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Scientists demand: stone charr be added to the Red Book

23 december 2021
Stone charr is a subspecies of Northern Dolly Varden trout which inhabits only the Kamchatka River. In 2021, WWF-Russia and the Kronotsky State Nature Reserve launched a project to assess the state of key habitats of stone charr and develop recommendations on how to protect this endemic species.
© Eugene Yesin

The major problem in developing conservation and restoration measures is the extremely low level of knowledge of the stone charr’s biology. These fish are rarely encountered, thus specialists do not know the structure within the species, or the spawning stock biomass. It is important to find new spawning grounds to conserve the fish, study their biology, and plan conservation projects. During the project, supported by WWF-Russia, scientists of the Kronotsky Nature Reserve found new spawning grounds of the Dolly Varden trout’s rare subspecies.

“Stone charr is a specialized predator which lives only in the Kamchatka River and its tributaries. The fish cannot be confused with any other charr species because of their black-and-red marble-ish color. We are positive that stone charr is related to Northern Dolly Varden trout (Salvelinus malma) which also inhabits the Kamchatka River. These species are unique subjects for the evolution fundamental problems research. Stone charr is the first known case where two related species of Salmonids evolved together in the same ecosystem without geographic isolation”, says Grigory Markevich, the Senior Researcher with the Kronotsky Reserve.

The scientists of the Kronotsky Reserve proved that stone charr’s ancestors started to spawn in the small streams in spruce forests creating a new species. Those areas vary significantly from the other Northern Dolly Varden trout spawning grounds – here, the riverbed is covered with a thick layer of spruce needles which contain large number of resin acids and essential oils. When the concentration of these substances is fairly low, they are healthy. However, at a high level of concentration they poison the fish. Previous researches showed that there were more toxic contaminants at spawning grounds of stone charr than at those of Northern Dolly Varden. A number of experiments proved that such poisonous surroundings were deadly for Northern Dolly Varden trout while the stone charr’s fries survived it very well.

“The adaptation is connected to the number of enzymes speeding up metabolism. Thyroid produced hormones which regulate fish early development processes such as time of embryogenesis, bone and muscle growth, and body coloration. Due to the high level of these enzymes, stone charr acquire specific characteristics and even young species differ distinctly from the Northern Dolly Varden species,” said Eugene Esin, the researcher from the Kronotsky Nature Reserve.

Scientists ascertained that the adaptation to the specific conditions of early development limited the stone charr’s area down to the relict boreal forests of the central part of the Kamchatka peninsula. For the last 40 years, the number of stone charr has been steadily declining. In the 21st century, these species are at the brink of extinction which is probably caused by cutting of old-age spruce forests along river banks. Without spruce trees, the conditions in the streams are changing leaving no place for the stone charr to spawn. The last large spawning grounds remain only in the tributaries of the Schapina River within the boundaries of the Kronotsky Reserve where there was no logging.

“Every year, WWF-Russia hosts a grant contest for protected areas. The project of the Kronotsky Reserve was one of the winners in the category “Key ecosystems conservation”. We expect that during the research work the specialists will develop recommendations on how to improve measures to protect stone charr. In particular, we think that establishing nature conservation status over charr’s spawning grounds, in this case, can be of vital importance”, stated Sergey Rafanov, the Director of WWF-Russia’s Kamchatka/Bering Sea Ecoregional Office.

Scientists of the Kronotsky Reserve intend to draw more attention to the problem of stone charr conservation. They will seek to add these species to the Russian federal list of endangered species.

old-age spruce forests are home for stone charr
© Nikolai Melnik
For additional information please contact
Head of WWF Kamchatka/Bering Sea Ecoregional Office