In the remote wilderness of Russia’s Kamchatka Peninsula, a remarkable evolutionary story is unfolding. Scientists have launched a new phase of research into a unique population of landlocked sockeye salmon, known as kokanee, that inhabit the isolated Kronotskoye Lake. This expedition aims to unravel the mysteries of a species that has been charting its own evolutionary course for millennia, far from the ocean.
The kokanee of Kronotskoye Lake are a living testament to evolution in action. Trapped and cut off from the sea approximately 12,000 years ago after the last Ice Age, this single population has since diverged into two distinct ecological forms. One group has adapted to feed on plankton in the open water, while the other specializes in consuming organisms from the bottom of the lake. This split provides a rare, real-world laboratory for studying how new species can emerge in nature.
A joint team from the Kronotsky Nature Reserve and the Russian Academy of Sciences’ A.N. Severtsov Institute of Ecology and Evolution is spearheading the new studies. “To clarify unresolved questions, we have begun a new series of field studies this year, distributed over three expeditions,” stated Grigory Markevich, a senior ichthyologist at the reserve. The initial phase has already involved surveying nearly 20 spawning grounds, yielding new discoveries about the distinct breeding times and dietary habits of the two salmon groups.
The ultimate goal of the project is to determine just how separate these two forms have become. By collecting comprehensive data on their feeding specialization and reproductive isolation, the team will lay the groundwork for future molecular-genetic analysis. This advanced genetic testing will offer definitive insights into whether the plankton-eaters and bottom-feeders are on an irreversible path to becoming entirely new species, providing a profound glimpse into the fundamental processes of life’s diversity.