Impacts of Hypoxia on Impacts of Hypoxia on Reproductive Function in the Reproductive Function in the
Gulf Killifish, Gulf Killifish, Fundulus Fundulus grandisgrandis
Ann Oliver Cheek
EaGLeEaGLe
Chl a
Grass shrimp Benthic consumers
N cycle Bacteria Aerobic BacteriaLand Use
decomposition
N nutrients
N, P nutrients
Gulf killifish
Blue crabs Atlantic croaker
1° producers
3° consumers
1° consumers
2° consumers
larval
juvenile
juvenile
Pensacola Bay, Garcon Point marsh July 2003
0
2
4
6
8
10
12
7/25/030:00
7/26/030:00
7/27/030:00
7/28/030:00
7/29/030:00
7/30/030:00
7/31/030:00
8/1/030:00
DO
(m
g/L
)
Marsh Creek sonde
GOALS & HYPOTHESISGOALS & HYPOTHESIS
1.1. Develop indicators of hypoxic effects Develop indicators of hypoxic effects in a common marsh resident – in a common marsh resident – Fundulus grandisFundulus grandis
2.2. Advance understanding of Advance understanding of howhow hypoxia regulates reproduction in fishhypoxia regulates reproduction in fish
Hypoxia impairs Hypoxia impairs reproductionreproduction
Gulf killifishGulf killifish
REPRODUCTIVE LIFE REPRODUCTIVE LIFE HISTORYHISTORY
J F M A M J J A S O N D
Batch SpawnerBatch SpawnerR
epro
du
ctiv
e P
aram
eter
sR
epro
du
ctiv
e P
aram
eter
s
INDICATORS of EFFECTINDICATORS of EFFECTFulton’s condition factor (100,000*W/LFulton’s condition factor (100,000*W/L33))
Gonadosomatic index (100*WGonadosomatic index (100*Wgonadgonad/W/Wbodybody))
Estradiol (females)Estradiol (females)
Testosterone (males & females)Testosterone (males & females)
11-Ketotestosterone (males)11-Ketotestosterone (males)
Vitellogenin (females)Vitellogenin (females)
Reproductive Hormone Reproductive Hormone FunctionFunction
liverliver
ovaryovary
pituitarypituitary
estrogenestrogen
brainbrain
FSHFSH
testosteronetestosterone
VITELLOGENINVITELLOGENIN
Reproductive Hormone Reproductive Hormone FunctionFunction
liverliver
testistestis
pituitarypituitary
brainbrain
FSH, LHFSH, LHT, 11KTT, 11KT
Laboratory ExposureLaboratory ExposureChronic HypoxiaChronic Hypoxia
15 ppt salinity15 ppt salinity2727°C°C
Chronic HypoxiaChronic HypoxiaFemalesFemales
0.0
2.0
4.0
6.0
8.0
GSI T E2 VTG
6.68 mg/L
1.34 mg/L
**
Chronic HypoxiaChronic HypoxiaEgg ProductionEgg Production
0
5
10
15
20
25
30
35
7/10 7/11 7/12 7/13 7/14 7/15 7/16 7/17 7/18
Da
ily #
eg
gs
/fe
ma
le
6.68 mg/L1.34 mg/L
Chronic HypoxiaChronic HypoxiaMalesMales
0.0
0.5
1.0
1.5
2.0
GSI T 11KT
6.68 mg/L
1.34 mg/L
*
How do indicators respond in GOM estuaries?
Weeks Bay, ALWeeks Bay, ALPensacola Bay, FLPensacola Bay, FL
Weeks Bay Creek
Weeks Bay Mouth
Mobile Bay
Weeks Bay Mouth & Creek, Jul - Aug 2004
0
2
4
6
8
10
12
7/12/04 12:00 7/19/04 12:00 7/26/04 12:00 8/2/04 12:00
DO
(m
g/L
)
Weeks Bay Mouth sonde Weeks Bay Creek sonde
2 mg/L 2 mg/L 41 41 mmHgmmHg@ 31C @ 31C
WBM 4.03 mg/L = 82 mmHg
0.79 hr 3/18
WBC 0.93 mg/L = 19 mmHg
3.40 hr 18/19
Severe Hypoxia reduces Severe Hypoxia reduces Sex Steroid ConcentrationsSex Steroid Concentrations
WB Jul 04 - MALES
0.0
1.0
2.0
3.0
GSI T KT
WBS WBC
******
WB Jul 04 - FEMALES
0.0
2.0
4.0
6.0
8.0
GSI T E2 VTG
WBS WBC
*** ***
***p < 0.001
WBS = Mild hypoxia WBC = Severe hypoxia, PO2 ~ 82 mmHg PO2 ~ 19 mmHg
