ИСТИНА

Изучить современное состояние ртутного загрязнения перелетных птиц в течение всего годового цикла между Россией и Китаем

Mercury (Hg), especially its organic compound methylmercury (MeHg), is extremely toxic and raises great concern due to its easy bioaccumulation in the food chains. Anthropogenic inputs of mercury into air, water, and soil have resulted in a two-to threefold increase of Hg loads in terrestrial and ocean ecosystems, and the risk to ecological systems has become a global environmental problem. As top predators in the food chains, some species of seabirds and terrestrial birds accumulate extremely high levels of MeHg from their habitats, which damages physiological processes, disrupts foraging and mating behavior, leads to embryonic ectopy, reduces hatching success and the number of clutches, and interferes with navigation, flight endurance, oxidative balance, and stopover refueling. Global mercury pollution poses a challenge and threat to the survival and reproduction of migratory birds. Global mercury pollution is a complex problem and threatens the survival and reproduction of many migratory birds. A total of 150 countries around the world are currently making efforts to reduce mercury emissions into the environment and its impacts on ecosystems through the Minamata Convention on Mercury. Among the contaminants that may impact Arctic wildlife, mercury pollution has received widespread attention and has become a major concern for the Arctic Monitoring Program (AMAP, 2019). Despite the growing concern about mercury accumulation in migratory birds, a large knowledge gap remains about mercury threats to birds. Bird migration is the regular seasonal movement along the flyway over the course of the annual cycle, while travelling from breeding grounds to wintering areas and back. There are eight broad flyways across the world, and three flyways including the East Asian-Australasian Flyway (EAAF), the Central Asian Flyway (CAF) and the West Asia/East Africa Flyways (WAEAF)) pass through China and Russia. To the best of our knowledge, there are currently only a few systematic research projects conducted along these three flyways, such as ARCTOX (Pan-Arctic Bird Mercury Monitoring Network, established in 2014), ASDN (Arctic Shorebird Demographics Network, obtained in 2016) and AMAP (Arctic Monitoring and Assessment Programme) studying biological effects of mercury on Arctic biota. It should be noted that all these previous works have been focused on Arctic breeding regions, but mercury accumulation in migratory birds, especially carnivorous, is complex and depends on the diet, habitat characteristics, climate and environmental parameters throughout the annual cycle. Although, in the course of the Sino-Russian bilateral agreement on the conservation of migratory birds and their habitats (signed 22 March 2013), our countries are making efforts to study threats that could have a negative impact on migratory bird opulations, little attention has been paid and no systematic investigation has been conducted on MeHg accumulation by migratory bird across countries and flyways. On the other hand, bird feathers are widely used as a crucial indicator of MeHg exposure in habitats, since feathers can be collected non-lethally, are easy to sample and long-term stored. However, feather mercury is affected by moulting and migration rhythms, and there is dissociation and dislocation between mercury assimilation in feathers and diet from habitats based on the internal dynamics and metabolism of MeHg in the bird body. Therefore, a valid paradigm is required to comprehensively assess the threats of global mercury pollution to migratory birds. The proposed project will conduct collaborative close-loop studies (breeding in Russia, wintering in China, as well as migratory stopovers in both countries) of mercury in migratory birds over the annual cycle to identify current levels of MeHg exposure in migratory birds and its spatial patterns on a large scale along three flyways passing in Russia and China. Bird feathers, which are characterized by the accumulation of mercury from the environment depending on the season, will be used as indicators of mercury content. Remote tracking methods will be used to track the migration links of key bird species. The state-of-the-art methods including Hg isotope odd-MIF signature, stable multi-isotopes, and biotelemetry will be used to develop a new paradigm for research on mercury exposure in migratory birds and to perform a first regional comprehensive review of the threats of mercury pollution to migratory birds. Ultimately, an up-to-date paradigm will be developed to comprehensively assess the threats of global mercury pollution to migratory birds, which will inform recommendations for the conservation of migratory birds. The proposed project will provide an important arena for Sino Russia development of young scientists and exchange of expertise concerning bird diversity conservation and implementation of Minamata Convention on Mercury.