The Ecology of the Clear Lake Hitch (

7/30/2019 The Ecology of the Clear Lake Hitch (

1/27

The Ecology of the Clear Lake HitchThe Ecology of the Clear Lake Hitch(Lavinia exilicauda chi)(Lavinia exilicauda chi)

Greg GiustiGreg Giusti

University of CaliforniaUniversity of CaliforniaCooperative ExtensionCooperative Extension


2/27

Clear Lake, fish and peopleClear Lake, fish and people Native fish have longNative fish have long

been an important part ofbeen an important part ofpeoples lives based onpeoples lives based on

archeological discoveriesarcheological discoveries

around Clear Lake.around Clear Lake.

Tule perch


3/27

Clear Lake, fish and peopleClear Lake, fish and people

Ancient relationshipsAncient relationshipscontinue todaycontinue today..

New relationshipsNew relationshipshave developed overhave developed over

time and with newtime and with new

speciesspecies


4/27

Clear Lake HitchClear Lake HitchThen and nowThen and now


5/27

Native Fishes (1872)Native Fishes (1872) Pacific lampreyPacific lamprey

ThreespineThreespine sticklebackstickleback

Sacramento perchSacramento perch

Tule perchTule perch

Prickly sculpinPrickly sculpin

Rainbow troutRainbow trout

CyprinidaeCyprinidae

ThicktailThicktail chub*chub*

Clear lakeClear lake splittailsplittail**

Sacramento pikeminnowSacramento pikeminnow

Sacramento blackfishSacramento blackfish Clear lake hitchClear lake hitch

Prickly sculpin

Sacramento perch


6/27

Clear LakeClear Lakes minnowss minnows

Clear Lake hitch

Sacramento pikeminnow(chappaul)

Sacramento blackfish(greaser)

Thicktail chub

splittail


7/27

Introduced fishesIntroduced fishes

Brown bullheadBrown bullhead (1880)(1880) White catfishWhite catfish (1880,1923)(1880,1923)

Channel catfishChannel catfish (1950)(1950)

Largemouth bassLargemouth bass (1888)(1888)[FSLMB 1970s][FSLMB 1970s]

Smallmouth bassSmallmouth bass (1895)(1895)

BluegillBluegill (1909(1909--10)10)

Black crappieBlack crappie (1915)(1915)

White crappieWhite crappie (1950s)(1950s)

Common carpCommon carp (1880)(1880) Green sunfishGreen sunfish (1941*)(1941*)

GoldfishGoldfish (1950(1950--63*)63*)

MosquitofishMosquitofish (1925)(1925)

Golden shinerGolden shiner (1896)(1896)

RedearRedear sunfishsunfish (1973*)(1973*)

Inland silversideInland silverside (1967)(1967)

Threadfin shadThreadfin shad (1985)(1985)

* When first appeared in the record.* When first appeared in the record.


8/27

Key datesKey dates

18401840 European settlers in Lake CountyEuropean settlers in Lake County

18801880 Start of successful fish introductions into Clear LakeStart of successful fish introductions into Clear Lake

18881888 Largemouth black bass (Largemouth black bass (Micropterus salmoidesMicropterus salmoides) are introduced into Clear Lake by the CFC) are introduced into Clear Lake by the CFC

18951895 13 native species, 4 introduced species known in Clear Lake13 native species, 4 introduced species known in Clear Lake

19231923 2nd white catfish introduction is successful in Clear Lake2nd white catfish introduction is successful in Clear Lake

19381938 ThicktailThicktail chub is last seen in Clear Lakechub is last seen in Clear Lake

19431943 LinquistLinquist reportsreports largelarge splittailsplittail and hitch runsand hitch runs

1949,1949, 54,54, 57 DDT treatment of Clear Lake57 DDT treatment of Clear Lake

19491949 Murphy reportsMurphy reports hitchhitch runs decreased (probablyruns decreased (probably splittailssplittails))

19511951 Murphy reportsMurphy reports squawfish almost extinctsquawfish almost extinct

19621962 Hitch and blackfish are reported to be abundantHitch and blackfish are reported to be abundant

19631963 Cook reports methyl parathion applied annually (3Cook reports methyl parathion applied annually (3--4x/summer)4x/summer)

