51813_Sturgeon biodioversity an.PDF

(Martin Jones) #1

SinceGengerke’s(1986)report,fivestates (Ala-
bama,Iowa, Louisiana, Oklahoma, and Virginia)
haveprohibitedcommercial harvest of paddlefish
(Table3). Most ofthese states were concerned
aboutoverfishing, illegal fishing or declines in adult
stocks. Conclusions
Arkansas andTennesseereport thelargest com-
mercial fisheries (Table 3).Arkansas estimates
136 000–181000 kg of paddlefish are taken commer-
cially each year from its several river systems. These
figures arereducedslightlysince 1983 because of a
continueddecline in somepopulations. Tennessee
reports 60 328 kgharvestedcommercially in1992,
comparedto197 768 kg in 1975. Allstatesbordering
the pooled portion of theMississippiRiver report
declines in theircommercial fisheries since1983.
All states bordering theMissouriRiver now pro-
hibit commercial fishing for paddlefish because
harvestsweresmall andsize of fish wasdecreasing.
Commercial exploitation, particularly insouthern
reservoirs, continues tobe a major factoraffecting
the viability ofpaddlefish populations throughout
theirrange. The incentive forillegalharvest has in-
creased tremendously in the past 10 years because
paddlefisheggs forcaviarroutinelysell for$100 t o
$200 per kg. Thevulnerability of paddlefish to com-
mercial(legal and illegal)harvest,behavioral char-
acteristics, and lowrecruitmentrate(slowmatura-
tion) iswelldocumented byPasch&Alexander
(1986;also seeBoreman 1997 thisvolume).Because
of theseproblems,several stateshaveremoved
paddlefishfromtheir commerciallist orimple-
mented regulations to protect paddlefish from
overexploitation.


lahoma,Pennsylvania,Texas, andWestVirginia are
attempting torecoverremnantstocks in selected
watersheds.

(1)The primarydifficulty in assessing thecurrent
status or trends ofpaddlefish populations in most
states is alack ofinformationaboutpopulation siz-
es, age structure,growth, or harvest rates. While
several paddlefish populationsappear to bestable
or increasing,Polyodonspathulais in decline in
much of itscurrent range because ofcontinued hab-
itatmodificationand degradation, increased con-
tamination, andoverfishing.
(2) Declines in paddlefish populations were iden-
tified byfive oftwenty-two stateswherepaddlefish
currentlyexist.Most ofthesestates consider the
loss oralteration of habitat assignificant.Because
of theseserious resource impacts, states should con-
tinue seeking mitigation for habitat losses in select
rivers torestorepaddlefishhabitat.Efforts should
includerestoration or maintenance of habitat di-
versity,includingpurchase or long-termeasement
on selected private lands sothatold river channels
and oxbows can be reconnected tomain channels.
Potential and known spawningareasshould be pro-
tectedfrom degradation.
(3) Resourceagenciesmustremain alert forille-
gal harvests ofeggs forcaviar, for paddlefish pop-
ulations can be damaged quickly if illegal activities
are not recognized andstopped.
(4)Although the peripheral range ofpaddlefish
has diminishedslightly,theystilloccur in the major-
ity of theiroriginalrange, and incomecases are re-
invading areas previously occupied. Aggressive
stocking programs are currently in planning stages
or actuallyunderway torestorepaddlefish to his-
toric ranges. Waterquality has improved in many
previouslypollutedrivers and stockingshould be
successful. While stateswait forstocked paddlefish
populations to develop, they mustquicklyinvento-
ry available and potential spawning and nursery
habitat and determine ifpaddlefish can prosper
naturally. It hastakenlessthan 100 years to destroy
the future for many paddlefish populations. Ifstate

Stocking programs

Ten statescurrently stock paddlefish juveniles to
supplementexistingstockswhere natural recruit-
ment islacking or insufficient tomaintainpopula-
tions, or are stocking torecover paddlefish stocks in
the periphery of itsnativerange(Table3).Wiscon-
sin and Minnesota have not yet stockedfish but
have drafted plans to guide recovery efforts for pad-
dlefish in thelowerWisconsin andMinnesota riv-
ers,respectively. It isencouragingthatKansas, Ok-
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