Tigerfish Powerpoint Presentation Honours

University of Johannesburg Zoology Department

Metal bioaccumulation in Metal bioaccumulation in muscle tissue of tigerfishmuscle tissue of tigerfish

(Hydrocynus vittatus) (Hydrocynus vittatus) from from the Pongolapoort Dam and the Pongolapoort Dam and

Okavango RiverOkavango River

By: E. M FisherSupervisor: Prof. V. WepenerCo-Supervisor: Dr. N Smit

IntroductionIntroduction• tigerfish

• Declining populations (Skelton, 2001)

» Human impacts

» Biological

• Protected species (Government Gazette, 2008)

• High trophic level

• Commercially important (Skelton, 2001)

• Bioaccumulate and biomagnify (Mhlanga, 2000)

University of Johannesburg Zoology Department (McHugh,2009)

BioaccumulationBioaccumulation

• What is it? (Connell et al., 1999)

• What does it tell you?• Environmental exposure• Bioavailability• Biomagnification

• What doesn’t it tell you?• What the effects are.• Non-hazard determination


(Gerber & McHugh, 2009)


Pongolapoort DamPongolapoort Dam

Photos taken from DWAF(2004)


Pongolapoort DamPongolapoort Dam

• The Phongolo river: east of Wakkerstroom

• Pongolapoort dam wall (1972).

• 2492 million m3 water.• DDT sprayings (1940). • Current uses (DWAF,2004).• Pongolapoort Dam: Tigerfish

http://flickr.com/photos/65196834@N00/2538492822http://www.prafrica.co.za/img/jpg/photos/pongola-dam.jpg


Olifants riverOlifants river

http://www.dwaf.gov.za/iwqs/rhp/state_of_rivers/state_of_crocsabieolif_01/maps/olif_eco_600.jpg


Cont. Olifants riverCont. Olifants river• Olifants river (du Preez

& Steyn, 1992).

• “mining, industrial and other related activities” (du Preez & Steyn, 1992)

http://images.travelpod.com/users/mattersdorff/1.1219433160.bird-glides-in-for-sunset-on-olifants-river.jpghttp://www.telegraph.co.uk/telegraph/multimedia/archive/00746/france-nuclear-404_746493c.jpg


Okavango RiverOkavango River

http://na.unep.net/AfricaAtlas/AfricaAtlas/AtlasDownload/Maps/okavango_catchments.jpg


Cont. Okavango RiverCont. Okavango River • The Okavango

river• Threats:

• Possible canalization

• Potential

development http://www.cfnews13.com/uploadedImages/Site_Content/Features/Kissimmee_River/Rest1.jpg

http://www.geog.ucl.ac.uk:8080/print-version/about-the-department/people/academics/martin-todd/accord/images/map2.jpg

QUESTION?QUESTION?

Are the metal concentrations in the muscle tissue of the tigerfish

reflecting environmental exposure to metals?



HypothesisHypothesisMetal concentrations in muscle

tissue of tigerfish in non-impacted areas will be lower

than those from impacted areas.


AimAim

To determine whether metal concentrations in muscle tissue of

tigerfish in non-impacted areas will be lower than those from

impacted areas.


ObjectivesObjectives• To compare metal concentrations in

the muscle tissue of tigerfish in the Pongolapoort Dam to studies in the Okavango Delta; Botswana, and the Olifant's river; Kruger National Park, South Africa.

• To compare muscle tissue concentrations to those found in sediment and water to determine bioavailability


The StudyThe Study

• Historical study: Olifants (du Preez & Steyn, 1992)

• Study: Okavango (Whitlow,2008)• Pongolapoort

Dam (2009)

(Van der Bank & Smit ,2007. as cited by Whitlow, 2008)

SITE 5

Olifants site


MethodMethod

• SAMPLING• Caught• Anesthetized & Sacrificed• Dissected• Frozen

• PROCESSING• Drying• Digestion

• Fly, bait and artificial lures.• Anesthetic: Clove Oil in ethanol and sacrificed• Portions of axial muscle removed. • Muscle tissue frozen and taken back to the lab.

(Gerber & McHugh, 2009)


Cont. of MethodCont. of Method

• ANALYSIS• ICP-OES• ICP-MS

• STATISTICAL ANALYSIS• Unpaired Student t-Test• SPSS (15.0)• Significance P<0.05

http://www.wcaslab.com/images/icpms/plasma.jpg

RESULTS AND DISUSSIONSediment and Water Comparison

Cr Co Ni Cu Zn As Cd Pb0.000

0.001

0.002

0.003

0.004

0.0051

26

Pongola water

0.000

0.001

0.002

0.003

0.004

0.0051

26Pongola sediment

* * *

Pongola Metals

met

al S

ed [

] u

g/g

Metal w

ater [ ] ug

/mL

Cr Co Ni Cu Zn As Cd Pb0.000

0.005

0.010

Okavango sedimentOkavango water

0.11.12.13.14.15.16.1

0.000

0.005

0.0100.11.12.13.14.15.16.1

* * *

Okavango Metals

met

al S

ed [

] u

g/g

Metal w

ater [ ] ug

/mL

•Olifant river water and sediment (Seymore, 1994)•Bioaccumulation dependent on water concentration (Connell et al., 1999)

