Long-term monitoring studies as a powerful tool in marine ecosystem research

Global environmental challenges, such as climatic shifts, ocean acidification, and anthropogenic pressures urgently require detailed knowledge on functioning of the marine biota in order to create realistic models that predict future changes in populations, communities, and ecosystems. The long-term monitoring observations remain one of the best and sometimes the only way of acquiring knowledge on the complex seasonal and multiannual processes taking place in marine realms. This volume focuses on the long-term studies conducted for the past several decades in the White Sea, a relatively small marine basin located in sub-Arctic and Arctic zone in the northwest of Russia. It has a peculiar hydrologic structure: the upper water layers which experience strong seasonal temperature fluctuations and are inhabited by boreal organisms almost do not mix with the deeper waters which have negative temperatures the year round and are occupied by the Arctic species complex. The White Sea has a long-standing history of extensive environmental monitoring spanning all levels of the ecosystem. The goal of this special issue is to present the key findings of these studies to international research community and to identify environmental and biological processes that are involved in the ecosystem change of this important sub-Arctic marine basin.