According to this 2010 Barents Observer article (thanks, Heikki) this area is no longer restricted to travellers, including foreigners. The application one had to fill out in advance last year seems to have disappeared from the Ministry of Natural Resources and Ecology of the Murmansk region site so we can probably assume it is no longer required. Better call someone based on Sredni or Rybachi, or get me to call them on your behalf to get up-to-date information, before going there.
Kandalaksha+
The City of Kandalaksha, Murmansk oblast, and its vicinity. Getting there, where to stay, what to do. The ultimate source of Kandalaksha and area info in English.
Какой смысл ориентироваться на статью 2010 года? Совсем недавно в очередной раз распространялась информация о необходимости заполнения форм на сайте для посещения Рыбачьего-Среднего, поскольку это территория нац.парка. Не помню, шла ли там речб отдельно про иностранцев, но в любом случае для посещения нужна эта регистрация.