species in the Arctic Mediterranean: from life history to ecosystem dynamics

Hein Rune Skjoldal Institute of Marine Research, Bergen, Norway Outline

• Preludium – looking back • Main part – Three Calanus species – finmarchicus, glacialis, hyperboreus- Life history features – Habitat characteristics – Nordic Seas and – Ecosystem dynamics – Barents Sea and Norwegian Sea LMEs • Epilogue – some concluding remarks Life in pelagial – open space * Be small with rapid turnover * Hide in the deep dark PRO MARE

Balsfjorden MARE COGNITUM

St. M

Lindåspollene

Korsfjorden

Firth of Clyde

Barents Sea

Norwegian Sea W - Whelping area seals

wB

B w B – Wintering area Bowhead w and/or beluga wB B

w Pro Mare Temperature Kola section Mare Cognitum 20 2.0

18 1.8 Mare 16 Cognitum 1.6

14 1.4

12 1.2

10 Pro 1.0 Mare

8 0.8

Fangst(mill. tonn) Bestand (mill. tonn) 6 0.6

4 0.4

2 0.2

0 0.0 1951 1956 1961 1966 1971 1976 1981 1986 1991 1996 2001 2006

Gytebestand Umoden bestand Føre-var gytebestand Fangst

Calanus finmarchicus Monoculus finmarchicus by Gunnerus 1770

Calanus hyperboreus Krøyer 1838

Calanus glacialis Jaschnov 1955

Sars 1903 Ruud 1929 Marshall and Orr 1955 (1972) Sømme 1934 The biology of a marine Wiborg 1954 Østvedt 1955

1000 + papers On the biology of - Conover - Hirche I-XIII – 1933-1966 - Tande - Runge - Melle - Heath - Head -and many others !! Growth

• Exponential growth – copepodites different from nauplii • Equiproportional rule • Allometric – weight-specific decline • Temperature dependent – Bèhlerádek’s equation (development time) – Generation length 1  5 mo for 10 to 0 C Size

• Variation within stage – By an order of magnitude in weight – By a factor 2 in linear dimension • Individual – normal distribution • Within stage – factor ca 3 • Sex – bimodal • Temperature (latitude) - decrease • Food - increase Growth of Calanus species copepodites Dry weight – ug per individual

10000 finmarchicus glacialis CV fin = 1000 CIV glac = hyperboreus CIII hyp

100

10

1 CI CII CIII CIV CV CVI Growth of Calanus species copepodites Dry weight – ug per individual

5000 finmarchicus Wintering 4000 glacialis

3000 hyperboreus

2000

1000

0 Predation CI CII CIII CIV CV CVI Marshall et al. 1934 – Loch Striven, Clyde Sea

400 G2 350 G1 G3 300 250 200 150

100 Female

50 CV 0 17 30 44 66 86 100114128142156170184198212226240275 F M A M J J Wintering

• Dormant, inactive state – diapause? • Maturation process ongoing • Active metabolism reflected in weight loss • Ca 0.5 ug dry weight per day at 4C • Apparently Lower than predicted from respiration - Saumweber and Durbin 2006 • Limited capacity for wintering in a non-feeding state – they burn up through metabolism Weight loss (dry weight ind-1) of CV Calanus finmarchicus CV through winter

400

350

300 Marshall 250 CV mean 200 Tande Small 150 Large 100 Mean Tande

50

0 0 200 400 600 Weathership Halldal 1953 Station ’M’

Weekly sampling Oct 1948 – Nov 1949

Østvedt 1955 Melle and Skjoldal 1998 Arctic – 0C 5-6 mo

Ca. 3-4 mo – June-Sept

3.5-4 mo

Atlantic - 6C 2-2.5 mo Mixed – 2C

Ca. 5 months – April- Sept Calanus hyperboreus Dry weight ug ind-1

6000

5000

4000

3000

2000 CV 1000 Ad fem 0 0 100 200 300 400 Life cycle – Calanus hyperboreus

Wi Su Wi Su Wi

CI CII CIII CIV CIII CIV CV CVI Nauplii CVI Egg Egg

CVI- CIII im CIV CVI-mat CV CVI-mat CVI-im Selected for Calanus large size – glacialis ’no fish’ Calanus hyperboreus

Calanus finmarchicus

Selected for minimum size

WGICA

WGIBAR

WGINOR

Integrated Ecosystem Assessment Groups in ICES Capelin Polar cod - Boreogadus

Mackerel

Herring

Blue whiting

Myctophid

Distribution and overlap of mackerel and herring

Survey design 2015

Hydrography and plankton stations Bottom and pelagic trawl stations Biomass distribution- PINRO/IMR

2014 - 6.7 gm-2 (232 st.) 2014 2013 – 7.1 gm-2 (305 st.) 2012 – 7.6 gm-2 (287 st.)

2013 2012 Pro Mare capelin 1983-herring Zooplankton biomass g dry weight m-2

14.00

12.00

10.00

8.00 Zoopl biomass total Zoopl medium 6.00 Zoopl small Zoopl large

4.00

2.00

0.00

1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 Bowhead Atlantic inflow

Polyakov et al. (2012) Journal of Climate