NOAA Technical Report NMFS 14

Synopsis of Biolog·cal Oa a

on Shortnose Sturgeon,

Acipenser brevirostrum

LeSueur 1818

October 1984

212 RogI...,....

MIIoId. CT08480

203-783 4200

:1/ .mI.,m.l.gg¥I
NOAA TECHNICAL REPORTS NMFS

The major responsibilities of the National Marine Fisheries Service (NMFS) are to monitor and assess the abundance

and geographic distribution offishery resources. to understand and predict fluctuations in the quantity and distribution of

these resources, and toestablish levelsfor optimum use ofthe resources. NMFS is alsocharged with thedevelopment and implementation ofpolicies for manqing national fishing grounds, development and enforcement ofdomestic fisheriesregulations, surveillanceofforeign fishing offUnited States coutal waters, and thedevelopment andenforcement ofinternational

fishery agreements and policies. NMFS also assists the fishing industry through marketing service and economic analysis

programs. and mongage insurance and vessel construction subsidies. It collects. analyzes. and publishesstatisticson various

phases ofthe industry.

The NOAA Technical Repon NMFS series was established in 1983 to replace two subcategories of the Technical

Repons series: "Special ScientifIC Repon-Fisheries" and "Circular." The series contains the following types ofrepons:

ScientifIC investigations that document long-term continuing programs of NMFS. intensive scientific repons on studies of

restricted scope, papers on applied fishery problems. technical repons ofgeneral interest intended to aid conservation and

management, repons that review in considerable detail and at a high technical level cenain broad areas of research. and

technical papers originating in economics studies and from management investigations.

Copies ofNOAA Technical Repon NMFS are available free in limited numbersto governmental agencies, both Federal

and State. They are also available in exchange for otherscientific and technical publicationsin the marine sciences. Individual copies may be obtained from: Publications Services Branch (EIAl 13l, National Environmental Satellite, Data, and Information Service, National Oceanic and Atmospheric Administration, U.S. Depanment ofCommerce, 3300 Whitehaven

St., Washington, DC 20235.
NOAA Technical Report NMFS 14

Synopsis of Biological Data

on Shortnose Sturgeon,

Acipenser brevirostrum

LeSueur 1818

Michael J. Dadswell, Bruce D. Taubert,

Thomas S. Squiers, Donald Marchette,

and Jack Buckley

October 1984

FAO Fisheries Synopsis No. 140

U.S. DEPARTMENT OF COMMERCE

Malcolm Baldrige, Secretary

National Oceanic and Atmospheric Administration

John V. Byrne, Administrator

National Marine Fisheries Service

William G. Gordon, Assistant Administrator for Fisheries
The National Marine Fisherie3 Service (NMFS) does not approve, recommend or

endorse any propriety product or proprietary material mentioned in this publication.

No reference shall be made to NMFS, or to this publication furnished by NMFS, in

any advertising or sales promotion which would indicate or imply that NMFS

approves, recommends or endorses any proprietary product or proprietary material

mentioned herein, or which has as its purpose an intent to cause directly or indirectly the advertised product to be used or purchased because of this NMFS publication.
CONTENTS

Identity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I

1.1 Nomenclature................. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I

1.11 Valid Name. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I

1.12 Objective synonymy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I

1.2 Taxonomy........................................................................................ I

1.21 Affinities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I

1.22 Taxonomic status. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

*1.23 Subspecies

1.24 Standard common names, vernacular names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.3 Morphology....................................................................................... 3

1.31 External morphology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

*1.32 Cytomorphology

*1.33 Protein specificity

1.34 Internal morphology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2 Distribution........................................................................................... 4

2.1 Total area. 4

2.2 Differential distribution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.21 Spawn,larvae and juveniles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.22 Adults. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.3 Determinants of distribution changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.31 Temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.32 Current. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

*2.33 Waves

2.34 Depth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.35 Light. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.36 Turbidity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2.37 Substratum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

*2.38 Shelter

*2.39 Ice

*2.310 Dissolved gases

2.311 Dissolved (inorganic) solids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

*2.312 Pollutants

2.313 Vegetation................................................................................. II

2.314 Fauna..................................................................................... 11

2.4 Hybridization..................................................................................... 12

3 Bionomics and life history. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

3.1 Reproduction...................................................................................... 12

3.11 Sexuality. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

3.12 Maturity........................ 12

3.13 Mating...................................... 14

3.14 Fertilization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3.15 Gonads. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3.16 Spawning.................................................................................. 15

3.17 Spawn.................................................................................... 16

3.2 Preadult phase. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

3.21 Embryonic phase. . . .. .. .. . .. .. . . .. . .. . . . .. . . . . . . . .. 16

3.22 Larval phase.... . .. .. . . .. .. .. .. .. .. .. . .. .. .. . . . . . .. .. .. 16

3.23 Adolescent phase. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

3.3 Adult phase (mature fish) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

3.31 Longevity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

3.32 Hardiness. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

3.33 Competitors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

3.34 Predators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

3.35 Parasites, diseases, injuries and abnormalities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

*3.36 Physiology and biochemistry

3.4 Nutrition and growth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

3.41 Feeding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

3.42 Food. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

3.43 Growth rate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

3.44 Weight-length relationships, condition factors 25

*3.45 Metabolism

iii
3.5 Behavior......................................................................................... 25

3.51 Migrations and local movements 25

3.52 Shoaling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

3.53 Responses to stimuli 33

4 Population.................................................................... . . . . . . . . . . . . . . . . . . . . . . . . . 34

4.1 Structure............................................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

4.11 Sex ratio. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

4.12 Age composition. . . ... .. .. . . . . . . .. .. . . . . .. . . .. . . . ... .. . ... .. . .. . . . . . . . .. . .. . 34

4.13 Size composition. . .. .. . . .. . . . . . ... . . . . . . ... .. . . . ... . .. ... ..... . .. .... . .. 34

4.14 Subpopulations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

4.2 Abundance and density (of population) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

4.21 Average abundance-estimation of population size 36

4.22 Changes in abundance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

4.23 Average density. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

4.24 Changes in density. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

4.3 Natality and recruitment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

4.31 Reproduction rates. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

4.32 Factors affecting reproduction 39

4.33 Recruitment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

4.4 Mortality and morbidity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

4.41 Mortality rates. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

4.42 Factors causing or affecting mortality 40

*4.5 Dynamics of population (as a whole)

4.6 The population in the community and the ecosystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

4.61 Physical features of the biotope of the community 40

4.62 Species composition of the community. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

4.63 Interrelations within the community 41

5 Exploitation........................................................................................... 41

5.1 Fishing equipment. . . . . . . . . . . . . .. . . . . .. . .. . .. .. . . . .. .. . . .. 41

5.2 Fishing areas. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

5.21 General geographic distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

5.22 Geographic ranges. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

5.23 Depth ranges. . . . .. .. ... . . . . .. .. . . . . . . ... .. . .. . . . .. .. .. . . . .... . .. . . . .. .. . . . . ... .. . .... . . ... . 41

5.3 Fishing seasons. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

5.31 General pattern of seasons. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

5.32 Dates of beginning, peak and end ofseason. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

5.33 Variation in date or duration of season. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

5.4 Fishing operations and results 41

5.41 Effort. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

5.42 Selectivity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

5.43 Catches. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

6 Protection and management. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

6.1 Regulatory (legislative) measures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

6.11 Limitation or reduction of total catch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

6.12 Protection of portions of population. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

6.2 Control or alteration of the physical features of the environment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

*6.3 Control or alteration of the chemical features of the environment

*6.4 Control or alteration of the biological features of the environment

*6.5 Artificial stocking

*6.51 Maintenance stocking

*6.52 Transplantation, introduction

7 Pond fish culture. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

7.1 Procurement of stocks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

*7.2 Genetic selection of stocks

7.3 Spawning......................................................................................... 43

7.4 Rearing.......................................................................................... 43

Acknowledgments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Literature cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

*No information available.

iv
Synopsis of Biological Data on Shortnose Sturgeon,

Acipenser brevirostrum LeSueur 1818

MICHAEL J. DADSWELL,! BRUCE D. TAUBERT,2 THOMAS S. SQUIERS,3

DONALD MARCHETTE,4 and JACK BUCKLEy5

ABSTRACT

Information on the biology and populations of the shortnose sturgeon, Acipenser brevirostrum, is compiled,

reviewed, and analyzed in the FAO species synopsis style. New information indicates this species exhibits

biological and life-cycle differences over its north-south latitudinal range and that it is more abundant than

previously thought.

IDENTITY

1.1 Nomenclature

1.11 Valid name

Acipenser brevirostrum LeSueur 1818 Ref: Trans. Am. Phi)os.

Soc. 2:383. Type locality: Delaware River. Type specimen

lodged at Academy of Natural Sciences of Philadelphia,

ANSP 16953.

1.12 Objective synonymy

Acipenser brevirostris Richardson 1836:278. Type locality:

Eastern North America. Type specimen: None.

Acipenser lesueurii Valenciennes-Dumeril 1870: 166. Type

locality: New York. Type specimen: Paris Museum National d'Histoire Naturelle.

Acipenser microrhynchus Dumeril 1870:164. Type locality:

Hudson River. Type specimen: None.

Acipenser dekayii Dumeril 1870:168. Type locality: Hudson

River. Type specimen: None.

Acipenser rostellum Dumeril 1870:173. Type locality:

Hudson River. Type specimen: Paris Museum National

d'Histoire Naturelle.

Acipenser sinus Valenciennes Dumeril 1870:175. Type

locality: New York. Type specimen: Paris Museum National d'Histoire Naturelle.

Acipenser brevirostris Jordan et al. 1930:34

Acipenser brevirostris Vladykov and Greeley 1963:36

Acipenser brevirostris Magnin 1963:87

LeSueur originally described the species from the Delaware

River as Acipenser brevirostrum. Acipenser (masculine noun) is an

'Fisheries and Environmental Sciences. Department of Fisheries and Oceans,

Biological Station, St. Andrews, N.B., EOG 2XO, Canada.

'Massachusetts Cooperalive Fishery Research Unil. Department of Forestry and

Wildlife, University of Massachusetts, Amherst, Mass.; presenl address: Arizona

Game and Fish Department, Phoenix, AZ 85023.

'Maine Department of Marine Resources, Augusta, ME 04333.

'South Carolina Wildlife and Marine Resources. Charleslon. SC 29412.

'Massachusetts Cooperative Fishery Research Unit. Department of Forestry and

Wildlife, University of Massachuseus, Amherst, MA 01002.

old word for sturgeon and brevirostrum, short snout, (neuter, 2nd

declension, noun in apposition). This was correct. Article 30 of

the Rules of Zoological Nomenclature states only a species-group

name which is an adjective has to agree. Others, starting with

Richardson (1836) and followed by Jordan et al. (1930) and

Vladykov and Greeley (1963), changed the species designation to

brevirostris (ablative, masculine noun) to obtain agreement. This

was unnecessary.

1.2 Taxonomy

1.21 Affinities

Suprageneric

Kingdom Animalia

Phylum Chordata

Subphylum Vertebrata

Superclass Gnathostomata

Class Osteichthyes

Subclass Actinopterygii

Infraclass Chondrostei

Order Acipenseriformes

Family Acipenseridae

Subfamily Acipenserinae

Generic

Genus: Acipenser Linnaeus 1758

Ref: Systema naturae, ed. X, p. 237

Diagnostic characteristics:

Ref: Vladykov and Greeley 1963: Order Acipenseroidei.

Mem. Sears Found. Mar. Res.

Body elongate and fusiform. Scutes in five rows: One dorsal,

two lateral, two ventral; and scutes very sharp and strongly

developed in young individuals, but becoming progressively

blunter with age. Snout protruding, subconical. Mouth inferior,

protractile. Teeth absent in adults. Barbels 4, in cross row anterior

to mouth. Gills 4, and an accessory opercular gill. Gill rakers < 50,

lanceolate. Gill membranes joined to isthmus, spiracles present,
one branchiostegaJ (McAllister6 ). Opercle present, suboperculum

present or absent. Head covered by bony plates separated by

sutures, dermal skeleton without ganoine. Tail depressed, completely mailed, caudal fin with fulcra; tail heterocercal. Dorsal and

anal fins behind ventraIs. Air bladder large, simple, opening into

oesophagus through a short, wide duct. Rectum with spiral valve.

Anadromous and freshwater fishes of northern hemisphere; Upper

Cretaceous to Recent, 16 species.

Specific

Key to North American, Atlantic coastal species of Acipenser

(after Vladykov and Greeley 1963; Scott and Crossman 1973)

la. Mouth width inside lips usually < 55% (range 43-66%)

of interorbital width; interorbital width < 29% (range

22-36%) of head length (Fig. 1); average TL:FL = 1.14;

gill rakers 17-27 (X = 21.6); postdorsal and preanal

shields usually in pairs, usually 2-6 plates between anal

base and lateral row of scutes (Fig. 2); dorsal plates

generally touch or overlap; viscera pale; has fontanelle

................. .Acipenseroxyrhynchus Mitchill 1814

I b. Mouth width exceeds 62% (range 63-81 %) of interorbital width; interorbital width usually exceeds 29%

(range 29-40%) of head length (Fig. 1); average TL:FL

= 1.12, gill rakers 22-40, postdorsal and preanal shields

usually in single row, usually no plates between anal

'D. E. McAllister, Curator of fishes, National Museum of Canada. Ottawa. Canada

KIA OM8, pers. commun. September 1979.

Figure I.-Ventral view of Atlantic sturgeon (left) and shortnose sturgeon

(right); note short snout and wide mouth of the shortnose sturgeon.

2

base and lateral scute row (Fig. 2); viscera blackish; no

fontanelle 2

Figure 2.-Lateral view of shortnose sturgeon (above) and Atlantic sturgeon

(below); note small bony plates (arrows) above the anal fin of the Atlantic

sturgeon (from Gorham and McAllister 1974).

2a. Anal fin rays 25-30; insertion of anal fin behind insertion of dorsal fin; gill rakers 25-40 (X = 33.1); caudal

peduncle long, tip of anal fin not reaching origin of

caudal fin, lateral plates 29-42 (X = 35.4); interorbital

width 29-35% of head length (adults); dorsal and lateral

shields same color as background .

. . . . . . . . . . . . . . . . . .Acipenserfulvescens Rafinesque 1817

2b. Anal fin rays 19-22; insertion of anal fin opposite insertion of dorsal, gill rakers 22-29 (X = 25.4); caudal

peduncle short, tip of anal fin reaching origin of caudal

fin; lateral plates 22-33 (X = 28.3); interorbital width

34-40% (X = 37%) of head length; dorsal and lateral

shields pale, contrasting with dark background .

. . . . . . . . . . . .Acipenser brevirostrum LeSueur 1818 (Fig.3)

Remarks on Identification. Among these three species, various

characters change considerably with growth. Young have longer

snouts than adults and their scutes (shields) are sharper and closer

together. Mouth width is the best character for separating all sizes

of shortnose sturgeon and Atlantic sturgeon including all larvae

(Fig. 4) except prolarvae (Taubert and Dadswell 1980; Bath et al.

1981). The absence of plates between the lateral scutes and the

anal fin is the best character for distinguishing dressed (headless)

shortnose sturgeon, but occasionally Atlantic sturgeon also lack

these plates (Squiers and Smith 19787 ). Morphologically, shortnose sturgeon are quite variable. A complete gradation of morphs

from sharp-plated, rough-skinned individuals to flat-plated,

smooth-skinned shortnose sturgeOil exist in the Saint John estuary

(Dadswell, pers. obs.).

'Squiers, T. S., and M. Smith. 1978. Distribution and abundance of short nose

sturgeon and Allantic sturgeon in the Kennebec River estuary. Prog. Rep. Project

#AFC-19-1. Dep. Mar. Resour., Maine, 31 p.
Figure 3.---Acipenser brevirostrum. Lateral view of spawning female (580 mm TL) from the Hudson River, N.Y. (after Vladykov and Greeley 1963).

Figure 4.-Ventral view of heads of 17.0 mm larval Acipenser oxyrhynchus (left)

and A. brevirostrum (right) from the Hudson River, N.Y., Illustrating difference

In mouth size and structure (after W. L. Dovel. 1979. The biology and management of shortnose and Atlantic sturgeon of the Hudson River. N.Y. Dep. Environ. Conserv. Rep. AFS9·R, 54 p.).

1.22 Taxonomic status

A morpho-species, not established by breeding data.

1.23 Subspecies

No subspecies described.

1.24 Standard common names, vernacular names

The standard common name is shortnose sturgeon (Robins et al.

1980). Vernacular names include shortnosed sturgeon, little sturgeon (Saint John River, N.B.), pinkster and roundnoser (Hudson

River, N.Y.), bottlenose or mammose (Delaware River), salmon

sturgeon (Carolinas), soft-shell or lake sturgeon (Altamaha River,

Ga.).

3

1.3 Morphology

1.31 External morphology

Acipenser brevirostrum is distinguished by wide mouth, absence

of a fontanelle, almost complete absence of the postdorsal shields,

and by preanal shields usually arranged in a single row (paired

preanals, Kennebec R., Squiers and Smith footnote 7).

Scutes in all five main rows not closely set, weakly developed in

adults, sharp and close together in juveniles.

Dorsal scutes 7-13, lateral scutes 21-35, ventral scutes 6-11;

scutes behind dorsal fin either in single row (75%) or paired

(25%), enlarged supra-anal plates absent, double preanal scutes

present (25%) or absent (75%); elongated fulcrum at base of lower

caudal lobe shorter than base of anal fin (Table 1).

Head short, 22-28% of FL, snout short, blunt rounded (Fig. 3),

70% of postorbital length in adults, convex in side view but longer

than postorbital length in young, sharp, triangular concave in side

view; fontanelle absent; postorbital length in adults 51-61 % (avg.

55%) of head length, but 33% in young; interorbital width

24-43% (avg. 37%) of head length, mouth width (excluding lips)

69-81 % (avg. 74%) of interorbital width, no teeth; 4 barbels in

front of mouth; gill rakers long, triangular, 23-32 (avg. 26) on first

arch.

Fins: Single dorsal far back, above anal, trailing edge crescentic,

38-42 rays; caudal heterocercal, lower lobe long for sturgeon, no

notch at tip of upper lobe, difference between TL and FL 11-12%;

caudal peduncle short, tip of depressed anal reaching base of

caudal fin; anal fin base about 60% of dorsal fin base, trailing edge

emarginate, 18-24 rays; paired fins with heavy ossified first ray,

pelvics abdominal, far back, pectoral large, pectoral girdle wider

than head width; no lateral line.

Color: Body yellowish brown with green or purple cast in saltwater, to nearly black on head, back, and sides level to lateral

plates, whitish to yellowish below. Young particularly yellowish

in the Saint John River, Canada. Ventral surface and barbels

white; all fins pigmented but paired fins outlined in white, scutes

pale and obvious against dark background (Fig. 5). Young have

melanistic (black) blotches (Fig. 6).

The skin of preserved specimens often acquires a greenish cast

(Vladykov and Greeley 1963).

1.32 Cytomorphology

No data available.
Table I.-Comparative morphometric and meristic data for adult Acipenser brevirostrum. TL = total length, MW = mouth width (inside

lips), SL = snout length, lOW = interorbital width, POL = postorbital length, HL = head length, FL = fork length. In parentheses, juvenile

data.

Characler

MWfLS

MWflOW

SUHL

SUPOL

POUHL

IOWfHL

HUFL

TUFL

Gill rakers

Anal rays

Dorsal scutes

Ventral scutes

Lateral scutes

SainI John, Canada

Gorham and

McAllister (1974)

0.60±O.08

0.76±0.06

0.44±0.03

1.2

27.6±2.5

20.8± 1.6

10.2± 1.3

8.5±0.9

Mean for ri ver system

Kennebec-Sheepscol Connecticut Hudson

Squiers and Smilh Hoff and

(see texl footnole 7) Taubert Vladykov and Klauda

Fried and McCleave (1973) (1980b) Greeley (1963) (1979)'

0.71 ±0.09 71.6 0.58

0.81 ±0.06 0.73 0.74 (same) 0.68

0.38±0.03 0.35 0.45

0.73±0.09 0.70 (1.83) 0.76

0.56±0.03 0.55 (0.33) 0.60

0.34±0.03 0.37 0.39

0.20±O.01 0.22 (0.28) 0.19

1.11 ±0.02 1.1 1.1

26.2±0.03 25.5 25

9.7±1.3 11.0 10

8.0±0.9 7.9 8

26.5±2.6 27.7 28

Delaware

Brundage and

Meadows

(1982)

0.71±0.10

0.68±0.05

0.38±0.05

0.68±0.05

0.58±0.04

0.39±0.01

0.21 ±0.02

1O.2±2.0

7.6±1.0

27.3±2.5

1Hoff. T. B., and R. J. Klauda. 1979. Data on shortnose s:urgeon (Acipellser brevirostrum) collected incidentally from 1969 through June 1979 in

sampling programs conducted for lhe Hudson River ecological study. Texas Instruments Inc., Buchanan, N.Y., MS Rep., 25 p.

Figure S.--Acipenser brevirostrum. Dorsal view of 430 mm FL juvenile from the

Saint John River, Canada.

1.33 Protein specificity

No data available.

1.34 Internal morphology

A considerable number of publications on the internal 3tructure

of sturgeon exist (Parker 1882; Jollie 1980), but little directly

concerns shortnose sturgeon. Ryder (1890) illustrated the spiral

valve, pyloric end of the stomach, and cartilaginous elements of

the ventral fins of A. brevirostrum. Vladykov and Greeley (1963)

described, but did not illustrate, other internal structures. Viscera

is black and peritoneum pigmented.

4

Figure 6.--Acipenser brevirostrum. Lateral view of juvenile from the Holyoke

Pool, Connecticut River, showing sharp, closely set scutes and melanistic

blotches.

