Lithuanian National Report on Salmon by Vytautas Kesminas VU Institute of Ecology INTRODUCTION
Total Page:16
File Type:pdf, Size:1020Kb
Lithuanian National Report on Salmon by Vytautas Kesminas VU Institute of Ecology INTRODUCTION • Monitoring and restoration works of salmon and sea-trout have been carried out in accordance with Lithuanian Salmon Action Plan, 1997 – 2010 • Monitoring took place in 80 rivers inhabited by salmonids, 100-110 sites • Responsible institutions are Institute of Ecology of Vilnius University and University of Klaipėda Lithuanian Salmon and Sea-trout restoration and protection program for 1997-2010 • Action plan: • Juridical – institutional regulation, • Protection of migration ways and spawning places, • Restoration of natural spawning places, • Scientific research and monitoring, • Artificial rearing, • Education and teaching. Material and methods • Monitoring of smolt migration. Lower reaches of Mera, Siesartis and Veiviržas rivers • Monitoring of parr abundance of salmonids. Electrofishing (Zippin, 1958; Seber, Le Cren, 1967; Bohlin et al., 1977; Junge & Libosvarsky, 1965; Guidelines.., 1997) • Monitoring of spawning nests. Žeimena, Mera, Vilnia, Upper Minija, Veiviržas, Šalpė rivers Material and methods • Telemetry study • Tagging study • Genetic study • Migration of salmon and sea-trout (CPUE) into the Nemunas river basin aa B B B B B B B B B B e B e B B e B B e B e B e B ee B ee B ee B e B e B ee B B B ee B B e B B e B B e B B B B B B B Šv B B Šv B B Šv B B Šv B Šv B ŠvŠv B SS ŠvŠvŠveeentnntntttojojoj B toj a tojoj a c tojoj a c tt a c toji a i a c tojoj a c i a cc tojoj a c a cc tojii a cc i a c oji a cc tojoji a cc i a cc tojoji (B a c ii a cc oj (B a c ii a c ojj (B a c i a c ojji (B a i a c ojii (B a ii a oj (B a j a ii a ( a ji (B a a a i (B(B a a jii (B(B a a jii ((B a i (B a i a i i (B a a i ii(B a a i ii (B(B a a ii ii ((B(B a ii iii (B(B a ii ii (B(B a llttii ii ((B(BBaalaalllttttiiic a l lttiic r l lttiic r l ttiiic r c r lttiic r c r lttiic r r ttiic r lt c r tt ) r tiicc r lt ) r iic r t ) r ttiiic) r t c r ic r tic)) r ic r ti )) r ic r tiic)) r ic r ic)) r r ic) r i ) r r iic)) r r c) r ic)) r r icc) r ) r ic) r r r c)) r r c) r r a c)) r a r a c)) r a ))) r aa c)) r aala ))) r ⎢⎢⎢⎢⎢⎢ ) ⎢⎢ t ⎢⎢⎢ t ⎢⎢ t ⎢⎢ t ⎢⎢ t ⎢ t ⎢⎢ t t ⎢⎢ t ⎢ t ⎢ t ⎢ t t ⎢ t t ⎢ t t B t t B t t B t t BB t BB t B t B t BB t t BB t B t t BB t t BB t B t B t t t B t t B t t t t t t t t u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u u ⎢⎢ u ⎢⎢ v ⎢ v ⎢⎢ v ⎢ v ⎢ v ⎢ v ⎢ v v ⎢⎢ v ⎢ v ⎢ v ⎢ v ⎢ v ⎢ v ⎢ v ⎢ v v ⎢ v v ⎢ v v v v v v v v v v v v v v v v v v v v v v v v v v v v v v a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a ⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢ MMMiiiininniniiiijjjjaaa CCCuuurrrooonnniiiiaaannn llllaaagggoooooonnn ⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢ KALININGRAD REGION ⎢⎢⎢⎢⎢⎢ ⎢⎢ ⎢⎢⎢⎢⎢⎢ ⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢ ⎢ Salmon and sea-trout rivers Sea-trout rivers Lost or unimportant river sections Monitoring stations: ⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢ V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V V salmon and sea-trout - 50 st. V V V V V sea-trout - 117 st. V e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e e Dams e n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n n ⎢⎢⎢⎢⎢⎢ n t t t t t t t t t t t t t t t t t t t t t t t t t t t t t t t t t t t t t t t t t t t t t t t t t a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a ⎢⎢⎢⎢⎢⎢ JJūūrarara ⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢ ⎢⎢⎢⎢ ⎢⎢ NNN ⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢ ememememem uuuu POLAND nnnn aaaa sssss ⎢⎢ ⎢⎢ ⎢⎢⎢⎢⎢⎢ ⎢⎢⎢⎢⎢⎢⎢ NN ⎢⎢⎢⎢⎢⎢ ererer ⎢⎢⎢⎢⎢ iiiisss ŠŠ Švvveee nnttttoo oojjjjiiii ⎢⎢ ⎢⎢⎢⎢⎢⎢ ⎢⎢⎢⎢⎢⎢ ⎢⎢⎢⎢⎢ ⎢⎢⎢⎢⎢⎢⎢ ⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢ LATVIA ⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢ ⎢⎢⎢⎢⎢⎢ ŽŽeei iiimmee eennaa ⎢⎢⎢⎢⎢⎢ MeMMe e eerrrr rrrraaa BELARUS 3. Catches of Salmon. 