MEPS 269:121-129 (2004)  -  doi:10.3354/meps269121

Effects of steroidal estrogens on coral growth and reproduction

A. M. Tarrant1,4,*, M. J. Atkinson2, S. Atkinson3

1Department of Oceanography, University of Hawaii at Manoa, 1000 Pope Road, Honolulu, Hawaii 96822, USA
2Hawaii Institute of Marine Biology, University of Hawaii at Manoa, PO Box 1346, Kaneohe, Hawaii 96743, USA
3Alaska SeaLife Center, University of Alaska Fairbanks, PO Box 1329, Seward, Alaska 99664, USA
4Present address: Woods Hole Oceanographic Institution, Biology Department, MS-32, Woods Hole, Massachusetts 02543, USA

ABSTRACT: Steroidal estrogens are well-described vertebrate hormones that also occur in invertebrates, where they have diverse biological effects. Estradiol-17β is contained in coral tissues and released into the surrounding water during multi-species coral mass-spawning events. Estrogens are also widely distributed environmental pollutants in coastal waters; thus corals and other reef invertebrates are exposed to a variety of estrogens and estrogen-like compounds with unknown organismal and ecological effects. Until now, there has been no experimental evidence to suggest that estrogens are biologically active in corals. We describe the effects of exogenous estradiol on the size and number of gametes spawned by coral colonies and the effects of estrone on coral growth rates and tissue thickness. Montipora capitata coral colonies treated with estradiol for 3 wk prior to spawning released fewer egg-sperm bundles than controls (29% decrease). Porites compressa coral fragments (Œnubbins¹) exposed continuously to estrone for 2 to 8 wk had lower (13 to 24%) skeletal growth rates than controls. Large coral nubbins that were treated with estrone had thicker tissue. While the mechanism for estrogen action for corals remains unknown, these experiments represent the first account of biological activity of steroidal estrogens in coral.

KEY WORDS: Estrogen · Coral · Reproduction · Endocrine disruption · Reef · Calcification

Full text in pdf format