2 DISTRIBUTION

2.1 Total area

Shortnose sturgeon are restricted to the east coast of North

America (Vladykov and Greeley 1963). They have been recorded

from the Saint John River, New Brunswick, Canada (Leim and

Day 1959), to the Indian River, Fla. (Evermann and Bean 1898)

(Fig. 7a, b). Since the species is considered endangered, a summary of occurrence records and catches is given in Table 2.

Throughout its range, shortnose sturgeon occur in rivers, estuaries, and the sea. The majority of populations have their greatest

abundance in the estuary of their respective river. All captures at
sea have occurred within a few miles of land (Schaefer 1967;

Holland and Yelverton 1973; Wilk and Silverman 1976; Marchette and Smiley 1982 see Table 2, footnote 24). Partially

landlocked populations are known from the Holyoke Pool section

of the Connecticut River (Taubert 1980a) and the Lake MarionMoultrie system South Carolina (Marchette and Smiley 1982 see

Table 2, footnote 24).

This species has no known fossil record.

2.2 Differential distribution

2.21 Spawn, larvae and juveniles

The species is anadromous (Dadswell 1979) but can be landlocked (Taubert 1980a; Marchette and Smiley 1982 see Table 2,

footnote 24). The young are hatched in freshwater usually above

tidal influence. Ripe adults have been captured as far upstream as

rkm (river kilometer) 186 in the Altamaha River, Ga. (Heidt and

Gilbert 1978 see Table 2, footnote 27), rkm 198 on the Pee Dee

River, S.C. (Marchette and Smiley 1982 see Table 2, footnote 24),

rkm 222 in the Delaware River (Hoff 1965), rkm 246 in the Hudson River (Dovel 1981 see Table 2, footnote 15), and adults, eggs,

and larvae have been taken at rkm 190 in the Connecticut River

(Taubert 1980a).

Eggs are demersal and adhesive (Meehan 1910). Juveniles may

remain inland of saline water until 45 em FL. That length is attained between 2 and 8 yr of age depending on the geographical

location of the population. Larvae and juveniles are benthic and

occupy the deep channel areas of rivers where currents are strong

(Dadswell 1979; Taubert 1980a).

2.22 Adults

Once shortnose sturgeon attain adult size (45-50 em), they

commence migratory behavior, travelling downstream in fall and

upstream in spring (Dadswell 1979; Dovel 1981; Marchette and

Smiley 1982 see Table 2, footnote 24; Buckley 1982). An

unknown portion of most populations appear to move short

distances to sea (Bigelow and Schroeder 1953; Schaefer 1967;

Holland and Yelverton 1973; Wilk and Silverman 1976; Dadswell

1979). Each fall, in some of the large rivers (Hudson, Connecticut,

Saint John), a portion of the adults which will spawn the following spring migrate upstream to deep, overwintering sites adjacent

to the spawning grounds (Greeley 1935; Dadswell 1979; Dovel

1981 see Table 2, footnote 15; Buckley 1982). Males apparently

lead the upstream migration (Pekovitch 1979 see Table 2, footnote 14; Dovel 1981 see Table 2, footnote 15; Dadswdl, un pub!.

data). Some ripening and most nonripening adults spend the

winter in deep, saline sites (Fig. 8) (Dovel 1978 see Table 2, footnote 13; Dadswell 1979; Marchette and Smiley 1982 see Table 2,

footnote 24). On the other hand, mass migrations were not noted

in the Holyoke Pool population (Taubert 1980b), and some

nonripening adults in most rivers remain in freshwater, do not

concentrate, and may be active all winter (Dadswell 1979;

Buckley 1982).

2.3 Determinants of distribution changes

2.31 Temperature

The preferred temperature range and upper and lower lethal

temperatures for shortnose sturgeon are unknown.

5

Spring spawning migrations from overwintering sites or arrival

on the spawning grounds occurs at temperatures of 8 0_9°e (Dovel

1978 see Table 2, footnote 13; Squiers 1982 see Table 2, footnote

4). In the northern part of its range, shortnose sturgeon are seldom

found in shallow water once temperature exceeds 22°e (Dadswell

1975;8 Dovel 1978 see Table 2, footnote 13). In the Saint John

River, Canada, surface temperatures over 21°C appeared to

stimulate movement to deeper water. Heidt and Gilbert (1978 see

Table 2, footnote 27), however, found shortnose sturgeon in the

lower Altamaha River in June at water temperatures of 34°C and

in the lower Connecticut River they were frequently captured in

< I m of water at 27°-30°C (Buckley9).

Dadswell (1979) and Marchette and Smiley (1982 see Table 2,

footnote 24) found a 2°_3°e decline in temperature during fall

stimulated downstream migration. In the Saint John River,

Canada, they overwinter in regions with temperatures between 0°

and 13°C. In Winyah Bay, S.c., overwintering sites have

temperatures of 5 0_10°C (Marchette and Smiley 1982 see Table

2, footnote 24).

2.32 Current

Juveniles appear to prefer living in deep channel regions (Table

3) with strong currents (15-40 cm/s) (Pottle and Dadswell 1979

see Table 2, footnote 1). During summer, adults are generally

found in regions of little or no current (McCleave et al. 1977;

Dadswell 1979; Taubert 1980b).

2.33 Waves

No data.

2.34 Depth

See 2.22 and 2.31. Pottle and Dadswell (1979 see Table 2, footnote 1) found juveniles occupied depths in excess of 9 m ip river

channels. Trawling surveys in the Hudson River indicate a s'hnilar

situation there (Dovel 1978 see Table 2, footnote 13; Hof~~ al.

1977 see Table 2, footnote 12). Adults are found in shallow water

in summer (2-10 m) (Dadswell 1979; Dovel 1981 see Table 2,

footnote 15; Marchette and Smiley 1982 see Table 2, footnote 24)

and in deep water in winter (10-30 m) (Dadsit,elt 1979; Dovel

1981 see Table 2, footnote 15; Marchette and ~S"'miley 1982 see

Table 2, footnote 24).

2.35 Light

Light appears to be important in the biology of shortnose

sturgeon but is still largely un assessed. Gilbert and Heidt (1979)

found, although nets were fished during daylight and darkness, all

shortnose sturgeon were caught during darkness. During radio

tracking studies, they found tagged sturgeon remained more or less

stationary in deep water during daylight but at night they moved

into shallow water or extensively up- or down-stream.

'Dadswell, M. J. 1975. Biology of the shortnose sturgeon (Acipenser

brevirostrum) in the Saint John estuary. New Brunswick, Canada. In Baseline survey

and living resource potential study of lhe Saint John estuary, Vol. III Fish and

fisheries, 75 p. HUnlsman Marine Laboratory, SI. Andrews, N.B.

'J. Buckley, Graduate Student, Massachusetts Cooperalive Fishery Research Unit,

Department of Forestry and Wildlife, University of Massachusetts, Amherst, MA

01002, pers. commun. February 1982.
A

~.

.~"

j

CJO

1965 III

1969 (II

1970 (I)

Delaware River

Section

-------- 1907 180)

1906 (18)

1911 (41

1913 (31)

1914 I?)

o - 1818 - 1944

o -1945 - 1964

• - 1965 -1982

Figure 7.-A. Northern portion of shortnose sturgeon distribution indicating known occurrences with date of capture and number captured (in

parentheses). B. Southern portion of shortnose sturgeon distribution indicating known occurrences with date of capture and number captured (in

parentheses).

2.36 Turbidity

No data. Dadswell (pers. obs.) observed that catches of shortnose sturgeon in both invisible monofilament and heavy duty,

multifilament gill nets increase appreciably on windy days when

the water is more turbid than usual. This suggests shortnose sturgeon are more active under lowered light conditions, or such conditions as have been documented by Gilbert and Heidt (1979).

6

2.37 Substratum

Dadswell (1979) noted that foraging grounds of shortnose sturgeon in freshwater are over shallow, muddy bottoms with abundant macrophytes and foraging grounds in saline waters were over

gravel-silt bottoms 5-15 m deep. Marchette and Smiley (1982 see

Table 2, footnote 24) found shortnose sturgeon among macrophytes over sandy bottom in summer and over mud bottom in
Figure 7.---Continued.

B

.. 1917(1) . 1918 II)

IS' . 1919 (2)

%... .. 1949 (I)

... o~.1949(1) o .

~'. "'\I> ; 11 :.

,--,-;--1896 (I)

7

o - 1818 -1944

o - 1945 -1964

• - 1965 - 1982
Table 2.-0ccurrence and number caplured of shorlnose slurgeon collecled on Ihc easl coasl of Norlh America since 1818.

Locality

NEW BRUNSWICK. CANADA

Saint John River

MAINE

Sheepscot Estuary

Montsweag Bay

Kennebec RiverMontsweag Bay

Montsweag Bay and

Androscoggin River

Penobscot River

NEW HAMPSHIRE

Piscataqua River

Gulf of Maine

MASSACHUSElTS

Provi ncclown

Waquoit

Rockport

Woods Hole

Merrimack River

Parker River

Holyoke Pool

Connecticut River

RHODE ISLAND

Point Judith

Narragansell Bay

CONNECTICUT

Lower Con neel icut River

NEW YORK

Fire Island

Hudson River

Hudson River (Gravesend Bay)

Hudson River

Hudson River (Albany)

Hudson River

Date

1957

1959

1960

1965

1971

1971

1974

1973-77

1976

1979

1980

1971-73

1973

1976

1977

1978

1979

1980

1981

1982

1978

1971

1971

1907

1871

1898

1949

1974

1972

1942

1964-75

1974

1976-77

1977-78

1956

1957

1951-52

1977-78

1978

1979

1979

1980

1981

1982

1962

1870

1896

1915

1935

1936

1965

1969

Number

caught

I

3

10

8

99

45

32

4.218

II

2 larvae. 300

juveniles,

42 adults

292

31

3

15

264

72

72

324

272

233

I

I

4

I

100+

40-50

+8 juveniles

14

229

13 larvae

4

5

70

I

71

32

22

166

I

3

I

2

I

95

I

1

8

Source

Leim and Day (1959)

Vladykov and Greeley (1963)

Magnin (1963)

Gorham (1965)

Meth (1973)

Gorham (1971)

Gorham and McAllister (1974)

Dadswell (1979)

Appy and Dadswell (1978)

POllIe and Dadswell (1979)'

Anonymous (1980)2

Fried and McCleave (1973)

Fried and McCleave (1974)

McCleave et al. (1977)

Squiers and Smith (see text footnote 7)

Squiers et al. (1981)'

Squiers (1982)4

Squiers5

Spurr"

Bigelow and Schroeder (1953)

Goode and Bean (1879) (unconfirmed)

Baird (1873)

Bumpus (1898)

McLaughlin 7

Rideout'

McCabe (1942) (in fish markets)

Student collections. U. Mass.• Amherst,

Mass.

Texas Instruments (1975)'

Taubert (l980b)

Gordon (1960)

Gordon (1960) (unconfirmed)

Vladykov and Greeley (1963)

Taubert'·

Reed and Buckley (1978)"

Impinged, Haddam Neck

Buckley (1982)

Schaefer (1967)

Dumeril (1870) (in Paris museum)

Bean (1897)

MacCallum (I 92 I)

Greeley (1935)

Greeley (1937); Curran and Ries (1937)

Boyle (1960)
Table 2.-Continued.

Number

Locality Date caught Source

Hudson River 1969 I AIZ and Smilh (1976)

1970 1 Kosk i et aI. (I 97 I)

1971 I Raytheon Inc.

1969-77 194 Hoff el al. (1977)"

1975 3 Brundage and Meadows (1982)

1976-77 274 Dovel (1978)"

(9 yoy &

juveniles)

1977 32 Nalco Environmental Sciences

(4 larvae)

(19 yoy)

1978 106 Texas Inslruments, ESA Permit E20

1978 174 Dovel, ESA Permit Ell

1979 1,594 Pekovitch (1979)14

(2 larvae)

(10 yoy)

1979 92 Texas Instruments, ESA Permit E20

1980 1,469 Dovel (198 I)IS

NEW JERSEY

Sandy Hook Bay 1970 6 Wilk and Silverman (1976)

Bay at Green Creek 1907 1 Vladykov and Greeley (1963)

Cape May Co., Delaware River 1817 I leSueur (1818) (type specimen)

Delaware River 1887 5 Ryder (1890)

Apr. 1906 18 Meehan (1910)

Torresdale, Phil Co. (4 9 ripe. 2 0')

1907 80-90 Meehan (1910) (50% 0')

1909 8 Meehan (I 910) (2 9, 6 0')

1911 4 Vladykov and Greeley (1963)

1913 3

Trenton 1905 1 Fowler (1905)

Delaware River 3 Fowler (1910)

Bristol. Bucks Co. 1908 I Fowler (1912)

Delaware River Fowler (1920)

Burlington Co., Mercer Co.,

G10ucesler Co. 1914 Smith (1915) (commercial catch)

Scudders Falls 1954 2(20 seen) Hoff (1965)

1983 15 Brundage (unpub/. data)

(Apr.lMay)

Little Ck., Del. 1969 10 Carl Baren"

Rm 28 1969 I

Lambertville 1972 2

Rm 102-124 1973 I

Rm 52-69 1975 2

Rm 149 1977 I

Rm 61 1977 1

Trenton 1977 2

Delaware Memorial Bridge

Delaware River 1973 I Miller et al. (1973)

Burlington Co. 1975 2 Martin Marietta Corp. (1976)"

Salem Nuclear

Generating Station 1978 2 Masnik and Wilson (1980)

1981 I Brundage (unpubI. data)

Artificial Island 1979 2 Brundage and Meadows (1982)

Edgewaler Park

Rm 115 1982 I Brundage (unpubl. data)

Lambertville 1981 II Lupine 18

Trenton. Delaware 1981 176 Haslings (1983)"

1982 398

1983 30

Newbold Island 1971 3 Anselmini (1976)

Mercer Zone 1972 3 Anselmini (1974)

MARYLAND

Still Pond Neck 1976 Miller'·

Upper Chesapeake

Elk River 1978 4 S. Bristo

Upper Chesapeake Bay

Susquahanna Flats 1980 4 Saul"

1981 4 Hogan"

9
Table 2.-Continued.

Locality

Potom ac Ri ver

ATLANTIC OCEAN

Cape Henry, Va.

to Cape Fear, N.C.

NORTH CAROLINA

Salmon Creek

Beaufort

North, New, and Neuse Rivers

Ashepoo Ri ver

SOUTH CAROLINA

Charieston

South Santee River

South Edisto River

Atlantic Ocean

Pee Dee River

Waccamaw RiverWinyah Bay

(running-ripe male 1st wk April)

Charlestown Harbour

Lake MarionWateree River

GEORGIA

Lower Savannah River

Lower Ogeechee Ri ver

Altamaha River

Ocumulgee River

(16 mi from fork)

FLORIDA

Big Lake George

Saint Johns River

Lake Crescent

Murphy Creek

Saint Johns River

Welaka

Cedar Ck.

Clay/Putnam Co. Line

Date

1876

1899

1968-71

1886

1877

1970

1896

1978

1978

1979

1980

1982

1978

1979

1980

1981

1982

1978

1979

1980

1981

1975

1979

1980

1973

1975

1974-77

1978

1979

1979

1978

1949

1949

1977

1978

1979

1979

Number

caught

abundant?

I

3

1

2

2

3

20

39

37

39

3

11

I

1

8

16

18

I

Source

Uhler and Lugger (1876)

Smith and Bean (1899)

Holland and Yelverton (1973)

Vladykov and Greeley (1963) (NSNM

64330)

Jordan (1886)

Yarrow (1877)

Anderson 2J

Jordan and Evermann (1896)

Marchette and Smiley (1982)24

Smith"

Recovery Team Shad Fishery Survey

1979

Marchette (unpubl. data)

Smith (footnote 25)

Dahlberg (1975)

Adams26

Heidt and Gilbert (1978)27

Gilbert and Heidt (1979)

Recovery Team Shad Fishery Survey

1979

Heidt and Gilbert (1978)

Kilby et al. (1959)

Moody"

1 Pottle, R., and M. 1. Dadswell. 1979. Studies on larval and juvenile shortnose sturgeon. Rep. to N.E. Utilities, Hartford,

Conn., 87 p.

'Anonymous. 1980. Studies on the eariy life history of the shortnose sturgeon, (Acipenser brevirostrum). Washburn and

Gillis Assoc. Ltd., Fredericton, N.B., Canada, 119 p.

'Squiers, T. S., M. Smith, and L. Flagg. 1981. American shad enhancement and status of sturgeon stocks in selected Maine

waters. Completion Report, Dep. Mar. Resour. Maine Proj. AFC-20, p. 20-64.

'Squiers, T. S. 1982. Evaluation of the 1982 spawning run of shortnose sturgeon (Acipenser brevirostrum) in the Androscoggin River, Maine. MS Rep., Dep. Mar. Resour., Maine. 14 p.

'T. S. Squiers, Fisheries Biologist, Maine Department of Marine Resources. Augusta, ME 04333. pers. commun. June 1979.

'E. W. Spurr, New Hampshire Fish and Game, Portsmouth, NH 03891, pers. commun. June 1977.

'C. L. McLaughlin, Jr., Assistant Aquatic Biologist, Massachusetts Fish and Game, Westboro, MA 01581, pers. commun.

'S. Rideout, Massachusetts Fish and Game, Westboro, MA 01581, pers. commun. June 1977.

"Texas Instruments Inc. 1975. Connecticut River ecological survey of the aquatic biology and water quality. Survey of the

Montague, Massachusetts, study area. May-December 1974. Prepared for Northeast Utilities Service Co., April.

lOB. D. Taubert, University of Massachusetts, Amherst, Mass., pers. commun. May 1979.

10
II Reed, R. J., and J. Buckley. 1978. Survey of the Connecticut River for short nose sturgeon, Acipenser breviroslrum, below the

Holyoke Dam, Holyoke, Massachusetts. Report to Northeast Utilities, Massachusetts Cooperative Fisheries Unit, 3 p.

12Hoff, T. B., R. 1. Klauda, and B. S. Belding. 1977. Data on distribution and incidental catch ofshortnose sturgeon (Acipenser

brevirostrum) in the Hudson River estuary 1969 to present. Texas Instruments Inc., Buchanan, N.Y., MS Rep., 21 p.

iJDovel, W. L. 1978. Sturgeons of the Hudson River, New York. Final Performance Rep. for N.Y. Dep. Environ. Conserv.,

181 p.

14Pekovitch, A. W. 1979. Distribution and some life history aspects of the short nose sturgeon (Acipenser brevirostrum) in the

upper Hudson River estuary. Hazelton Environ. Sci. Corp., III., 23 p.

I'Dovel, W. L. 1981. The endangered shortnose sturgeon of the Hudson estuary: Its life history and vulnerability to the activities of man. The Oceanic Society. FERC Contract No. DE-AC 39-79 RC-10074.

I'e. F. Baren, Project Leader, U.S. Fish and Wildlife Service, Delaware River Basin Anadromous Fishery Project, P.O. Box 95,

Rosemount, NJ 08556, pers. commun. June 1977.

17Martin Marietta Corp. 1976. Monitoring fish migration in the Delaware River. Final Report. March 1976,86 p.

I'A. Lupine, Biologist, New Jersey Fish and Game, Rosemount, NJ 08556, pers. commun. April 1982.

I'Hastings, R. W. 1983. A study of the shortnose sturgeon (Acipenser brevirostrum) population in the upper tidal Delaware

River; assessment of impacts of maintenance dredging. Draft Rep. U.S. Corp. Engineers, Philadelphia Dist., 132 p.

20p. Miller, Chesapeake Bay Institute, The Johns Hopkins University, Baltimore, MD 21218, pers. commun. January 1978.

21 W. G. Saul, Collection Manager, Department of Ichthyology, The Academy of Natural Sciences, Philadelphia, PA 19103, pers.

commun. July 1977.

"w. Hogan, Biologist, Maryland Tidewater Commission, Annapolis, Md., pers. commun. April 1981.

"w. D. Anderson, Grice Marine Biological Laboratory, 205 Fort Johnson, Charleston, SC 29412, pers. commun. June 1977.

24Marchette, D. E., and R. Smiley. 1982. Biology and life history of incidentally captured shortnose sturgeon, Acipenser

brevirostrum in South Carolina. S.e. Wildl. Mar. Res. unpubl. ms, 57 p.

"L. Smith, Department of Natural Resources, Fisheries Management, Box 219, Richmond Hill, GA 31324, pers. commun. July

1977.

26J. G. Adams, Senior Biologist, Georgia Power Company, Allanta, Ga., pers. commun. August 1977.

"Heidt, A. R., and R. J. Gilbert. 1978. The shortnose sturgeon in the Altamaha River drainage, Georgia. MS Rep., Contract

03-7-043-35-165, NMFS, 16 p.

28H. L. Moody, Project Leader Lower SI. John's River Fishery Project, Florida Game and Freshwater Fisheries Commission, P.O.

Box 1903, Eustis, FL 32726, pers. commun. May 1977.

winter. Recent experiments (Pottle and Dadswell 1979 see Table

2, footnote 1) indicate juveniles prefer a sand or gravel

substratum.

In contrast, shortnose sturgeon were not found in vegetated

backwater regions of the Holyoke Pool. The preferred habitat for

this population was riverine and nonvegetated (Taubert 1980b).

During summer, adults in the lower Connecticut River were encountered most often over sand substrates (Buckley footnote 9).

2.38 Shelter

No data.

2.39 Ice

No data.

2.310 Dissolved gases

No data.

