FWS/OBS-82/10.58

SEPTEMBER 1983

HABITAT SUITABILITY INDEX MODELS:

ALEWIFE AND BLUEBACK HERRING

.

..-

SK

361

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n o. 82 -

10 .58

and Wildlife Service

Department of the Interior
This model is designed to be used by the Division of Ecological Services in

conjunction with the Habitat Evaluation Procedures.
FWS/OBS-82/10.58

September 1983

HABITAT SUITABILITY INDEX MODELS:

ALEWIFE AND BLUEBACK HERRING

by

Garland B. Pardue

Virginia Cooperative Fishery Research Unit

Department of Fisheries and Wildlife Sciences

Virginia Polytechnic Institute and State University

Blacksburg, VA 24061

Project Officer

Carroll L. Cordes

National Coastal Ecosystems Team

U.S. Fish and Wildlife Service

1010 Gause Boulevard

Slidell, LA 70458

Performed for

National Coastal Ecosystems Team

Division of Biological Services

Research and Development

Fish and Wildlife Service

U.S. Department of the Interior

Washington, DC 20240
This report should be cited as:

Pardue , G.B.

herring.

1983. Habitat suitability index models: alewife and blueback

U.S. Dept. Int. Fish Wildl. Servo FWSjOBS-82/l0.58. 22 pp.
PREFACE

The habitat suitability index (HSI) models for alewife and blueback

herring (collectively, river herring) in this report are intended for use in

impact assessment and habitat management. The model s were developed from a

review and synthesis of existing infonnation and are scaled to produce an

index of habitat suitability between 0 (unsuitable habitat) and 1 (optimally

suitable habitat). Assumptions used to transfonn habitat use infonnation into

the HSI models and guidelines for model application are described.

These models are hypotheses of species-~abitat relationships, not statements of proven cause and effect relationships. The models have been applied

to six sample data sets that are included. Users are encouraged to convey

comments and suggesti ons that may hel p increase the uti l i ty and effectiveness

of this habitat-based approach to fish and wildlife management. Please send

any comments or suggestions on the alewife and blueback herring HSI models to:

National Coastal Ecosystems Team

U.S. Fish and Wildlife Service

1010 Gause Boulevard

Slidell, LA 70458

iii

CONTENTS

PREFACE •••• ACKNOWLEDGMENTSiii

vi

Cover • • • • • • • • . • • • •

Water Quality and Depth

Special Considerations ••• HABITAT SUITABILITY INDEX (HSI) MODELS •••• t"1odel Appl icabil ity • • • • • •••• Model Descriptions. • •••••••••••• Spawni ng Adult, Egg, La rva1 t~odel • • • • ••• Juvenile Model •••••••••.•••••••••

Suitability Index (SI) Graphs for Habitat Variables

Component Index Equations • • • • • •••• HSI Determination ••• Field Use of Models

. . .

INTRODUCTION

Distribution ••••••• LHe Hi story Overvi ew • • •• SPECIFIC HABITAT REQUIREMENTS •• Food • • • • • • • • • •

. . . . . . . . . . .

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. . . .

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1

1

3

3

4

4

5

6

6

6

7

7

9

13

13

15

REFERENC ES . . . . . . . . . .

v

17
ACKN m~L EDG~1E NTS

Development of the habitat suitability index models and narratives for

river herring was monitored, expertly reviewed, and constructively criticized

by Dr. J.G. Loesch, Virginia Institute of Marine Science, Gloucester Point,

and r·1r. M.W. Street, North Carol ina Department of Natural Resources and Community Development, Division of Marine Fisheries, Morehead City.

Thorough evaluations of model structure and functional relationships were

provided by personnel of the U.S. Fish and Wildlife Service's National Coastal

Ecosystems Team and Western 'Energy and Land Use Team. Model and supportive

narrative reviews were provided by regional personnel of the U.S. Fish and

Wildlife Service. Funding for model development and publication was provided

by the U.S. Fish and Wildlife Service.

vi
ALEWIFE (Alosa pseudoharengus)

and

BLUEBACK HERRING (Alosa aestivalis)

INTRODUCTI ON

Alewives and blueback herring are anadromous clupeids found along the

Atlantic coast in marine, estuarine, and riverine habitats, depending upon

life stage. Bo th are important commercial species, used fresh or salted for

human consumption, and used as crab bait, fish meal (particularly in animal

food manufacturing), and fish oil. Alewife and blueback herring are marketed

collectively as "river herring," a term that will be used for both species in

this report. River herring play important ecological roles. In marine, estuarine, and riverine food webs, they occupy a level between zooplankton, their

principal food, and piscivores.

Distribution

Alewives range from Newfoundland (Winters et al . 1973) to South Carol ina

(Berry 1964). Blueback herring range from Nova Scotia (Scott and Crossman

1973) to the St. Johns River, Florida (Hildebrand 1963), and have established

populations in the St. Johns and St. Marys Rivers and minor populations in the

Nassau and Tomaka Rivers, Florida (Rulifson and Huish 1982).

Catch, records over a 16-year period (1963-78) provide some information on

the offshore distribution of river herring (Neves 1981). During summer and

autumn , all ca tches of both s peci es were confi ned to the regi on north of 40°

north latitude in three general areas: Nantucket Shoals, Georges Bank, and

the perimeter of the Gulf of Maine. Winter catches were between 40° and

43° north latitude, and spring catches were distributed throughout the continental shelf area between Cape Hatteras, North Carolina, and Nova Scotia.

Life History Overview

School s of river herring enter fresh- and bracki sh wa ter once a year to

spawn (Raney and Massman 1953). There is some evidence that they return to

natal rivers to spawn (Reed 1964; Joseph and Davi s 19G5j. Spawning periods

range from March through July, occurring later as one proceeds north (Hildebrand 1963; Loesch 1969; Smith 1971; Tyus 1974; Loesch and Lund 1977). Alewives generally spawn 3-4 weeks earlier than blueback herring in sympatric

areas, with peak spawning separated by 2-3 weeks (Jones et al. 1978).

Eggs of river herring are initially demersal and adhesive in still water

or pelagic in running water (Loesch and Lund 1977; Jones et ale 1978). After

water-hardening, all eggs become pelagic and lose their adhesive properties.

