Unveiling Priority Actions and Opportunities for the Restoration of Endemic Trout (Salmo ischchan Kessler, 1877) in Lake Sevan

Given the low efficiency of current actions regarding the restoration of a critically endangered species, the Sevan trout, there is an urgent need for the evaluation of ongoing strategies and prioritization of the most efficient ones. Thus, the aim of this study was the scientific justification of the effectiveness of various restoration strategies for Sevan trout wild stocks. For this, we developed an experimental design to estimate the efficiency of stocking the main spawning rivers with fingerlings. Sevan trout subspecies were released and re-captured to measure their growth rates and biological features. Also, we conducted assessments of the abiotic conditions and ecological status of rivers. Because Sevan trout fingerlings have also been used to directly stock Lake Sevan by the Foundation for “Restoration of Sevan trout stocks and development of aquaculture” in recent years, we set gill nets to capture and study Sevan trout from the lake. The results showed that releasing summer trout less than 1 g in weight into the inlets of Lake Sevan is ineffective. Although larger gegharkuni had higher survival rates, the current state of the rivers will hardly ensure the sustainability of stocks. Current investigations have also shown the viability of stocking into the lake, as supported by both 2+- and 3+-year-old specimens being reported. However, further studies of the spatial dispersion and survival of stocked juvenile trout and the state of spawning grounds in the lake would help improve restoration strategies.