2.311 Dissolved (inorganic) solids

Dadswell (1975, 1979) described shortnose sturgeon in the

Saint John estuary, Canada, as concentrated in the 1-3 0 / 00 salinity

zone but occurring throughout the estuary from freshwater of 70

!A ohm conductance to saltwater of29 0/00 (Fig. 8a). Marchette and

Smiley (1982 see Table 2, footnote 24) found the summer concentration zone was in the 0.5-1.0 0/00 zone of the Winyah Bay complex (Fig. 8b). In the Saint John River, Canada, an annual

upstream migration of the shortnose sturgeon effectively maintains the population in the 1-3 0/00 salinity range during summer

and Marchette and Smiley (1982 see Table 2, footnote 24)

observed similar behavior in Winyah Bay, S.C. Shortnose sturII

geon have been reported from coastal water of 27 0 / 00 (Wilk and

Silverman 1976), 30 0/00 (Squiers and Smith footnote 7), and

30-31 0/00 (Holland and Yelverton 1973; Marchette and Smiley

1982 see Table 2, footnote 24). Taubert (1980b) described a

population in the Holyoke Pool of the Connecticut River of which

a majority apparently remains in and completes its entire life cycle in freshwater.

2.312 Pollutants

No data.

2.313 Vegetation

Dadswell (footnote 8, 1979) and Dovel (1978 see Table 2, footnote 13) found shortnose sturgeon adults were abundant among

rooted macrophytes in 2-5 m depths during summer. Dadswell

(1979) attributed this occurrence to an abundance of preferred

prey (small gastropods) on the bottom and on the stems and leaves

of the macrophytes. Marchette and Smiley (1982 see Table 2,

footnote 24) observed shortnose sturgeon swimming upside down

at night feeding off snails on the undersides of lily pads (Nuphar

luteum).

2.314 Fauna

Appy and Dadswell (1978) and Dadswell (1979) noted that

adult shortnose and juvenile Atlantic sturgeon tend to segregate

themselves in the Saint John estuary, the Atlantic sturgeon

dominating in more saline water. A salinity of 3 0/00 appeared to

be the boundary across which the distributions of the two species

diffuse. Pottle and Dadswell (1979 see Table 2, footnote I)

observed that young Atlantic sturgeon (0+ - 3 + yr) were intermixed with juvenile shortnose sturgeon in the upper Saint John

River estuary. Marchette and Smiley (1982 see Table 2, footnote
2.4 Hybridization

3.11 Sexuality

100. E. McAllister, Curator of fishes, National Museum of Canada, Ottawa,

Canada KIA OM8, pers. commun. May 1977.

11 D. E. Marchette, Fisheries Biologist, South Carolina Wildlife and Marine

Resources, Charleston. SC 29412, pers. commun. February 1982.

Age of first maturation of males varies from south to north,

possibly occurring at 2-3 yr in Georgia, at age 3-5 yr from South

Carolina to New York, and increasing northward to 10 or 11 yr in

the Saint John River, Canada (Table 4). Females exhibit a similar

south-north trend, maturing at age 6 or younger in Georgia, age

6-7 from South Carolina to New York, and age 13 in the Saint

John River, N.B. Sexual differentiation is possible 1-2 yr younger

Sexual dimorphism

3.1 Reproduction

3 BIONOMICS AND LIFE HISTORY

The species is normally heterosexual.

Atz and Smith (1976) described a shortnose sturgeon from the

Hudson River with a gonad containing intermingled testicular and

ovarian tissue. One ovatestis contained small, cystlike structures

consisting of disorganized tissues including cartilage, bone, blood

vessels, gut epithelium, and connective tissue which was attributed to abnormal development of a parthenogenetic or selffertilized egg.

No natural hybrids of shortnose sturgeon with other acipenserids have been reported to date, although one suspected hybrid

with an Atlantic sturgeon was captured from the Saint John River,

Canada (McAllister 10), and four suspected hybrids were captured

in Winyah Bay, S.c. (Marchette 11).

3.12 Maturity

Little sexual dimorphism is exhibited by this species. Adult

females are generally larger than adult males of the same age and

gravid females are distinct in spring because of their swollen appearance (Dadswell 1979). Males and females can be reliably

distinguished externally only during the final stages before spawning; males by abdominal pressure which causes milt to flow

(possible only during the final 2-3 d), and females because the

black eggs are apparent through the abdomen (during a 3-mo

period, March-May in the north, January to March in the south).

24) found that juvenile Atlantic sturgeon were mixed with adult

shortnose sturgeon but outnumbered them 2: 1 in Winyah Bay,

S.c.

Figure S.-A. Average June.August abundance of shortnose sturgeon in gill net

catches in the Saint John estuary, Canada, as related to surface salinities,

Winter concentration sites are those discovered to date. B. Location of known

summer concentrations and overwintering sites in the Winyah Bay.Pee Dee

River complex, S.C. Isohalines of salinity are approximate summer limits.

B

':[ . I II I 1 , I I I I' I JMMJSN

@ - Shortnose Sturgeon

Winter Concentrations

DIna bog

lL

jlJ.....7...•. a I, I i I I i I I 1

JMMJSN

E

o

A

12
Table 3.-Percent, number, and mean length of shortnose sturgeon <45 em and >45 em in gill net

catches in relation to capture site in the Saint John estuary, Canada. Mesh size range was 2.5-20.2 em

stretched. Habitat type was riverine (r) or lacustrine (I). Distance upstream is river kilometer from Saint

John Harbour on the Bay of Fundy.

Distance Depth Catch Mean length (em)

Locality Type (rkm) (m) Samples n«45 em) % <45 >45

Milkish Cove 5 4 3 I 1.6 41.0 83.2

Westfield 15 5 2 3 16.6 44.0 61.7

Oak Point (June) 35 15 I 8 32.0 26.6 66.9

Oak Point (fall) 35 15 3 12 8.6 41.5 70.1

Evandale 45 18 3 48 91.3 37.1 50.0

Belleisle 45 13 2 5 9.7 39.0 82.3

Wickham 55 12 I 6 42.8 34.8 50.9

Washademoak 60 20 3 15 26.4 40.6 83.9

Gagetown 70 12 3 38 82.2 40.5 55.5

Oromoctol •

2 90 10 I 7 58.0 31.4 49.4

Grand Lake' 90 20 4 3 21.0 24.2 60.2

IF. F. Meth. Biologist. Environment.l Prdection Service. Department of Environment. Halifax. Canada.

pers. commun. August 1976.

'New Brunswick Fish and Game. Head Office. Fredericton, N.B., pers. commun. August 1976.

Figure 9.-Maturity oglves Indicating length and age at 50%

maturity for male and female shortnose sturgeon from the Saint

John River, Canada, and incidence ofrlpenlng adults (stages IIIV) among those mature. Length-maturity data treated in 5 em

increments for both sexes; and age.maturity In 2.yr Increments

for females and l-yr Increments for males.

110

0--0

I

30

100

Males: Mature

Ri pe

Mature

Ripe

Females

6

172 Yr.

70 80 90

Length (eml

I

20 25

Age (Years 1

._._._. _ ...__.t.__.t.

/ /

./ /

/

I

/

I

II. t I

/

e_e_e_e_e

I

15

60

_..--...--. /

/ ./ ./

I

I

I

I

I

/

I ... _6.......

______ /ti" '6

/' /

/ : /

... / .1 /6. /: //

... / l /

I ' I

/ : //

/12.4 Yr.: /

+-,/

I

10

o

100

80

60

40

20

:0

0

""

u

100 0..

80

60

40

First spawning

Table 4.-Age and size at first maturation and first spawning of .•hortnose

sturgeon in various river systems~

Males Females

FL FL

Locality Age (em) Age (em) Autilority

First maturation

Saint John, Canada 11 50.0 13.0 58.0 Dadswell (1979)

Hudson 3-4 40.0 Greeley (1937); Pekovitch

(see Table 2, footnote 14)

Delaware 50.0 58.8 Hoff (1965); Hastings (see

Table 2, footnote 19)

Pee Dee 43.4 44.4 Marchette and Smiley (see

Table 2, footnote 24)

Allamaha 2-3 58.6 6 72.2 Heidt and Gilbert (see Table

2, footnote 27)

First spawning

Saint John, Canada II 54.0 15 66.0 Dadswell (1979)

Holyoke Poole 8 57.0 9 52.0 Taubert (1980b)

Connecticut

Lower Connecticut 10 15 Buckley (1982)

Hudson 3-4 44.5 6-8 51.5 Greeley (1937)

Delaware 50.0 7-10 61.2 Hoff (1965); Hastings (see

Table 2, footnote 19)

Pee Dee 53.0 7 56.5 Marchette and Smiley (see

Table 2, footnote 24)

Altamaha 2-3 58.6 6 72.2 Heidt and Gilbert (see Table

2, footnote 27)

than the above. Dadswell (1979) found 50% maturity in the Saint

John River occurred at 12.4 yr for males and 17.2 yr for females

(Fig. 9).

Length at maturity for this species is similar throughout its

range, occurring between 45 and 55 cm FL for both males and

females (Table 4).

First spawning in males occurs 1-2 yr after maturity, but among

females is delayed for up to 5 yr (Dadswell 1979; Fig. 9). Approximate female age at first spawning in the Saint John River,

Canada, is 15 yr, the Hudson-Delaware Rivers 7-10 yr, and the

Altamaha,6 yr or less (Table 4). Size of males at first spawning is

44 to 55 cm FL and of females 50 to 70 cm FL. Taubert (l980b)

found the first spawning of males in the Holyoke Pool was 8-12 yr

old (X == 9.8) and of females 9-14 yr or 52 to 67 cm FL. Marchette and Smiley (1982 see Table 2, footnote 24) found mean age

of first spawning of males in South Carolina was 5-10 yr (X == 7.5)

13
and of females 7-14 yr (X = 10.5).

3.13 Mating

Little is known of spawning behavior. Dovel (1981 see Table 2,

footnote 15) found that the entire spawning population in the

Hudson River moved upstream "en masse" from the overwintering site to the spawning site during the spring spawning run.

Observations in the Saint John River, Canada, Connecticut River,

and the Hudson River during each of 1977 through 1982 spawning periods indicated the entire spawning population was confined

to a short reach of the river (1-2 km) (Taubert 1980a; Anonymous

1980 see Table 2, footnote 2). In the lower Connecticut River

below Holyoke Dam (rkm 139), spawning occurred over a short

period of 2-5 d in a very small area 6,000 m long (Buckley 1982).

Telemetry and gill net captures indicated spawners were in the

deepest available areas (6 m).

Washburn and Gillis Associates (Anonymous 1980 see Table 2,

footnote 2) and Buckley and Kynard (1981) found single females

captured in gill nets on the spawning grounds were often surrounded by numerous males in the same region of the net.

Dadswell (1979) found that sequentially tagged shortnose sturgeon had a tendency to be recaptured together. The probability of

this occurrence at random was calculated to be 1.88 x 10-24 and

is highly unlikely. There is no proof, however, that this possible

"pair bonding" is carried over to the spawning act, nor is it known

whether the "pairs" consist of one of each sex.

3.14 Fertilization

Fertilization is probably external as in all other Acipenseridae

(Ginsburg and Dettlaf 1969). Fertilization rates in nature are

unknown. Meehan (1910) reported hatchery survival from fertilization to hatching on two occasions were 0.3% and 66%.

Buckley and Kynard (1981) reported a survival of 19.3% from

eggs to larvae under hatchery conditions. Whether these low survival values are due to low fertilization rates is l.nknown.

3.15 Gonads

Female and male shortnose sturgeon have two gonads. In

females, one gonad is usually slightly larger than the other. During

development the gonads change dramatically in color and size.

Dadswell (1979) has described the stages as shown in Table 5.

Dadswell (1976) found female gonad weight during stage II

averaged 10% of total body weight (Table 6). Dadswell (1979)

described the seasonal pattern of gonad tissue growth and found

an abrupt increase in weight during July to October with a subsequent further slow increase during winter. Between July and

September, ripening females gained between 15 to 30% of their

total body weight (Table 7). When fully ripe (stage V), female

gonads averaged 21-28% of total body weight (Table 6) (Dadswell

1979; Marchette and Smiley 1982 see Table 2, footnote 24).

Spent (stage IV) female gonads weighed 4-6% of total body

weight.

Male shortnose sturgeon gonads are usually of equal size. They

are grayish white to white throughout development (see above)

and vary between 5% in stage II and 15% in stage V of total body

weight.

Fecundity

Fecundity of shortnose sturgeon in the Saint John River,

Canada, ranged from 27,000 to 208,000 eggs/fish (Table 6) and

was directly related to total body weight. The fecundity relationship was LogF(eggs x 103 ) = 3.92 + 1.14 Log W(total weight in

kg) (Dadswell 1979).

Fecundity of Altamaha River shortnose sturgeon was between

79,000 and 90,000 eggs for fish between 75 and 87 cm FL (Heidt

and Gilbert 1978 see Table 2, footnote 27). Marchette and Smiley

(1982 see Table 2, footnote 24) found a 58 cm FL female from the

Pee Dee River contained 30,000 eggs. Saint John River fish had a

mean of 11,568 eggs/kg body weight (Dadswell 1979) but Heidt

and Gilbert (1978 see Table 2, footnote 27) and Marchette and

Smiley (1982 see Table 2, footnote 24) found southern shortnose

Table S.-Classificatlon and description of maturity stages in shortnose sturgeon.

._--_._-------- Stage

Period

present Female

Condition of gonad

Male

o Immature, sex macroscopically indeterminate

I

II

III

IV

V

VI

All year

All year

All year

June-Oct.

Sept.-Apr.

May-June

May-Apr.

Eggs small, 0.5 mm.

translucent golden brown

Eggs 0.5 mm, bright yellow,

rat body 70% by weight

Egg 1.0 mm, grayish, yellow

rat body

Eggs 2.0-2.5 mm. chocolate

brown, gray polar globule

Eggs 3.10 mm, black, graybrown polar globule

Spent, gonad pinkish, flaccid,

blood clots, a rew aborted

eggs

14

Almost clear ribbon,

1-2 mm in width

Ribbon about 5 mm wide,

whitish gray, large rat body 10

mm wide, yellowish gray

10 mm wide, whitish gray, rat

body = gonad size

Testes occupy most of body

cavity. white, no rat body, no

milt running

Testes occupy most or body

cavity, white, milt running

Spent, whitish pink, milt

present in body cavity. Males

regain condition II quickly,

stage VI not present arter July.
Table 6.-Gonad development and fecundity of shortnose sturgeon.

Egg Gonad % Number

FL TW diameter wt body of Eggs/g Eggs/kg

(cm) (kg) Stage (mm) (g) wt eggs gonad TW

Saint John River. N.B., Canada

100 8.6 6 505 5.9

107 8.7 6 525 6.0

75 4.8 6 210 4.4

89 6.3 2 0.52 530 8.4

101 9.3 2 0.54 918 9.8

95 7.7 2 0.54 910 11.8

94 7.7 2 0.53 943 12.2

85 7.5 3 2.01 1.940 24.0 69,150 36 9,220

95 9.2 3-4 2.40 2,310 23.0 125,670 54 13,660

85 7.9 4 2.50 2,020 25.0 85,400 43 10,810

95 12.0 4 2.50 3,100 26.0 148,590 48 12.380

107 18.3 4 2.70 4,810 27.0 208,000 43 11,370

66 2.5 5 3.10 425 17.0 26,775 63 10,710

76 5.2 5 3.05 1,030 19.8 63,345 61.5 12,181

83 7.3 5 3.00 1,776 24.3 88,800 50.0 12,164

90 5.2 5 3.00 1,318 25.0 49,000 38 9,430

98 7.2 5 3.20 1,650 22.9 96,525 58.5 13,406

109 10.7 5 3.18 2,511 23.5 126,379 50.3 11.811

Pee Dee River, South Carolina

58 1.8 3.15 518 28.0 30,000 57.9 16,216

Altamaha River, Georgia

76 5.3 5 79,383 14,865

77 5.5 5 80,049 14,475

87 6.6 5 90,361 13,608

sturgeon to have about 14,000-16,000 eggs/kg body weight. Egg

size in the examined South Carolina fish was the same as the northern population which may indicate southern shortnose sturgeon

produce more eggs at a given size. This is consistent with other

fish species having a wide north to south range of spawning

populations (Jones 1976).

3.16 Spawning

Shortnose sturgeon spawn once a year during spring but among

adults in northern populations and perhaps in southern ones also,

spawning is not a yearly event for each individual. Dadswell

(1979) found the spent/recovering condition persisted up to 10

mo after spawning and stage II females were present all year. Only

30% of adult females examined during the August to March ripening period were found to be developing sexually as were 50% of

the males. The evidence suggests females probably spawn at a

maximum of once every 3 yr and males every other year in the

Saint John River, Canada. In addition, check zones (a series of

closely grouped yearly annuli) of the pectoral ray, which can be

interpreted as leading up to spawning (Roussow 1957), may indicate a duration of as long as 5-11 yr between spawnings

(Dadswell 1979).

Taubert (1980b) described a similar situation in the Holyoke

Pool, Connecticut River. Using check zones, he found male shortnose sturgeon spawned for the first time at a mean of 9.8 yr and a

second time at a mean of 18.2 yr. Range in years between first and

second spawnings was 4-12 (X = 8.4 yr). Taubert (1980b) did not

identify any females spawning for the second time. Also of 193

sturgeon aged, 51 had spawned once (8-14 yr; X = 10) and 12

had spawned a second time (14-20 yr; X = 17.9). In the Hudson

River, tagged males returned to the spawning grounds in each of

15

Table 7,-Average percent weigbt gain (WG) and time at large

{liT) of mature, adult, shortnose sturgeon (+70 cm) between

successive captures June-September in the same year in the

Saint John estuary, Canada.

Reproductive Nonreproductive

females adults

Month of capture WG lIT WG lIT

and recapture N (%) (d) N (%) (d)

June-july 7 9.3 41.4 14 5.8 33.3

June-August 5 14.5 59.6 6 23 59.0

June-September 8 18.0 84.4 II 80 60.3

July-August 4 15.0 43.8 15 3.7 30.1

July-September 5 19.5 63.6 8 3.8 57.7

August-September 4 17.7 47.5 7 2.8 29.8

two successi ve years (Dovel 1981 see Table 2, footnote 15). Marchette and Smiley (1982 see Table 2, footnote 24), also using

check zones, identified a 3-yr spawning periodicity for one male

and two females from the Pee Dee River, S.c.

Spawning period and location

Spawning occurs between February and May depending on

latitude. Ripe and spent females were present in the Altamaha

River, Ga., during February (Heidt and Gilbert 1978 see Table 2,

footnote 27), and during January to April in the Savannah, Santee,

and Pee Dee Rivers, S.c. (Marchette and Smiley 1982 see Table

2, footnote 24). Ripe and running-ripe females occur during the

middle 2 wk of April in the Delaware (Meehan 1910; Hoff 1965),

the last week of April and first week of May in the Hudson

(Greeley 1937; Pekovitch 1979 see Table 2, footnote 14), the first

2 wk of May in the Connecticut (Taubert 1980a; Buckley 1982)

and the Androscoggin (Squiers 1982 see Table 2, footnote 4), and

the middle 2 wk of May in the Saint John River, Canada

(Dadswell 1979; Anonymous 1980 see Table 2, footnote 2).

Temperature is probably the major factor governing spawning.

Meehan (1910), Heidt and Gilbert (1978 see Table 2, footnote

27), Taubert (1980a), Dadswell (1979), and Buckley and Kynard

(1981) all reported shortnose sturgeon spawning to occur between

9° and 12°C. Other apparent factors influencing spawning are the

occurrence of freshets and substrate character. Taubert (1980a),

Dadswell (1979), Buckley (1982), and Squiers (1982 see Table 2,

footnote 4) indicated spawning occurs during or soon after peak

flows in the spring. Spawning grounds examined to date in the

north are in regions of fast flow (40-60 cm/s) with gravel or rubble bottoms (Taubert 1980a; Pekovitch 1979 see Table 2, footnote 14; Anonymous 1980 see Table 2, footnote 2; Buckley

1982). Locations are generally well upriver of the summer foraging and nursery grounds (rkm 100-200). In South Carolina, on the

other hand, spawning occurs in flooded, hardwood swamps along

inland portions of the rivers (Savannah, Pee Dee; Marchette, unpubl. data).

Ratio and distribution of sexes on spawning

grounds

Pekovitch (1979 see Table 2, footnote 14) found a ratio of 2.5: I

males to females on the spawning grounds between rkm 135 and

140 on the Hudson River during 1979. Taubert (l980b) found a

ratio of 3.5:1 males to females on the Holyoke Pool spawning

grounds over two spawning seasons.
There appeared to be no tendency for sexes to segregate on the

spawning grounds. There is some evidence to suggest males

migrate to the spawning ground first (Dovel 1981 see Table 2,

footnote 15).

surface protuberances like the spokes of "iron jackstraws"

(Meehan 1910; Markov 1978). Sinking rates of unfertilized and

fertilized eggs are 5.2 ± 0.8 and 5.2 ± 0.2 cm/s, respectively

(Anonymous 1980 see Table 2, footnote 2).

3.17 Spawn

3.2 Preadult phase

Shortnose sturgeon eggs are dark brown to black with a lightgray polar body (Meehan 1910; Dadswell 1979). Egg development in the gonad is illustrated in Figure 10. Size change is marked during late summer and early fall (Dadswell 1979). Ripe eggs

have a diameter of 3.00-3.20 mm (Table 6; Dadswell 1979) and

size does not change after fertilization or water hardening (Recd;12

Buckley and Kynard 1981). In the Saint John River, Canada,

shortnose sturgeon eggs are often parasitized by Polvpodium sp. (~

50% of females) but the number of parasitized eggs per female has

never been observed to exceed 1%. The egg is enlarged, light gray

in color (Fig. 11; Hoffman et al. 1974), and is most evident in

stage IV and V females.