12000 10000 8000 6000 4000 Nb of2000 individuals 0 Fishing quota (Nb of individuals) Total catch (Nb of individuals) Utilization (%) 1993 Total catch (Tons) 1994 1995 1996 1997 1998 1999 2000 Year 2001 2002 100 90 2003 80 70 utilization Tons, 2004 60 50 2005 40 30 2006 20 2007 10 0 3.6. Age and Length Composition and Mean Weight of the Catches • Data of 68 migrating adult salmon caught in Curonian lagoon been analyzed. Total length of salmon varied from 51,6-120 cm, weight - 1491- 18000 g. Majority of analyzed salmon spent 2 years in the fresh water. Salmon sea life ranged from few months up to 6 years and majority of salmon spent 1-2 years in the sea. Male consist only 12 % of all caught salmon Length classes of migrating salmon caught in Curonian lagoon in autumn of 2006 m. 3 2,5 2 vnt. 1,5 1 0,5 0 57-59,9 60-62,9 63-65,9 66-68,9 Kūno ilgis L, cm Fishery regulation • During salmon and sea-trout migration, commercial fishery is under regulation in Klaipėda strait and Curonian lagoon. Fishery is prohibited the whole year round in the Klaipėda strait – from northern breakwater to the northern border of 15- th fishing bay. From September 1 till October 31, during salmon and sea-trout migration, fishing with nets is prohibited in the eastern stretch of Curonian lagoon between Klaipeda and Skirvyte, in 2 km distance from eastern shore. From September 15 till October 31 fishing is prohibited in 1 km radius from Šventoji and Rėkstyne river mouths and from southern and northern breakwaters of Klaipėda strait. License fishing is allowed from 1st January of 2007 till 1st of October in designated stretches of listed rivers. The minimum size of salmon and sea-trout for commercial fishery is L – 60 cm 4.2 STATUS OF WILD SALMON POPULATIONS • here are 12 rivers in Lithuania inhabited by salmon populations of different abundance. The status of these rivers differs. Purely natural salmon population inhabits Žeimena River and its tributary – Mera, Saria. Mixed, i.e. natural and reared populations are in the rivers Neris, Šventoji, Vilnia, B. Šventoji, Dubysa, Siesartis. Populations formed of reared salmon inhabit Virinta, Vokė, Minija rivers and some smaller their tributaries. In the latter rivers artificially reared salmon juveniles are being released for several years already. Dynamics of salmon parr abundace in the Žeimena River catchement 6 Lašiša 5 4 2 Žeimena Mera 3 Maž. intakai vnt/100 m vnt/100 Vidurkis baseinui 2 1 0 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 Dynamics of salmon parr abundace in the Neris River catchement Lašiša 8 7 6 5 Neris 2 4 Did. intakai Maž. intakai 3 Baseinas vnt/100 m vnt/100 2 1 0 2000 2001 2002 2003 2004 2005 2006 2007 2008 -1 4.3. POTENTIAL SALMON RIVERS • Salmon density was higher in some larger tributaries of Neris and Šventoji River. Salmon parr were recorded at 18,2 ind./100 m² density in one stretch of Šventoji, average densities in this river were 6,1 ind./100 m². In Siesartis tributaries salmon parr densities were estimated at 36,2 and in Širvinta 10,9 ind./100 m² respectively. In other potential salmon rivers parr density was low. Dynamics of salmon parr abundace in the Šventoji River catchement Lašiša 18 16 14 12 2 Šventoji 10 Did. intakai 8 Baseinas vnt/100 m vnt/100 6 4 2 0 2000 2001 2002 2003 2004 2005 2006 2007 2008 4.4. Status of reared population • Summarizing, the results of restocking efficiency of salmon and sea-trout this year were better, than in previous one.