And I don't expect anyone wants to hear this, but - Googled fish feminization males - a sampling of results.
Obviously, this affects our aquarium fish as well, to speak only of fish.
It's in the water.
http
/www.sciencedirect.com/science?_ob=A...c68cec84791a861
Urogenital papilla feminization in male Pomatoschistus minutus from two estuaries in northwestern Iberian Peninsula
Abstract
'Recently, male urogenital papilla feminization (UGPF) in the sand goby Pomatoschistus minutus was reported in several UK estuaries with high levels of estrogenic compounds. The fact that this species is also common in southern European estuaries, together with its life-cycle characteristics, prompted us to investigate P. minutus UGPF in the northwestern of Iberian Peninsula. Specimens of P. minutus were periodically sampled during 2004 at several locations in two estuaries (Minho and Lima). Evidence for UGPF was recorded in both estuaries, the highest incidence being observed in the Lima estuary (50%). Estrogen levels (17β-estradiol and estrone) above 100 pg/l were observed in both estuaries, the higher concentrations being found in the Lima estuary. Overall, the results suggest a relationship between the feminization of male P. minutus urogenital papilla and the presence of estrogenic compounds. In the future, more in-depth studies are required in order to use P. minutus as a sentinel species for estrogenic compound monitoring in estuaries.'
http/www.ourstolenfuture.org/NEWSCIENCE/...edmundsetal.htm
'... Edmunds et al. report that a single exposure to o,p'-DDT can lead to a complete, permanent and functional sex reversal in this species of fish. They showed this experimentally by microinjecting small quantities of DDT directly into the egg yolks of medaka a few hours after fertilization, i.e., very early in embryonic development. Fish that under normal circumstances would have matured as males instead matured as females. Not only did these sex-reversed fish have a full complement of female reproductive characteristics, they were able to bear young at a breeding success rate comparable to normal females.
The researchers used microinjection into embryonic yolk as their experimental approach because they believed this route of exposure would be parallel to the actual maternal transfer of persistent lipophilic contaminants to the eggs. Other research has shown that o,p'-DDT concentrates highly in fish ovaries, and within the ovaries, almost all the DDT concentrates in oil droplets within the oocytes.
In medaka, sex is determined chromosomally. Normal males are XY while females are XX. Edmunds et al. examined the chromosomal sex and the morphological/functional sex of individuals at the age of 10 weeks, after injection. They found that at a DDT dose of 227 nanograms per egg (less than one half of the lethal dose, 511 ng/egg) 86% of the genetic males were sex-reversed. Genetic females showed no effects of treatment. None of the control group were sex reversed. They also exposed another treatment group to 2 ng/egg of 17ß-estradiol and found that 1 in 5 genetic males were sex reversed.
Edmunds et al. also tested whether treated, sex reversed males were fertile. They paired sex-reversed males with normal males and found that 50% (3 of 6 pairs) were fertile.
The doses needed to induce complete sex reversal (227 ng/egg or 227 ppm) were high relative to concentrations reported for background field levels. On the other hand, the lethal dose they observed was substantially higher than that reported for wild lake trout (10 ppm). The reasons for this discrepancy are unknown. They may involve species differences or differences in the toxicity of the form of DDT used, or differences in the impact of delivery via microinjection vs. maternal transfer. '
http/www.ourstolenfuture.org/NEWSCIENCE/...eminization.htm
'Fish feminization is widespread in Great Britain and in the US. The causes now appear to be a mixture of chemicals, including excreted byproducts of birth control pills and industrial chemicals. ...'
http/www.ce.berkeley.edu/~sedlak/CALFEDwebsite.htm
Identifying the Causes of Feminization of Chinook Salmon in the Sacramento and San Joaquin River System
University of California, Berkeley
University of California, Riverside
Applied Marine Sciences
Funding Agency: California Bay-Delta Authority
Project Overview
'Some organic compounds such as steroid hormones from livestock and surfactant metabolites can induce feminization of aquatic species when present at relatively low concentrations in water. The purpose of this project is to assess the estrogenicity of surface waters in the Sacramento/San Joaquin river system using both bioassays and targeted chemical analysis for steroid hormones and alkylphenolethoxylates. Additionally, samples exhibiting significant biological activity unexplained by known estrogenic compounds will be subjected to chemical fractionation and exhaustive analysis to identify the causative agents. Results of the research will be used to identify cost-effective approaches for controlling or preventing feminization of salmon and other important fish species. This research project is relevant to CALFED’s efforts to protect and restore Chinook salmon and other critical species because it provides much needed information about a family of chemical stressors that have not received much attention from the CALFED program.'
Better living through chemistry, or, how to tell if your fish is male or female, and at what time's in his/her life.
OMG 
Thanks for the warning.