1
Yolk-sac larvae for both species ar~ approximately 2.5-5.0 mm (0.1-0.2 inches)

total length (TL) at hatching and average 5.1 mm (0.2 inches) at yol k-sac absorption (Mansueti 1962). Vol k-sac absorp t ton takes 2-3 days for blueback

herring and 2-5 days for alewives (r1ansueti 1962; Cianci 1969). Transformation to the juvenile stage is gradual, but generally c~nplete at approximately

20 mm (0.78 inches) TL, and individuals are usually fully scaled at 45 mm

(1.8 inches) TL (Hildebrand 1963; Norden 1967).

Juveniles may remain in the lower ends of r ive rs where spawning occurred

(Street et ale 1975). Some juveniles appear to move upstream in summer

(Warinner et ale 1969; Burbidge 1974) before migrating downstream in late

fall. Juvenile alewives were most abundant in surface waters through September before increasing in abundance at 4.6 m (15.1 f t ) and on the bottom in

September and October prior to emigration (Warinner et al , 1969). Juvenile

blueback herring densities remained high in and near surface waters throughout

their freshwater phase (Warinner et al. 1969; Burbidge 1974) and were not collected in bottom trawls (Warinner et ale 1969).

In most Atlantic coast populations, juvenile river herring emigrate from

freshwater-estuarine nursery areas between June and November of their first

year of life (Burbidge 1974; Kissil 1974; Richkus 1975; O'Neill 1980). By

this time alewives have attained a mean length of 44-113 mm (1.7-4.5 inches)

(Joseph and Davis 1965 [measured fork length]; Davis and Cheek 1966 [measured

fork length]; Marcy 1969 [measured total length]; Richkus 1975 [measured

standard length]) and blueback herring a mean length of 36-71 mm (1.4-2.8

inches) (Hildebrand and Schroeder 1928 [measured total length]; Burbidge 1974

[measured fork length]). Young-of-the-year alewives are reported to grow

somewhat faster in Chesapeake Bay than young blueback herring (Hildebrand and

Schroeder 1928); however, Davis and Cheek (1966) found similar growth rates in

North Carolina. Weaver (1975) documented growth rates ranging from 0.004 to

0.020 glday (0.0001 to 0.0007 oz/day) for juvenile alewives from the James

River, Virginia.

Little information is available on growth rates for river herring between

age 0+ and the time of first spawning. Age 1 alewives reached total lengths

of 66-224 mm (2.6-8.8 inches) while spring age 1 blueback herring ranged from

64 to 119 mm (2.5 to 4.7 inches) TL (Hildebrand and Schroeder 1928). Age 2

alewives and bluebacks in Albemarle Sound, North Carolina, reached 153 and

148 mm (6.0 and 5.8 inches) TL, respectively, and at Georges Bank, age 2 fish

of both species reached approximately 180 mm (7.1 inches) TL (Netzel and

Stanek 1966). Females of both species are slightly larger and heavier than

males of the same age (Cooper 1961; Netzel and Stanek 1966; Marcy 1969; Loesch

and Lund 1977).

Age at first spawning, percentage of repeat spawners, and longevity in

alewife populations fluctuate annually, but seem to increase slightly as one

proceeds north. Spawning populations of alewives have not been determined for

South Carolina, and consist primarily of 4- and 5-year-old fish in North

Carol ina (Sholar 1975, 1977; Street et ale 1975; Johnson et ale 1977; Fischer

1980; Hawkins 1980b; Rulifson and Huish 1982) except for a spawning population

of 3-year-old fish in Lake r~attaJnuskeet (Tyus 1971, 1974). Spawning alewife

populations are represented by ages 3-8 in Chesapeake Bay and the Connecticut

River (Joseph and Davi s 1965; ~1arcy 1969; Loesch and Lund 1977) and by ages

4-10 in Nova Scotia (O'Neill 1980). Percentage of alewife repeat spawners was

2
10%-45% for North Carol ina (Tyus 1974; Street et ale 1975; Sholar 1977), 61%

in Virginia (Joseph and Davis 1965), and 60% in Nova Scotia (O'Neill 1980).

No a1ewi ves 01 der than 9 years have been captu red in North Carol ina (Street

et ale 1975; Johnson et ale 1977), but 10-year-old fish have been recorded in

Nova Scotia (O'Ne-ill 1980). Generally, males dominate age groups 3-5 on the

spawning grounds, while females dominate age groups 7 and older.

Blueback herring vary more than alewives in age at first s pawn i nq ,

although, in general, maturation rates are similar for the two species (Joseph

and Davis 1965; Street et al. 1975; Loesch and Lund 1977; O'Neill 1980). Like

the longevity of the alewife, that of the blueback herring increases northerly

with ages up to 7 and 8 years in Florida and South Carolina, respectively

(Rulifson and Huish 1982),9 in North Carolina (Street et al. 1975), and 10 in

Nova Scotia (O'Neill 1980). Age group composition is dominated in the Southern States by 4-, 5-, and sometimes 6-year-old fish (Rulifson and Huish 1982)

and by age group 5 in Connecticut (Loesch and Lund 1977). Blueback herring

runs consisted of 80% repeat spawners in the Altamaha River, Georgia, 32%-52%

in North Carolina (Street et ale 1975; Johnson et ale 1977), 65% in Virginia

(Joseph and Davis 1965), 82% in Connecticut (Loesch and Lund 1977), and 75% in

Nova Scotia (OINeill 1980).

Fecundity estimates for alewives ranged from 60,000 to 100,000 eggs per

female in Chesapeake Bay (Foerster and Goodbred 1978); and 48,000 to 360,000

in Bride Lake, Connecticut (Kissil 1974). Estimates for Connecticut River

blueback herri ng ranged from 45,200 to 349,700 eggs per female (Loesch and

Lund 1977). Fecundity-to-age relationships for Georgia blueback herring were

not linear (Street 1969), and the relationship may be asymptotic for both species, with "fecundal senility" occurring in long-lived individuals (Street

1969; Loesch and Lund 1977).

