Marine ecosystems are an intricate network of living organisms within the ocean environments. Understanding the balance of these ecosystems is imperative, especially when external, human factors disrupt this delicate balance. One alarming disruption prevalent in the 21st century would be the genetic mutation of male fish into female fish, which is a phenomenon increasingly linked to the remnants of human medicines such as birth control pills in our waterways. After reading an article on News Medical “Male fish mutating into females- A toxicological fallout from remnants of human medicines in the ecosystems” which discusses the issue of genetic mutations of gender in the field of ecotoxicology, I felt compelled to delve deeper into this pressing issue.

 

Professor Tyler, who has been researching this field for over a decade, addressed this rising global issue in his lecture titled “Feminisation of Nature- an Unnatural History” at the 50th Anniversary Symposium of the Fisheries Society, strongly suggesting that more scientists should work on the impact of these drugs on marine ecosystems. The details of his lecture included his large-scale study, conducted in 2008, where the results taken from 51 different sites on the English rivers revealed that 1 in 4 male roach fish were turning into females as they were found to have ova in their testicles. Furthermore the research suggests how the levels of oestrogen were found to be higher in the waters where these fish were found. Oestrogen and Progesterone are found in birth control pills which are utilised to stop women from ovulating and prevent undesired pregnancies. Once flushed down the toilet, these hormone-induced pills affect the physiology of male fish, damaging major organs such as kidneys, liver, brain and the heart. The feminisation of fish impacts more than the individual fish, but the entire school of fish in the marine ecosystem as the male fish are unable to breed and pass on their genetic material to offspring. Professor Tyler concludes by demanding action to be taken and for this issue to be rectified. 

​

Another article written by National Geographic in 2016, uncovers similar instances in the United States and Canadian border. Scientists from the U.S. Fish and Wildlife Service coupled with the U.S. Geological Survey observed fish in 19 national wildlife refuges in the U.S. Northeast where they witnessed exactly what had happened in the United Kingdom. An alarming 60-100 percent of all the male smallmouth bass they examined had female egg cells growing in their testes. Scientists have coined this term as intersex and while the root cause is unknown, it has previously been linked to man made, environmental chemicals that mimic or block sex hormones. Feminised male fish have been discovered in 37 species in lakes and rivers in different parts of the world and therefore this issue must be remedied immediately before entire marine ecosystems are collapsing and fading. 

In conclusion, the feminisation of male fish, illustrated in the studies from the United Kingdom and North America reveal the astonishing impact these pollutants have on marine life. Immediate action needs to be taken, such as enhancing wastewater treatment technologies to filter these hormones and to protect our marine environments.