*.
ANIMAL/PLANT SPECIES ASSOCIATIONS -
Pike
Burbot
Lake trout
Sheefish
REFERENCES FOR SPECIES ASSOCIATIONS - 232
COMMENTS ON SPECIES ASSOCIATIONS -
Predation presumably has some influence on least cisco populations.
Anadromous fish species use the nearshore coastal marine zone because there
is low predator density in that environment. Freshwater predators of least
cisco include pike, burbot, lake trout, and sheefish. Eggs and young least
cisco are very improtant in the diets of these predators *232*
Habitat Associations - 1 (DRAFT) - Food Habits
Species cisco, least
Species Id M010059
Date 27 AUG 96
FOOD HABITS
TROPHIC LEVEL -
CARNIVORE
REFERENCES FOR TROPHIC LEVEL - 232
LIFESTAGE FOOD FOOD PART
General Invertebrate Cordates Not Specified
General Crustaceans Not Specified
General Copepods Not Specified
General Branchiopods Not Specified
General Malacostraca Not Specified
General Osteichthyes Not Specified
General Perciformes Not Specified
General Gasterosteiformes Not Specified
General Insects Not Specified
General Plecoptra Juvenile stage
General Plecoptra Adult stage
General Hemiptera Adult stage
General Insects: aquatic Not Specified
General Insects:terrestrial Not Specified
General See Comments; Food See Comments
REFERENCES FOR GENERAL FOOD - 232
COMMENTS ON FOOD -
Least cisco are generalists in their food habits. They consume a wide
variety of the secondary producers (invertebrates) in both marine and
freshwater environments. Composition of food items is largely dependent
upon the specific location at which least cisco species are sampled.
Primary food items recorded are various species of copepods, cladocerans,
mysiids, amphipods, and isopods; some fish (fourhorn sculpin and nine-spine
stickleback); and some surface-dwelling insects (Plecoptera nymphs and
adults, hemiptera adults) *232*.
Types of Feeding Areas Used: Least cisco are primarily planktonic feeders,
utilizing the mid-water column in lakes, sloughs, and coastal marine waters.
Populations of least cisco that inhabit rivers apparently feed also on
aquatic and terrestrial insects *232*.
Factors Limiting Availability of Food: Availability of food is undoubtedly
related to seasonal abundance in marine coastal regions in the arctic and in
coldwater rivers and lakes throughout the Arctic, Western, and Interior
regions in Alaska. In arctic habitats, there is no productivity throughout
most of the year, and an outburst of exceedingly high productivity occurs in
the short summer season. Similarly, productivity in winter in the inland
freshwater environments is much reduced because of cold temperatures,
icecover, and reduced light availability. However, least cisco captured in
winter have been known to be feeding *232*.
Food Habits - 1 (DRAFT) - Environment Associations
Species cisco, least
Species Id M010059
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
G Coastal Features: Specified in Comments
G Dissolved Oxygen: High [greater than 7 mg/l] oxygen concentrations
G Dissolved Oxygen: Specified in Comments
G Turbidity: Specified in Comments
G
G
G
G
G
G
G
G Aquatic Features: Specified in Comments
G Water Velocity [Instream Flow Group Increments]: Specified in Comments
G Flow: Specified in Comments
G Water Depth Preference: Specified in Comments
BA Water Depth Preference: 1-5 ft.
BA Water Depth Preference: 5-10 ft.