SPECIFIC HABITAT REQUIREMENTS

River herri ng occupy di sti nct1y different habitats dependi ng upon 1i fe

stage and "time of year. Juvenile river herring are the dominant life stage

found in freshwater and estuarine habitats; adults enter freshwater only to

spawn. Specific habitat requirements are summarized for each life stage or

group of combined life stages.

Food

Adult. Food habits of adult river herring are poorly documented. Both

species are primarily size-selective zooplankton feeders, though fish eggs,

other eggs, insects and small fishes may be important foods in some areas or

for larger individuals (Bigelow and Schroeder 1953). They do not feed extensively during upstream spawning migrations (Bigelow and Schroeder 1953); but

while in the ocean, adults apparently migrate vertically following the diel

movements of zooplankton in the water column (Janssen and Brant 1981; Neves

1981).

Larva and Juvenile. Larvae (about 6 mm or 0.2 inches) begin feeding on

rel at i vely small cl adocerns and cope pods, addi ng 1a rger speci es as they grow

(Norden 1968; Nigro and Ney 1982). Young-of-the-year alewives in Hamilton

Reservoir, Rhode Island, consumed primarily Chironomidea (Dipteran midges) in

July, switching to cladocerans in August and September (Vigerstad and Cobb

3
1978). Young-of-the-year blueback herring in the James River, Virginia, consumed Bosmina spp , , copepod naupl ii, copepodi tes, and adul t copepods

(Eurvtemora affinis and Cyclops vernalis) most frequently (Burbidge 1974).

Electivity (Ivlev 1961) was strongest for adult copepods, neutral for Bosmina

s pp, and copepodites, and strongly negative for copepod naupl t i , Young-ofthe-year of both species were compared (Davis and Cheek 1966) in the Cape Fear

River, North Carolina. Blueback herring selected copepods and dipterian

larvae more frequently than did alewives; alewives consumed more ostracods,

insect eggs, and insect parts than did blueback herring. Crustacean eggs were

eaten equally by both species.

Cover

Adult (spawning). Alewives spawn in large rivers, small streams, and

ponds, including barrier beach ponds. Spawning substrates include gravel,

sand, detritus, and submerged vegetation with sluggish water flows and water

depths of 15 cm-3 m (5.9 inches-9.8 f t ) (Edsall 1964; t1ansueti and Hardy

1967). Blueback herring spawn in swift-flowing, deeper stretches of rivers

and streams with associated hard substrate (Sholar 1975; Loesch and Lund 1977)

and in slower-flowing tributaries and flooded low-lying areas adjacent to main

strc .ns with soft substrates and detritus (Street et al , 1975; Sholar 1975,

1977; Fischer 1980; Hawkins 1980a).

Water Quality and Depth

Adult. Spawning runs for river herring begin in spring and minimum

spawning temperatures are 10.5°C and 14°C (50.9° and 57.2°F) for alewives and

blueback herring, respectively (Cianci 1969; Loesch and Lund 1977). Both species cease spawning when water temperatures exceed 27°C (80.6°F) (Loesch 1969;

Edsal 1970). Alewife spawning runs occur in a chronological south-to-north

progression at water temperatures between 12° and 16°C (53.6° and 60.8°F)

(Bigelow and Schroeder 1953; Havey 1961; Thunberg 1971; Jones et al. 1978).

Blueback herring spawn at water temperatures between 17°-26°C (62.6°-78.8°F)

(Kuntz and Radcliffe 1917; Bigelow and Schroeder 1953; Hildebrand 1963; Sholar

1975, 1977; Hawkins 1980b).

Adult distributions of river herring are largely confined to depths less

than 100 m (328 f t ) at water temperatures between 2° and 1rC (35.6° and

62.6°F) (Neves 1981). They are wi del y distributed along the ~,1iddle Atlantic

Bight during spring, appear to move north to the Nantucket Shoals, Georges

Bank, and coastal Gulf of Maine areas during summer an~ early autumn, and then

return south to the mid-Atlantic coast in winter and early spring (Neves

1981). Catches of river herring off the North Carolina coast were in areas no

deeper than 38.4 m (126 f t ) ; most blueback herring were caught betwe-en 5.5 and

18.3 m (18 and 60 f t ) and most alewives between 20.1 and 36.6 m (66 and

120 f t) (Holland and Yelverton 1973; Street et al , 1973). River herring were

most often caught at bottom temperatures between 4° and 7°C (39.2° and 44.6°F)

(Neves 1981). Both species may exhibit seasonal movements in conjunction with

preferred i so therms or preferred prey isotherms (Call i ns 1952; Leggett and

Whitney 1972), but direct evidence is lacking (Richkus 1974).

I9..9.. Hatching times for fertilized alewife eggs vary with water temperature as follows: 2.1 days at 28.9°C (84°F) (Edsall 1970),3.7 days at 21.1°C

(lO°F) (Edsall 1970), 3.4-5 days at 10.00-12.0°C (50 0-53.6°F) (Cianci 1969),

4
6 days at 15.6°C (60.1°F) (Hildebrand 1963), and about 15 days at 7.2°C (45°F)

(Edsall 1970; Rulifson and Huish 1982). Fertilized blueback herring eggs

hatch in 80-94 hr at 20°-21°C (68°-69.8°F) (Morgan and Prince 1976), 36-38 hr

(Street and Adams 1969) and 50 hr at 22°C (71.6°F) (Bigelow and Schroeder

1953), and 55-58 hr at 22.2°-23.7°C (72°-74.7°C) (Cianci 1969; Rulifson and

Huish 1982). Typically, ha tchinq requires 38-60 hr for blueback herring

(Adams and Street 1969; Cianci 1969; Morgan and Prince 1976, 1977) and 80-

95 hr for alewives (Edsall 1970).

Hatching success of alewives is directly correlated with water temperatures (Kellogg 1982). Hatching was maximally successful at 20.8°C (69.4°F),

fell significantly at 26.7°-26.8°C (80.1°-80.2°F), and did not occur at 29.7°C

(85.5°F). Average time to median (middle) hatch varied inversely with temperature, ranging from 7.4 days at 12.7°C (54.9°F) to 3 days at 23.8°-23.9°C

(74.8°-75°F) and 26.7°-26.8°C (80.1°-80.2°F).