19661966 Sacramento perch are considered rareSacramento perch are considered rare

19671967 Inland silversides introduced into Clear LakeInland silversides introduced into Clear Lake

19691969 Crappie and bluegill equal 79% of catch in this yearCrappie and bluegill equal 79% of catch in this year

19881988 Crappie population in declineCrappie population in decline

19951995 Barrington writes he believes chub,Barrington writes he believes chub, splittailsplittail and trout or extirpated from Clear Lake.and trout or extirpated from Clear Lake.

20122012 7 native species, 15 introduced species7 native species, 15 introduced species


9/27

Hitch factsHitch facts

A member of theA member of theCyprinidaeCyprinidae minnowminnow

familyfamily

Adult females tend toAdult females tend tobe larger than adultbe larger than adult

malesmales

Spawn in creeks,Spawn in creeks,migrate and grow inmigrate and grow in

Clear Lake.Clear Lake.


10/27

More Hitch factsMore Hitch facts

Spawn in streams in lateSpawn in streams in latewinter early spring.winter early spring.

Females can lay betweenFemales can lay between99--63K eggs (63K eggs (avgavg = 36K;= 36K;

dependent on size ofdependent on size offemale).female).

Females mature either inFemales mature either inthe 2the 2ndnd or 3or 3rdrd year.year.

Males can mature in theMales can mature in the11stst, 2, 2ndnd or 3or 3rdrd year.year.


11/27

Early life of hitchEarly life of hitch Eggs hatch in about 7 daysEggs hatch in about 7 days

(depending on H(depending on H22O temp)O temp)

Young begin moving (freeYoung begin moving (free

swimming) downstream inswimming) downstream inabout 7 days.about 7 days.

Seek tule beds near mouths ofSeek tule beds near mouths ofcreek for protection.creek for protection.

Remain near or in tules forRemain near or in tules forabout 80 days until they reachabout 80 days until they reachabout 50mm (2 inches).about 50mm (2 inches).

Feed heavily on chironomidFeed heavily on chironomidlarvae (rice flies)larvae (rice flies)

Chironomid larvae

Hitch larvae


12/27

First year of lifeFirst year of life

At about 2 inches move from tuleAt about 2 inches move from tulebeds to deeper water.beds to deeper water.

From this point they move out toFrom this point they move out tothe lake (the lake (limnecticlimnectic) where food is) where food ismore abundant.more abundant.

Nothing known about lakeNothing known about lakebehavior or movements.behavior or movements.

When mature return to spawn inWhen mature return to spawn instreams.streams.

Not known if they return to theirNot known if they return to theirnatal stream.natal stream.


13/27

Growth Rate of Clear Lake hitchGrowth Rate of Clear Lake hitch

4040--50 mm (1.550 mm (1.5--22) within) within3 months3 months

110110--170 mm (4.3170 mm (4.3--6.66.6))

by the end of their firstby the end of their first

yearyear

150150--300 (5.9300 (5.9--11.811.8) mm) mm

by the end of 2by the end of 2ndnd yearyear

To a max of about 350To a max of about 350mm (13.78mm (13.78))


14/27

Profile of recent hitchProfile of recent hitchspawning runs (2005spawning runs (2005--2010)2010)

0

2

4

6

8

10

12

14

16

Feb March April May

Month

Average#Days

Average number of days permonth when hitch were observed

from 2005 to 2010.

0

10

20

30

40

50

60

70

80

90

100

2005 2006 2007 2008 2009 2010

Year

To

tal#

D

ays

Total number of days of springhitch run 2005 2010 based on

the first and last visual sighting inall creeks. Combined average for

all years = 72 days.


15/27

Predation vs. CompetitionPredation vs. Competition

PredationPredation.. Not linear, multipleNot linear, multiple

and complexand complex

interactions.interactions.