The eggs are separate when spawned but become adhesive

within 20 min of fertilization. Adhesiveness is probably due to

"R. 1. Reed, Professor, Massachusetts Cooperalive Fishery Research Unit, Depanment of Forestry and Wildlife, University of Massachusetts, Amherst, MA 01002,

pers. commun. June 1975.

3.21 Embryonic phase

Little is known about embryonic development of shortnose

sturgeon but it is probably very similar to other species of

Acipenser (Ryder 1890; Ginsburg and Dettlaf 1969). Meehan

(\ 91 0) gave the following description: During development there

was little change in the hue (i.e., brown for about two-thirds circumference, grayish white on the other), between 8 ° and 12°C the

eggs hatched 13 d after fertilization, eyes appeared first on day 6

and were light colored, on day 8-9 they darkened, fish shape was

distinguishable on day 10. At 17°C, hatching occurs in 8 d but the

development period is similar if converted to degree-days (136 vs.

143) (Buckley and Kynard 1981). Near time of hatching, eggs

may become clear and amber and emergence is tail first

(Anonymous 1980 see Table 2, footnote 2).

Mortality

Figure H.-Shortnose sturgeon stage V egg (left) and egg parasitized by

Polypodium sp. (right). Enlarged eggs average 4 mm in diameter.

Figure to.-Duration of ripening conditions and change in mean egg diameter

during gonad development between spawning of female shortnose sturgeon.

Bars are range of egg diameter.

In Meehan's (1910) hatching experiments, no swim-up occurred and the larvae remained for several days at the buttom of the

jar, but Buckley and Kynard (1981) found larvae to be active and

photopositive during the first 2 d. Larvae of approximately

10-d-old attempt to remain on the bottom or placed themselves

under any available cover in aquaria (Pottle and Dadswell 1979

see Table 2, footnote 1; Anonymous 1980 see Table 2, footnote

2). Buckley and Kynard (1981) found week-old larvae to be

photonegative and form aggregations with other larvae in concealment.

Hatching size is 7.3-11.3 mm (Taubert 1980a; Anonymous

1980 see Table 2, footnote 2; Buckley and Kynard 198\). Hatchlings < 8.0 mm did not survive (Anonymous 1980 see Table 2,

footnote 2). Taubert and Dadswell (1980), Pekovitch (1979, see

Table 2, footnote 14), and Bath et al. (198\) have described captured or reared larvae (Table 8).

At hatching, the larvae are tadpolelike and dark gray, with a

large yolk sac, the head is closely attached to the yolk sac, the

mouth is unopened, and pectoral and pelvic fins are undeveloped

(Fig. 12). At 14 mm TL, approximately 10 d after hatching, the

barbels are formed, the mouth is large and distinctly brevirostrumlike but has teeth (9-12 upper, 8-11 in lower jaw), pectoral but not

pelvic fins are present, eye size averages 0.70 mm, the anlage of

the dorsal fin is present, and the yolk sac is gone (Fig. 13)

(Taubert and Dadswell 1980). By 16.3 mm pelvic fins are present

(Fig. 14) and by 20 mm scutes, nose shape, and dorsal and anal

fins are characteristic of the species (Fig. 14) (Pekovitch 1979 see

Table 2, footnote 14; Anonymous 1980 see Table 2, footnote 2).

3.22 Larval phase

No data on natural egg mortality are available.

Meehan (1910) reported a fertilization to hatching survival of

0.3% and 6.6% for two attempts under artificial conditions.

Buckley and Kynard (1981) reported hatching survival of 19.3%.

S

3 - Spawning 2nd Wave of I- E Maturation jl

E r '" 2 1 st Wave 0jl '" Maturation E

c5 I X Years I

g: I-!-'-' w

o J'--,I-------,I----Ir---~I

May May May May May May

S Sx SX.1

Years

16
Table 8.-Morphological and meristic parameters ofshortnose sturgeon larvae from Pekovitch (see Table 2, footnote 14), Taubert and Dadswell (1980), Anonymous f.see

Table 2, footnote 2), and Bath et a!. (1981). Larvae are from (a) Saint John River, Canada; (b) Connecticut River; (c) Hudson River and their status is (\) reared from egg

or (2) captured in drift sampling nets.

Probable

Total Snout to Yolk sac Head Mouth Dorsal or known

Locality length Preanal Postanal vent length Eye length width widtb MW/HW Upper Lower fin Dorsal age

and status (mm) myomeres myomeres Total % TL diameter % TL (mm) (mm) % teeth teeth rays scutcs (d)

a. 1 7.3 34 24 58 68 1.0 <I

a, 1 7.9 35 23 58 68 36 0.9 <I

a, 1 8.1 33 24 57 63 0.9 <J

a, 1 8.6 33 19+ 52+ 70 0.43 34 1.0 0.28 28 <I

b, 2 9.1 34 22 56 69 0.30 31 <I

a, I 9.5 34 24 58 70 0.64 37 1.1 0.34 31 I

a, 1 9.6 35 24 59 67 0.64 34 1.1 0.42 38 I

b, 2 10.0 34 20 54 70 0.32 32 <I

a, I 10.1 36 24 60 63 0.57 32 1.1 0.45 41 I

b, 2 11.0 33-36 20-21 53-57 67 0.32 <I

b,2 11.1 34 22 56 65 I"

b,2 11.3 33-34 22-23 55-57 68 0.34 <I

b, 2 12.5 33 22 55 66 I?

a, 2 13.0 34 22 56 61 0.79 2.0 1.50 75 8

a,2 14.7 34 22 56 61 0.79 2.1 1.50 71 12 11 14 8

c,2 15.3 59 0.70 2.0 1.50 75 10?

c,2 15.5 61 0.70 2.0 1.50 75 10?

c,2 15.6 58 0.70 2.0 1.50 75 10?

c,2 16.0 55 0.70 2.3 1.50 65 10"

a, 1 16.2 35 26 61 62 0.86 2.5 2.07 83 9 10 15 10

c,2 16.3 37 21 58 54 16 10

a, 1 17.1 35 24 59 58 1.00 2.6 2.28 87 II 8 14 13

a, 1 17.2 61 0.85 2.8 2.00 71 16 13

c, 2 17.5 36 22 58 57 1.80 16 15?

c,2 18.0 37 22 59 58 1.80 17 15?

c,2 18.2 37 22 59 58 1.60 15 15?

a, 1 20.4 59 1.07 3.1 2.85 92 10 6 17 28

Figure 12.-0ne~ or 2-d old, 10 mm TL shortnose sturgeon protolarvae from

the Holyoke Pool, Connecticut River. Note large yolk sac, continuous fin fold,

lack of barbels, and no lateral fins (courtesy of B. Taubert, Univ. of Mass.).

Figure B.-Upper. Approximately 10-d-old, 14.7 mm TL shortnose sturgeon

mesolarvae from the Saint John River, Canada. Note: barbel (b) just anterior to

eye on ventral surface and anlage (a) dorsal fin. Lower. Ventral view of head of

14.7 mm TL mesolarvae illustrating mouth (m), teeth (t), barbels (b), and pectoral fins (p).

17
Figure IS.-Larval growth of shorlnose slurgeon. Figure is composile of data

from Ihe Saint John River, Canada, Ihe Conneclicul River (Taubert 1980a), and

Ihe Hudson River (Pekovilch 1979 see Table 2, foolnote 14). May 10th was

selecled as mean halching dale in all Ihree river syslems.

May 10

o'---'------;I~O-~20:;------,3;-;0;-----;4l;:-0--f50::------,6:!:0----,-----=7~0----,J80

June 10 July 10

Days After Hatching

140

120

100

E

E

.<: 80 C'

co

-'

60 c

I-"

40

20

Figure 14.-Upper. Ventral, dorsal, and lateral views of 16.3 mm TL shortnose

slurgeon from Ihe upper Hudson River (afler Pekovilch 1979 see Table 2, foolnole 14). Lower. Laleral view of 20 mm shortnose slurgeon reared in captivity

from Connecticut River slock (courlesy of Buckley, Univ. Mass).

Growth of fry

Early growth of shortnose sturgeon is rapid (Fig. IS). This

species attains between 14 and 30 cm by the end of its first growing season, depending on latitude. Juveniles are between 15 and

19 cm during July of their second summer season in the Saint

John River (Fig. 16) (Dadswell 1979). Evidence from the Hudson

River suggests the juveniles may reach 25.0 em by the end of their

first growing season (Pekovitch 1979 see Table 2, footnote 14)

and growth averages 3.0 mm every 10 d (Fig. IS). Growth may be

even more rapid in the southern United States (Heidt and Gilbert

1978 see Table 2, footnote 27).

A growth equation for shortnose larvae using data from the

Hudson, Connecticut, and Saint John Rivers was derived as

follows:

where Lo = 10.7 mm and t is time in days from hatching date

(chosen as 10 May). In the Saint John Rinr, Canada, shortnose

sturgeon exhibit a two-phase growth curve (Fig. 17) with a slow

growing "parr" stage between ages I and 9 (Pottle and Dadswell

1979 see Table 2, footnote I). Similar growth patterns are known

for Russian sturgeon species (Pavlov 1971).

A. B

Survival

No information on natural survival rates of shortnose sturgeon

larvae and juveniles is available.

Figure 16.-Transverse seclions of Ihe marginal ray of Ihe pecloral fin of shortnose slurgeon showing annuli. Dark zones are summer-formed dense bone;

Iranslucenl zones, winler bone. (A) 14.7 em, captured 20 May 1979, 1 yr. (B)

19.2 em, I Augusll979, 1 + yr. (C) 29 em, 11 July 1979, 3 + yr. (D) 45 em, 9 yr

(Pollie and Dadswell 1979 see Table 2, foolnole I).

18
80

76

60

g 50

30

20

10

6 7

Age (Years I

10 12

3.3 Adult phase (mature fish)

3.31 Longevity

The oldest shortnose sturgeon determined to date was a 67 -yrold female from the Saint John River, Canada; the oldest male examined, also from the Saint John River, was 32 yr (Dadswell

1979). Maximum ages determined to date for other river systems

are less but may be a reflection of smaller sample size. They are:

Kennebec, 40 yr (Squiers 14); Connecticut, 34 yr (Taubert 1980b);

Hudson, 37 yr (Dovel 1981 see Table 2, footnote 15); Pee Dee, 20

yr (Marchette and Smiley 1982 see Table 2, footnote 24);

Altamaha, 10 yr (Heidt and Gilbert 1978 see Table 2, footnote

27), but based on a small female (89 cm FL). In general, northern

populations of shortnose sturgeon have a life span similar to other

Acipenser, but southern populations may be relatively short-lived.

Figure 17.-Juvenile growlh of shorlnose slurgeon from age 1 10 11 in Ihe Saini

John River, Canada (Paille and Dadswell 1979 see Table 2, foolnole I). Bars

represent range of length at age and open dots are mean size.

Predators

The only record of predation on larval or juvenile shortnose

sturgeon is the occurrence of 24 juveniles approximately 5 cm FL

found in perch (Percaflavescens) stomachs from the Androscoggin

River, Maine (Squiers!3).

3.23 Adolescent phase

Young shortnose sturgeon begin to resemble adults by the time

they are 20-30 mm in length (Fig. 18), but they remain juveniles

until 45-55 cm FL or from 3 to 10 yr of age, depending on

latitude.

3.32 Hardiness

No research has been done on the physiological hardiness of

shortnose sturgeon.

Shortnose sturgeon have been captured in the Altamaha River

in 34°C water but Dadswell (unpub!. data) found young from the

Saint John River, Canada, to experience distress and/or rapid mortality at temperatures over 25°C.

Shortnose sturgeon are known to live in salinities up to 30 0 / 00

(Holland and Yelverton 1973; Marchette and Smiley 1982 see

Table 2, footnote 24).

Dovel (1981 see Table 2, footnote 15) found that shortnose

sturgeon from the Hudson estuary have severe cases of fin rot and

body sores, presumably from industrial pollutants, but are

reasonably healthy otherwise (i.e., weight-length relation normal;

Fig. 19).

3.33 Competitors

Shortnose sturgeon probably have no other competitors for

spawning area since they utilize the habitat early in the spring and

"T. S. Squiers, Fisheries Biologist. Maine Deparlment of Marine Resources,

Augusta. ME 04333. pers. commun. October 1976.

I4T. S. Squiers, Fisheries Biologist. Maine Department of Marine Resources.

Augusta, ME 04333. pers. commun. November 1981.

Fork

5

.'

I

I

I

I

:

I

I

,{'I

/

Greeley 1937 ./

Log W' 2.85 (Log FI) -482 /.

\ ./

",7' .....:::::.... ' Dovel 1978

a~:L-LOg W' 3.25 (Log FI)- 5.56 ~-::-::: ...

oL._--'---......,....,::--="'-::..:-:-=---'---_-_-_---'---_---L_----'__-l.-_---'--_--l._----l

o 10 20 30 40 50 60 70 80 90 100

Length (em)

Figure IS.-Dorsal and venlral views of 5 em TL, young-of-the-year shorlnose

slurgeon laken from Ihe stomach of a perch caplured in the Androscoggin

River, Maine.

Figure 19.-Weight-length relationships ofshortnose sturgeon from the Hudson

River, N.Y. There was a 40-yr interval between the two studies.

19
14 16

Gastropods Lymnaea" Physa

Gastropods Lymnaea" Physa

o Whitefish (Nov.>

[=~ Eckman (Nov.)

o Sturgeon (Aug.)

L} Eckman (Aug. Sample)

6 8 10 12

Gastropod Length (mm)

,

,

I

I

,

,

L,

,

L,

2

.-,

.I

I

I

Amn/cola, Valvata

I I

4

o

8

12

16

12

8

4

20

24

>.

g

":J

g 0

u:

_ Amnlcola, Valvata j 2

T i

16~

Figure ZI.-Size and frequency of gastropods found in stomachs of

shortnose sturgeon and lake whitefish feeding on the same resource

but at ditTerent limes of the year.

habitat. In the south, alligators; gars; and striped bass, Morore saxati/is; may be suspected as predators. In marine habitats, they

could be preyed upon by sharks or seals but the only evidence for

this may be the occasional specimen lacking a tail (see section

3.35).

\

\

\

\

\

"

,

\

'.

\

\

\

\

\

o

I

I

I

:

I

I

:

,

,

I

I

I

,

I

I

,

I

I

"z... M M J

Monlh

--------J----- .........-

~2z

10

u:::: 4

E 6

o

'"

temporally avoid the spawning of Atlantic sturgeon. Other possible competitors could be walleye, Stizostedium vitreum, and/or

spring-spawning rainbow trout, Salmo gairdneri.

Shortnose sturgeon compete for food with most other benthic

feeders, particularly those which exploit molluscs. In the Saint

John River, Canada, juveniles apparently avoid competition with

suckers (Catostomus) and Atlantic sturgeon, Acipenser oxyrhynchus, by spatial separation, i.e., juveniles occupy the deep, freshwater channels; the suckers, the shallows; the Atlantics the deeper

saline parts of the estuary (Dadswell 1979). A large degree of

habitat overlap occurs but darkness and/or turbidity may enhance

the success of the sturgeon because of the presence of barbels.

In the Saint John River, Canada, shortnose sturgeon and whitefish, Coregonus clupeaformis, compete for gastropods in the upper

estuary and shortnose sturgeon and winter flounder, Pseudopleuronectes americanus, for Mya arenaria in the lower estuary. Competition with the whitefish, however, is limited because the two

fish populations are segregated by temperature (Fig. 20) and there

appears to be some resource partitioning between the two (Fig.

21). The sturgeon utilize the gastropods during summer, the

whitefish, during the cooler period of the year; the sturgeon select

the smaller Amnicola and Valvata, the whitefish, the larger Lymnaea and Physa.

3.35 Parasites, diseases, injuries, and abnormalities

Figure ZO.-Utilization of the same feeding site in the Saint John River, Canada,

by whitefish (dark bars) and shortnose sturgeon (open bars) on a seasonal basis.

Competition with other fish species for food resources in central and southern Atlantic coast estuaries has not been studied.

More intense competition would, however, be expected because of

the large and complex fish communities present in the region.

Adult shortnose sturgeon may compete for space with similar

sized juvenile Atlantic sturgeon. In the Saint John River, Canada,

the two rarely occupy the same habitat and the separation seems

to be based on a salinity relationship. Large Atlantic sturgeon

juveniles predominate in water> 3 0/00 and shortnose adults in <

3 %0 (Appy and Dadswell 1978; Dadswell 1979). In the saline

water of Winyah Bay, S.c., Atlantic sturgeon outnumber shortnose sturgeon 2 to I (Marchette and Smiley 1982 see Table 2,

footnote 24) and may compete with them.

3.34 Predators

Adult shortnose sturgeon may have few predators. In general,

they are one of the larger fish occurring in their freshwater

A checklist of parasites recorded from shortnose sturgeon is

given in Table 9. Intensity of infestation is low in most cases except for Capillospirura. None appear harmful to the sturgeon.

No diseases have been recorded from shortnose sturgeon.

Abnormalities and healed injuries appear to be a common

occurrence among shortnose sturgeon. Fried and McCleave

(1974) described two shortnose sturgeon from Montsweag Bay,

Maine, one with only one barbel and one with forked barbels.

They also observed a bilaterally blind specimen. Table 10 summarizes the numerous abnormalities and healed injuries observed

during 6 yr of sampling in the Saint John estuary, Canada

(Dadswell, unpub!. data). One blind specimen was observed with

the eyes completely overgrown by flesh, another had no suggestion of an eye on its right side. The first fish was large and otherwise in excellent condition and was completely black in color,

both dorsally and ventrally. Figure 22 illustrates two other findings: No nasal septum (3 specimens); no tail (observed twice).

Dovel (1981 see Table 2, footnote 15) found that many adult

shortnose sturgeon from the Hudson River have severe cases of fin

rot and abdominal sores. Both problems were thought related to

industrial pollution. Pekovitch (1979 see Table 2, footnote 14)

20
Table 9.-Parasites recorded from shortnose sturgeon.

Group and Parasite Capture

species location locality

Coelenterata

Polypodium sp. Eggs Saint John River'

Diclybothrium armatum Gills Saint John River'

Spirochis sp. Mesenteric Saint John Riverl

blood vessels

Nitzschia sturionis Gills N.Y. Aquarium (may be

unnatural infection)

Nematoda

Capillospirura Gizzard Saint John River'

pseudoargumentosus

Acanthocephala

Fessesentis friedi Spiral valve Saint John Riverl

Echinorhynchus atlenuatus ? Woods Hole

Hirundinea

Calliobdella vivida External Connecticut Ri ver

Piscicola milneri External Connecticut River

Piscicola punctata External Connecticut River

Arthropoda

Argulus a/osa External Saint John River'

Pisces

Petromyzon marinus External Saint John River'

'Saint John River, N.B., Canada.

Authority

Hoffman et al. (1974)

Appy and Dadswell (1978)

Appy and Dadswell (1978)

MacCallum (1921)

Appy and Dadswell (1978)

Appy and Dadswell (1978)

Sumner et al. (1911)

Smith and Taubert (1980)

Smith and Taubert (1980)

Smith and Taubert (1980)

Appy and Dadswell (1978)

Dadswell (pers. obs.)

3.36 Physiology and biochemistry

Time of day

Table to.-Abnormalities and healed injuries found among shortnose sturgeon

from the Saint John River, Canada, and the Hudson River, N.Y.

Birth defect?

Remarks

Birth defect, entire sturgeon

melanistic

Eye completely missing

Birth defect

Birth defect?

Birth defect

Healed injury

Healed injury, extra long rays

in dorsal and anal fin

Healed injury

Sometimes nose cleft

Genetic (Hudson only)

Hudson River only

2

3

I

3

4

2

21

76% of

population

Times observed

Extreme blunt nose

3.41 Feeding

V-shaped snout

Fin rot

One eye blind

Lacking nasal septum

Bent backbone, shortened

caudal peduncle

Lateral spine curvature

(scoliosis)

Extra pelvic fin

Loss of pelvic or pectoral

fin

No tail

Condition

3.4 Nutrition and growth

No data available.

Total blindness (no eyes)

described a physical deformity involving a V-shaped section

missing from the snout of shortnose sturgeon in the Hudson River.

A total of 21 specimens, one as large as 87 mm TL, had the

deformity and he thought the trait was probably inherited.

Dadswell (pers. obs.) found shortnose sturgeon were most active

(most readily captured) during night or on windy days when water

Figure 22.-Defects and/or injuries of shortnose sturgeon: top. no nasal septum: bollom, caudal fln missing.

21
turbidity was high. Gill net catches were large during these periods

and sampled fish always contained full gastrointestinal tracts.

Dovel (1978 see Table 2, footnote 13) described Hudson River

shortnose sturgeon as moving into shallows during the night,

presumably to feed. Marchette and Smiley (1982 see Table 2,

footnote 24) observed shortnose sturgeon feeding at night on

molluscs off the undersides of lily pads.

Place

All feeding of shortnose sturgeon seems to be either benthic or

off plant surfaces. In freshwater portions of the Saint John estuary,

Canada, adult shortnose sturgeon foraged in weedy backwaters or

along the river banks over mud bottoms in depths of 1-5 m

(Dadswell 1979). During late summer, feeding areas tended to be

in deeper water (5-10 m), perhaps in response to higher temperatures in the shallows. What little feeding occurred in freshwater

during the fall and winter took place in deep water (15-25 m).

Juvenile shortnose sturgeon feed primarily in the deep channels

(10-20 m) over sandy-mud or gravel-mud bottoms (Pottle and

Dadswell 1979 see Table 2, footnote I).

