Diversity in life histories and genetic structure in a large population complex of wild Atlantic salmon in the River Teno, northernmost Europe

Jaakko Erkinaro Finnish Game and Fisheries Research Institute, Oulu,

DSRRN 2013 Science Meeting January 2013

Acknowledgements

Juha-Pekka Vähä Morten Falkegård Eero Niemelä Panu Orell Maija Länsman Jorma Kuusela Matti Kylmäaho Jari Haantie Jorma Ollila Kjell-Magne Johnsen

Teno//Deatnu

Catchment area 16 380 km2

Mean discharge 170 m3/s (max. 3000 m3/s)

> 1200 km and >30 tributaries available for anadromous salmon

Green = tributaries with predominantly 1-sea-winter salmon

Black= stretches and tributaries with high % of multi-sea-winter salmon Salmon fishing in the River Teno • nets (weir, gill net, drift net, seine) • rods (boat fishing, fly fishing) Monitoring of salmon stock diversity • all fishing season (late May-end of August) • all catchment (main stem, tributaries) • all user groups, fishing methods • 3 - 9000 scale samples per year (age, genetics) Life histories of the River Teno Atlantic salmon Smolt age

Sea age 2 3 4 5 6 7 8 + previous x 2X 3X 4X 5X 6x x spawning 1 1S1 x 2X 3X 4X 5X 6 times x X X X x 2 3S2 x X X X X 2S1 x X X X x 3 x 1S1S1X xX XX X x X x 3S1 x X X X x 4 2S1S1X xX X x X X x 1S2 X X x x x x 5 3S1S1 X X x 2S2 x x x 1S1S1S1 x x x

96 combinations ! Size difference within male individuals reproducing at the same time & place up to 10 000 –fold ! (3g vs. 30 000g) Atlantic salmon catch in the River Teno

250000 Finland 200000

150000

100000

Catch, kg Catch, 50000

0 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 Salmon catch of the River Teno

110000 260 Previous spawners 240 100000 4-5 SW 3 SW 220 90000 2 SW 200 80000 1 SW 180 70000 160 60000 140 50000 120

40000 100

80 Total catch (tonnes) 30000 60 20000 40 10000

Estimated number of salmon in the catch 20 0 0 1975 1980 1985 1990 1995 2000 2005 2010 Year Distribution (%) of salmon from 1990 year class across later spawning years

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

Maiden 0.05 11.6 39.7 29.4 15.1 3.8 0.4 0.01 0.01 salmon Previous 0.1 8.3 33.4 32.6 17.9 5.8 1.7 0.3 0.1 0.05 spawners

 A single year class may contribute to reproduction over 12 years  So…what if there wasn’t this diversity?  Less buffer/resilience against environmental/human disturbances, less adaptation to various habitats  Portfolio effect?  Diversity is stabilizing ecosystems and the services they provide – analogy: asset diversity & stability of financial portfolios Genetic structure of Luft the River Teno Leva salmon stock complex Baiss

Nili • 30+ baseline populations

Geaimm Aku e

Karigas

Iskuras Noiaid at

Vuoma

Anar

Skietsha m

Univ Turku Genetics of the River Teno salmon

- Substantial genetic differences between populations

- Mean pairwise FST 0.10 (max 0.21) (Vähä et al. 2007)

- Large populations more diverse, small more diverged - Life history matters: % of MSW females linked to gen variation  large females important in maintaining biodiversity (Vähä et al. 2007 Mol. Ecol)

- Temporal stability in population complex structure - 1970s > 80s > 90s > 2000s ( Vähä et al. 2008 Evol. Appl.)

- Run timing of salmon to the Teno is population- specific - Life history matters: 1SW males from populations with high % of MSW females migrate later (Vähä et al. 2011 Evol. Appl.)