BA Water Depth Preference: Specified in Comments
BA Water Velocity [Instream Flow Group Increments]: Specified in Comments
G Water Temperature: Below 15 degrees C
G Water Temperature: Specified in Comments
BA Water Temperature: Below 15 degrees C
BA Water Temperature: Specified in Comments
BA Bottom Type [Aquatic]: Sand
BA Bottom Type [Aquatic]: Gravel
BA Bottom Type [Aquatic]: Specified in Comments
E Bottom Type [Aquatic]: Sand
E Bottom Type [Aquatic]: Gravel
E Bottom Type [Aquatic]: Specified in Comments
E Water Depth Preference: Specified in Comments
REFERENCES FOR ENVIRONMENTAL ASSOC_ - 232
REFERENCES FOR BREEDING ADULT ENVIRONMENTAL ASSOC_ - 232
REFERENCES FOR EGG ENVIRONMENTAL ASSOC_ - 232
COMMENTS ON ENVIRONMENTAL ASSOCIATIONS -
Dissolved oxygen (DO) and pH: An average DO level of 9.8 ml/l during the
Environment Associations - 1 (DRAFT) - Environment Associations
Species cisco, least
Species Id M010059
Date 27 AUG 96
open-water period in Simpson Lagoon, Beaufort Sea (range - 7.0 to 12.0
ml/l) was reported. Least cisco were widely distributed and abundant in
this area. No other exists on the DO and pH requirements of least cisco
*232*.
Turbidity: Little information is available on the turbidity requirements
of least cisco. A study defined a narrow band of water immediately
adjacent to the shoreline in the Beaufort Sea where wind-generated
turbidity fluctuated widely from day to day (1-146 NTU, recorded 80 m from
shore). This band of coastal water was inhabitated throughout the summer
by anadromous fishes, of which least cisco was one of the most abundant
species *232*.
Salinity: Anadromous least cisco inhabit brackish waters throughout the
summer, at which time they make extensive migrations along the coast (at
least 100 mi distance). A study measured salinities in Simpson Lagoon,
Beaufort Sea, during the open-water period, in which anadroumous least
cisco are present. Salinities ranged from nearly fresh to saline. In late
June and early July, melting ice and river flooding caused low salinities
(1-10 ppt) in the lagoon. Between mid July and September brackish
conditions existed (18-25 ppt). In fall, least cisco migrated back into
freshwater rivers and lakes to spawn and overwinter. Presumably, their
coastal environment becomes uninhabitable in winter because of thick
nearhsore ice and hypersaline conditions, which are common in winter. A
high abundance of least cisco has been reported in the Imuruk Basin -
Grantly Harbor - Port Clarence area. Salinity values there ranged from 23
ppt in Grantly Harbor and 29 ppt in Port Clarence to 3.8 ppt in the upper
Imuruk Basin *232*.
Water Velocity and Depth: Least cisco inhabit a wide variety of habitats:
shallow, slow-moving lakes and sloughs; large, deep, fast-moving rivers;
and shallow tributary streams. Migratory forms of least cisco spend the
winter in freshwater rivers and river deltas and the summer and early fall
in coastal regions immediately adfacent to the shoreline. On the Beaufort
Sea coast, least cisco were found abundant in the nearshore brackish-water
zone. The depth of this zone fluctuated widely with freshwater input,
nearshore currents, prevailing winds, and topographic features. In the
Chatanika River, near Fairbanks, least cisco spawning sites have been
defined. Water depths range between 1.3 and 2.6 m at these sites, and the
average velocity is about .5 m/s. Water depth and stream velocity appeared
to be important for spawning, because males and females move toward the
surface, perpendicular to the current, while the eggs are released and
fertilized. In connection with building roads and culverts along the gas
pipeline route, the critical velocitites of 17 species of fish in the
Mackenzie River was studied. It determined that flow rates in culverts
(100 m long) should be kept below .3 to .4 m/s to allow successful passage
of the majority of mature individuals of migratory species *232*.
Water temperature: Least cisco are apparently tolerant of a wide range of
temperatures. July temperatures of 12 to 13 oC has been reported in
shallow, slow-moving waters of the Imuruk Basin area. A study reported
temperatures of 0 to 6 oC during the spring and fall and 7 to 10 oC during
the summer in Simpson Lagoon on the arctic coast. The nearshore
Environment Associations - 2 (DRAFT) - Environment Associations
Species cisco, least
Species Id M010059
Date 27 AUG 96
distribution of anadromous fishes is attributed to an association with the
band of relatively warm and brackish water that flows along the Beaufort
Sea coast. The habits of feeding during summer in the sea and moving up
rivers and into lakes for the winter might be an arctic adaptation to
escape the low winter temepratures (below 0 oC) in sea water yet also take
advantage of higher food abundance in coastal waters during the short
arctic summer *232*.