Fertilized river herring eggs are extremely tolerant of suspended sediments (Auld and Schubel 1978) and probably other environmental variables such

as flow rate and salinity.

Larva. Daily weight gains in young alewives were greatest at 26.4°C

(79.5°F) and their temperature preference was estimated at 26.3°C (79.3°F) in

thermal gradient tests (Kellogq 1982). Larvae in Chesapeake Bay apparently remain near or slightly downstream of presumed spawning areas and were collected

only in areas with salinities less than 12 parts per thousand (ppt ) (Dovel

1971). In Nova Scotian rivers, larvae are associated with relatively shallow

«2 m or <6.6 f t} , sandy, warm areas in and near areas of observed spawning

( 0 I Ne i 11 1980).

Juvenile. Juvenile river herring migration from freshwater-estuarine

nursery areas at age 0+ is a response to heavy rainfall, high water, and water

temperature decl ines (Cooper 1961; Ki ssel 1974; Burbidge 1974; Richkus 1975;

O'Neill 1980). During the winter they have been found in lower portions of

estuaries out to 8 km (5 mi ) offshore (near outer limit of influence of estuary on salinity-temperature) at temperatures between 4.5° and 6.5°C (40.1° and

43.7°F), and salinities from 29 to 32 ppt (Milstein 1981). River herring in

North Carolina sounds overwinter in the more brackish water areas during winter and disperse to the ocean the following May at adult spawning peaks

(Street et al. 1975). Fish about 80 mm (3.1 inches) fork length may enter the

ocean during the winter (Holland and Yelverton 1973).

Both species exhibit significant diel movements (Kernehan 1974; Lindenburg 1976), moving toward the bottom during the day and toward the surface at

night. Light intensity seems to be an important stimulant to these movemerrts :

(Warinner et al. 1969) as does temperature (Meldrim and Gift 1971; Brandt

1978; Brandt et al. 1980).

Special Considerations

Timing of reproduction for clupeids is believed to have evolved as a

mechanism to synchronize the occurrence of larval stages with the optimal

phase of the annual plankton production cycle (Blaxter et ale 1982).

Spawners, however, must depend on indirect signals like photoperiod and temperature to link the production cycle to spawning. Year-class failures,

5
therefore, may be a mismatch between plankton and larval production, but this

hypothesis has not been quantified. Spawners move from a marine environment

in response to temperature and light intensity during spring and early summer

into estuarine, riverine, and even pond and lake environments. During this

peri od , habi ta t constantl y changes and has not been quant ifi ed , The same

problem occurs during late summer and fall when juveniles move downstream into

lower estuarine areas in response to changes in temperature, water flow, light

intensity, precipitation, and water leveis.

Although adults and older juveniles are extremely tolerant of a wide

salinity range (0-28 ppt) (Chittenden 1972) and suspended sediments (up to

100 mg/l), envi ronmental pollutants and habi tat al terations such as dams and

stream channel izations are considered detrimental. They create unsuitable

habitat for river herring either through the effects of the contaminants and

habitat alterations themsel ves or by creati ng adverse oxygen and other water

quality conditions.

Mortal ity estimates as 'high as 70% have been reported for river herring

(Johnson et al , 1977). The greatest limits to populations of river herring

appear to be food availability, predation, and fishing mortality. Studies

relating various levels of each of these environmental factors to river herring abundance have not been conducted.

HABITAT SUITABILITY INDEX (HSI) MODELS

Model Applicability

These model s are designed to apply to river herring throughout their

range on the Atlantic coast from Newfoundland to Florida in riverine and/or

estuarine habi tats.

Season. The habitat suitability index (HSI) models are designed to apply

only during those seasons when habitats are used by river herring.

Minimum habitat area. Minimum habitat is defined as the minimum area of

contiguous suitable habitat required for a species to live and reproduce. No

minimum habitat size requirements for river herring have been identified in

the 1i tera ture.

Verification level. Two biological experts outside the U.S. Fish and

Wildlife Service reviewed and evaluated the river herring HSI models: Dr.

J.G. Loesch, Virginia Institute of ~larine Science, Gloucester Point; and Mr. ~1.W. Street, North Carol ina Department of Natural Resources and Community

Development, Oivision of Marine Fisheries, Morehead City. The models have not

been verified in the field, but are based upon infonnation documented in the

literature. Adjustments to the model may be required after adequate field

tests have been completed.

Mode1 Desc ri ptions

The HSI models provide an index between 0 (unsuitable habitat) and 1.0

(optimal habitat). Separate HSI models Here developed for two distinct life

stages of river herring. One stage invol ves the rel atively brief period of

6
spawning and development of eggs and larvae in riverine habitat. The second

stage involves an extended period when juveniles (less than 1 year of age) are

in riverine and/or estuarine environments. Two models were devel oped because

certain areas may be good for spawning but poor for juveniles, or poor for

spawning but good for juveniles.

No consideration was given to the marine phase of the river herring life

history since it is not a habitat where users would likely apply the river

herring models. Landlocked populations also have not been considered in the

two models for either species.

Figure 1 illustrates the relationship of habitat variables in riverineestuarine habitats to the HSI for the spawning adult, egg, and larval stages

and the juvenile stage.

Spawning Adult, Egg, Larval Model

The HSI model for spawn inq adults, eggs, and larvae is composed of two

life requisite components: cover and water quality. A food component is not

incl uded because spawning adul ts sel dom feed and both eggs and larvae have a

sel f-conta ined food source in the yol k and yol k sac.

Cover cOOlponent. Substrate characteristics (VI) and associated vegetation are assumed to be a measure of the ability of a habitat to provide cover

to spawning adult river herring and their eggs and larvae. The characteristics of substrate are influenced by long-tenn effects of flow. For example,

in areas of constant high flow, little vegetation or detritus accumulates; in

low flow areas, detritus and silt accumulate and vegetation occurs. Substrates with 75% silt or other soft materials containing detritus and vegetation, and sluggish water flows are considered optimal for river herring. Substrate type can be measured during any period of the year.