Cr Ni Cu Zn Pb0

1

2

Olifants Sediment

Olifants Water

0

1

26

31

6

31

Olifants Metals

met

al S

ed [

] u

g/g

Metal w

ater [ ] ug

/mL

RESULTS AND DISCUSSIONWater comparison between sites

Cr Ni Cu Zn Pb0.00000.00010.00020.00030.00040.00050.0006

Pongola water

Okavango water

Olifants Water

0.0007

0.0107

0.04

1.04

Metals

met

al W

ater

[ ] u

g/m

L

0.0070.002

0.0001

0.003

0.002

Cu,Zn (Sawula,2004)


Results & DiscussionResults & Discussion

• No statistical significant difference between sites for Al, As, Co and Cr.

• As (Huntsman-Mapila et al., 2006)

Pongola Okavango0.00.51.01.52.02.53.03.54.04.55.05.5

SitesAl

(

g/g

dry

wei

ght)

Pongola Okavango0.00

0.01

0.02

0.03

0.04

Sites

As (

g/

g dr

y we

ight

)

Pongola Okavango0.000.010.020.030.040.050.060.070.080.090.100.11

Sites

Co (

g/

g dr

y w

eigh

t)

Pongola Okavango0.0

0.1

0.2

0.3

SitesCr

(

g/g

dry

wei

ght)


Cont. of DiscussionCont. of Discussion

• Much higher lead in Olifants than other sites

• In water, Pb was higher in Okavango than Pongola, and highest in Olifants Pongola Okavango Olifants

0.0

2.5

5.0

7.5

10.0

12.5

15.0

17.5

Sites

Pb

(g/

g dr

y w

eigh

t)


Cont. of DiscussionCont. of Discussion• There is a statistically

significant difference between sites for Cu,Cd and Fe.

• In water, Cu was higher in Okavango than Pongola, and highest in Olifants.

• Coal mining and shales: Cu, Fe (Johnson et al., 2006)

Pongola Okavango Olifants0.0

2.5

5.0

7.5

*

Sites

Cu

(g

/g d

ry w

eig

ht)

Pongola Okavango Olifants0

1

2

3

*

Sites

Cd

(g

/g d

ry w

eig

ht)


25

50

75

100

*

Sites

Fe (

g/g

dry

weig

ht)


Cont. of DiscussionCont. of Discussion• There is a statistically

significant difference between sites for Mn (Sawula, 2004), Zn (Sawula, 2004) and Ni (Sawula, 2004).

• In water, Zn higher in Okavango than Pongola,and highest in Olifants

• In water, Ni was higher in Pongola than Okavango, and highest in Olifants


0.5

1.0

1.5

2.0

2.5

*

Sites

Mn

(g

/g d

ry w

eig

ht)


5

10

15

20

*

Sites

Zn(

g/g

dry

weig

ht)


2.5

5.0

7.5

10.0

*

Sites

Ni

(g

/g d

ry w

eig

ht)


ConclusionConclusionIS THE HYPOTHESIS SUPPORTED?

YES!ALTHOUGH HUMAN IMPACTED AREAS

GENERALLY HAVE HIGHER METAL CONCENTRATIONS THAN NON-

IMPACTED AREAS, OTHER FACTORS INFLUENCE THE OCCURANCE OF

METALS.

OTHER FACTORS NEED TO OTHER FACTORS NEED TO BE TAKEN INTO ACCOUNTBE TAKEN INTO ACCOUNT

• SUCH AS– GEOLOGY– FISH ADAPTATION TO TOXICANTS– pH, WATER HARDNESS,

CONDUCTIVITY,TURBIDITY– OTHER IONS AND METALS IN WATER– SEQUESTRATION OF HEAVY METALS IN

OTHER AREAS THAN MUSCLE



RECOMMENDATIONSRECOMMENDATIONS

• More recent studies.

• For future studies it is recommended that a sample size of at least 20 fish is used.

• Water and sediment properties should be taken into account

• Geology of the area must be taken into account

• Take into account adaptation of fish to the toxicant


ACKNOWLEDGEMENTSACKNOWLEDGEMENTS

• PROFESSOR V. WEPENER (Supervisor)

• DR. N. SMIT (Co-supervisor)

• DR. H. VAN NIEKERK (SPEC-RAU)

• MISS LIESEL WHITLOW (Data from the Okavango)

• MISS NATALIE DEGGER (Assistance with SPSS)

• MR. KYLE MCHUGH (Sample Collection & Pictures)

• MS. MICHELLE SOEKOE (Sample Collection)

• MS. YOLANDI CLOETE (Sample Collection & other)

• UNIVERSITY OF JOHANNESBURG ZOOLOGY DEPARTMENT ( Moral Support & Resources)


THANK YOU!THANK YOU!

Tigerfish Powerpoint Presentation Honours

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