Substrate: Little is known about substrate requirements for least cisco.
Adults are known to spawn over sand and gravel bottoms in shallow areas of
lakes and streams *232*..
COMMENTS ON BREEDING ADULT ENVIRONMENTAL ASSOC_ -
In the Chatanika River, near Fairbanks, least cisco spawning sites have
been defined. Water depths range between 1.3 and 2.6 m at these sites, and
the average velocity is about .5 m/s. Water depth and stream velocity
appeared to be important for spawning, because males and females move
toward the surface, perpendicular to the current, while the eggs are
released and fertilized *232*.
Adults are known to spawn over sand and gravel bottoms in shallow areas of
lakes and streams. They have been found spawning over a gravel bottom in
the upper Innoko River in 4 to 8 ft of water. Surface temperatures of 0
to 3 oC have been reported during the spawning period *232*.
COMMENTS ON EGG ENVIRONMENTAL ASSOC_ -
Eggs are simply scattered over the sand and gravel bottoms in shallow areas
of lakes and streams *232*.
Environment Associations - 3 (DRAFT) - Life History
Species cisco, least
Species Id M010059
Date 27 AUG 96
LIFE HISTORY
Reproductive Habitat: Least cisco spawn in freshwater rivers, river deltas,
tributary streams, and lakes. Adults spawn over sand and gravel bottoms in
shallow areas *232*.
Reproductive Seasonality: Least cisco spawn in the fall, as is
characteristic of many coregonids. Some variation in spawning time occurs
between geographically isolated populations, but spawning typically takes
place in late September and October. In the Chatanika River near Fairbands,
the peak spawning period was the last week of September *232*.
Reproductive Behavior: During the upstream spawning migration, least cisco
generally move at night and rest in quiet pools during daylight hours. They
migrate in small groups. Observations of least cisco in the Chatanika River
revealed that least cisco spawn at night, with most spawning activity
occurring from 10 PM to midnight. A study has observed least cisco actively
spawning at 1 PM in the Innoko River, a tributary of the Yukon River. During
spawning, a female swims almost vertically toward the surface, with her
ventral side upstream. As many as five males may join her (but usually only
one or two) and swim vertically and close to her. As they approach the
surface, eggs and milt are released. The fish break the surface, fall over
backward, and swim to the bottom of the pool. It is not known whether a
female deposits all her eggs in one night or whether more nights are
required *232*.
Age at Sexual Maturity: Age at sexual maturity apparently varies among
different geographically isolated populations of least cisco, as well as
among different life history types of least cisco that occur sympatically.
In the Minto flats area, Interior Alaska, some least cisco males mature at
two years and most mature by three years of age; some females mature at
three years, but most mature at four years. On the Colville River, in the
Arctic Region, individual least cisco mature at four years, whereas the
majority were mature at five years. In the Yukon Territory, North Slope,
and eastern MacKenzie River delta drainages, differences in age at sexual
maturity were found between sympatric "dwarf" and "normal" populations of
least cisco. Dwarf individuals matured at three to four years, and 100% of
the normal individuals were mature at seven years (freshwater population)
and eight years (anadromous population) *232*.
Frequency of Breeding: Information regarding frequency of breeding in least
cisco populations is inconsistent. Isolated geographic populations vary in
behavior and life functions because of the different environmental
conditions present. A study examined least cisco ovaries from specimens
captured during July and August in the Minto flats area. The presence of
retained eggs plus those that could develop fully by mid September indicated
that all individuals sampled were consecutive spawners. In Trout Lake,
Yukon Territory, least cisco spawn consecutively after reaching maturity.
In contrast, alternate-year spawning of least cisco has been reproted in
localized populations: MacKenzie River delta, Prudhoe Bay, and Colville
River delta. A great deal of subjectivity may be inherent in the methods
used to determine mature spawners (i.e., eggs have the potential to ripen
for the upcoming spawning season) and mature nonspawners (eggs are in
Life History - 1 (DRAFT) - Life History
Species cisco, least
Species Id M010059
Date 27 AUG 96
resting stage) *232*.
