Endocrine disruption and altered sexual development in aquatic organisms: an invertebrate perspective

Abstract

Contaminants causing sex-altering, endocrine disrupting-like (ED) effects, or otherwise influencing reproduction, have been of growing concern to humans for more than 50 years. They have also been a perturbing, though less well-studied, phenomenon in marine organisms, following the recognition of tributyltin (TBT)-induced imposex and population extinctions in (neo)gastropods in the 1970s. Whilst ED impacts in mammals and fish are characterized by mimicry or antagonism of endogenous hormones by environmental contaminants (acting through Nuclear Receptors which are present in all metazoans) much less is known regarding pathways to effects in invertebrates. Despite the absence of a defined steroidal/mechanistic component, the extent, severity and widespread nature of ED-like manifestations and altered sexual characteristics observed in marine invertebrates gives rise to comparable concerns, and have been a long-term component of the MBA's research remit. The manifestations seen in sensitive taxa such as molluscs and crustaceans confirm they are valuable indicators of environmental quality, and should be exploited in this capacity whilst we seek to understand the pervasiveness and underlying mechanisms. In so doing, invertebrate indicators address aims of organizations, such as the EEA, OECD, UNEP and WHO, charged with management and monitoring of chemicals and ensuring that adverse effects on humans and the environment are minimized (Bergman et al., 2013). In view of the recent general declines in marine biodiversity, and the potential contribution of ED-like phenomena, safeguarding against deleterious effects through increased research which links pollutant exposure with reproductive dysfunction among invertebrates, is seen as a high priority.

Editorial

“…Tributyltin is just one of a number of Endocrine Disrupting Chemicals (EDCs), as discussed in this issue in the review by Langston (2020). The role of EDCs as a contaminant has a high profile from a marine management point of view, being among the list of pollutants with targets for prevention and reduction under the EU's Marine Strategy Framework Directive (MSFD) and also under the United Nation's Sustainable Development Goals (specifically under target 14.1, SDG 14).…”

“…Langston (2020) provides a comprehensive review of EDCs and similar contaminants, particularly with regard to impacts on marine invertebrates. It would appear therefore that with an extensive body of research carried out and evidence of improvements in the marine ecosystem, the pathway from scientific research to the development of appropriate regulatory frameworks and legislation is well-established and working well.…”

“…For a start there are ongoing challenges in terms of new chemicals and substances appearing (Zacharias & Ardron, 2019: 127) and these will require additional monitoring and investigation. Langston (2020) also highlights a number of knowledge gaps where further research is required including: additive/interactive effects of EDCs; cumulative impacts of multiple stressors; better understanding of the mechanisms leading to deleterious effects, particularly at the population level; the need for ongoing monitoring to better understand recovery; and the fact that more work is required specifically on marine invertebrates.…”

Research for Ocean Sustainability

“…As part of our celebration of our 100 th volume we have published a series of reviews (Dando & Southward, 2020, Rainbow, 2020, Raven & Beardall, 2020, Langstone, 2020, Hawkins et al, 2020) reflecting on subjects typical of the Journal for more than one hundred years. We encourage authors to submit review articles and will continue to welcome such reviews and the insights they provide in the future.…”

Obituary: Dr W.J. (Bill) Langston (1951–2020)

“…He was an active member of the Hong Kong University Grants Committee life sciences grant panel. It was particularly poignant that he wrote a review article for the 100th volume of JMBA describing the ecotoxicology of endrocrine disruption, which was published just before he passed away (Frost, 2020; Langston, 2020). Despite the pressures on his time he never forgot to contribute to the scientific community of which he was part – it was no surprise that on hearing the news, tributes came in from various organizations in Plymouth but also from colleagues internationally including China.…”