Water quality component. Water temperatures (V2) determine the time of

spawning by each species and also dictate duration of egg and larval development. Temperature extremes can tenninate spawning attempts or kill eggs and

larvae. Optimum spawning temperatures are assumed to be 15°-20°C (59°-68°F)

for alewives (V2a) and 20°-24°C (68.0 o-75.2°F) for blueback herring (V2b).

Temperatures should be measured in spring and early summer, depending on location, when adults would nonnally be spawning.

Juvenil e r~odel

The juvenil e river herring HSI model has food and wa ter qual ity 1ife

requisite components. No cover requirement for juveniles was indicated in the

literature. The model can be applied in riverine and estuarine habitats.

Food component. The number of zooplankton per liter (V3) is assumed

critical for survival and growth of juvenile river herring. Both alewives and

blueback herring are size-selective zooplankton feeders that move within the

water column in response to their prey. The identification of zooplankton

species is difficult under field conditions, but measuring their numbers is

easy. Habitat suitability is assu~ed to increase as the number of zooplankton

increases from a to an optimum of 100 or more individuals per liter. Adequate

numbers of zooplankton are assumed to provide the species conposition and

sizes needed by river herring.

7
Habitat variable Life reguisite Li fe stage Habitat

VI Substrate characteristics Cover

V2 ~1ean water temperature --- Water qual ity

Spawning adult

Egg ---Riverine HSI

Larva

OJ

V3 Number of zooplankton/liter Food

V4 ~1ean salinity

Wa ter quality

Vs ~1ean water temperature

Juvenile Riverine HSI

Estuarine

Figure 1. Relationship of habitat variables and life requisites to the habitat suitability index (HSI)

for river herring as spawning adults, eggs, and larvae or as juveniles.
IJater guality ccmponent. Salinity (V4) and temperature (V5) comprise the

water quality component of the juvenile model. River herring are tolerant of

high salinities, hut have preferences and are not normally found at salinities

greater than 5 ppt. For purposes of this model, sal inities of 5 ppt or less

are considered optimal, and sal inities grp.ater than 5 ppt are less than optimal. Juvenile al ewives were collected from areas with water temperatures up

to 25°C (77°F), hut they avoided higher temperatures. Optimal temperatures

for al ewives are considered to be between 15° and 20°C (59° and 68°F) (V5a).

All other temperatures are less than optimal. ,Juvenile blueback herring

tolerate higher temperatures than alewives and optimal temperatures are considered to be between 20° and 30°C (68° and 86°F) (V5b). All other temperatures are less than optimal. Water temperature is measured at the surface

during summer and ea~y fall.

Suitability Index (SI) Graphs for Habitat Variables

This section presents graphic representation of the various values of

habitat variables and habitat suitability for the alewife and blueback herring

in riverine (R) and estuarine (E) habitats. The suitability index (SI) values

are to be read directly from the graph. Optimal suitability for a habitat is

read as 1.0; 51 values less than 1.0 indicate the corresponding values of the

variable are less suitable for river herring. For those habitat variables

that differ between species, each is designated as "a" for alewife and "b" for

blueback herring. Components not labeled "a" or "b" are assumed identical for

bot h spe ci es•

Equations for ccmbining habitat variables into a composite HSI for riverine and estuarine habitats are presented in a following section. Data sources

and assumptions associated with documentation of the SI graphs are presented

in Table 1.

Habitat Variable Suitability Graph

rrIo

e .. . 0.2

1.0

0.0

0.4

0.6

)( 0.8

Q)

'0

C

-

2) 50% mu d or silt,

some sand and vegetation.

Dominant substrate

type for river herring

spawning.

1) 75% mud or sil t

or other soft

material >- containing ::

detri tus and vege- :0

tation. CD

:t:

::J

rn

R,E

3) 75% sand or other

hard material with

no vegetation.

1 2

Class

3

9
Table 1. Data sources and assumptions for river herring suitability indices.

Variable and source

VI Edsall 1964

Mansueti and Hardy 1967

Shol ar 1975

Street et al. 1975

Shol ar 1977

Fischer 1980

Hawkins 1980a

V2 Cianci 1969

Loesch 1969

Edsall 1970

Loesch and Lund 1977

V3 Bigelow and Schroeder 1953

Norden 1968

Burbidge 1974

Vigerstad and Cobb 1978

Nigro and Ney 1982

V4 Dovel 1971

Street et al. 1975

OINeill 1980

V5 Meldrim and Gift 1971

Brandt 1978

Brandt et al. 1980

Street (pers. conm. )

Assumption

The type of substrate over which river

herring spawn most frequently is

optimal.

Quantitative information on optimal spawning temperature for river herring

is lacking. t~an daily water temperatures during the spawning season of

15°-20°C (59°-68°F) and 20°-24°C

(68.0o-75.2°F) are assumed to be

optimal for alewives and blueback

herring, respectively.

One hundred or more zooplankton per

liter is an optimal food resource for

river herring.

Low sal inity waters are optimal for

juvenile river herring prior to fall

migrations.

Optimal temperatures for juvenile

river herring are those that result

in optimum growth.

10
Habi tat Variable Su itabi 1ity Graph

R,E V2a Mean daily water tem- 1.0

perature during spawning season (alewife).

)( 0.8

CD

"

;5 0.6

:5

'"

:c 0.4 as

·S0 0.2

0.0

5 10 15 20 25 30

°C

R,E V2b Mean daily water t em- 1.

perature during spawni ng season (blueback 0.8 herri ng)• )(

CD

"

;5 0.6

:=

'"

:c

as

=

0

0

12 16 20 24 28

°C'

R,E ~1ean number of zooplankton per liter.

)( o.

CD

"

.5

0.4 ..

:i

(0 0.2

o.o~-....-..-..,.-....-"...

o 25 50 75 100 125

Number/liter

11
Habitat Variable Suitability Graph

Mean salinity during spring or summer.

1.

)( 0.8

CD

"

.5 0.6

==:a 0.4

as

i 0

o 2 4 6 8 10 12 14

ppt

R,E Mean surface water

temperature (alewife).

)(

CD

"

.5

1.0.J-..........--t-p.-...........--.......