In saline water of the lower Saint John estuary, adult shortnose

sturgeon feed over sandy-mud or mud bottoms in 5-10 m depths,

both in summer and winter. McCleave et al. (1977) found shortnose sturgeon in Montsweag Bay (salinity 18-25 0/00) were

feeding over mud-tide flats, mostly in 1-5 m depths. Townes

(1937) described the shortnose sturgeon as feeding in coves along

the Hudson River over mud bottoms in 4-10 m of water. Marchette and Smiley (1982 see Table 2, footnote 24) found the summer feeding habitat was characterized by shallow water with

sandy bottoms and emergent macrophytes and the winter feeding

habitat with deeper water and mud bottom.

Manner of feeding

The shortnose sturgeon, particularly the young, may simply use

its protuberant mouth to vacuum the bottom extracting substrate

as well as animals. Curran and Ries (1937) described shortnose

sturgeon stomachs from Hudson River fish as having 85-95% mud

intermingled with plant and animal debris. During winter in South

Carolina, sturgeon stomachs contained 90% by volume nonfood

matter (Marchette and Smiley 1982 see Table 2, footnote 24).

Dadswell (1979) found a similar situation among juvenile shortnose sturgeon from the Saint John River implying they employed

random suctorial feeding.

The stomach contents of many adults from the Saint John

River, Canada, and Winyah Bay, S.C., contained little or no nonfood matter. In most adults examined from freshwater portions of

the estuary, crop contents were solely food organisms, implying

either efficient separation of food and bottom debris between

mouth and crop (possibly with ejection of debris out through the

gills), or feeding was precisely oriented and took place off

vegetative surfaces rather than off mud (Marchette, pers. obs.).

The latter possibility is likely a normal occurrence since major

shortnose sturgeon prey such as the small gastropods Annicola limnosa and Valvata spp. (Dadswell 1979), live mainly on the leaves

and stems of submerged macrophytes. Stomach contents of adults

feeding in saltwater on Mya arenaria or Corbicula manilellsis

however, often had a high portion of mud and bottom debris

(30-60%), implying that in the situation of partially buried food,

they probably vacuumed the bottom.

22

Regular spatial dispersion of foraging shortnose sturgeon captured in gill nets suggests they feed individually (Dadswell, pers.

obs.).

Frequency

Feeding frequency of individual adult shortnose sturgeon is

unknown but completely filled gastrointestinal tracts at all times

of daily capture during summer in the Saint John River, Canada,

suggest feeding is continuous.

Variation of feeding with availability, season,

age, size, sex, and physiological condition

The ventral, protrusible mouth and barbels of the shortnose

sturgeon are adaptations for a diet of small, live, benthic animals.

Adult shortnose sturgeon (+50 cm) generally feed on whatever

mollusc is readily available. In the Saint John River, Canada,

Dadswell (1979) found shortnose sturgeon fed on Mya arenaria in

saline water, Macoma balthica where it was dominant in brackish

water, Amnicola limnosa and Valvata spp. in freshwater of high

chloride content (100-1,000 ppm), and Pisidium spp. and Elliptio

complanata in permanent freshwater regions. Marchette and

Smiley (1982 see Table 2, footnote 24) found molluscs were

abundant in the sturgeon's diet in freshwater and polychaetes in

saltwater. Juvenile shortnose sturgeon feed primarily on benthic

insects and crustaceans and their diet is dominated by crustaceans

where they are most available and insects where they are most

abundant (Townes 1937; Currand and Ries 1937; Dadswell

1979).

Feeding in freshwater portions of the Saint John River, Canada,

and Winyah Bay, S.c., is largely confined to periods when water

temperature exceeds lOoC (Table 11; Dadswell 1979; Marchette

and Smiley 1982 see Table 2, footnote 24). During the warmwater

season, gastrointestinal tracts of New Br·mswick sturgeon were

crammed with prey but in South Carolina many fish were empty.

Feeding in freshwater was minimal during winter. At most, a few

shortnose sturgeon were found to contain 1-5 small amphipods or

isopods. Shortnose sturgeon captured in saline water, however,

were found to feed all year but food volume in the gut during

winter was about half the summer level (Table 11; Dadswell 1979;

Marchette and Smiley 1982 see Table 2, footnote 24). Reduced

feeding activity during winter was probably a result of low water

temperature.

Dadswell (1979) found that female shortnose sturgeon ceased

feeding about 8 mo before spawning. The stomachs of all females

examined with stage III or more developed gonads after the beginning of August through to when spawning occurred were empty.

Developing males, on the other hand, feed during fall and winter if

they are in saline water. Immediately after spawning males and

females fed heavily.

3.42 Food

Juvenile shortnose sturgeon eat available benthic crustaceans or

insects (Table 12). Townes (1937), Curran and Ries (1937),

Dadswell (1979), Pottle and Dadswell (1979 see Table 2, footnote

1), and Taubert (l980b) all found Hexagenia sp., Chaoborus sp.,

Chironomus sp., Gammarus sp., Asellus sp., and Cyathura polita to

be important prey items. Pottle and Dadswell (1979 see Table 2,

footnote 1) found young shortnose sturgeon (20-30 cm FL) often

feed extensively on Cladocerans. Adult shortnose sturgeon from
Table ll.-Incidence, mean volume, mean dry weight, and fullness of food in stomachs of adult

shortnose sturgeon captured in freshwater «3 0/00) and saline (>3 0/00) portions of the estuary,

Saint John River, Canada (N.B.), and Winyah Bay, S.c. (S.C.), in relation to month. Fullness is

Bleguard's index (W x 10,000) / WI where W = weight of ration and WI = weight of fish.

Freshwater

Sample Number Incidence Volume Index of

size empty (%) (ml) Dry weight fullness

Month N.B. S.c. N.B. S.c. N.B. S.C. N.B. S.c. (g) N.B. S.C.

January 8 0 8 0 0.0 0.0 0.00 0.0

February 10 0 9 0 10.0 0.6 0.28 0.7

March 8 0 8 0 0.0 0.0 0.00 0.0

April 7 6 5 4 28.6 33.3 2.0 32.0 0.19 2.5 21.2

May 9 3 3 2 66.6 33.3 16.0 2.5 7.32 12.1 2.5

June 12 8 I 7 91.6 12.5 21.9 35.5 9.56 15.7 22.2

July 16 13 4 6 75.0 53.8 30.1 28.2 9.73 22.4 16.3

August 24 16 4 12 83.3 25 40.7 40.5 12.52 25.6 27.1

September 10 0 I 0 90.0 40.2 17.83 24.8

October 3 0 2 0 33.3 20.l 7.88 12.4

November 4 0 3 0 25.0 1.4 0.31 3.8

December 5 0 4 0 20.0 0.5 0.18 1.0

Saline water

September 16 0 2 0 87.5 37.4 10.85 24.5

December 6 I - 83.0 12.1

February 8 6 2 5 75.0 16.7 21.0 0.5 8.20 16.5 0.1

March 1 I 0.0 0.0 0.0

April 2 0 100.0 19.6 1.49 2.5

the Saint John River, Canada, eat mostly molluscs (Dadswell

1979). Marchette and Smiley (1982 see Table 2, footnote 24)

found Physa sp. (53%), Heliosoma sp. (47%), and Corbicula

manilensis (33.3%) to be the most commonly occurring items in

stomachs of fish captured in freshwater in South Carolina (Table

13). Curran and Ries (1937) combined adult and juvenile food

data, making it impossible to interpret their findings beyond the

fact that molluscs constituted 25-53% by volume of the gut contents of all their sampled fish. Benthic crustaceans and insects appear to be relatively more important in the diet of adult shortnose

sturgeon from the upper Connecticut River (Taubert 1980b;

4,000+ mayflies in one stomach) and the Hudson River (Curran

and Ries 1937), but these findings may be a reflection of food

availability rather than a preference change. Dadswell (1979) and

Marchette and Smiley (1982 see Table 2, footnote 24) found that

electivity of shortnose sturgeon for preferred prey was marked and

it is possible the occurrence of nonpreferred prey in the gut is a

byproduct of the suctorial feeding method. McCleave et al. (1977)

found adult shortnose sturgeon in Montsweag Bay (salinity 18-24

0/00) were feeding on Mya arenaria, Crangon septemspinosa, and

small flounder, Dadswell (1979) found Mya arenaria dominated

the diet in the lower Saint John estuary (20 0/00)' and Marchette

and Smiley (1982 see Table 2, footnote 24) found mollusc-shell

fragments as well as polychaetes in all sampled shortnose

sturgeon.

3.43 Growth rate

Growth in length and weight of shortnose sturgeon has been

reported from the Saint John River, Canada (Dadswell 1979), the

Kennebec River (Squiers and Smith footnote 7), the Connecticut

River (Taubert 1980b; Buckley 1982), the Hudson River (Greeley

1937; Pekovitch 1979 see Table 2, footnote 14; Dovel 1981 see

Table 2, footnote 15), the Pee Dee-Winyah Bay region (Marchette

and Smiley 1982 see Table 2, footnote 24), and the Altamaha

23

River (Heidt and Gilbert 1978 see Table 2, footnote 27). Because

of the slow growth of this species, ageing, which is best done by

cross-sectioning a pectoral ray, can be difficult (Fig. 23). The first

year's growth (Fig. 16) is often lost by sectioning too far from the

body or by subsequent growth processes (Fig. 23). Tight belts of

annuli, thought to be caused by slow growth during gonad ripening

(Roussow 1957), also make interpretation difficult. Recently,

Stone et al. (1981 )15 have developed a method for Giemsa staining of decalcified ray cross sections which improves readability.

Figure 24 shows the known growth rates in length of shortnose

sturgeon for its latitudinal range and Figures 25, 26, 27, 28, and

29 illustrate length and weight growth for shortnose sturgeon of

different age and sex in the Saint John River, Canada (Dadswell

1979), and the Pee Dee-Winyah system, S.c. (Marchette and

Smiley 1982 see Table 2, footnote 24).

Shortnose sturgeon grow fastest in the southern portion of their

range but apparently attain smaller maximum size than in the

north (Fig. 29; Table 14). The von Bertalanffy growth parameter

K varies from 0.044 to 0.149 over the north to south latitudinal

range of the species. Juvenile growth is rapid in the south and

shortnose sturgeon reach 50 cm after only 2-4 yr (Fig. 24).

Growth ofjuveniles is very similar for the three populations so far

studied in the central portion of the range. The Holyoke Pool of

the Connecticut River has the slowest growing adults known to

date (Fig. 24). This slow growth is probably a reflection of early

maturity, and the limited food resources available in the freshwater portion of the river to which the population is confined

(Taubert 1980b). The maturity inflection (depression of growth

rate) of the length-growth curve is very obvious for the Holyoke

Pool population (Fig. 24). Growth of juveniles is slowest in the

"Stone. W. B.• A. M. Narahara. and W. L. Dove!. 1981. Oiesma stained se".

tions of pectoral fin rays for determining the age of sturgeons. Unpub!. ms.. 4 p.

N.Y. Dep. Environ. Conserv.
Table 12.-Percent occurrence (%J and mean percent volume (%V) of prey in stomachs of

juvenile «SO em) and adult (>50 em) shortnose sturgeon from fresh «3 0/00 ) and saline (>3 0/00 )

portions of the Saint John River estuary, Canada.

Juveniles Adults

Fresh (n=49) Saline (n=8) Fresh (n=50) Saline (n=26)

% %V % %V % %V % %V

ANNELIDA: total 0 0 8 23

Polychaeta: total 0 0 4 23

Scoleolepides viridis 0 23 13

Hirundinea 0 4

CRUSTACEA: total 50 100 25 16

Cladocera

Eurycercus glacio/is 8

Latona setifera 15

Ostracoda 20 10 0 0

Isopoda: total 30 75 6 12

Cya/hura polito 30 61 75 60 6 4 12

Amphipoda: total 30 50 12 0

Hyalella az/eea 0 12 2

Gammarus tigrinus 30 67 50 45 4 I 0

Mysidacea: total 10 13 0 0

Neomysis americana 10 2 13 0 0

Decapoda

Crangon septemspinosa 0 4 2

INSECTA: total 70 63 26 12

Ephemeroptera 40 4

Hexagenia sp. 40 57 4 2

Trichoptera 30 38 8 2

Diptera 60 63 25 12

Chironomidae 60 35 63 40 25 3 12 2

Chaoborus punctipennis 20 5 0 0

Culieoides sp. 31

MOLLUSCA: total 10 13 100 95

Gastropoda: total 10 13 94 23

Heliosoma anceps 0 66 8

Eyraulus deflee/us 0 26 2

Physa aneillaria 0 14 2

Lymnaea elodes 0 60 10

Va/vola Iriearinala 0 62 16

Valvala sincera 0 0 56 5 4

Amnicola limnosa 10 15 13 10 88 64 19

Pelecypoda: total 0 0 52 95

Ellip/io camplanala 0 I I

Sphaerium sp. 0 30 18

Pisidium sp. 0 12 2

Macoma baltica 0 38 40

Mya arenaria 0 81 85

Pisces 0 0 2 4

Anguilla rostrala 0 0 2 10 4

(larvae)

24
Table B.-Percent occurrence (%) and mean percent volume (% V) of

prey in stomachs of adult shortnose sturgeon from fresh «3 0/ 00) and

saline (>3 0/00) portions of the Winyah Bay estuary, S.C.

Saint John River, Canada, but adult growth is sustained throughout life, resulting in a larger maximum size in this population.

Figure 25 illustrates the different growth rates between adult and

juvenile shortnose sturgeon in the Saint John River. The maturity

inflection which begins between ages 7 and 10 is overridden when

the juveniles migrate to the inshore regions of the lower estuary

and a richer food base, resulting in subsequent growth increment

increase (Fig. 30; Dadswell 1979). A similar behavior pattern and

growth change occurs in South Carolina (Fig. 30; Marchette and

Smiley 1982 see Table 2, footnote 24). Most of the Holyoke

population is apparently unable to carry out such a migration

(Taubert 1980b) and slow adult growth rates may be the result.

The smaller L oo of adults in the Kennebec and Hudson Rivers, as

compared with the Saint John may be due to stress caused by

pollution. In other southern populations, smaller L oo is probably

an expression of younger maturity and more frequent gonad ripening because of faster juvenile growth and warmer water

temperatures. This phenomenon is common to fishes with distinct

populations over a south-north latitudinal range (Jones 1976). The

weight-age relationship of shortnose sturgeon from four studied

populations is illustrated in Figure 31. Weights of stage V females

from Altamaha River (Heidt and Gilbert 1978 see Table 2, footnote 27) were adjusted to reflect stage II condition (x 0.80).

Weight gain is rapid in the south, slower but sustained in the

north, and least during the freshwater stage or for solely freshwater populations (Holyoke). The weight-age relationship for the

entire life span of shortnose sturgeon in the Saint John River,

Canada, is illustrated in Figure 26. The von Bertalanffy growth

equation for this population is Wt = Woo (l_e-0041 (,-l.061 »3.

Average length and weight gain/year in various populations are:

5 cm/yr and 400 g/yr, Altamaha River; 2.0 cm/yr and 260 g/yr,

Kennebec River; 1.3 cm/yr and 167 g/yr, Holyoke Pool; 1.5 cm/yr

and 300 g/yr, Saint John River, Canada. Dadswell (1979) found in

a capture-recapture study over a 4-yr period in the Saint John

River that observed average length and weight gain among recaptured shortnose sturgeon was 0.72 cm/yr and 490 g/yr (Table 15).

Taubert (l980b) found growth of recaptured fish was 1.8 cm/yr.

Buckley (1982) found ripe adults massed below the spawning site

Fresh (n = 15)

% % V

Annelida

Polychaeta

Crustacea

Amphipoda 26.6 0.9

Isopoda 20.0 0.25

Insecta

Euphemeroptera

Hexagenia sp. 13.3 51.4

Diptera

Chironomidae 6.6 0.2

Mollusca

Corbicula manilensis 33.3 64.3

Heliosoma sp. 46.6 12.3

Physa sp. 53.3 85.9

Shell fragments 6.6 16.0

Vegetative matter 20.0 3.5

Detritus 6.6 40.0

Sand 13.3 80.0

Saline (n = 6)

% % V

16.7 0.5

33.3 0.75

100.0 89.7

33.3 15.0

25

in the Connecticut River lost an average 15% of body weight during winter before spawning.

In the Saint John River, Canada, Dadswell (1979) found male

and female shortnose sturgeon had different growth relationships

(Figs. 27, 28). Males grew more rapidly until mature but growth

rate as adults decelerated at a greater rate than females. A similar

growth pattern occurs in males and females from South Carolina

(Fig. 29; Marchette and Smiley 1982 see Table 2, footnote 24).

More frequent ripening of gonads among males may be the cause

of this type of growth relationship.

3.44 Weight-length relationships, condition factors

The weight-length relationship for shortnose sturgeon from the

Saint John River is illustrated in Figure 32 (Dadswell 1979). It is

essentially similar to weight-length relationships of other sturgeon

species. Weight gain is slow for the first years of life, then increases for most of the remainder of the life span.

The weight-length relationships for shortnose sturgeon populations studied to date are given in Table 16. Some were calculated

from preliminary data provided by various workers. In general,

the relationships are similar. Calculated condition factors were

lowest for the Kennebec River (Squiers and Smith footnote 7) and

the Holyoke Pool populations (Taubert I 980b). Both these populations are somewhat stressed, the Kennebec by pollution (Squiers

et al. 1981 see Table 2, footnote 3), the Holyoke by confinement

to freshwater. Figure 19 compares the weight-length relationship

of the Hudson River population for studies 40 yr apart; capture

gear differences aside, the two relationships are remarkably

similar. Dadswell (1979) found no statistical difference (paired

I-tests) between the weight-length relationships of various spawning stage and sexes of shortnose sturgeon from the Saint John

River, Canada (Fig. 33).

Condition factor (k = W/V) of shortnose sturgeon in the Saint

John estuary varied through the year, reaching a peak in late

winter as gonads of ripe fish reached their maximum size, and

declining to the lowest level in May after spawning (Table 17).

Average summer condition of shortnose sturgeon was 0.87 and

recovery to this level occurred soon after spawning, probably

because of the increased feeding observed at this time (Dadswell

1979).

3.45 Metabolism

No data are available on the metabolism of shortnose sturgeon.

3.5 Behavior

3.51 Migrations and local movements

Extent of movements

In estuarine and riverine environments where shortnose

sturgeon have been tagged and recaptured, they are known to

move considerable distances. In the Saint John estuary, the mean

minimum distance travelled by those shortnose sturgeon which

moved more than I km between recaptures was 22.9 ± 6.7 km.

The maximum channel distance travelled between tagging and

recapture was 160 km (Dadswell 1979). The mean minimum rate

of upstream movement of I I shortnose sturgeon in the Saint John

River between June and August was 4.0 ± 1.5 km/d (Fig. 34). In

the Altamaha River, Ga., a shortnose sturgeon moved 193 km
A B 1y

Figure 23.-Transverse sections of the marginal ray of the pectoral fin of shortnose sturgeon showing annuli. Dark

zones are summer·formed dense bone; translucent zones, winter period. (A) Juvenile: 45 em, 0.8 kg; 9 yr (X 18). (B)

Male: 97 em, 9.4 kg; 27 yr (x8) (annuli 17 and 19 each have a false annulus associated; year 1 is almost obscured, arrow).

(C) Female: 112 em, 12.5 kg; 40 yr (x5). Matured age 11, spawned at 21, 26, 32, 37 yr. (D) Female: 86 em, 6.1 kg; 23 yr

(x5). Matured at 10, spawned at 16, but no later spawning checks discernible.

26
50 60 70 30 40

Age I Years)

20

n: 446

10

Adults 10·67 Years 3

W,' 23.0 (,., -0.047 (1.2.061) 1/

/ I" /1' '

.•I,.I-H·}r

1- Altemeh. R., Georili. (Heldt It Gilbert, pers. comm.l

2- Hud.on R., N.Y. (Gre.ley 11137)

3- Kennebec R., 1Il.lne (Squier. It Smith pers. comm.)

4- S.lnt John R., New Brun.wlck (O.d.well 1979)

S- Holyoke Pool, Connecticut R., 1Il....chu.ets

(T.ubert 1980b)

4 110

100

90

80

E 70

2

s::.

C. 60 co

..J

"

""l5 SO LL

10 6- Pee Dee R. o S.C.

7- Hud.on R., N.Y.

Figure 26.-Weight.age relationship for shortnose sturgeon from the Saint John

River, Canada.

Figure 24.-Growth of shortnose sturgeoD in various rivers within the species

range. (Sexes combined.)

O'--_J-_--L_--l_~L---'--__='=----'-~

o 10 20 30 40

Age (Years)

60 70

('-0.791)

Females 10 - 67 Years , WI' 24.8 (I-e -0.042 (I -0.80 I')

,-II' ___

60

Females 10 - 67 Years

L,'I270 (,.,-004711'1.101)

,'112

.. ·~]i;

.) .... '

~;?tfP~ l~~( p Moles 10·32 Years

;, iT L, ' 108.7 (, _, -0063

'@IT ~' ,'55

40L----'-'/.J.;_/_'_

L

..J:_'_--'-_-'-__LI_-'-_--'I__~_.J.I_--'__L__~_.J W W 50

Age (Years)

120

24

16

20

'E 'OO

Figure 27.-Growth of male and female shortnose sturgeon from the Saint John

River, Canada, fork length versus age.

30 40 50 60 70

Age I Years)

10 20

120 ---'- 100

~~'f 10 - 67 Years 60 -0042 (I +1 961 :'; (I-e

c 60 f' --' '------- . Juveniles I - 9 Yea rs

0 L, : 65.8 (I-e - 0.104 (1 + 1.52 J

... 40 i

Figure 25.-Growth of juvenile and adult shortnose sturgeon from the Saint

John River, Canada. Bars represent range and crossbars 95% confidence limits

of year sample. Note sharp change in growth pattern at age 9·10.

Figure 28.-Growth of male and female shortnose sturgeon from the Saint John

River, Canada, weight versus age.