Applicable management implications - - - > Photo: Panu Orell

Coast

Fjord, estuary Main stem

Accumulated population-specific Tributary exploitation Máskejohka Exploitation in different fisheries and spawning escapement in two River Teno Coastal tributaries (% of pre-fishery abundance) 19 %

Spawning stock 41 % Main stem 11 %

Máskejohka 29 %

Iésjohka Mixed-stock exploitation in the River Teno main stem fishery; Multi-sea-winter-salmon catch in 2008

Univ Turku 100 % Iesjohka (N) 90 % (N)

80 % (N/F) Akujoki (F) 70 % Valljohka (N) 60 % Baisjohka (N) Levajohka (N) 50 % Kuoppilasjoki (F) 40 % (F)

30 % Vetsijoki (F) Laksjohka (N) 20 % (N/F) 10 % Luovttejohka (N)

0 % Maskejohka (N) 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 Tana main stem Week Early season exploitation of populations and life-history groups: – Driftnet catch in lower part of the River Teno main stem

250 YläTeno Vetsi Valjoki Utsjoki 200  Karasjohka and Iesjohka salmon are importantTsarsjoki contributors to the maiden MSWTanaBru salmon catch  LotsPulmanki of previously spawned salmon in 150 theOutakoski driftnet catches MaskeMany small grilse populations well Luftrepresented (e.g. Pulmanki, Kevo, Tsars, Valjoki) where PS salmon are the Leva 100 ~only large females Laksjoki  Critical exploitation on the largest Kuoppilasfemales in multpile populations of small Kevotributaries ? 50 Keskiteno Karasjoki Inarijoki Univ Turku 0 Iesjoki Previous157 Maiden215 21 42 spawnersPS MSWmaiden PS maiden Baisjoki Tana Teno Akujoki Females Males Total catch 200 120 100 150 80 100 60 40 50

Catch (tonnes) 20 0 0 1975 1980 1985 1990 1995 2000 2005 2010 1975 1980 1985 1990 1995 2000 2005 2010 All age groups 35000 40000 30000 25000 30000 20000 20000 15000 10000 10000 5000 0 0 1975 1980 1985 1990 1995 2000 2005 2010 1975 1980 1985 1990 1995 2000 2005 2010 Previous spawners 3500 2500 3000 2000 2500 2000 1500 1500Negative trend for 3-4SW1000 -salmon in the 1000 500 River500 Teno salmon catches 0 0 1975 1980 1985 1990 1995 2000 2005 2010 1975 1980 1985 1990 1995 2000 2005 2010 4 SW 1000 1000

800 800

600 600

400 400

200 200

0 0 1975 1980 1985 1990 1995 2000 2005 2010 1975 1980 1985 1990 1995 2000 2005 2010 3 SW 18000 6000 16000 5000 14000 12000 4000 10000 3000 8000

Estimated number of salmon in the catch 6000 2000 4000 1000 2000 0 0 1975 1980 1985 1990 1995 2000 2005 2010 1975 1980 1985 1990 1995 2000 2005 2010 Females 2 SW Males 16000 2000 14000 12000 1500 10000 8000 1000 6000 4000 500 2000 0 0 1975 1980 1985 1990 1995 2000 2005 2010 1975 1980 1985 1990 1995 2000 2005 2010 1 SW 10000 35000 30000 8000 25000 6000 20000 4000 15000 10000 2000 5000 0 0 1975 1980 1985 1990 1995 2000 2005 2010 1975 1980 1985 1990 1995 2000 2005 2010 Year Year Females Males Total catch 200 120 100 150 80 100 60 40 50

Catch (tonnes) 20 0 0 1975 1980 1985 1990 1995 2000 2005 2010 1975 1980 1985 1990 1995 2000 2005 2010 All age groups 35000 40000 30000 25000 30000 20000 20000 Positive15000 trend for previous spawners; 1-2SW? 10000 10000 5000 0 Major change in fishing0 regulations 1975 1980 1985 1990 1995 2000 2005 2010 1975 1980 1985 1990 1995 2000 2005 2010 Previous spawners 3500 2500 3000 2000 2500 2000 1500 1500 1000 1000 500 500 0 0 1975 1980 1985 1990 1995 2000 2005 2010 1975 1980 1985 1990 1995 2000 2005 2010 4 SW 1000 1000

