Environment Biology of fishes 48:335-398, 1997.
© 1997 KluwerAcademicPublishers.Printed in theNetherlands.Molecular analysis in the conservation of sturgeons and paddlefish
Isaac I.Wirgin^1 , Joseph E .Stabile^1 & John R.Waldman^2(^1) Nelson Institute of Environnment Medicine, New York University Medical Center, Long Meadow Road,
Tuxedo NY, 10987, U.S.A.
(^2) Hudson River Foundation, 40 West 20th Street, Ninth Floor, New York, NY 10011, U.S.A.
Received15.4.1995 Accepted14.5.1996
Key words: mitochondrial DNA, nuclear DNA, Acipenser, Scaphirhynchus, Polyodon, stock identification,
hybridization
Synopsis
Sturgeon andpaddlefish populations worldwide have declined because ofanthropogenicinfluences. The
structure and magnitude ofgeneticdiversity ofnaturalpopulations serves to bufferthesefishesagainst envi-
ronmentalvariation and should bemaintained.Modernmolecularbiologicaltechniquesprovide theability to
sensitivelycharacterize and quantify theextent ofgenetic variation innatural populations. We provide a
summary ofthose problems insturgeonpopulationbiologythat areamenable toinvestigationwith D N A
approaches, andtheir applications todate. Thesehaveincluded genetic identification and discrimination of
taxa. identification of hybrids,stockidentification,mixed-stock analysis, andestimation ofgeneflow and
homingfidelity. Todate,almost all studies have been restricted toNorthAmerican fauna. Improvements to
thesetechnologies, including nondestructive sampling, shouldpermitmorewidespread application ofmole-
cularapproaches to problems ofacipenseriformconservation. Wesuggestthat the use of moresensitivemole-
cular toolssuch asanalyses of hypervariable repetitive and non-codingsingle copynuclear DNA mayassist
management even in thosetaxawhichexhibit overall lowlevels ofgeneticdiversity.
Introduction
The worldwidediversity ofsturgeons and paddle-
fishes iscurrentlythreatened, and infact, theextir-
pation ofsomeforms inEurope andAsia hasbeen
reported (Rochard et al.1990,Birstein1993,Wald-
man 1995). At thesametime,populationabundane-
es of mostspecies arc athistorically low levels, in-
cludingmanyNorthAmericantaxa (e.g., Kynard
1997 thisvolume, Smith & Clugston 1997 this vol-
ume). Althoughmolecularanalysis hasrapidly be-
come aprimarytool in themanagement andcomer-
vation offishes(Hallerman &Beckmann 1988, Wir-
gin & Waldman1994,Bernatchez1995), its use for
problems involving acipenseriforms has lagged,
perhaps due to thescarcity ofmany of thesespecies
and the consequentialdifficulty ofobtaining ade-
quatenumbers oftissuesamples.However, im-
provements to DNAanalysistechnologies,includ-
ing nonlethalsampling, slackening oftissuepreser-
vationrequirements. and theability of PCR to al-
low analysis ofminute amounts oftissuehave
relaxed many of the constraintsthatchallenged
sample collection.Thus, weanticipate anexpand-
ing role for molecularanalysis in theconservation
of thesehighlythreatenedfishes.
Wirgin &Waldman(1994)listed 12areas of in-
vestigation in fisheriesbiologyamenable to DNA
analyses.Here, wereviewstudies inthese areas in
whichmolecular techniques havebeenapplied to
problems in theconservation ofsturgeons and pad-
dlefishes. We also suggestotherareas towhich