10th Anniversary Perspective: Reflections on endocrine disruption in the aquatic environment: from known knowns to unknown unknowns (and many things in between)

Endocrine disruption in the aquatic environment has been a much-researched topic worldwide for the last fifteen years. We have not attempted to write a traditional review of the topic with this paper. Instead, based on unpublished reports and our own personal memories, we provide a history of the development of endocrine disruption research in the last 30 years, since the initial, accidental discovery of intersex fish in an English river in 1978. We focus on how the key questions were tackled, and the often surprising answers to some of these questions. We cover what we now know, and what we still do not know. Based on our current understanding, we emphasize the crucial role played by interdisciplinary research in moving the issue forward. The paper concludes with a selection of general messages about chemicals in the environment which have emerged from endocrine disruption research, and how these have changed our understanding of chemicals in the environment. If lessons have been learnt, and are acted upon when the next chemical 'scare' emerges (as it inevitably will), then it should be possible to act more efficiently and effectively to better protect the environment than was achieved during the oestrogens in the environment'' era.