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.

A Day in the life of EE2

Copyright © 2004 American Chemical Society

En route to treatment

Image source: http://www.wplwloo.lib.ia.us/wfr/trng3.html

All estrogens

EE2

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

(Wolfand, et al., 2007)

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

Schafers, et al., (2007)

Schafers, et al., 2007

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.

Questions?