Fecundity: Fecundity in least cisco is more closely correlated with age
than with length. In samples (from the Chatanika River) of individual least
cisco ranging from 2+ to 7+ years, fecundity ranged from 27,825 to 93,500
eggs. Fecundity varies greatly between local populations of least cisco in
the Yukon Territory's north slope and the eastern Mackenzie River delta
drainages. In sympatric "normal" and "dwarf" populations, fecundity of
normal least cisco exceeded that of dwarf least cisco by nearly 30 times.
Fecundity of normal, nonmigratory populations in Trout Lake, Yukon
Territory, ranged from 7,886 to 19,261 eggs. The dwarf populations from the
same lake had a lower fecundity, ranging from 223 to 1,080 eggs. Egg
diameter at time of spawning for normal individuals was consistently 1.5 mm.
Egg diameter for dwarf individuals at time of spawning exceeded that for
normal individuals by an average of 0.3 mm diameter *232*.
Incubation Period/Emergence: Eggs are demersal and lodge in crevices
between gravel where they incubate and overwinter (late September to late
May or early June). In Siberia, larvae of the migratory forms move
downstream toward the sea soon after hatching. Young-of-the-year least
cisco undertake a slow downstream migration to rearing areas in slower,
deeper waters of the lower Yukon River *232*.
Movements Associated with Life Functions: Least cisco are characterized by
several life history types. Three types defined are: anadromous,
freshwater migratory, and freshwater nonmigratory. Anadromous forms of
least cisco generally spend the summer months feeding in the nearshore
coastal marine zone and migrate into the lower reaches of coastal rivers and
river deltas in the fall. In the Beaufort Sea, this movement is associated
with the ice-free period; in Prudhoe Bay, e.g., ice-out generally occurs in
the first two weeks of June, and least cisco first appear during the first
week of July. Tagging studies indicate that the Colville River is the
freshwater source of these fish. Tagged individuals showed an eastward
movement through Simpson Lagoon, followed by a build-up in Prudhoe Bay from
breakup through mid August, and then a westward movement until freeze-up.
Similar findings have been found in the Mackenzie River delta population.
In September, the nearshore brackish water zone freezes over, and least
cisco move into the freshwater deltas to spawn and overwinter. The presence
of shore-fast ice and hypersaline conditions prevent least cisco from
utilizing the marine environment until breakup occurs again in the spring.
Utilization of the more productive marine environment for feeding generally
fosters greater growth rates and greater maximum age in these migratory
least cisco than in the nonmigratory forms. A study defined a second
migratory form of least cisco that remains in fresh water rather than
migrating to sea. It concluded from seasonal sampling results that least
cisco migrated into Peter Lake, Yukon Territory, in September to spawn. This
population had direct access to the Mackenzie River delta and the Beaufort
Sea, but growth rates (similar to other lake resident populations) indicated
they resided in fresh water throughout the year. In the Innoko River, a
tributary of the lower Yukon River, least cisco begin an upstream migration
in late spring, or soon after ice-out. They move into lakes and sloughs to
feed along the migration route. This feeding migration is composed mainly of
mature fish, although immature individuals of ages 1 and 2 are present. In
Life History - 2 (DRAFT) - Life History
Species cisco, least
Species Id M010059
Date 27 AUG 96
late summer (August), the mature fish continue the upstream movement towards
spawning areas. After spawning occurs, they apparently move downstream again
to the Yukon River. It is not known whether this population is anadromous or
not. Similar movements were recorded in the Chatanika River near Fairbanks
*232*.
Natural Factors Influencing Populations: It is apparent that natural
environmental factors influence nearly all local populations of least cisco.
