Prioritising research on endocrine disruption in the marine environment: a global perspective

A healthy ocean is a crucial life support system that regulates the global climate, is a source of oxygen and supports major economic activities. A vast and understudied biodiversity from micro- to macro-organisms is integral to ocean health. However, the impact of pollutants that reach the ocean daily is understudied for marine taxa, which are also absent or poorly represented in regulatory test guidelines for chemical hazard assessment. Inspired by the United Nations Decade of Ocean Science, which aims to reverse the decline in ocean health, this communication calls for global coordination in building resources for studying the effects of marine pollution. The bibliographic analysis, a collective product of scientists from diverse backgrounds, focused on endocrine-disrupting chemicals (EDCs). In this review, we (i) critically analyse the literature on endocrine signalling pathways and high-level physiological impacts of EDCs across 20 representative marine taxa; (ii) identify knowledge and regulatory gaps; (iii) apply bioinformatics approaches to marine species genomic resources, with relevance for predictions of susceptibility; and (iv) provide recommendations of priority actions for different stakeholders. We reveal that the scientific literature on EDCs is biased towards terrestrial and/or freshwater organisms, is limited to a handful of animal taxa, and marine organisms are dramatically underrepresented. Our bibliographic analysis also confirmed that only a small number of (neuro) endocrine pathways are covered for all animals, whilst basic knowledge on endocrine systems/endocrine disruption for most marine invertebrate phyla is minimal. Despite significant gaps in genomic resources for marine animals, endocrine-related protein conservation was evident across more than 500 species from diverse marine taxa, highlighting that they are at risk from EDCs. Despite recent technological advances, translation of existing knowledge into international regulatory test guidelines for chemical hazard assessment and monitoring programs is limited. Furthermore, the current understanding is confounded in part by transposing vertebrate endocrinology onto non-vertebrate taxa. In this context, specific recommendations are provided for all stakeholders, including academia (e.g. to expand knowledge across metazoan taxa and endocrine targets and translate it to New Approach Methodologies and Adverse Outcome Pathways; to increase and improve tools for comparative species-sensitivity distributions and cross-species extrapolations), regulators (e.g. increase awareness of specific risks for the marine environment, prioritise international standardisation of testing methods for marine species and request evidence for absence of endocrine disruption in marine phyla), policy makers (e.g. implement sustained, long-term international marine monitoring programs and increase global co-operation) and the public or non-governmental organisations (e.g. foster public engagement and behaviours that prevent marine chemical pollution; promote citizen science activities; and drive political actions towards protective and restorative marine policies). We hope that this and past reviews can contribute towards meeting ambitious international plans for marine water quality assurance, mitigation of marine pollution impacts and protection of marine biodiversity. The importance of marine biodiversity for climate change mitigation, food security and sustainable ecosystem services calls for urgent, cooperative action.