LITHUANIA
Fisheries Service activities contribute to the abundance of salmonids in Lithuanian waters
Breeding salmon and sea trout for restocking Fishermen have been catching salmon and sea trout for years in Lithuanian rivers such as the Nemunas and its tributaries. However, a significant decrease in the population of these fish in Lithuanian waters has been observed since the fifties. Intense fishing pressure, pollution, and poaching were the main causes for the dramatic decline in salmonid numbers. Natural resources were also considered a legitimate source of food, an attitude that was widespread during that period and not only in the Soviet region.
S
ince 1991, when Lithuania regained its independency, the scientific community and administrative authorities have drawn attention to the status of fish and shellfish stocks in the country’s water bodies. Discussions about artificial salmon breeding were initiated. Latvia’s success in using artificially bred salmon to boost the catch of Baltic fishermen also contributed to the enthusiasm. The work intensified when Lithuania joined the European Economic Area and started participating in the activities of the IBSFC (International Baltic Sea Fishery Commission) and its Salmon Action Plan 1997-2010. This provided the basis for a national programme for the recovery and protection of salmon resources including artificial breeding measures.
Recirculation systems introduced with Danish assistance The first activities started at the Žeimena fish farm, named after the adjacent river, a natural spawning ground for salmon and sea trout. Rainbow trout have been bred at this facility since 1965 so all the infrastructure necessary for salmon breeding existed. However, a new salmon and sea trout breeding plant based on recirculation was established in cooperation 36
At the hatchery eggs are hatched and the fry grown to 1-2 g before they are released in to rivers.
with the Danish government. The first plant was equipped with an incubator with growing tanks for juveniles built in 1998. The next year the first salmon juveniles were released into rivers. Over the years, production capacity has been expanded and today the Žeimena subdivision of the Division of Pisciculture controlled by the Fisheries Service under the Ministry of Agriculture operates three independent closed water systems breeding salmon, sea trout, and grayling. At Žeimena the focus is exclusively on the recovery and strengthening of natural resources. Salmon
and sea trout are bred only using broodstock from the wild, which are returned to the natural environment after taking roe and milt. On average, 80 percent of the salmon and sea trout grown in the hatcheries are released at 1-2 g of body weight. This enables the fish to adapt better to natural conditions and promotes the development of the homing instinct. The rest is released as 1 year smolts. In recirculation systems salmon smolts can grow from 30 g to more than 100 g in one year. The number of juvenile salmon released annually during each of the last eight years
amounts to about 150 thousand parr and 25 thousand smolts. The figures for sea trout are slightly higher reaching on average 170 thousand parr and 30 thousand smolts annually.
Breeding and releasing fish has helped threatened salmonid populations Studies of salmon and sea trout abundance in Lithuanian rivers conducted by Nature Research Centre and Fisheries Service specialists since 2008 show significant growth in resources (Fig. 1 and 2).
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08/06/17 6:23 pm