VLADIVOSTOK, Russia, June 6 (Xinhua) -- The Sea of Okhotsk off the coast of Sakhalin, Russia has turned yellow due to pollen, local news reported Wednesday.

At the end of May and the beginning of June every year, islanders say that they observe a yellow coating on the water surface, said Dmitry Lisitsyn, head of the Sakhalin Environment Watch, a non-governmental organization.

"I want to calm everyone -- this is normal for this time of year. On the surface of lakes, seas and rivers, pollen of flowering plants gathers," Lisitsyn was quoted by the RIA Novosti news agency as saying.

Lisitsyn said he has been observing this phenomenon for 20 years. His organization took samples, studied them and came to the conclusion that nothing dangerous for the life and health of the Sakhalin residents is contained in the coating.