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, Finland
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
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
Teno/Tana/Deatnu
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)
2 3 4 5 6 7 8
1 x X X X X x x
2 x X X X x
3 x X X X x
4 X X x
5 x x x
Smolt age
Sea age
2 3 4 5 6
1S1 x X X X X
2S1 x X X X x
3S1 x X X X x
1S2 X X x
2S2 x x x
2 3 4 5 6 3S2 x X X X X
1S1S1 x X X X x
2S1S1 x X X X x
3S1S1 X X x
1S1S1S1
x x x
+ previous
spawning
times
96 combinations !
Life histories of the River Teno Atlantic salmon
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
0
50000
100000
150000
200000
250000
1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012
Norway
Finland
Cat
ch, k
g
Salmon catch of the River Teno
Year
1975 1980 1985 1990 1995 2000 2005 2010
Tota
l ca
tch
(to
nn
es)
0
20
40
60
80
100
120
140
160
180
200
220
240
260
Estim
ate
d n
um
be
r o
f salm
on
in
th
e c
atc
h
0
10000
20000
30000
40000
50000
60000
70000
80000
90000
100000
110000
1 SW
2 SW
3 SW
4-5 SW
Previous spawners
Distribution (%) of salmon from 1990 year class across later spawning years
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Maiden
salmon
0.05 11.6 39.7 29.4 15.1 3.8 0.4 0.01 0.01
Previous
spawners
0.1 8.3 33.4 32.6 17.9 5.8 1.7 0.3 0.1 0.05
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
Noiaid
at
Geaimm
e
Iskuras
Vuoma
Skietsha
m
Anar
Karigas
Baiss
Nili
Aku
Leva
Luft
Genetic structure of
the River Teno
salmon stock complex • 30+ baseline populations
Univ Turku
Photo: Panu Orell
- 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 - - - >
Genetics of the River Teno salmon
Accumulated
population-specific
exploitation
Fjord,
estuary
Main stem
Tributary
Coast
Máskejohka
Iésjohka
Spawning
stock
41 %
Máskejohka
29 %
Main stem
11 %
Coastal
19 %
Exploitation in different fisheries and
spawning escapement in two River Teno
tributaries (% of pre-fishery abundance)
Mixed-stock exploitation in the River Teno main stem fishery; Multi-sea-winter-salmon catch in 2008
0 %
10 %
20 %
30 %
40 %
50 %
60 %
70 %
80 %
90 %
100 %
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
Week
Iesjohka (N)
Karasjohka (N)
Anarjohka (N/F)
Akujoki (F)
Valljohka (N)
Baisjohka (N)
Levajohka (N)
Kuoppilasjoki (F)
Utsjoki (F)
Vetsijoki (F)
Laksjohka (N)
Polmak (N/F)
Luovttejohka (N)
Maskejohka (N)
Tana main stem
Univ Turku
Early season exploitation of populations and life-history groups: – Driftnet catch in lower part of the River Teno main stem
0
50
100
150
200
250
157 215 21 42
PS maiden PS maiden
Tana Teno
YläTeno
Vetsi
Valjoki
Utsjoki
Tsarsjoki
TanaBru
Pulmanki
Outakoski
Maske
Luft
Leva
Laksjoki
Kuoppilas
Kevo
Keskiteno
Karasjoki
Inarijoki
Iesjoki
Baisjoki
Akujoki
Univ Turku
Karasjohka and Iesjohka salmon are
important contributors to the maiden
MSW salmon catch
Lots of previously spawned salmon in
the driftnet catches
Many small grilse populations well
represented (e.g. Pulmanki, Kevo, Tsars,
Valjoki) where PS salmon are the
~only large females
Critical exploitation on the largest
females in multpile populations of small
tributaries?
