effects of 17α -ethinyl estradiol on the reproductive success of freshwater fish ensc 202 april 24,...
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Effects of 17α -Ethinyl Estradiol on the Reproductive Success of
Freshwater Fish
ENSC 202
April 24, 2008
Katie Chang
Lucas Chapman
Jackie Travers
Alea Tuttle
Overview• Introduction to 17α-ethinyl estradiol (EE2)
• EE2 in wastewater treatment effluent
• Effects of EE2 on the sexual characteristics and development of individual fish
• Effects of EE2 on reproductive success of fish populations
• Case study Kidd et al. 2004
17-ethynyl-13-methyl-7,8,9,11,12,13,14,15,16,17- decahydro-6H-cyclopenta[a] phenanthrene-3,17-diol
(image source:wikipedia.org, 2008)
WikimediaCommons.org
Problem Statement
• EE2, distributed in freshwater systems by wastewater effluent discharge, negatively impacts reproductive success in freshwater fish.
EE2 removal in Sewage Treatment
http://www.waterencyclopedia.com/
Ineffective at breaking down E1 and EE2
Hydrophobicity of EE2 plays a role in Activated Sludge treatment
Studies inconsistent due to detection limits and variability among treatment type, and loading.
Alternative treatment:
Physical: SonolysisUV radiation with HOOH
Biological: White rot fungi-laccase Rhodococus Bacteria
Surface Water and Effluent Concentrations
Environmental concentrations of estrogens are typically in the low parts per trillion (>5ng/L or 5pptr).
Taipei Taiwan: Dan-Shui Riversurface water = 15 ng/Ltreatment effluent = 26 ng/L(Chen et al. 2007)
3 out of 7 British STW effluenthad detectable concentrations between 0.2-7 ng/L (Desbrow et al. 1998)
Vs.
What is “Environmentally Relevant”? Tricky to Answer.
Depends on: % of waterbody dischargeeffluent strengthdetection limit plays a role
Effects of EE2 on Sexual Development of Individual Fish
Feminization of FishAt lifetime exposure to 5ng/L EE2
• VTG production in males
• phenotypic changes of males*
• no expressible sperm
• no normal testes development
• ovary-type tissue development in males
*effect also seen at lifetime exposure to 0.96ng/L EE2
http://cobbers.com/wp-content/uploads/2006/09/lady-fish.jpg
Blood VTG concentrations for a zebrafish population exposed to EE2 for 40 days (A), and an offspring population with life-long exposure (B).
(Nash et al ., 2004)
Effects of EE2 on Sexual Development of Individual Fish
Egg Production and Embryo Viability• Number of eggs produced after exposure
• Lifetime exposure to 0.5ng/L and 5.0ng/L (Nash, et al., 2004) >3.5ng/L (Parrott, et al., 2004)
• 3 week exposure to 0.1ng/L and 1.0ng/L (Pawlowski, et al., 2004)• embryo survival rates
• Lifetime exposure to 0.2ng/L and 1.0ng/L (Lange, et al., 2001) 0.5ng/L and 5.0ng/L (Nash, et al., 2004) 10ng/L (Balch et al., 2004)
• reduced gonadosomatic index• Lifetime exposure to >3.5ng/L (Parrott, et al., 2004)
• Mortality• 10 day exposure to 50ng/L (Nash, et al., 2004)
Breeding Behavioral Effects
• Little research done• Nash, et al. study (zebrafish)
– Increased aggression in males
• Wolfand, et al. study (fathead minnows)– Decreases competitiveness and aggression in
males– Lowered male interest in cleaning nests
Acute vs. Chronic Effects
• Duration and timing of exposure key
• Different for each species
• Studies:– Schafer, et al.– Nash, et al.
Schafer et al. (zebrafish)
• Three experiments– F1 - partial life cycle (0-75days post fertilization (dpf))– F1 - full life cycle– F2 - full life cycle
• Four concentrations – (0.05, 0.28, 1.7, and 10ng/L)
• Zebrafish exposure to 9.3ng/L– Full life cycle: reproduction unsuccessful– Partial life cycle: able to recover
LOAEL
• Values calculated by Schafer et al.
• For zebrafish*– First generation: 1.1ng/L – Second generation: 2.0ng/L
• Reduced fecundity and fertility– 23% and 45% in F1 generation– 83% and 98% in F2 generation
*Will be different in other species, e.g. Chinese Rare Minnow (Zha et al., 2008)
Karen Kidd et al. Study
•What makes the Kidd et al. study so important?
•Where did it take place?
•What [EE2] was achieved during the experiment? Why?
•What type of fish was used? Why?
•Conclusions? What kind of species are at risk?
Kidd et al. results• Both male and female fathead were found to
have increased VTG production• Male gonad development was effected: Sperm
mobility and production decreased, ovatestes.• Altered oocytes in females• Population collapse due to loss of YOY• Short lived species may be at the greatest risk
of population collapse after chronic EE2 exposure.