2 mg/L 2 mg/L 41 41 mmHgmmHg
WBM 4.65 mg/L = 91 mmHg
0 0/6
WBC 2.61 mg/L = 51 mmHg
0.63 3/6
Weeks Bay Jul 15-22, 2005
0
1
2
3
4
5
6
7
8
9
10
7/15/05 7/16/05 7/17/05 7/18/05 7/19/05 7/20/05 7/21/05 7/22/05 7/23/05
DO
(m
g/L
)
Weeks Bay Mouth sonde Weeks Bay Creek
Moderate Hypoxia reduces Moderate Hypoxia reduces GSI & 11KTGSI & 11KT
**p < 0.01, ***P < 0.001
WBS = Normoxic, PO2 ~ 91 mmHg WBC = Hypoxic, PO2 ~ 51 mmHg
WB Jul 05 - MALES
0.0
1.0
2.0
3.0
GSI T KT
WBS WBC
*****
WB Jul 05 - FEMALES
0.0
2.0
4.0
6.0
GSI T E2 VTG
WBS WBC
*****
Garcon Point
Indian Bayou
2 mg/L 2 mg/L 41 41 mmHgmmHg
GP1 4.39 mg/L = 89 mmHg
0 0/9
IB 2.41 mg/L = 49 mmHg
1.53 4/8
Pensacola Bay marshes July 2005
0
2
4
6
8
10
12
7/18/05 7/19/05 7/20/05 7/21/05 7/22/05 7/23/05 7/24/05 7/25/05 7/26/05 7/27/05 7/28/05
DO
(m
g/L
)
Indian Bayou sonde GP1
Moderate Hypoxia reduces Moderate Hypoxia reduces GSI & 11KTGSI & 11KT
**p < 0.01, ***P < 0.001
GP = Normoxic, PO2 ~ 89 mmHg IB = Hypoxic, PO2 ~ 49 mmHg
PB Jul 05 - MALES
0.0
1.0
2.0
3.0
GSI T KT
GP IB
*** ***
PB Jul 05 - FEMALES
0.0
1.0
2.0
3.0
GSI T E2 VTG
GP IB
******
REPRODUCTIVE IMPACTREPRODUCTIVE IMPACTHypoxi
aSetting M
GSIM T
M 11KT
F GSI
F T
F E2
F VTG
Cyclic 49/1.5/50%
Field PB ● ● ● ● ● ● ●
Cyclic 51/0.6/50%
Field WB ● ● ● ● ● ● ●Cyclic
19/3.4/95%Field WB ● ● ● ● ● ● ●
Cyclic 27/3.0/100
Lab ● ● ● ● ● ●Chronic 25/24/100
Lab ● ● ● ● ● ● ●Not changed by hypoxia
Reduced by hypoxia
Reproductive Impacts of Reproductive Impacts of Diel HypoxiaDiel Hypoxia
• In the fieldIn the field– Male steroid hormones & GSI are Male steroid hormones & GSI are
reducedreduced– Female GSI can be reducedFemale GSI can be reduced
• In the labIn the lab– Male steroid hormones are reducedMale steroid hormones are reduced– Female steroid hormones & GSI are Female steroid hormones & GSI are
reducedreduced– Fecundity is reducedFecundity is reduced
AcknowledgmentsAcknowledgmentsChristie Landry, Christie Landry,
Amy Sutton, Amy Sutton, Stacy Steele, Stacy Steele, Brett Henry, Brett Henry, Sarah Temple, Sarah Temple, Lisa Cohen, Lisa Cohen, Bern Wood, Bern Wood, Ross Turlington; Ross Turlington; SLUSLU
Dick Snyder & lab; Dick Snyder & lab; UWFUWF
Steve Manning, Steve Manning, Thea Hoexum-Thea Hoexum-Brouwer; USMBrouwer; USM
Scott Phipps, Eric Scott Phipps, Eric Brunden; Weeks Brunden; Weeks Bay NERRBay NERR
Shaye Sable, LSUShaye Sable, LSUChad Ellington, Chad Ellington,
UNOUNO
Cyclic HypoxiaCyclic Hypoxia
Cyclic Hypoxia Normoxia
DOmin1.4 mg/L ≈ 26.6
mmHg6.5 mg/L ≈ 123
mmHg
Period ≤ 2 mg/L 3.0 hr 0 hr
0
1
2
3
4
5
6
7
8
7/28/06 8/2/06 8/7/06 8/12/06 8/17/06 8/22/06 8/27/06 9/1/06
DO
(m
g/L
)
Fish placed in tanks
Begin cyclic DO exposure
Cyclic Hypoxia Cyclic Hypoxia Steroids & GSISteroids & GSI
MalesMales FemalesFemales
0
2
4
6
8
10
T E2 GSIng
/ml
Normoxia Cyclic Hypoxia
0
1
2
3
T 11 KT GSI
ng/m
l
Normoxia Cyclic Hypoxia
** *
Cyclic Hypoxia Cyclic Hypoxia Egg ProductionEgg Production
0
10
20
30
40
50
8/3/06 8/10/06 8/17/06 8/24/06 8/31/06
Dai
ly E
gg
s/F
emal
e 6.48 mg/L
1.4 mg/L
Cyclic Hypoxia Cyclic Hypoxia FertilizationFertilization
50
70
90
110
130
8/3/06 8/10/06 8/17/06 8/24/06 8/31/06
% e
gg
s fe
rtil
ized
6.48 mg/L
2 mg/L