0.8

0.6

0.4

O~

20 30 40

°C

10

0.0...........,..--.---.-................

o

R,E VSb Mean surface water 1~0

temperature (blueback

herring). )( 0.8

CD

"

.5 0.6

>-

,g 0.4 as

:::J

(/) 0:.2

0.0

12 0 10 20 30 40

°C
Component Index Equations

The SI values for habitat variables must be combined into a canponent

index for each life requisite included in the models. Suqqes ted equations

follow:

Spawning adult, egg, and larval model.

Component

Cover (C)

Water Quality (WQ)

Juvenile model.

Component

Food (F)

Water Quality (WQ)

HSI Detenlli nati on

Equation

SI

V2(a or b)

Equation

(SI V x SIV )1/2

4 5(a or b)

A 1imiting factors approach is used to determine an HSI for the spawning

adult, egg, and larval (SAEL) stage and the juvenile (J) stage for alewife or

blueback herring. Similarly, when appropriate, an overall HSI for all life

stages combined may be determined by the limiting factors approach. The following steps must be taken to determine an HSI for any application.

i, Review the section on model applicability for validity of model use.

2. Identify the bounda ri es of the evaluation area and obtain data for

each model variable.

3. Determi ne the correspondt ng SI value for each measured variable and

the component indicies. .

4. Calculate the HSI as:

HSI(SAEL) = WQ or C, whichever is lower

HSI(J) = F or WQ, whichever is lower

HSI(SAEL + J) = HSI(SAEL) or HSI(J)' whichever is lower

Six sample data sets with suitability indices and overall HSI index

values derived from the models' equations are listed in Table 2. Three

13
Table 2. Calculation of suitability indices (S1) and life stage habitat suitability index (HSI) for three

alewife and three blueback herring data sets, using habitat variables (V), suitability indices (S1), and

model equations.

Al ewi fe Blueback herring

Model Data set 1 Data set 2 Data set 3 Data set 4 Data set 5 Data set 6

canponent Data SI Data SI Data SI Data SI Data SI Data SI

VI [1] 1.0 [2] 0.5 [3] 0.1 [1] 1.0 [2] 0.5 [3] 0.1

V2a 18°C 1.0 24°C 0.43 8°C 0

V

2b 22°C 1.0 18°C 0.67 2re 0

V3 100 1.0 50 0.5 25 0.25 100 1.0 50 0.5 25 0.25

V4 6 ppt 0.86 14 ppt a 20 ppt a 6 ppt 0.86 14 ppt 0 20 ppt 0 I-'

+:>

V5a 18°C 1.0 10°C 0.5 30°C a

V5b 18°C 0.8 lOoe 0 20°C 1.0

HSI (SAEL) 1.0 0.43 a 1.0 0.5 0

HSI (J) 0.93 0 0 0.83 0 0
hypothetical data sets are shown for the alewife and three are al so shown for

the blueback herring.

Field Use of Models

Because alewives and blueback herring have different habitat requirements, a habitat should be evaluated separately for each species. As a rule,

use the spawning adult, egg, and larval model in known spawning areas. Use

the juvenile model in areas where there is no spawning. The user may wish to

combine the life stages into an overall HSI for each species when all life

stages are known to be present.

The simplicity of the HSI model for either alewives or blueback herring

eliminates the need for extensive field sampling and all but the most basic of

collecting gear. Suggested techniques for measuring habitat variables are

provided in Table 3. This simplified version of the many biological and

physiochemical parameters that may affect alewife and blueback herring distribution and abundance necessitates careful measurement of the identified habitat variables used in this model. One-time measurements of variables are not

recommended because model reliability will depend, in part, upon having sufficient data.

Table 3. Suggested techniques for measuring variables "in riverine/estuarine

habitats for application in the alewife-blueback herring HSI models.

Habitat variable Techniquea

Substrate samples can be obtained with a coring

device such as an Ekman dredge or Ponar grab, and

visually examined for percent composition of the

various substrate materials. Rooted aquatic vegetation may be visually estimated.

Temperature can be measured with any of a variety of

thermometers at or near the surface to provide a

usable instantaneous value:

Zooplankton may be collected wi th a Kemmerer water

sampler, concentrated through a lO-micron mesh net,

subsampled and counted under a simple compound

micr 0 sc 0 pe•

Salinity can be determined by using a refractometer,

or a conductivity meter, or by titration.

aCollection and chemical methods can be found in American Publ ic Heal th Association (1976).

15
The model user is required to measure flow during the site visit. This

is easily done by measuring the average time required in repeated trial s

(minimum of 3) for an object to float past a known distance (usually 15 ITI or

49.2 ft). Simple calculations then provide surface flow in feet per second

(ft/sec). If the surface flow is between 0 and 1.0 ft/sec, conditions appear

suitable for spawning, egg, and larval development; and the user is instructed

to proceed with the model. If the surface flow is 0 or greater than 1 ft/sec,

the HSI = O. Surface flow is measured along the bank in that zone of depths

ranging from 15 cm to 3 m (6 inches to 10 f t}, where spawning usually occurs

during the spring season.

16
REFERENCES

Adams, J.G., and M.W. Street. 1969. Notes on the spawnlnq and embryological

development of blueback herring, Alosa aestavilis (Mitchill), in the

Altamaha River, Georgia. Ga. Game Fish. Comm., Coastal Fish. Off.

Contrib. Sere No. 16. 14 pp,

American Publ ic Heal th Association. 1976. Standard methods for the examination of water and wastewater. 14th ed. APHA, Washington, D.C. 1193 pp.

Auld, A.H., and J.R. Schubel. 1978. Effects of suspended sediment on fish

eggs and larvae: a laboratory assessment. Estuarine Coastal t4ar. Sci.

6:153-164.

Berry, F.H. 1964. Review and emendation of Family Clupeidae. Copeia 1964:

720-730.

Bigelow, H.B., and W.C. Schroeder. 1953. Fishes of the Gulf of Maine. U.S.

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Blaxter, J.H.S., F.S. Russell, and ~1. Yonge. 1982. Advances in marine

biology. Vol. 20. Academic Press, Inc., London. 398 pp.

Brandt, S.B. 1978. Thermal ecology and abundance of alewife (Alosa pseudoharengus) in Lake Michigan. Ph.D. Dissertation. University of Wisconsin, Madison. 226 pp.