10 '0

e·

I I

30 40

Age (Years)

50 60 70

27
Figure 29.-Growth of male and female short nose sturgeon from the Pee DeeWinyah system, S.C.

Juveniles

Saint John

4

Juvenile Fork length (em)

o 20 40 60

1

27.

4 \ I I

, \

\

\

I

\

I Juveniles I?Pee Dee- Win yah

I

, \

I

I

I

,\

\ Adults

\ Pee Dee· Winyah ,0 loa= 90cm

'\'~'-'-' II -~....::..~\ • \~ sa~~~~~n Loo'130cm

-- ..,...... \ ~.. \ ..-.~. .. l1li.__ ...... '-a.........~.

o'---'-----,4'=0-.LL--:e"=o---'---e:'co:---=:o"L--,...J.oo---'---'..l2..:"O=.lL..-

Adult Fork length Lt (em)

t

~12~ -'

8 12 16

Age (Years)

Females 5-17 Years ,,-

L

t

=83.8 (I-e -0.13 (t+2.33)) "o,o,,,~ ,0

:.-------

,0,0

</,'

,,0" 0,,0 Males 5-18 Years

,,/ L t=73.9 (l_e- 0 .

11 (t+4. S0 1)

0 1

80

E 70

3

.::

C,

c: 60 Ql

...J

.>£

(;

U- 50

40

0

Figure 30.-Yearly length-increment change during growth of shortnose

sturgeon from the Saint John estuary, Canada, and the Pee Dee-Winyah

estuary, S.C. Growth increments of < SO em (open circles) and> SO em (solid

circles).

.

( Table 14.-Von BertalanfTy growth parameters for length relationships of §'

'j

shortnose sturgeon populations of eastern North America. 10 ...

$'

",ftJ

L oo . Locality Latitude (FL) K Source

Altamaha R., 32°N 97.0 0.149 -3.15 Heidt and Gilbut l

8

Georgia

Pee Dee-Winyah, 34°N

S.c. 0'

Females 83.8 0.133 -2.33 Marchette and

Males 73.9 0.114 -4.50 Smiley (see .c

Combined 87.0 0.093 -6.02 Table 2, .'=?' 6

~/ /~ footnote 24)1 ~.

Hudson R., N.Y. 42°N 0 'CJ~Q.c?;- Females 102.6 0.079 -3.17 Greeley (1937)1 I0 ~"lJ

Males 57.9 0.305 -1.80 !::'~':::..~

Combined 106.4 0.044 6.39 Dovel (see Table ~. /"" ftJ • (p~

4

!"" j/' 2, footnote 15)'

Connecticut R. 43°N .. 0 0

Lower 100.0 0.073 -2.73 Buckley (unpubl. 00/0 i .' dalal'

Holyoke Pool, 87.8 0.084 -2.64 Taubert (1980b)

Kennebec

Mass.

R., 44°N '93.8 0.098 -3.89 Squiers and SmLh o

;!,//1 "

(see text . / ~.

footnote 7) o •

Saint John R., 45°N . Canada

Females 127.0 0.047 -1.10 Dadswell (1979) 5 10 15 20 25 30 35 40

Males 108.7 0.063 0.79 Age (Years l

Combined 130.0 0.042 -1.96

,Calculated from original data by Dadswell.

2Sturgeon longer than this were observed.

Figure 31.-Weight-age relationship of shortnose sturgeon from four

rivers spanning the range of the species.

28
Table 16.-Weight·length relationships for shortnose sturgeon populations

from the east coast of North America.

Table IS.-Observed mean length (Iii) and mean weight (6W)

change of tagged shortnose sturgeon during I to 4 yr at large in the

Saint John estuary, Canada. Obvious large I-yr weight increases

due to female gonad maturation were excluded from data. Locality Relationship Source

32 0.8 0.2 0.8 0.2

19 0.7 0.1 0.7 0.1 -- -- mcan 1ii/6T=0.75 6W/6T=0.15

15 1.3 0.5 0.65 0.25

19 1.4 1.5 0.70 0.75

4 2.2 1.2 1.1 060

mean M../6T=0.82 6W/6T=0.53

2 0.0 2.8 0.0 0.93

II 3.7 2.4 1.23 0.80

mean 1ii/6T=0.62 6W/6T=0.86

4 2.2 1.2 0.55 0.30

All data mean 1ii/6T=0.72 6W/6T =0.49

Period at large

1973-74

1974-75

1973-75

1974-76

1975-77

1973-76

1974-77

1973-77

6T

(yr)

2

2

2

4

N

Iii

(cm)

6W

(kg)

Altamaha R.. Georgia

Pee Dee R., S.c.

Delaware R., N.J.

Hudson R., N.Y.

Hudson R., N.Y.

Hudson R., N.Y.

Holyoke Pool

Connecticut R., Mass.

Lower Connecticut R.

Kennebec R., Maine

Saint Jobn R., Canada

'LogW = 2.95(LogFL)-5.01

LogW = 3.06(LogFL)-5.29

'LogW = 3.1 I (LogFL)-4.25

'LogW = 2.85(LogFL)-4.82

'LogW = 3.25(LogFL)-5.56

JLogW = 2.73(LogTL)-1 0.12

JLogW = 3.03(LogFL)-5.23

LogW = 2.98(LogFL)-5.08

'LogW = 3.10(LogFL)-4.90

'LogW = 3.20(LogFL)-5.45

Heidt and Gilbert'

Marchette and Smiley

(see Table 2. footnote

24)

Hastings (see Table 2,

fOOlnote 19)'

Greeley (1937)'

Dovel (see Table 2,

footnote 13)'

Pekovitch (see Table 2,

footnote 14)

Taubert (1980b)

Buckley (unpubl. data)

Squiers and Smith (see

text footnote 7)

Dadswell (1979)

100120

I I

70 80 90

Log ro For k Leng th (em)

50 60

'w in kg. FL in cm.

'Calculated by Dadswell.

JW in g, TL in mm .

15

10

8

co

6

.z:

co

; 4

e 3 co

0

..J

40 60 80 100 120

FOlk lenglh leml

20

.