Previous Maiden
spawners MSW
Negative trend for 3-4SW-salmon in the
River Teno salmon catches
1 SW
Year
1975 1980 1985 1990 1995 2000 2005 2010
0
5000
10000
15000
20000
25000
30000
35000
Year
1975 1980 1985 1990 1995 2000 2005 2010
0
2000
4000
6000
8000
10000
2 SW
1975 1980 1985 1990 1995 2000 2005 2010
0
500
1000
1500
2000
1975 1980 1985 1990 1995 2000 2005 2010
0
2000
4000
6000
8000
10000
12000
14000
16000
3 SW
1975 1980 1985 1990 1995 2000 2005 2010
0
1000
2000
3000
4000
5000
6000
1975 1980 1985 1990 1995 2000 2005 2010
Estim
ate
d n
um
ber
of
salm
on in the c
atc
h
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
4 SW
1975 1980 1985 1990 1995 2000 2005 2010
0
200
400
600
800
1000
1975 1980 1985 1990 1995 2000 2005 2010
0
200
400
600
800
1000
Previous spawners
1975 1980 1985 1990 1995 2000 2005 2010
0
500
1000
1500
2000
2500
1975 1980 1985 1990 1995 2000 2005 2010
0
500
1000
1500
2000
2500
3000
3500
All age groups
1975 1980 1985 1990 1995 2000 2005 2010
0
10000
20000
30000
40000
1975 1980 1985 1990 1995 2000 2005 2010
0
5000
10000
15000
20000
25000
30000
35000
Females MalesTotal catch
1975 1980 1985 1990 1995 2000 2005 2010
0
20
40
60
80
100
120
1975 1980 1985 1990 1995 2000 2005 2010
Catc
h (
tonn
es)
0
50
100
150
200
Females Males
Positive trend for previous spawners; 1-2SW?
1 SW
Year
1975 1980 1985 1990 1995 2000 2005 2010
0
5000
10000
15000
20000
25000
30000
35000
Year
1975 1980 1985 1990 1995 2000 2005 2010
0
2000
4000
6000
8000
10000
2 SW
1975 1980 1985 1990 1995 2000 2005 2010
0
500
1000
1500
2000
1975 1980 1985 1990 1995 2000 2005 2010
0
2000
4000
6000
8000
10000
12000
14000
16000
3 SW
1975 1980 1985 1990 1995 2000 2005 2010
0
1000
2000
3000
4000
5000
6000
1975 1980 1985 1990 1995 2000 2005 2010
Estim
ate
d n
um
ber
of
salm
on in the c
atc
h
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
4 SW
1975 1980 1985 1990 1995 2000 2005 2010
0
200
400
600
800
1000
1975 1980 1985 1990 1995 2000 2005 2010
0
200
400
600
800
1000
Previous spawners
1975 1980 1985 1990 1995 2000 2005 2010
0
500
1000
1500
2000
2500
1975 1980 1985 1990 1995 2000 2005 2010
0
500
1000
1500
2000
2500
3000
3500
All age groups
1975 1980 1985 1990 1995 2000 2005 2010
0
10000
20000
30000
40000
1975 1980 1985 1990 1995 2000 2005 2010
0
5000
10000
15000
20000
25000
30000
35000
Females MalesTotal catch
1975 1980 1985 1990 1995 2000 2005 2010
0
20
40
60
80
100
120
1975 1980 1985 1990 1995 2000 2005 2010
Catc
h (
tonn
es)
0
50
100
150
200
Major change in fishing regulations
Females Males
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)
Col 1 vs k1swk
Col 1 vs k2swk
Gillnet
1975 1980 1985 1990 1995 2000 2005 2010
50
60
70
80
90
Weir
1975 1980 1985 1990 1995 2000 2005 2010
Le
ngth
(cm
)
40
50
60
70
80
90
100
Rod
Year
1975 1980 1985 1990 1995 2000 2005 2010
40
50
60
70
80
90
1 SW
2 SW
1 SW
2 SW
1 SW
2 SW
Fis
h lengt
h, c
m
Selective fishing on River Utsjoki (tributary)
salmon in the River Teno main stem?
Sea age distribution of salmon in:
Video monitoring
Video monitoring Catch in the main stem
Catch in the main stem
Video at the Utsjoki river mouth Teno main stem catch of salmon assigned to R. Utsjoki origin
Video station at the Utsjoki river mouth
Lower main stem fishing area
River Utsjoki catchment
Challenge
How to manage the mixed-stock fishery and
diverse salmon stock complex in the Teno system?
Small tributaries
Large tributaries
Large tributaries
Upper main stem
Lower main stem
Run timing of 1SW salmon in the lowest part of
the River Teno main stem
Univ Turku
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
Days starting from 20 May = 1. R. Karasjohka
R. Iesjohka
Lower main stem fishing area
3SW Karasjohka 3SW Iesjohka
2SW Karasjohka
2SW Iesjohka
1SW Karasjohka
1SW Iesjohka
The RIVER TENO
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