Brandt, S.B., J.J. Magnuson, and L.B. Crowder. 1980. Thermal habitat partitioning by fishes in Lake Michigan. Can. J. Fish. Aquat. Sci. 37:1157-

1564.

Burbidge, R.G. 1974. Di stributi on, growth, sel ective feedi ng and energy

transformations of young-of-the-year blueback herring in the James River,

Virginia. Trans. Am. Fish. Soc. 103:297-311.

Carlander, K.D. 1969. Handbook of freshwater fishery biology. Vol. 1. Iowa

State University Press, Ames. 752 pp.

Chittenden, M.E. 1972. Salinity tolerance of young blueback herring. Trans.

Am. Fish. Soc. 101:123-125.

Cianci, J.t·1. 1969. Larval development of the alewife and the glut herring.

M.S. Thesis. University of Connecticut, Storrs. 62 pp.

Collins, G.B. 1952. Factors influencing the orientation of migrating

anadromous fishes. U.S. Fish Wildl. Servo Fish. Bull. No. 73:373-396.

17
Cooper, R.A. 1961. Early life history and spawning migration of the alewife,

Alosa pseudoharengus. M.S. Thesis. University of Rhode Island, Kingston. 58 pp,

Davis, J.R., and R.P. Cheek. 1966. Distribution, food habits, and growth of

young clupeids, Cape Fear River System, North Carolina. Proc. Annu.

Conf. Southeast. Assoc. Game Fish Comm. 20:250-260.

Dovel, W.L. 1971. Fish eggs and larvae of the upper Chesapeake Bay. Univ.

Md. Nat. Resour. Ins t , Spec. Rep. No.4. 71 pp,

Edsall, LA. 1964. Feeding by three species of fishes on the eggs of spawning alewives. Copeia 1964:226-227.

Edsall, T.A. 1970. The effect of temperature on the rate of development and

survival of alewife eggs and larvae. Trans. JIm. Fish. Soc. 99:376-380.

Fischer, C.A. 1980. Anadromous fisheries research program. Cape Fear River

system, phase II. Conpl , Rep. Proj. AFCS-15. N.C. Dep, Nat. Resour.

Comm. Develop., Div. Mar. Fish. 65 pp.

Foerster,- J.W., and S.L. Goodbred. 1978. Evidence for a resident alewife

population in the northern Chesapeake Bay. Estuarine Coastal Mar. Sci.

7:437-444.

Havey, K.A. 1961. Restoration of anadrrmous alewives at Long Pond, ~1aine.

Trans. Am. Fish. Soc. 90:281-286.

Hawkins, J.H. 1980a. Anadromous fisheries research program, Tar-Pamlico

River. Attachment Compl. Rep. Proj. AFCS-13. N.C. Dep. Nat. Resour.

Comm. Develop., Div. ~1ar. Fish. 26 pp,

Hawkins , J.H. 1980b. Investigation of anadromous fishes of the Neuse River,

, North Carolina. N.C. Dep. Nat. Resour. Comm. Develop., Div. Mar. Fish.

Spec. Sci. Rep. No. 34. 111 pp.

Heinrich, J.W. 1981. Culture, feeding, and growth of alewives hatched in the

laboratory. Prog. Fish-Cult. 43(1):3-7.

Hildebrand, S.F. 1963. Family Clupeidae. Pages 257-454 in Fishes of the

western North Atlantic. Mem. Sears Found. Mar. Res. 1(3):

Hildebrand, S.F., and W.C. Schroeder. 1928. Fishes of Chesapeake Bay. Bull.

U.S. Bur. Fish. 43:1-36Q.

Holland, B.F., Jr., and G.F. Yelverton. 1973. Distribution and biological

studies of anadromous fishes offshore North Carol ina. N.C. Dep. Nat.

Econ. Res. Spec. Sci. Rep. 24. 132 pp.

Ivlev, V.S. 1961. Experimental ecology of the feeding of fishes. Yale University Press, New Haven, Conn. 302 pp,

Janssen, J., and S.B. Brandt. 1980. Feeding ecology and vertical migration

of adult alewives in Lake r~ichigan. Can. J. Fish. Aquat. Sci. 37:

177-184.

18
Johnson, H.B., B.F. Holland, Jr., and S.G. Keefe.

research program, northern coastal area.

I~.C. Div. Mar. Fish. 137 pp,

1977. Anadromous fisheries

Compl. Rep. Proj. AFCS-11.

Jones, P.W., F.D. Martin, and J.D. Hardy, Jr.

the mid-Atlantic Bight: an atlas of the

Vol. I Acipenseridae through Ictalurida.

Servo Program. FWSjOBS-78j12. 366 pp.

1978. Development of fishes of

egg, 1a rva1 and juven i 1e stage.

U.S. Fish Wildl. Servo Biol.

Joseph, LB., and J. Davis. 1965. A prel iminary assessment of the river

herrtnq stocks of lower Chesapeake Bay, Va. Inst. Mar. Sci. Spec. Sci.

Rep. No. 51. 23 pp,

Kellogg, R.L. 1982. Temperature requirements for the survival and early

development of the anadromous alewife. Prog. Fish.-Cult. 44:63-73.

Kernehan, R.J. 1974. Early life history and seasonal, horizontal and

vertical distribution patterns of ichthyoplankton collected in the

Chesapeake and Delaware Canal in 1973. r~.s. Thesis. University of

r1assachusetts, Amherst.

Kissil, G.W. 1974. Spawning of the anadromous alewife, Alosa pseudoharengus,

in Bride Lake, Connecticut. Trans. Am. Fish. Soc. 103:312-317.

Kornegay, J.W. 1978. Comparison of aging methods for alewife and blueback

herring. N.C. Dep. Nat. Resour., Div. Mar. Fish. Spec. Sci. Rep. No. 30.

51 pp.

Kuntz, A., and L. Radcliffe. 1917. Notes on the embryology and larval

development of twelve teleostream fishes. Bull. U.S. Bur. Fish. 35:

1-134.

Leggett, W.C.G., and R.R. Whitney. 1972. Water temperature and the migration

of the American Shad. U.S. Natl. Mar. Fish. Servo Fish. Bull. No. 70.

