Foraging areas of streaked shearwater Calonectris leucomelas nesting on the Karamzin Island (Peter the Great Bay, East Sea)

Karamzin Island (the Peter the Great Bay, the East Sea) is the only nesting point of streaked shearwaters in Russian Federation. To understand and determine distribution patterns of streaked shearwaters along the Eastern Sea waters during nesting period, the Trackers WT-300 were set to 10 adult birds. Over the observation period (from 5 July 2016 to 7 January 2017), 4812 locations were registered. Analysis of data obtained revealed that main feeding points of colony studied were situated in the Peter the Great Bay along 50 m isobath and, to the less extension, near the eastern coast of Korean Peninsula. It was determined that streaked shearwaters most frequently visited waters with circular flows or zones of junctions of multidirectional flow. It was also shown that these zones had high concentrations of zooplankton

Invasive earthworms unlock arctic plant nitrogen limitation

Abstract Arctic plant growth is predominantly nitrogen (N) limited. This limitation is generally attributed to slow soil microbial processes due to low temperatures. Here, we show that arctic plant-soil N cycling is also substantially constrained by the lack of larger detritivores (earthworms) able to mineralize and physically translocate litter and soil organic matter. These new functions provided by earthworms increased shrub and grass N concentration in our common garden experiment. Earthworm activity also increased either the height or number of floral shoots, while enhancing fine root production and vegetation greenness in heath and meadow communities to a level that exceeded the inherent differences between these two common arctic plant communities. Moreover, these worming effects on plant N and greening exceeded reported effects of warming, herbivory and nutrient addition, suggesting that human spreading of earthworms may lead to substantial changes in the structure and function of arctic ecosystems