Log W' 3.21 (Log FLI-5.45

/ r' 0.99

n ' 2 890

5

1/

0

5

0

~~~~

20

_I

.;;;

Figure 32.-Weight-length relationship for shortnose sturgeon from the Saint

Jobn River, Canada. Circles are mean weight for I ern length increments, bars

are range of weight.

Figure 33.-Log·log regressions of weight·length relationships for stage 11, and

V male and stage 11, V, and VI female shortnose sturgeon from the Saint Jobn

River, Canada.

Table 17,-Mean condition factor (K = [W

)( 10) / LJ) by month for shortnose sturgeon

in the Saint John estuary, Canada.

downstream in II d (Heidt and Gilbert 1978 see Table 2, footnote

27) and in the Connecticut River one radio-tagged shortnose

sturgeon moved 60 km in 2 d (Buckley, unpubJ. data). McCleave

et aJ. (1977), using sonic tags, documented a mean daily rate of

shortnose sturgeon movement of about 20 km in Montsweag Bay,

Maine. Shortnose sturgeon movement during the Montsweag

study appeared to be predominately nondirected, random feeding

movements, often into very shallow water.

On the other hand, Taubert (1980b), using radio tags, found

that for the landlocked population of shortnose sturgeon in the

Holyoke Pool, Connecticut River, individuals had small home

ranges which they inhabited year around unless they migrated

upstream in spring to spawn. No general migration of the population to spawning or overwinterin~ sites was observed, but it may

have gone unnoticed because of small population size. It appeared

that the tagged sturgeon had the ability to leave their home area

Month

January

February

March

April

May

June

K

0.85

1.12

1.28

0.91

0.73

0.88

Month K

July 0.82

August 0.86

September 0.91

October 1.11

November 1.19

29
Lorge

\ 99036

99281

99294

99379

99399

99794

June-July, '75

99291

:::-;:0;)'~"g/-J July 17, '75

33338

•••. Togged

00" - Recapture

::::::~ Hypothetical Track

_-::~ =and Direction

•••. Togged

o 0 '" - Recapture ____ Hypothetical Track

-~~--~ and Direction

99123

Sept 10

(70)

Channel width exaggerated

July24

( 37)

99048

June 17

•••- Togged

00" -Recapture

-Hypothetical Track

and Direction

17560

July 23,'74

.17560

- Aug 20, '75

99134 - July 9' •.

(6)

•••. Togged

" 00 • Recapture

...::.~~-=~...: -Hypothetical Tiock

and Di rection

44292

99134

60481

June 3:78

99429

99469

99529

Ju Iy 22

Recapture

July II

( 3)

Channel width exaggerated

I Channel width exaggerated

Figure 34.-Movement ofselected shortnose sturgeon In the Saint John estuary, Canada: Top left, short-term movement, July-August, movement predominantly upstream; top right, movement between late summer to early spring, generally downstream; bottom left, long-term migratory movement; bottom right,

residential behavior during summer and movement to winter concentration sites. Numbers in parentheses under dates in top figures Indicate number of days at

large between capture and recapture.

30
A

F

Summer

Feeding

Concentration

B

NEW YORK CITY

c

Rkm 180

Summer

Concentration

..-& Over Wintering

HOLYOKE DAM 0

Spawning' Rkm 140

Site ~:.. Over Winter Site

!. ".... Spawners (Oct.-Noy-J Spent '. "'.

(Apr.-May) iffiR-k-m-1-1-2-

Summer

Concentration

Rkm 84

LONG ISLAND SOUND

Figure 3S.-Migration patterns of various life stages ofshortnose sturgeon in river systems studied to date. A) Saint John River, Canada: B) Kennebec River, Moine; (')

Holyoke Pool, Connectieut River, Moss.; D) Lower Connecticut River; E) Hudson River, N.Y.; F) Pee Dee-Winyah Boy system, S.C.

31
Direction and mode of migratory movements

Otnabag Lake 60 km

10 -- - - 0

July I Aug. Sept Oct May June I Nov

Time or season of migration

Spawning migrations to the upstream spawning grounds occur

in spring or fall. Spring movement onto the spawning grounds apmany ripening males and females either migrated farther upriver

in the fall or remained at upriver locations over winter (Fig. 34;

Dadswell 1979; Buckley 1982). Abundance peaks during downstream migration were of shorter duration, suggesting this

migratory phase was more rapid.

Squiers and Smith (footnote 7) reported similar behavior of

shortnose sturgeon in the Kennebec River. Recaptures of tagged

shortnose sturgeon during July occurred upstream of June tagging

sites and downstream sites had bimodal abundance peaks, while

upstream sites had unimodal peaks.

Heidt and Gilbert (1978 see Table 2, footnote 27) and Gilbert

and Heidt (1979), however, observed a different migration pattern

in the Altamaha River, Ga. There, shortnose sturgeon were found

upstream during February and March while spawning but during

the remainder of the year were taken only in the first few

kilometers of the river within tidal influence. Marchette and

Smiley (1982 see Table 2, footnote 24; Fig. 8b) reported a similar

migration pattern in the tributaries of Winyah Bay, S.c., with

adults spending the winter in the estuary or the sea within 5,000

m of shore. Documentation of shortnose sturgeon movements in

the Hudson River is still in progress but current information suggests a combination of patterns occur. There is a spawning run in

spring to the upper reaches of the estuary (rkm 130-150; Dovel

1981 see Table 2, footnote 15; Pekovitch 1979 see Table 2, footnote 14; Greeley 1937), many actively feeding adults occur in the

river during summer (Curran and Ries 1937; Dovel 1978 see

Table 2, footnote 13), and adults are also captured in the sea during summer about the mouth of the river (Schaefer 1967; Wilk

and Silverman 1976). In the Holyoke Pool of the Connecticut

River, shortnose sturgeon were found to move only short distances

except during upstream spawning migration (Taubert 1980b). In

the lower Connecticut River, movement patterns are similar to

those in the Saint John River (Kynard et al. 1982;16 Buckley

1982; Fig. 35). Dadswell (1979) found that a portion of the Saint

John River shortnose sturgeon population migrated to the Bay of

Fundy but remained close to the river mouth.

In contrast with the migratory behavior of the adults, juvenile

shortnose sturgeon are nonmigratory and largely confined to the

inland riverine portion of estuaries upstream of the salt wedge

(Pottle and Dadswell 1979 see Table 2, footnote 1). In the Saint

John River, juveniles are only captured seaward of the normal

salt-wedge excursion region during flood periods (Dadswell

1979). The mean length of shortnose sturgeon in the under 45 em

size group was least in upriver portions of the estuary and the

length difference between size classes with a mean length of < 45

em and > 45 em was greatest in downstream and lacustrine

regions (Table 3). These data suggest there is a gradual downstream movement of juveniles as they become older. Recent work

has shown that the major juvenile concentration is just inland of

the salt wedge and they move in the estuary according to saltwedge perturbations (Pottle and Dadswell 1979 see Table 2, footnote I). Dovel (1978 see Table 2, footnote 13) found a similar

distributional relationship for juvenile shortnose sturgeon in the

Hudson River.

-~ .

Westfield 13 km Upriver

10

20

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20

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-<= Main Channel 35 km N

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:z: ,

,

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The normal pattern of migration in shortnose sturgeon conforms to the simple model of Harden Jones (1968) in which, during life, fish move between feeding, wintering, and spawning

areas (Fig. 35).

Seasonal gill net catch data from discrete estuarine localities in

the Saint John River demonstrated bimodal abundance peaks in

the mid-estuary and a unimodal peak in the upper estuary (Fig.

36; Dadswell 1979). Recaptures of tagged shortnose sturgeon in

the Saint John River indicate changing abundance patterns 'Nhich

represent annual migration upriver in spring-summer and downriver in fall by most of the nonripening portion of the population

(Fig. 34). Some ripening males carried out a similar migration but

and return after long-distance movements. Buckley (1982) found

that radio-tagged shortnose sturgeon in the lower Connecticut

River also tended to stay in localized areas during sumLler but

migrations occurred in spring and fall similar to those il other

rivers (Fig. 35). He found the mean daily rate of migration against

the current, from feeding grounds to spawning grounds, was 0.82

± 0.47 km/d.

To date short nose sturgeon have not been shown to move in the

sea away from the influence of their home river system (Fig. 7).

As recent studies suggest, continued research may reveal that

marine movements of this species are extensive (Wilk and Silverman 1976; Holland and Yelverton 1973; Marchette and Smiley

1982 see Table 2, footnote 24).

Figure 36.-Number ofshorlnose slurgeon caplured per slandard gill nel sel in various localities of Ihe Saini John River,

Canada, during May 10 November.

IOKynard. B., J. Buckley, and W. Gabriel. 1982. Shortnose sturgeon biology

below Holyoke Dam. Mass. Coop. Fish. Res. Unit, Univ. Mass., Amherst. 8 p.

32
pears to be initiated by water temperatures rising above 8°C

(Pekovitch 1979 see Table 2, footnote 14; Taubert 1980a;

Anonymous 1980 see Table 2, footnote 2). Limited available data

suggest males migrate upstream in the fall to winter holding areas

before females and perhaps occupy the spawning grounds first

(Pekovitch 1979 see Table 2, footnote 14; Anonymous 1980 see

Table 2, footnote 2). However, sampling of overwintering fish on

the spawning grounds below Holyoke Dam on the Connecticut

River revealed the ratio of males to females was 1: I (Buckley

1982).

Feeding migrations occur immediately after spawning. Spent

fish in the Saint John and Connecticut Rivers migrate back downstream rapidly and join the slower, general upstream movement of

the remainder of the population (Fig. 35; Dadswell 1979; Buckley

1982). Upstream migration during summer in the Saint John

River, Canada, and Kennebec River may be the adaptational

response of a warmwater species to environmental conditions at

the northern end of its range. However, in both the Saint John and

Winyah systems, the abundance of shortnose sturgeon on foraging

grounds was highest in mid-estuary where salinities averaged I

0/00 (Fig. 8; Dadswell 1979; Marchette and Smiley 1982 see Table

2, footnote 24). During summers of high river flow (i.e., reduced

estuarine salinity) summer abundance peaks in the Saint John

River were displaced seaward. The opposite situation occurred

during summers with reduced flows (i.e., increased estuarine

salinity). In addition, interspecific competition with juvenile

Atlantic sturgeon may influence distribution of shortnose

sturgeon. Dadswell (1979) found that juvenile Atlantic sturgeon

dominated catches in higher salinities (> 3 0 / 00) and adult shortnose sturgeon dominated catches in freshwater. Rapid downstream migration, which occurs in early fall in the Saint John and

Pee Dee Rivers, was probably in response to seasonal cooling

(Figs. 8, 34). Salinity relationships during this period seemed of

little consequence as large numbers of shortnose sturgeon occupied lower estuary foraging grounds in salinities over 20 0/00

(Dadswell 1979; Marchette and Smiley 1982 see Table 2, footnote 24). Squiers and Smith (footnote 7) noted a similar occurrence in the Kennebec estuary.

Wintering migrations occur in autumn, specifically during the

last few weeks of September in the Saint John River, Canada

(Dadswell 1979). Wintering sites are discrete (Fig. 8) and generally occur in deep areas of lakes and river channels or in halocline

regions of the lower estuary (Dadswell 1979). Overwintering sites

in the lower Saint John estuary are characterized by salinities

averaging 20 0 / 00 and temperatures of 2°_13 °C. They are usually

occupied by nonripening adults, stage IV males and large

juveniles. Freshwater overwintering sites were characterized by

depths in excess of 10m, moderate tidal currents, and cold water

(0°-2°C) and were occupied mainly by juveniles and stage IV

females (Dadswell 1979).

Buckley (1982) found one overwintering site for ripe adults in

the Connecticut River was a discrete 1,500 m section below the

Holyoke Dam. Other shortnose sturgeon moved to the estuary for

the winter.

Dovel (1979,17 1981 see Table 2, footnote 15) and Pekovitch

(1979 see Table 2, footnote 14) found a similar wintering

behavior of shortnose sturgeon in the Hudson River. Concentration of shortnose sturgeon occurred in deep parts of the estuary in

both fresh and brackish water from Kingston to the George

"Dovel, W. L. 1979. Atlantic and shortnose sturgeon in the Hudson River

estuary. Rep. for U.S. Environ. Prot. Agency, The Oceanic Soc., Conn., 26 p.

33

Washington Bridge (rkm 94-12). Greeley (1935) reported a ripe,

female, shortnose sturgeon captured at Albany during the winter

of 1934.

In the Pee Dee-Winyah system, S.c., a temperature decline of

2°_3°C stimulated downriver migration in September to overwintering sites. Overwintering sites were in the lower estuary in

channels leading into shallow estuarine lakes, in the estuary proper, and in the ocean within 5,000 m of the beach (Marchette and

Smiley 1982 see Table 2, footnote 24). Overwintering sites had

surface water temperatures of 50 -10°C and salinities of 18-30

0/00'

Changes in pattern with age and condition

See juveniles and spawning migrations above.

3.52 Shoaling

Shoaling or schooling of shortnose sturgeon has not been

reported for young-of-the-year or juveniles, although it is known

to occur in other sturgeon species (Scott and Crossman 1973).

Most workers report that capture of shortnose sturgeon in gill nets

suggests the adults space themselves evenly over the foraging area

with no suggestion of shoaling.

Dadswell (1979), however, found that although there was a

general upriver movement of the entire population during summer, multiple recaptures of individual shortnose sturgeon within

confined areas during July-September suggested that once

reaching a certain locality a portion of the population became

resident there (Fig. 34). Additionally, the incidence of recapture

of individuals in a particular locality from year to year was high

(Table 18). Either sampling merely intercepted the movement

pattern at the same time and place annually, which suggests a

regular, cohort-type migration, or segments of the population

"homed" to foraging areas. Both Taubert (l980b) and Buckley

(1982) have observed similar behavior in the Connecticut River.

There, radio-tagged sturgeon occupied small home ranges to

which they returned after migration.

A further striking feature about shortnose sturgeon recaptures

in the Saint John River, Canada, and the Connecticut River was

their tendency to be grouped (Dadswell 1979; Buckley 1982).

Shortnose sturgeon which had been captured and tagged in the

same locality on the same day one year were recaptured together

in the same or a different locality after a l-yr or more interval. On

the Saint John River, nine shortnose sturgeon tagged in a single

day were recaptured together after periods at liberty of 1 yr or

more. Also, on seven occasions in the Saint John River shortnose

sturgeon tagged in sequence were recaptured together, often side

by side, after 1- to 3-yr intervals. The probability of the latter

event occuring at random is 1.88 x \0-24 and is highly unlikely.

3.53 Responses to stimuli

Environmental stimuli

No research on shortnose sturgeon has been carried out in this

field.

Artificial stimuli

While transporting adult shortnose sturgeon, Dadswell (pers.

obs.) found they tolerated light and temperature variations well

but were very susceptible to mechanical shock. A small accident
Table 18.-Numbers of shortnose sturgeon in the Saint John River, Canada, recaptured

during July and August in the same site during the year of initial tagging and in subsequent

years in the same or a different site. Site defined as area within I km radius of original

capture site.

Recaptures

Same site and yearl After I yr After 2 yr After 3 yr

Tagging site IX 2X 3X Same2 Diff. Same Diff. Same Diff.

Mistake Cove' 47 4 I 48 12 4 2 2

Belleisle Bay 27 2 I 6 7 I I 0

Darlings Lake 24 3 I No sampling subsequent years

Tennants Cove 4 0 0 10 4 5 6 0 3

Otnabog Lake 3 0 0 4 0 3 2 2 0

Total 105 9 468 23 13 11 4 5

'Recapture efforts at a minimum of 4-wk intervals.

'Total effort in ahernate sites 4X effort in anyone original tagging site except Mistake Cove

whcre ahemate effort only 2X more.

'Total initial tagging effort in Mistake Cove was twice that of other sites.

41ncidence of "Homing" 1st yr 68/91 = 0.75, 2nd yr 13/24 = 0.59, 3rd yr 4/9 = 0.44.

on the highway in which the shortnose sturgeon were knocked

about in their transport tank, but during which no water spilled,

resulted in instantaneous, complete mortality of nine specimens of

all sizes. Before and after that accident, large numbers of shortnose sturgeon have been transported in both New Brunswick and

South Carolina for up to 15 h, held in tanks for 15 d, and handled

during experiments for periods up to 1.5 yr with no mortality.

4 POPULAnON

4.1 Structure

4.11 Sex ratio

Among adult shortnose sturgeon from the Saint John River, the

ratio of females to males in the general population was 2: I

(Dadswell 1979); in the Pee Dee River it was 1: I (Marche~te and

Smiley 1982 see Table 2, footnote 24). In both studies, adults

were either randomly selected from the daily catch and sacrificed

or were net mortalities and, since sex can not be determined prior

to dissection, observed sex ratio was likely a true representation of

the adult population. At younger ages, the ratio of females to

males was I: I, but among shortnose sturgeon over 20 yr old in the

Saint John River, Canada, and 10 yr old in the Pee Dee River,

S.C., females were more numerous (Table 19). The observed

population structure was thought an expression of a shorter life

span for males (Dadswell 1979). Greeley (1937) found a ratio of

Table 19.-Sex ratio of shortnose sturgeon from the Saint John

River, Canada, and the Pee Dee River, S.C., as related to age.

Saint John. Canada Pec Dee, S.c.

Age Number % female Age Number % female

5-9 5-7 4 30.8

10-14 17 47.1 5-10 12 40.0

15-19 60 55.0 11-13 11 78.6

20-24 42 76.0 13-15 5 83.3

25-29 31 81.0 16-18 4 80.0 - 30-34 16 81.2 Total 36 X= 62.5

35-70 5 100.0

Total 171 X= 70.6

34

1.42:1 females to males among Hudson River shortnose sturgeon.

Meehan (1910) found that among a sample of over 100 shortnose

sturgeon from the Delaware River, taken at random from commercial fishermen catches, females represented more than 50%.

Gilbert and Heidt (1979) captured four females and three males

from the spawning run in the Altamaha River, but their sampling

was limited and the sex ratio is probably not representative.

During 1977 and 1978 Taubert and Reed (1978)18 captured 14

males and 4 females on the spawning grounds in the Holyoke Pool

and Pekovitch (1979 see Table 2, footnote 14) captured 157

males and 63 females on the spawning grounds in the Hudson

River. The preponderance of males to females during the spawning runs is a common occurrence among Acipenser species

(Vladykov and Greeley 1963; Cuerrier 1966; Magnin 1966), and

among fish in general, and without adequate sampling cannot be

regarded as representative of the population as a whole.

4.12 Age composition

Shortnose sturgeon may not exhibit strong year-to-year variation in year class strengths due to their long life span. Dadswell

(1979) found that among a relatively nonbiased sample (ages

15-50) there was a regular decrease in year class size with age and

no particular abundance of anyone year class (Fig. 37).

Perhaps among southern populations, which have shorter life

spans, year class strength will be observable.

4.13 Size composition

Figure 38 illustrates the size composition of captured shortnose

sturgeon during 3 yr sampling on the Saint John River. In the size

range adequately sampled by the gear (60-120 cm), no

predominance or stratification of sizes was observed. The

relatively greater catches of large shortnose sturgeon during 1974

was attributed to the greater selectivity of the large mesh gill nets

(Fig. 39). When selectivity and effort were adjusted for, no size

class dominance was observed (Table 20) (Dadswell 1979).

I 'Taubert, B. D., and R J. Reed. 1978. Observations of shortnose sturgeon

(Acipenser brevirosrrum) in the Holyoke Pool, Connecticut River, Massachusetts.

Rep. to Northeast Utilities Service Co., Hartford, Conn., 24 p.
"

120

120

liD

\

\

.\

\

o '.

\

\

\

\

\

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100

80 100

Fork Length (em)

70 80 90

Fork Length (em)

60

60

30

25

20 <J">

Z

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.0

E

z

'I

40

0.7

0.6

0.5

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0 0.4

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60 <J">

Z

<J">

40 "0

20 E

z

0

'"I

1975

40

20

0 48 60 72 84 96 108 120

Fork Lenglh (em)

Figure 37.-Age composition of shortnose sturgeon sampled from the Saint

John River, Canada. Predominance offish around age 20 is an artifact of gill net

selectivity for that size of sturgeon. Fewer shortnose sturgeon of younger age

refleds small amount of effort with nets selective for that size and the differential distribution of juveniles and adults (Dadswell 1979).

Figure 38.-Size composition of gill net catches of shortnose

sturgeon from the Saint John River, Canada, during each of 3 yr. Figure 39.-Indlrect selectivity (top) and direct selectivity (bottom) of #12

monofilament gill net of various stretched-mesh sizes for shortnose sturgeon.

Note the greater efficiency of large mesh size nets.

Maximum size

The maximum known size for shortnose sturgeon is a 122 cm

FL, 143 cm TL female captured in the Saint John estuary

(Dadswell 1979). Total weight of this sexually resting (stage II)

individual was 23.6 kg (52 lb.) The specimen is deposited at the

Royal Ontario Museum, Toronto, Canada (Cat. No. ROM 34310).

Shortnose sturgeon longer than 100 cm FL and weighing more

than 10 kg are common in the Saint John River (Gorham and

McAllister 1974). The largest male on record is a 97.0 cm FL, 108

cm TL, 9.4 kg specimen from the Saint John estuary (Dadswell

1979).

Maximum size among shortnose sturgeon populations varies

over the north to south range of the species (Table 21) with larger

maximum sizes known from northern populations. Larger maximum sizes may be found in southern populations after more

sampling with large mesh gill nets (20 cm stretched mesh).

Length and weight relationships

See section 3.44.

4.14 Subpopulations

Data collected so far suggest that within each river along the

Atlantic seaboard there is one shortnose sturgeon population, except perhaps in the Connecticut River where populations are

physically separated by the Holyoke Dam. Whether each river

population is a distinct entity from others awaits future chemical

or genetic population discrimination studies. Southern populations may mix in the sea. Northern populations appear confined to

their separate drainage systems.

35
Table 20.-Catch by size class and assigned mean age, actual (Cac) and adjusted (Cad) total

catches ofshortnose sturgeon for various mesh gill nets during 1974 and July-August 1975 in the

Saint John River, Canada. EffOl-t by mesh size was: 1974, 15.2 cm = 143 net-nights, 20.2 = 162

net-nights; 1975, all meshes = 24 net-nights. Total adjusted catch ~Cad = ~Cac / §iX, / X, where

X, is effort/mesh and X, is tOI'al effort of overlapping catch curves. Selectivities used were

smoothed estimates from Figure 39. Underlined counts are from selectivity plateau of each

mesh-size curve and were used to calculate total instantaneous mortality.

1974 1975

Length Age

(em) (yr) 15.2 20.6 ~Cae ~Cad 12.7 15.2 17.5 20.2 22.7 ~Cae ~Cad

61-63 14 46 46 1.608 39 19 0 58 2.093

64-66 15 87 87 761 2j 29 5 68 1,188

67-69 16 78 2 80 333 29 6 2 65 754

70-72 17 78 3 81 253 22 19 10 2 74 747

73-74 18 !7 3 50 127 7 11 7 2 28 288

75-76 19 2Q 6 56 134 9 n 11 4 49 487

77-78 20 ]l 6 41 93 6 1Jl 1Jl 4 1 31 410

79-80 21 II 7 44 94 5 ..2 11 6 3 40 528

81-82 22 22 15 37 78 2 2 11 8 3 29 508

83-84 23 15 24 39 97 I 3 ...1 4 2 17 297

85-86 24 14 19 33 118 0 6 14 5 7 32 531

87-88 25 11 33 44 161 I 4 8 8 7 28 439

89-90 26 4 2j 38 102 I 4 11 2 18 224

91-92 27 2 41 43 109 0 2 ..2 6 17 212

93-94 28 I l!! 39 73 I 3 14 26 324

95-96 29 2 ]l 37 67 I 11 14 26 335

97-98 30 l§ 36 69 0 ...1 6 13 129

99 31 11 14 27 I ..l 6 12 102

100 32 lJ 15 29 0 ..1 8 10 105

101 33 11 II 21 0 ..1 3 5 41

102 34 10 10 19 ..l 4 7 57

103 35 ..l 5 10 .-l 4 5 36

104 36 .Jl 8 15 ..l 3 6 42

105 37 8 8 21 0 2 2 12

106 38 5 5 13 1 4 5 33

107 39 7 7 27 0 3 3 15

108 40 7 7 27 2 4 6 45

109 41 4 4 25 I I 2 25

110 42 3 3 18 1 1 2 25

111 44 0 0 0 0 ..l 3 21

112 45 I I 15 .-l I 7

113 47 0 0 0 .-l I 7

114 48 0 0 0 .J)

115 50 .J) 0

116 51 .J) 0

117 53 .-l 7

118 55 .-l 7

119 58 .J) 0

120 61 .-l 7

Z 0.19 0.14 0.12 0.22 0.37 0.15 0.13 0.06 0.15

4.2 Abundance and density (of population)

4.21 Average abundance-estimation of population

size

Adequate estimation of the population size of shortnose

sturgeon in most river systems requires the use of multiple-census

population models because of the size of the systems and the different behavior of various age and spawning groups (Dadswell

1979).

Using gill net mark-recapture data over a 4-yr period, Dadswell

(1979) estimated the adult population in the Saint John estuary

with a Seber-Jolly population model as 18,000 ± 30% (Table 22).

Back calculating through the use of the mortality curve for this

population suggests there are about 100,000 shortnose sturgeon in

the Saint John estuary.

36

Estimates of other shortnose sturgeon population sizes havL

been made for the Kennebec River (Squiers et a1. 1981 see Table

2, footnote 3), the Holyoke Pool (Taubert 1980b), the lower Connecticut River (Buckley, unpub1. data), the Hudson River (Dovel

1981 see Table 2, footnote 15), and the Delaware R. (Dadswell,

from Hastings 1983 see Table 2, footnote 22) (Table 22).

Estimates were largely made by single and/or multiple Peterson

types (Schnabel), and recapture levels have met the Peterson

validity requirements of me > 4N (Robson and Regier 1964). All

estimates are biased by gear use (gill nets only); nonetheless,

population sizes obtained to date are probably good first estimates

for the various river systems. Population sizes of shortnose

sturgeon in other river systems are unknown to date but the accumulation rate of new captures is similar for both well- and

poorly studied populations (Fig. 40). The number of actual,

observed shortnose sturgeon in all populations since 1970 is ap-
Table 21.-Maximum known sizes among shortnose sturgeon populations along the Atlantic coast. Lengths are in centimeters, weights in

kilograms.

Sample Female Male Unsexed

Locality size TL FL Wt TL FL Wt TL FL Wt Source

Saint John R., Canada 4,500 143.0 122.0 23.6 108.0 97.0 9.4 Dadswell (1979)

Kennebec R., Maine 18 118.1 107.4 8.5 80.7 72.1 2.6 Fried and McCleave

(1973 )

Kennebec R., Maine 728 120.5 111.0 12.3 Squiers et al. (see Table

2. footnote 3)

Holyoke Pool, Connecticut R., Mass. 270 95.1 7.2 87.9 79.2 4.1 Taubert (1980b)

Lower Connecticut R. 360 107.0 97.0 9.2 93.1 83.9 Buckley and Kynard

(1981 )

Hudson R., N.Y. 3,000 105.0 94.5 7.2 99.0 89.0 5.3 Dovel (see Table 2, footnote 15)

Delaware R., N.J. 282 86.4 77.7 5.1 74.0 66.0 2.0 107.0 98.3 8.3 Hastings (see Table 2,

footnote 19)

Pee Dee R., S.C. 135 92.7 4.3 84.0 3.1 Marchette and Smiley

(see Table 2, footnote

24)

Lake Marion, S.c. 13 77.5 66.0 2.4 Marchette and Smiley

(see Table 2, footnote

24)

Altamaha R., Georgia 37 99.5 87.5 6.6 69.4 58.6 1.9 Heidt and Gilbert (see

Table 2. footnote 27)

Saint Johns R.. Florida 2 73.5 Vladykov and Greeley

(1963)

Table 22.-Estimates of adult (+50 em) shortnose sturgeon populations of North American Atlantic coast.

Population

Locality and Marked Captured Recaptured estimate "'- estimate type m c N (95% conf. limits) mcl4N Source

Saint John R., N.B.

Seber-Jolly 1973-77 3,705 4,082 343 18.000 ± 30% >1 Dadswell (1979)

Kennebec R., Maine

Modified Peterson 1977-80 381 322 7 15,423 ± 66% >1 Squiers et al. (see Table 2, footnote 3)

Modified Peterson 1977-82 917 233 19 10,741 (6,960-17,038) >1 From Androscoggin spawners only

Modified Schnabel 1977-80 381 322 13 11,646 (6,998-20,639) From Androscoggin spawners only

Modified Schnabel 1977-81 703 272 56 7,222 (5,046-10,765) For total river population

Connecticut R., Conn.

Holyoke Pool

Simple Peterson 1976-77 51 162 16 516 (317-898) >1 Taubert (I 980b)

Simple Peterson 1976-78 51 56 4 714 (280-2,856) >1 Taubert (1980b)

Simple Peterson 1977-78 119 56 18 370 (235-623) >1 Taubert (I 980b)

Simple Peterson 1976-77-78 170 56 24 297 (267-618) >1

Lower Connecticut R.

Schnabel 1977-82 186 (106-359) Rkm I 10-139 Buckley (unpubl. data)

Schnabel 1981 28 (10-55) Holyoke spawners only (Buckley, unpubl.

data)

Schnabel 1982 38 (25-59) Holyoke spawners only (Buckley, unpubl.

data)

Schnabel 1977 -82 800 'Rkm 04139

Hudson R., N.Y.

Modified Peterson 1979 350 544 7 '23,911 (1,322-68,000) >1 Calculated Dadswell (total)

Modified Peterson 1979 548 899 38 12,669 (9,080-17,735) >1 Dovel (see Table 2, footnote 15) (spawners

only)

Modified Peterson 1980 811 698 40 13,844 (10,014-19,224) >1 Dovel (see Table 2, footnote 15) (spawners