A significant amount of plasticity occurs in morphological characteristics
of whitefish genera because of coinhabitation of certain species. In least
cisco, tihs may be related to the sympatric "dwarf" and "normal"
populations. A jumbo spotted form of least cisco has been reported in lakes
of the southern Yukon Territory. A variety of natural factors that could
cause such distinct differentiation from other least cisco are: glacial
isolation, high levels of dissolved solids in the lakes, high lacustrine
productivity and summer temperatures, lack of significant competition, and
the migratory nature of the population. Predation presumably has some
influence on least cisco populations. Anadromous fish species may use the
nearshore coastal marine zone because there is a low predator density in
that environment. Freshwater predators of least cisco include pike, burbot,
lake trout, and sheefish. Eggs and young least cisco are very important in
the diets of these predators *232*.
Human-related Factors Influencing Populations: Anadromous least cisco would
potentially be vulnerable to disturbances from construction and/or oil
development in the nearshore marine zone during the summer feeding
migrations. The presence of a solid-fill causeway in the nearshore coastal
zone of the Beaufort Sea (Prudhoe Bay) has been shown to cause temperature
and salinity gradients that affect least cisco movements. In freshwater
streams, construction of roads, culverts, dams, etc., would create unnatural
barriers (either physical or due to water velocity) and possibly cause a
loss of spawning habitat. A summary of possible impacts from human-related
activities includes the following: alteration of preferred water
temperatures, pH, dissolved oxygen, and chemical composition; introduction
of water-soluble substrates; increase in suspended organic or mineral
material; increase in sedimentation; reduction in food supply; human
harvest; and seismic shock waves *232*.
Limitations of Information: Least cisco inhabit much of Interior Alaska in
the Yukon and Kuskokwim river drainages and coastal Alaska from Bristol Bay
through the Bering, Chukchi, and Beaufort seas. Because of the variations
in local populations, apparently caused by geographic isolation and
numerous natural environmental factors, it is difficult to generalize about
the life history characteristics of the species. Information on least cisco
is available primarily in areas where studies actually targetted on other
species. Thus, there is a general data gap for least cisco distribution and
abundance in many portions of its range, particularly uninhabited areas
and/or areas not yet proposed for development *232*.
LIFE HISTORY CODES -
Spawning Site: Gravel
Nest Materials: Sand
Nest Materials: Gravel
Life History - 3 (DRAFT) - Life History
Species cisco, least
Species Id M010059
Date 27 AUG 96
LIFE HISTORY CODES -
Breeding/Spawning Season: August
Breeding/Spawning Season: September
Breeding/Spawning Season: October
Periodicity: Active at night
Average Number of Offspring/Reproductive Effort: Grea
Average Number of Offspring/Reproductive Effort: 101-
Average Number of Offspring/Reproductive Effort: 1,00
REFERENCES FOR LIFE HISTORY- 232
Life History - 4 (DRAFT) - Management Practices
Species cisco, least
Species Id M010059
Date 27 AUG 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Beneficial Developing/maintaining suitable salinity
Beneficial Developing/maintaining suitable pH
Adverse Salinity alteration
Adverse Migration barriers
Adverse Construction of navigational improvements [dams, locks, etc.]
Adverse Locating/constructing roads
Beneficial Controlling sedimentation
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
COMMENTS ON MANAGEMENT PRACTICES -
Anadromous least cisco would potentially be vulnerable to disturbances from
construction and/or oil development in the nearshore marine zone during the
summer feeding migrations. The presence of a solid-fill causeway in the
nearshore coastal zone of the Beaufort Sea (Prudhoe Bay) has been shown to
cause temperature and salinity gradients that affect least cisco movements.
In freshwater streams, construction of roads, culverts, dams, etc., would
create unnatural barriers (either physical or due to water velocity) and
possibly cause a loss of spawning habitat. A summary of possible impacts
from human-related activities includes the following: alteration of
preferred water temperatures, pH, dissolved oxygen, and chemical
composition; introduction of water-soluble substrates; increase in suspended
organic or mineral material; increase in sedimentation; reduction in food
supply; human harvest; and seismic shock waves *232*.
Management Practices - 1 (DRAFT) - References
Species cisco, least
Species Id M010059
Date 27 AUG 96
References
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