Founding Director of the SKLMP, Professor Rudolf Wu Shiu-sun, Research Chair Professor of Biological Sciences at EdUHK, said the Laboratory has a laudable mission, which he is happy to see continues to this day. He recalled the exciting moment when he built a team of experts from six universities in Hong Kong in response to the invitation of China’s Ministry of Science and Technology for the establishment of State Key Laboratories in the Hong Kong Special Administrative Region in 2007.
Professor Wu said that to his knowledge, it was the first State Key Laboratory to conduct research involving scholars from different disciplines (including biology, chemistry, physics, statistics and engineering) and different universities, working towards a common goal. “It’s a true collaborative effort; we share projects, resources, facilities, graduate students and manpower across different universities,” he said. As a consortium member, EdUHK brings its competitive advantage in environmental education and a strong relationship with the school sector to the SKLMP. EdUHK team members are leading a project to examine the prevalence and health effects of endocrine-disrupting chemicals (EDCs), and how these chemicals may affect our marine environment, our school children, and future generations.
Long ago, Professor Wu already recognised that it was necessary to tap into the vast amount of funding across the border, and he is currently looking to build partnerships with universities and organisations on the mainland. “It’s not only about doing research,” he said. “The mandate of State Key Laboratories is to make an impact in China and beyond, especially in tackling scientific issues of national importance.” The excellent results attained in the review of 2019 are perhaps the best testimony of the synergistic advantages of this inter-institutional platform, which is making an impact through high-quality, world-leading research in marine pollution.
Water: a precious resource
Professor Wu has served on many expert advisory groups of the Hong Kong Government and international organisations, including the United Nations, the International Maritime Organization and the Intergovernmental Oceanographic Commission. He said water is our greatest resource, especially in the coming decades. He explained that the interconnected ocean system makes the Earth habitable for mankind by playing a role in regulating global temperatures and weather, hosting a vast array of organisms, and providing sustenance for all living beings. Indeed, one of Professor Wu’s main research focuses is on marine life, one of the UN Sustainable Development Goals, in particular, the molecular and ecological responses of marine animals to environmental stresses, such as EDCs, xenobiotics and hypoxia.
Rising global temperatures and worsening coastal pollution are altering the marine environment, he pointed out. In particular, low oxygen in water (known as hypoxia), caused by various human activities, is affecting vast areas of the ocean, and is impairing the reproduction and development of marine life worldwide. He said this has resulted in the depletion of fish stocks to alarming levels, and warned that in the long run, it could lead to the extinction of many species.
Fundamental research of practical value
Bisphenol A (BPA), which is commonly used in plastic products, such as baby bottles, may disturb hormonal systems in humans, leading to cancers and reproductive impairments. Polybrominated diphenyl ethers (PBDEs), are used as flame retardants in a wide array of products, including building materials, electronics, furnishings and textiles. Professor Wu explained that many harmful chemicals have now become unavoidable in our daily lives. “The aim of our basic research is to identify harmful chemicals that can cause a public health risk for the next few generations, even in cases where the children have never been exposed to these chemicals before,” he said. “Armed with this knowledge, we will also assess the environmental and public health risks of these chemicals by monitoring their level in the environment, and develop novel technologies for in-situ detection of EDCs and their effective removal from waste water.” As an expert on environmental matters, Professor Wu explained that he understands people’s concerns about pollutants, plastics, and the like, but cautioned that often the public’s fears are not based on credible scientific evidence. He emphasised that scientific studies and evidence, like the research conducted by the SKLMP, are crucial for informing government policies and decision making.
Professor Wu’s earlier research showed that hypoxia is an endocrine disruptor, which impairs the reproduction of fish, and which is also likely to occur in mammals, including humans. In a recent research on male fish, “Hypoxia causes transgenerational impairments in reproduction of fish” published in Nature Communications, Professor Wu and his team found that hypoxia can cause reproductive impairment, growth retardation, abnormal development, and sex changes in subsequent generations. This disturbing finding is consistent with the hypothesis of ‘transgenerational stress inheritance’, that is, parental exposure to stress or environmental changes can lead to modification of gene expression, or epigenetic changes, in their offspring. His research has been reported by many public, scientific and government media worldwide. To date, few studies have explored transgenerational impairment in females. In “Hypoxia causes transgenerational impairment of ovarian development and hatching success in fish” published in Environmental Science and Technology this year, Professor Wu and his collaborators at The University of Hong Kong, City University of Hong Kong and The Chinese University of Hong Kong revealed that the ovarian functions and hatching success of eggs of female marine medaka fish exposed to hypoxia were reduced, but more importantly, the study showed that the second generation of female offspring were also similarly affected despite never having been exposed to hypoxia.
Taken together, these two milestone studies revealed that while the mechanisms of reproductive impairment are sex-specific, the effect of hypoxia can be passed down to subsequent generations in both males and females by altering gene expression, despite there being no change in the DNA sequence. Hence, hypoxia may pose a significant, long-lasting threat to the sustainability of fish stocks, threaten food security, and perhaps also pose a threat to human reproduction and development, once again, highlighting the important work done by scientists in the SKLMP and their collaborators around the world in marine ecosystem management and environmental risk assessment.