Calanus 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 Arctic Ocean – 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 copepod Østvedt 1955 1000 + papers On the biology of - Conover Calanus finmarchicus - 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 10.00 12.00 14.00 0.00 2.00 4.00 6.00 8.00 1987 1988 1989 1990 1991 1992 m weight g dry biomass Zooplankton 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 - 2011 2 2012 2013 2014 2015 Zoopl large Zoopl small Zoopl medium Zoopl biomass total Bowhead Atlantic inflow Polyakov et al. (2012) Journal of Climate .