670 pp,

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Alosa Q..seudoharengus (Wilson) in a shallow eutropic lake. Trans. Am.

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Loesch, J.G. 1969. A study of the blueback herring' in Connecticut waters.

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blueback herring. Trans. Am. Fish. Soc. 106:583-589.

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mediocris, with comments on its ecology in the estuary. Chesapeake Sci.

3:173-205.

Mansueti, R.J., and J.D. Hardy, Jr. 1967. Development of fishes of the

Chesapeake Bay region, an atlas of egg, larval, and juvenile stages,

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19
r~arcy, B.C., Jr. 1969. Age detennination from scales of A10sa pseudoharengus

and A10sa aestiva1is in Connecticut waters. Trans. Am. Fish. Soc. 98:

622-630.

~1e1drim, J.W., and J.J. Gift. 1971. Temperature preference, avoidance and

shock experiments with estuarine fishes. Ichthyol. Assoc. Bull. No.7.

75 pp,

Milstein, C.B. 1981. Abundance and distribution of juvenile A10sa species

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eggs and larvae. Chesapeake Bio1. Lab. Univ. Md. Cent. Environ. Estuarine Stud. Ut~CEES Ref. 76-116 CBL. 122 pp,

~10rgan, R.P., II, and R.D. Prince. 1977. Chlorine toxicity to eggs and larvae of five Chesapeake Bay fishes. Trans. Am. Fish. Soc. 106:380-385.

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Michigan. Proc. 11th Conf. Great Lakes Res.:103-110.

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the Parnunkey River, Vi rginia.

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1485-1497.

20
1975.

Campl.

Richkus, W.A. 1975. ~1igratory behavior and growth of juvenile anadrcrnous

alewives, Alosa pseudoharengus, in a Rhode Island drainage. Trans. Am.

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Fish. Canm., Mar. Fish. Div. Contrib. Sere No. 17. 15 pp.

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Anadromous fisheries research program, northern coastal region.

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Thunberg, B.E. 1971. Olfaction in parent stream selection by the alewife.

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North Carol ina. Ph.D. Dissertation. North Carol ina State University,

Ra1e i gh• 77 PP•

Tyus, H.M. 1974. Movements and spawning of anadromous alewives at Lake

Mattamuskeet, North Carolina. Trans. Am. Fish. Soc. 103:392-396.

Vigerstad, T.J., and J.S. Cobb. 1978. Effects of predation by sea-run juvenile alewives on the zooplankton canmunity at Hamilton Reservoir, Rhode

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21
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Weaver, J.E. 1975. Food selectivity, feeding chronology, and energy transfonnations of juvenile alewife (Alosa pseudoharengus) in the James River

near Hopewell, Virginia. Ph.D. Dissertation. University of Virginia,

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Res. Board Can. 30:860-861.

22
50272 -rot

REPORT DOCUMENTATION Il:.J1EPORT NO.

PAGE I FWSjOBS-82j10.58 4. Title and Subtitle

Habitat Suitability Index Models: Alewife and Blueback Herring

7. Author(s)

G. B. Pardue

9. Perlorming Organization Name and Address

U.S. Fish and Wildlife Service

Virginia Cooperative Fishery Research Unit

Department of Fisheries and Wildlife Sciences

Virginia Polytechnic Institute and State University

Blacksburg, VA 24061

12. Sponsoring Organization Name and Address

U.S. Fish and Wildlife Service

Division of Biological Services

National Coastal Ecosystems Team

1010 Gause Blvd., Slidell, LA 70458

13. Recipient's Accession No.

I 5. Report Date

I September 1983

6.

8. Performing Org,anization Rept. No.

10. Project/Task/Work Unit No,

11. Contract(C) or Grant(G) No.

(C)

(G)

113, Type of Report & Period Covered

14.

------------ --- - ._-------------/ ·16. Abstract (limit: 200 ....ords)

A review and synthesis of existing information were used to develop habitat models

for alewives (Alosa pseudoharengus) and blueback herring (Alosa aestivalis). The models

are scaled to produce an index of habitat suitability between 0 (unsuitable habitat)

and 1 (optimally suitable habitat) for riverine and estuarine areas of the Atlantic

oast. Habitat suitability indices are designed for use with habitat evaluation proedures previously developed by the U.S. Fish and Wildlife Service. Guidelines for

model applications and techniques for estimating model variables are described.

17. Document Analysis a. Descriptors

Mathematical models

Fishes

Estuaries

b. Identifiers/Open·Ended Term'

Habitat

Habitat Suitability Index

Al ewife

Alosa pseudoharengus

c. COSATI Field/Group

18, Availability Statement

Un 1imited

(See ANSI-L39.18)

Blueback herring

Alosa aestivalis

Impact assessment

Habitat management

19. Security Class (This Report)

20. Security Cia" (This Page)

Uncl ass ifi ed

I 21. No. of Pag es

I vi + 22 ! 22. Price I

OPlION"l FORM 272 (I. 77)

(Formerly NTIS---35)

De p a rt rne nt of Commerce
" -~

'''0 ...

Hawauan Islands C.

1;( Headq uarters. DIvISion of BIological

Services. Washington . DC

)( Eastern Energy and Land Use Team

t.eetown. WV

* National Coastal Ecosystems Team

Slidell LA

• WeSlern Energy and Land Use Team

Ft Collins CO

• Locauons of Regional otnces

REGION I

Regional Director

U.S. Fish and Wildlife Service

Lloyd Five Hundred Building, Suite 1692

500 N.E. Multnomah Street

Portland. Oregon 97232

REGION 4

Regional Director

U.S. Fish and Wildlife Service

Richard B. Ru sell Building

75 Spring Street, S.W.

Atlanta, Georgia 30303

I

J- - - - - - -

6/

,-- ~-

---.J

-,

• 1- - -

I

REGION 2

Regional Director

U.S. Fish and Wildlife Service

P.O. Box 1306

Albuquerque, ew Mexico S710J

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Regional Director

U.S. Fish and Wildlife Service

One Gateway Center

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Regional Director

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federal Building, Fort Snelling

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P.O. Box 25486

Denver Federal Center

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