Predator/preyPredator/prey

interactions changeinteractions change

seasonally and overseasonally and over

the life cycle ofthe life cycle ofspecies.species.

CompetitionCompetition.. ReRe--distributes sourcesdistributes sources

of energy (food) atof energy (food) at

multiple levels.multiple levels.

Creates changes inCreates changes in

behavior betweenbehavior between

competitors.competitors.


16/27

Predation is not linearPredation is not linear


17/27


18/27

Zooplankton

Larval Largemouth bass

Larval Prickly sculpinLarval Hitch

Larval Black crappie


19/27

Energy FlowsEnergy FlowsE = foodE = food

2 Consumer

1 Consumer

1 Producers


20/27


21/27

Threadfin shadThreadfin shadClupeidaeClupeidae (Herring family)(Herring family)

Illegally introduced intoIllegally introduced intoClear Lake sometime inClear Lake sometime inthe 1980s.the 1980s.

Known to have causedKnown to have causedDaphnia (zooplankton)Daphnia (zooplankton)collapse in Clear Lake.collapse in Clear Lake.

Populations are cyclic.Populations are cyclic.Numbers can achieveNumbers can achievevery high densitiesvery high densities


22/27

Stress Factors affecting HitchStress Factors affecting Hitch

In the lakeIn the lake.. CompetitionCompetition

PredationPredation

PollutionPollution Introduced speciesIntroduced species

In the creeksIn the creeks.. DroughtDrought

HH22O diversionO diversion

Gravel extractionGravel extraction Stream incisionStream incision

Premature streamPremature stream

dryingdrying

Migration barriersMigration barriers

Loss of vegetationLoss of vegetation

Threadfin shad


23/27

Possible other stress factorsPossible other stress factorsaffecting hitchaffecting hitch

Secchi depth, Clear Lake - Upper Arm, 1969-2010

0

1

2

3

4

5

6

7

1/1/1969 1/1/1973 1/1/1977 1/1/1981 1/1/1985 1/1/1989 1/1/1993 1/1/1997 1/1/2001 1/1/2005 1/1/2009

Dep

th(m)

Clear Lake has been gettingClear Lake has been gettingclearerclearersince 1969since 1969 obvious changes inobvious changes in

phytoplankton (algae) cycles.phytoplankton (algae) cycles.


24/27

Possible other stress factorsPossible other stress factorsaffecting hitchaffecting hitch (Goldman and Wetzel 1963)(Goldman and Wetzel 1963)

The 1The 1 productivity of CL isproductivity of CL isalmost entirely limited toalmost entirely limited tophytoplankton & bacteria.phytoplankton & bacteria.

Because of theBecause of the highhigh

turbidityturbidity the littoralthe littoraldevelopment of higherdevelopment of higheraquatic vegetation is limitedaquatic vegetation is limitedalong the periphery of thealong the periphery of thelake in spite of thelake in spite of theextensive shallow areas.extensive shallow areas.

Increase in benthicIncrease in benthic(bottom) plant growth(bottom) plant growthimpacts on predator/preyimpacts on predator/prey

interactions.interactions.


25/27

Possible other stress factorsPossible other stress factorsaffecting hitchaffecting hitch

Problematic blueProblematic blue--green algae (green algae (cyanocyano--bacteria) isbacteria) isaaproductproductof a processof a process..

bb--gg algaealgae= water clarity + temp + wind + circulation= water clarity + temp + wind + circulation+ Fe + P + N+ Fe + P + N (atmospheric)(atmospheric)


26/27

Clear Lake Hitch

Lake parameters Stream parameters Species interactions

Introduced speciesWater quality

Juvenile habitats

Water quantityMigration corridors

Habitat quality

CompetitionPredation

The Ecology of the Clear Lake hitch=The Ecology of the Clear Lake hitch=sum of multiple partssum of multiple parts


27/27

Questions?Questions?

Documents

The Ecology of the Clear Lake Hitch (