only)

Modified Peterson 1980 30,311 Dovel (see Table 2, footnote 15) (total population: based on extrapolation of population

mortality relationship)

Delaware R.

Modified Peterson 1981-83 464 99 7 '6,452 (3,584-18,434) >1 Hastings (see Table 2, footnote 19) (Philadelphia to Trenton)

'Calculated by Dadswell.

'After Pekovitch (see Table 2, footnote 14), sturgeon tagged 1977 and 1978, recaptured 1979.

'Sturgeon tagged 1981-0cl. 1982, recaptured Nov. 1982-March 1983.

37
----,1...---..--,-1... ~-TI---rl-----"

'65 '70 '75 '80 '85

Endangered

Species Acl

Table 2, footnote 19), using proper sampling gear in the upper

estuary, captured over 600 in 2 yr. Whether the Delaware population changed in abundance between these periods, or fishing effort

with proper gear and subsequent reporting varied, can probably

never be determined. Beck (1973) described the disappearance of

Atlantic sturgeon from the Delaware by 1900 and subsequent

decline in fishing effort until the 1950's. But as late as 1909

(Meehan 1910) and 1914 (Smith 1915) shortnose sturgeon were

commonly caught by shad fishermen .

Greeley (1937) observed over 100 shortnose sturgeon incidently captured in the Hudson River shad fishery during 1936 but

stated the species was rare. Similarly, Dovel (1978 see Table 2,

footnote 13) observed about 100 shortnose sturgeon a year as incidental catch in the same fishery during 1976 and 1977. These

observations suggest the shortnose sturgeon population in the

Hudson River may have been stable during the 40-yr period between the two studies but casts no light on what actual population

levels were, especially since the sampling gear (drift gill nets) are

inappropriate for shortnose sturgeon. However, when Pekovitch

(1979 see Table 2, footnote 14) and Dovel (1981 see Table 2,

footnote IS) employed appropriate gear and were able to locate

the shortnose sturgeon spawning run in the Hudson River, they

captured almost 1,500 during each of the l-mo periods in 1979

and 1980.

Conversely, McCabe (1942) stated that up to 100 sturgeon/d

were caught in commercial gill nets below Holyoke Dam during

1940-42. McCabe reported these as Atlantic sturgeon but some

may have been shortnose sturgeon. Neither Taubert (l980b) or

Buckley (1982) ever achieved such a catch rate for either species,

which may signify a decline. Also, Yarrow (1877) stated that

shortnose sturgeon were common in North Carolina rivers, but

recently Schwartz and Link (1976) described them as extirpated

in the state.

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4.23 Average density

Figure 40.-Log,o cumulative lotal captures for individual known shortnose

sturgeon populations in easlern North America.

proximately 11,500 individuals and most are or were tagged with

individually numbered tags. The total estimated adult population

size for the best known rivers now stands at about 70,000 (Table

22).

4.22 Changes in abundance

Since the size of shortnose sturgeon populations was unknown

before the last few years, changes in abundance cannot be accurately determined.

The presence of shortnose sturgeon in the Saint John River,

Canada; the Kennebec River, Maine; the Winyah-Pee Dee and

Lake Marion systems, S.C.; and the Altamaha River, Ga.; were

unknown until the last two decades, but these apparently are some

of the larger populations. Ryder (1890) described himself as fortunate when he obtained five shortnose sturgeon from the

Delaware River and said the species had not been seen since

LeSueur's day, but the Geological Survey of New Jersey (1890)

reported a 5: 1 ratio of shortnose to Atlantic sturgeon and Meehan

(1910) obtained over 100 shortnose sturgeon from the Delaware

River in 1908 with relative ease. Since 1969, incidental catches in

the lower Delaware have amounted to at least 40 shortnose

sturgeon (Table 2; Brundage and Meadows 1982) as well as

another 20 observed (Hoff 1965), and recently Hastings (1983 see

Average density of shortnose sturgeon in the environment has

only been determined for the Saint John estuary (Dadswell 1976).

Population estimates from three or four recapture cycles at 4-wk

intervals were made in areas of feeding concentrations during the

June-September peak feeding period (Table 23). Average standing

crop or density was 5.2 shortnose sturgeon/ha or 1.66 g/m2 . Concurrent benthos studies at these sites determined the average

standing crop of benthic molluscs, which constitute the shortnose

sturgeon diet, was 24 g/m2 or a ratio of shortnose sturgeon standing crop to mollusc standing crop of 1:15. Since conversion between mollusc and shortnose sturgeon is direct and the energy

transfer found was within the normal range for a one-step converTable 23.-Schnabel population and standing crop estimates of

adult shortnose sturgeon for four discrete regions of the Saint John

estuary, Canada. Standing crop estimates in g/m' were determined

using 3.21 kg as the average weight of adult shortnose sturgeon in

this population.

Area Recapture Standing crop A Locality (ha) attempts N SNS/ha g/m 2

Mistake Cove 225 4 1.161 5.16 1.65

Tennants Cove 182 3 1.969 10.81 3.47

Belleisle Bay 387 3 838 2.16 0.69

Darlings Lake 419 4 1.102 2.63 0.84

Mean 303 1.267 5.19 1.66

38
sion (Odum 1959), density estimates of the shortnose sturgeon,

when concentrated on their feeding grounds, appear near the

carrying capacity.

Average densities for the whole adult population are possible to

calculate for the Saint John, Kennebec, Holyoke Pool and lower

Connecticut River, Hudson, and Delaware Rivers (Table 24).

Densities range between 0.04 and 0.9 adult shortnose sturgeon/ha.

Density estimates are very similar except for the Delaware River

where neither the population's size or its estuarine-riverine limits

are well known. Population size projections, for rivers with poorly

known populations, that use densities calculated for feeding concentrations rather than average densities, such as was done by

Masnik and Wilson (1980), are inappropriate.

4.24 Changes in density

See section 3.51 for effects of migration on density. In optimum

habitat of the middle Saint John estuary, Canada, peaks occur during early summer and early fall (Fig. 26). At inland estuary habitat

a peak occurs in July-August. Wintering site densities peak between October and May. Similar density/abundance changes have

been reported for the Kennebec estuary (Squiers and Smith footnote 7), the lower Connecticut (Buckley 1982), the Hudson

estuary (Dovel 1978 see Table 2, footnote 13, 1981 see Table 2,

footnote IS), and the Pee Dee-Winyah system, S.C. (Marchette

and Smiley 1982 see Table 2, footnote 24).

4.3 Natality and recruitment

4.31 Reproduction rates

Annual egg production

Annual egg production estimates for a shortnose sturgeon

population have not been done. One problem with any such

estimate is determination of what percentage of females in a

population spawn each year. Dadswell (\ 979) estimated one-third

of the Saint John shortnose sturgeon female population spawned

per year based on the proportion of ripening females present during the preceding summer. If one-third do spawn each year and

there are about 12,000 adult females in the Saint John population

(two-thirds of total 18,000 since sex ratio 2:19 :6), then approximately 4,000 females spawn each year in that river system. Mean

fecundity of 21 females sampled was 94,000 which means total

egg deposition could be about a maximum of 4,000 x 94,000 =

376 x 106 eggs/yr in the Saint John River, Canada.

Survival rates

Nothing is known about survival of eggs, larvae, or young-ofthe-year shortnose sturgeon in the wild. Survival under hatchery

conditions is usually poor due to fungus infections of eggs and

death of larvae after yolk sac absorption because of lack of required food (Anonymous 1980 see Table 2, footnote 2; Buckley

and Kynard 1981; Dovel 1981 see Table 2, footnote IS).

4.32 Factors affecting reproduction

Density dependent factors

No research has been done which indicates density factors affect reproduction. Shortnose sturgeon are usually found concentrated in a short stretch of their river during the spawning period

(Pekovitch 1979 see Table 2, footnote 14; Taubert 1980a;

Buckley 1982).

Dadswell (unpubl. data) found one small female (75 cm FL)

was resorbing her eggs in September, and because the body cavity

contained stage V eggs, it was thought she had not spawned during

the spring for unknown reasons.

Physical factors

Shortnose sturgeon spawning grounds are found in the upper

reaches of rivers (Taubert 1980a), below dams (Buckley and

Kynard 1981; Squiers et al. 1981 see Table 2, footnote 3), in

flooded cypress-tupelo swamps (Marchette, pers. obs.), and in

riverine regions just above tidal influence (Dadswell 1979;

Anonymous 1980 see Table 2, footnote 2; Dovel 1981 see Table

2, footnote IS). Known sites in the north have gravel or rubble

substrate, medium to strong current speeds (0.3-0.8 m/s), and are

I-10m in depth (Taubert 1980a; Anonymous 1980 see Table 2,

footnote 2; Buckley 1982; Squiers et al. 1981 see Table 2, footnote 3). They are usually in or near areas of deeper water (Taubert

1980a; Squiers et al. 1981 see Table 2, footnote 3). Some southern

sites (Pee Dee and Savannah Rivers) are in backwaters, with little

current and 1-3 m in depth (Marchette, pers. obs.).

4.33 Recruitment

Because there are no commercial fisheries for shortnose

sturgeon, no recruitment information is available. Dadswell

(1976) estimated a possible recruitment of 1,100 15-yr-old shortnose sturgeon to a commercial fishery using a 20 cm stretch mesh,

Table 24.-Average densities for adult shortnose sturgeon populations from rivers in eastern North

America.

Adult

Surface population

Boundary area estimate Density

System Lower Upper (ha) IV SNS/ha

Saint John R., N.B. Reversing Falls Fredericton 5.0x 10· 18,000 0.36

Kennebec R., Maine Popham Beach Augusta 1.1 x 10· 10,000 0.90

Holyoke Pool, Con- Holyoke Dam Turner's Falls 1.6x 103 400 0.25

necticut R., Mass.

Lower Connecticut R., Enfield Dam Holyoke Dam 0.8x 103 186 0.23

Conn. Long Island Sound Holyoke Dam 3.6x 10' 800 0.22

Hudson R., N.Y. Battery Troy Dam 2.9x 10' 27,000 0.93

Delaware R., N.J. Cape May Scudders Falls 1.9x 10' 10,000 0.05

C & D Canal Lambertville 2.4xI0· 10,000 0.42

39
4.4 Mortality and morbidity

4.41 Mortality rates

gill net if such a fishery was permitted in the Saint John River,

Canada.

Fishing

Besides natural mortality, fishing mortality caused by incidental catch in nets set for other species (mainly shad) is probably the

main cause of mortality of shortnose sturgeon. Dadswell (1979)

estimated the annual fishing mortality for shortnose sturgeon in

the Saint John River as 1% or approximately 200 adult sturgeon a

year. Many fishermen return sturgeon to the water alive but others

do not. Either they are killed and discarded as a nuisance (Leland

1968; Cobb 1900) or they are marketed locally (Bean 1893;

McCabe 1942). Incidental fishing mortality may be a major

reason for the disappearance of this species from the shallow

estuaries of Chesapeake Bay (Shortnose Sturgeon Recovery

Team23 ) and is a suspected major factor of mortality in South

Carolina (Marchette24 ).

Dovel (1981 see Table 2, footnote 15) observed that 78% of

adult shortnose sturgeon in the Hudson River were affected by fin

rot. Whether this has contributed to mortality is unknown.

Impingement of shortnose sturgeon on intake screens of power

stations may result in some mortality, but the cause of impingement may be from events or injury elsewhere (netting, natural

death). Hoff et al. (1977 see Table 2, footnote 12) reported that

three shortnose sturgeon were found dead on the intake screens of

Indian Point Power Plant, Hudson River, during 1978 and W.

Kirk l9 stated mortalities of two, two, and one shortnose sturgeon

were recorded at Indian Point in 1972, 1973, and 1979, respectively. Hoff and Klauda (1979 see Table 1, footnote I) reported

39 shortnose sturgeon impinged on intake screens of power plants

along the Hudson River between 1969 and 1979. Three shortnose

sturgeon were impinged on the intake screens of the Salem

Nuclear Station on the Delaware River in 1978 (Masnick and

Wilson 1980), one in 1981 (Brundage20 ), and one at the Delaware

Station in Philadelphia in 1975 (Brundage and Meadows 1982).

Two shortnose sturgeon have been impinged at the Connecticut

Yankee Nuclear Power Station. The most recent was in 1979

(Klattenberg21 ). Two shortnose sturgeon recovered dead were

impinged on the trash racks of the Maine Yankee Nuclear Power

Plant in 1980 (Squiers22 ).

30 40 50 60 70

Age (Yeors) 10 20

Mortality rate has been determined for the Saint John River,

Canada, population (Dadswell 1979), the Holyoke Pool population (Taubert 1980b), and the Pee Dee-Winyah population (Marchette and Smiley 1982 see Table 2, footnote 24). In all studies

catches were adjusted for gill net selectivity and effort. Total instantaneous mortality rate (2) for ages 14 through 55 was 0.12 for

1974 and 0.15 for 1975 in the Saint John River (Fig. 41). Mortality was relatively high among younger shortnose sturgeon but

declined with age (Dadswell 1979). In the Holyoke Pool, 2 was

0.12 for adjusted catches and 0.14 for all catches (Taubert 1980b).

Marchette and Smiley (1982 see Table 2, footnote 24) estimated

an instantaneous mortality in the Pee Dee-Winyah between 0.08

and 0.12.

o

-'

Figure 4I.-Mortality [loge of year class abundance adjusted for gill net selectivity (Table 19)] of shortnose sturgeon captured in the Saint John River,. Canada, during 1974 and 1975.

4.5 Dynamics of population (as a whole)

No studies on shortnose sturgeon population dynamics have

been done to date.

4.42 Factors causing or affecting mortality

4.6 The population in the community and the ecosystem

Predators

4.61 Physical features of the biotype of the community

See sections 3.34 and 3.35. Young are known to be eaten by

yellow perch and adults may possibly be attacked by seals, sharks,

gar, or alligators.

The shortnose sturgeon inhabits riverine, estuarine, and nearshore marine waters. It is most commonly found in productive

Physical factors

Dadswell (pers. obs.) observed a small kill of shortnose sturgeon

during the first week of August 1974. The sturgeon were found

dying or dead (four specimens) in an intensely eutrophic region of

the Saint John estuary that was choked with vegetation. It was

assumed that the heavy plant concentration caused an oxygen

depletion in the area during the night. Other species of fish

(suckers, perch) were killed at the same time.

lOW. Kirk. Research Scientist, Texas Inslruments Inc., P.O. Box 237, Buchanan,

NY 10511, pers. commun. March 1979.

2oH. M. Brundage III, Ichthyological Associates Inc., 100 South Cass Street,

Middleton, DE 19709, pers. commun. April 1983.

21 R. Klatlenberg, Northeast Utilities, P.O. Box 270, Hartford, Conn., 0610 I, pers.

commun. July 1981.

22T. S. Squiers, Fisheries Biologist, Maine Department of Marine Resources,

Augusta, ME 04333, pers. commun. June 1981.

2lShortnose sturgeon recovery team, National Marine Fisheries Service, State

Pier, Gloucester, MA 01930, pers. commun. March 1978.

24 0. E. Marchetle, Fisheries Biologist, South Carolina Wildlife and Marine

Resources, Charleston, SC 29412, pers. commun. August 1982.

40
mesohaline environments with salinities between I and 20 %0'

usually in and around the salt-wedge portion of estuaries (Squiers

and Smith footnote 7; Dadswell 1979; Marchette and Smiley

1982 see Table 2, footnote 24). Freshwater habitats are

characterized as deep river channels or in shallow regions with

soft bottoms and abundant macrophytes. Habitats in higher salinity are usually over sand-mud bottoms in and around the MyaMacoma zone. Populations may require access to a gravel-boulder

section of riverine habitat for spawning (Taubert 1980b; Buckley

1982). The habitat of the shortnose sturgeon while in nearshore

marine situations is undescribed, but shortnose sturgeon may occur in shallow water a few miles from shore associated with mixed

sediments containing Mya arenaria, Corbicula manilensis, or other

similar molluscs.

4.62 Species composition of the community

Juvenile shortnose sturgeon share the deep river channels with

few other species. In the Saint John River only juvenile Atlantic

sturgeon and ling, Lota Iota, occur in this habitat. Adult shortnose

sturgeon in the Saint John River were found in company with

American eels, Anguilla rostrata; ling, Lota Iota; suckers

(Catostomus spp.); and whitefish, Coregonus clupeiformis, in

freshwater and Atlantic sturgeon, A. oxyrhynchus; flounders

(Pseudopleuronectes americanus); hake, Urophycis tenuis; and tomcod, Microgadus tomcod; in saline water (Dadswell, pers. obs.). In

the Connecticut River, adult shortnose sturgeon associated with

channel catfish, Ictalurus punctatus, walleye, Stizostedion vitreum,

carp, Cyprinus carpio, and northern pike, Esox lucius (Taubert,

pers. obs.; Buckley, pers. obs.).

Community relationships of shortnose sturgeon populations in

other rivers are undescribed at present.

4.63 Interrelations within the community

Dadswell (1976) considered shortnose sturgeon and Atlantic

sturgeon to competitively exclude each other depending on the

salinity of the habitat. In the Saint John River, Canada, shortnose

sturgeon compete with flounder and whitefish for the same food

resource (see section 3.33).

5. EXPLOITATION

5.1 Fishing equipment

Shortnose sturgeon were captured with gill nets and traps. Gill

nets were either drifted or fixed (Ryder 1890; Greeley 1937;

McCabe 1942). Most shortnose sturgeon were (Meehan 1910;

Greeley 1937), and are presently caught in shad drift and set gill

nets (Dovel 1979, see Fig. 4 legend; Dadswell 1979; Shortnose

Sturgeon Recovery Team footnote 23). In the Saint John River,

Canada, many shortnose sturgeon are captured in commercial

alewife trapnets. Some of these shortnose sturgeon are processed

along with the alewife into fish meal. A few shortnose sturgeon

are captured by ocean trawlers (Brundage and Meadows 1982).

5.2 Fishing areas

Commercial shortnose sturgeon fishing areas were typically the

middle and upper reaches of the estuaries of large rivers. McCabe

(1942) described a sturgeon fishery below the Holyoke Dam in

41

the Connecticut River that may have principally utilized shortnose sturgeon.

5.21 General geographic distribution

Throughout its range shortnose sturgeon have entered the commercial fishery (see section 2.1) (Bean 1893; Greeley 1937).

Caviar from this species formerly commanded a higher price than

Atlantic sturgeon caviar (Vladykov and Greeley 1963).

5.22 Geographic ranges

See section 2.1.

5.23 Depth ranges

Adult shortnose sturgeon are usually captured in shallow water.

Depth of capture seldom exceeds 10 m but this is mainly because

of the commercial fishing gear used.

5.3 Fishing seasons

5.31 General pattern of seasons

Since the shortnose sturgeon is listed as endangered in the

United States, there is no open season for this species. Formerly, a

few fishermen in the Delaware and Hudson Rivers set nets for the

purpose of capturing this species during the few weeks (late April)

before the shad season (Greeley 1937).

In the Saint John River, Canada, the sturgeon season is open all

year except the month of June, but sturgeon are actively sought

only during July-August. If a season for shortnose sturgeon were

established in the Saint John River, Dadswell (1975) recommended it be confined to winter and early spring (January-April). This

would provide caviar in peak condition and flesh untainted by a

muddy flavor which becomes prevalent in late summer in this

river.

5.32 Dates of beginning, peak and end of season

See section 5.3 I.

5.33 Variation in date or duration of season

See section 5.31.

5.4 Fishing operations and results

5.41 Effort

At present there is no directed effort for shortnose sturgeon in

the United States because of its endangered status. Effort for

sturgeon in the Saint John River, Canada, amounts to I or 2 mo of

gillnetting per year, depending on the market. About 5% of the

sturgeon catch in the Saint John River is shortnose sturgeon

(Dadswell, unpubl. data).

5.42 Selectivity

Figure 39 illustrates the indirect and direct selectivity of

various size monofilament gill nets for shortnose sturgeon. Each

direct selectivity mode has a broad plateau because of the multiple
ways a shortnose sturgeon can mesh (Dadswell 1979). Larger

mesh sizes are more efficient in capturing shortnose sturgeon than

small mesh sizes. Dadswell (unpubl. data) found that monofilament nets were about twice as efficient as multifilament nets

unless multifilament twine size was very fine. The direct selectivity relationship for the commercial, multifilament nylon, shad gill

net (5 in or 12.7 cm stretched mesh) is illustrated in Figure 42.

Confidence limits of the selectivity curve indicate 95% of incidental shortnose ~urgeon catch is concentrated between 57 and

90 cm fork length (X = 73.6, SE = 8.1) which is the size range of

adult shortnose sturgeon in most U.S. rivers.

10

2.8 b

24

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: V'R:: 1.60 ,

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Fishing effort

Figure 43.-Theoretical yield/recruit relationship for a 20 cm (8 in) stretched

mesh gill net fishery for the shortnose sturgeon population in the Saint John

River, Canada, at two levels of instantaneous total mortality.

6. PROTECTION AND MANAGEMENT

50 60 70 80 90

Fork Length {eml

100 110 120

6.1 Regulatory (legislati ve) measures

Figure 42.-Direct selectivity of 15.2 cm (5 in) stretched mesh, 210/3 multifilament nylon, commercial shad net for shortnose sturgeon in the Saint John

River, Canada. Data from tag returns of shortnose sturgeon captured by commercial fishermen.

5.43 Catches

Total annual yield

The annual, incidental, shortnose sturgeon catch in most U.S.

rivers, except perhaps the Hudson, may not exceed 10 or 20 fish

per river (Shortnose Sturgeon Recovery Team shad fishery

bycatch survey). Annual yield of shortnose sturgeon before the advent of endangered species status is unknown since fishery

statistics data were listed as "sturgeon" only, thereby combining

the two Atlantic coast species (Hoff 1979). For landing statistics

of "sturgeon" on the east coast of the United States see Murawski

and Pacheco (1977).

In the Saint John River, Canada, about three or four legal size

shortnose sturgeon (total length 4 ft [122 cm TL] or more) are

captured each year (Gorham25 ). As many as 200 sublegal shortnose sturgeon may be harvested each year as a bycatch from the

shad gill net or alewife trapnet fisheries as determined by limited

local markets (Dadswell, pers. obs.). Additionally, an unknown

amount of shortnose sturgeon captured with alewives in the trapnet fishery become fish meal (Dadswell, unpubl. data). Dadswell

(1975) used a yield/recruit model based on a 20 cm gill net catch

curve (Fig. 43) to estimate a sustainable annual yield of approximately 2,000 kg or 350 adult shortnose sturgeon/yr could be

removed from the Saint John River, Canada, over and above the

present incidental catch.

"S. W. Gorham, Curator of vertebrates, New Brunswick Museum. Saint John.

N.B., pers. commun. August 1975.

42

6.11 Limitation or reduction of total catch

Since passage of the Endangered Species Act of 1973, as

amended, it has been unlawful to "take" (hunt, harass, capture, or

kill) shortnose sturgeon in the United States.

6.12 Protection of portions of population

At present all portions of the shortnose sturgeon population in

the United States are protected. In Canada, all sturgeon under 122

cm (4 ft) total length are protected.

6.2 Control or alteration of the physical features of the

environment

Not presently used for promotion of shortnose sturgeon stocks

but some alterations of fish-lift schemes or bypass systems are

now under consideration to assist natural populations (Klattenberg26 ). However, any other proposed alteration of the environment that may adversely affect shortnose sturgeon populations is

closely reviewed in the United States under the Endangered

Species Act. Any proposed action that might jeopardize the continued existence of a population will be modified to reduce these

adverse effects.

6.3 Control or alteration of the chemical features of the

environment

None used for the promotion of shortnose sturgeon stocks. See

section 6.2 for proposed alterations.

"R. Klattenberg, Northeast Utilities, P.O. Box 270, Hartford, Conn. 06101, pers.

commun. March 198 I.
6.4 Control or alteration of the biological features of the

environment

None used for the promotion of shortnose sturgeon.

6.5 Artificial stocking

6.51 Maintenance stocking

None has been attempted.

6.52 Transplantation, introduction

None has been attempted.

7. POND FISH CULTURE

Shortnose sturgeon have never been cultured. Meehan (1910)

described one successful and one unsuccessful attempt to overwinter shortnose sturgeon in catfish ponds near Philadelphia.

These fish were kept for the purpose of stripping eggs and milt

when ripe and not for growth experiments. Marchette (footnote

24) kept 12 shortnose sturgeon in hatchery ponds in South

Carolina for over a year, and work is now underway in South

Carolina to culture this species.

7.1 Procurement of stocks

Stocks appear to be available if enhancement or reintroduction

is attempted.

7.2 Genetic selection of stocks

None attempted to date.

7.3 Spawning

Artificial spawning has been successful for this species

(Anonymous 1980 see Table 2, footnote 2; Buckley and Kynard

1981; Dovel 1981 see Table 2, footnote 15), but only from

naturally ripe specimens. Hormonal inducement has been unsuccessful so far (Pottle and Dadswell 1979 see Table 2, footnote I;

Anonymous 1980 see Table 2, footnote 2).

7.4 Rearing

Artificially spawned shortnose sturgeon have been reared only

to an age of 40-60 d (Anonymous 1980 see Table 2, footnote 2;

Buckley and Kynard 1981). Most larvae in hatchery conditions

have died just after yolk sac absorption, probably because offered

natural or artificial diets were not correct.

ACKNOWLEDGMENTS

This synopsis of biological data on the shortnose sturgeon has

been prepared to fulfill part of the work program established for

the Shortnose Sturgeon Recovery Team of the U.S. National

Marine Fisheries Service.

The authors are pleased to acknowledge the help of the following people who supplied data and assisted in many ways: D.

Beach, National Marine Fisheries Service, Gloucester, Mass.,

U.S.A.; R. Bradford, R. H. Cook, and F. Cunningham, Department

43

of Fisheries and Oceans, St. Andrews, N.B., Canada; E. Dixon, R.

R. #1, Morrisdale, N.B., Canada; W. L. Dovel, The Oceanic

Society, Stamford, Conn., U.S.A.; E. Erdheim, National Marine

Fisheries Service, Washington, D.C., U.S.A.; B. Fawkes, Department of Fisheries and Oceans, Biological Station, St. Andrews,

N.B., Canada; R. J. Gilbert, Georgia Cooperative Fisheries

Research Unit, University of Georgia, Athens, Ga., U.S.A.; D.

Gorham, R. R. # I, Clifton Royal, N.B., Canada; S. W. Gorham,

New Brunswick Museum, Saint John, N.B., Canada; R. W. Hanks,

National Marine Fisheries Service, Portland, Maine, U.S.A.; A. R.

Heidt, Georgia Cooperative Fisheries Research Unit, University

of Georgia, Athens, Ga., U.S.A.; J. G. Hoff, Southeastern

Massachusetts University, North Dartmouth, Mass., U.S.A.; T. B.

Hoff, Texas Instruments, Buchanan, N.Y., U.S.A.; W. Hogan,

Maryland Tidewater Commission, Annapolis, Md., U.S.A.; J.

Hurley, Department of Fisheries and Oceans, Biological Station,

St. Andrews, N.B., Canada; B. Kinnear, U.S. Fish and Wildlife

Service, Boston, Mass., U.S.A.; R. Klattenberg, Northeast Utilities,

Hartford, Conn., U.S.A.; R. Klauda, Texas Instruments, Buchanan,

N.Y., U.S.A.; A. Lupine, New Jersey Fish and Game Department,

Rosemount, N.J., U.S.A.; D. E. McAllister, National Museum of

Natural Sciences, Ottawa, Canada; J. McClain, Nacote Creek

Research Station, Absecon, N.J., U.S.A.; J. D. McCleave, Department of Biology, University of Maine at Orono, Orono, Maine,

U.S.A.; C. L. McLaughlin, Massachusetts Fish and Game,

Westboro, Mass., U.S.A.; H. Moody, Florida Game and Freshwater Fish Commission, Eustis, Fla., U.S.A.; M. Newman, National Marine Fisheries Service, Oxford, Md., U.S.A.; A.

Pekovitch, Hazelton Environmental Sciences Corp., Illinois,

U.S.A.; R. J. Reed, Massachusetts Cooperative Fisheries Unit,

University of Massachusetts, Amherst, Mass., U.S.A.; M. Smith,

Department of Marine Resources, State House, Augusta, Maine,

U.S.A.; S. Testaverde, National Marine Fisheries Service,

Gloucester, Mass., U.S.A.; D. Themelis, BioIdentification

Associates, St. Andrews, N.B., Canada; R. T. Whittaker, National

Marine Fisheries Service, Gloucester, Mass., U.S.A.; B. Young,

New York Environmental Conservation Department, Stony

Brook, N.Y., U.S.A.

LITERATURE CITED

ANSELMINI, L. D.

1974. An ecological study of the Delaware River in the vicinity of the Mercer

Generating Station, Trenton, New Jersey. Ichthyological Associates Inc.,

Ithaca, N.Y., 377 p.

1976, An ecological study of the Delaware River in the vicinity of Newbold

Island, Ichthyological Associates, Inc., Ithaca, N. Y., 651 p.

APPY, R. G., and M, 1. DADSWELL.

1978. Parasites of Acipenser breYirostrum leSueur and Acipenser oxyrhynchus

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