800 800

600 600

400 400

200 200

0 0 1975 1980 1985 1990 1995 2000 2005 2010 1975 1980 1985 1990 1995 2000 2005 2010 3 SW 18000 6000 16000 5000 14000 12000 4000 10000 3000 8000

Estimated number of salmon in the catch 6000 2000 4000 1000 2000 0 0 1975 1980 1985 1990 1995 2000 2005 2010 1975 1980 1985 1990 1995 2000 2005 2010 Females 2 SW Males 16000 2000 14000 12000 1500 10000 8000 1000 6000 4000 500 2000 0 0 1975 1980 1985 1990 1995 2000 2005 2010 1975 1980 1985 1990 1995 2000 2005 2010 1 SW 10000 35000 30000 8000 25000 6000 20000 4000 15000 10000 2000 5000 0 0 1975 1980 1985 1990 1995 2000 2005 2010 1975 1980 1985 1990 1995 2000 2005 2010 Year Year Selectivity of marine drift nets

 Coastal drift nets in Norway mostly 65–70 mm knot to knot  Especially selective for mid-size salmon, 60–80 cm (TL)  Ban in Norway in 1989  Abundance of PS, 2SW, large grilse increased in the Teno  Size of 1SW increased (more large grilse escaped), 2SW decreased (more small 2SW escaped) Gillnet

90

80 , cm , 2 SW

length 70 Fish Fish 60 1 SW

50 1975 1980 1985 1990 1995 2000 2005 2010 Weir 100

90

80 2 SW 70 Col 1 vs k1swk 60 Col 1 vs k2swk Length (cm) 1 SW 50

40 1975 1980 1985 1990 1995 2000 2005 2010 Rod 90

80 2 SW 70

60 1 SW 50

40 1975 1980 1985 1990 1995 2000 2005 2010 Year Selective fishing on River Utsjoki (tributary) salmon in the River Teno main stem?

Sea age distribution of salmon in: Teno main stem catch of salmon Video at the Utsjoki river mouth assigned to R. Utsjoki origin

Video monitoring Catch in the main stem

Lower main stem fishing area

Video station at the Utsjoki river mouth

Video monitoring Catch in the main stem

River Utsjoki catchment Challenge

How to manage the mixed-stock fishery and diverse salmon stock complex in the Teno system?

Run timing of 1SW salmon in the lowest part of the River Teno main stem

Univ Turku

Small tributaries

Large tributaries

Upper main stem

Large tributaries Lower main stem

Vähä et al. 2011 Evol. Appl. Run timing of 1-3 SW salmon originating from the rivers Karasjohka and Iesjohka, captured in the lowest part of the Teno main stem Univ Turku

3SW Karasjohka 3SW Iesjohka Lower main stem fishing area 2SW Karasjohka 2SW Iesjohka

1SW Karasjohka 1SW Iesjohka

R. Iesjohka The RIVER TENO

Days starting from 20 May = 1. R. Karasjohka

Modern genetic methods, rigorous catch data, and monitoring programmes  collection of stock status data and spatial and temporal information on population-specific exploitation in mixed-stock fisheries  tailoring of population- and life-history group-specific management actions, depending on the status of different populations Negotiations on a new bilateral Finnish–Norwegian fishery agreement for the River Teno, started in 2012

 Management will be flexible, adaptive, knowledge (science)-based and population-specific  Decision structure (NASCO):  Criteria for stock status (conservation limits) for all populations  Monitoring the stock status: spawning stock size and diversity  Pre-agreed management actions, effective automatically when criteria are not met

Concluding remarks

• Large variety of life histories and genetic groups in the Teno salmon • Diversity improves resilience and economy (!?) – worth safeguarding • Management and conservation should be population- and life history- specific  Challenges! Opportunities! Photo: Panu Orell