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Introduction to the Circumpolar World The marine environment #2 Fisheries Hreiðar Þór Valtýsson, MSc in Fisheries Biology Assistant Professor, Faculty of Business and Science, University of Akureyri Director, the Fisheries Sciences Center at the University of Akureyri Borgir (2nd floor, office 228), Norðurslóð, 600 Akureyri Tel.: 460 8920 (office) E-mail: [email protected] Office hours: By appointment Drawings: Jón Baldur Hlíðberg – www.fauna.is Marine species 2 Hreiðar Þór Valtýsson University of Akureyri 2016 High Arctic • Few fish species • Low biomass – Fewer harvested • Low catches • Very few people • Mostly subsistence High Arctic Low Arctic Drawings: Jón Baldur Hlíðberg – www.fauna.is Marine species 3 Hreiðar Þór Valtýsson University of Akureyri 2016 But the SubArctic • Many fish species • High biomass • Some of the most important commercial fisheries in the world High Arctic Low Arctic Subarctic Arctic economies • • • • 5 Hreiðar Þór Valtýsson University of Akureyri 2016 16 greatest fishing nations (239 nations total) Icelandic catch 1 to 2 million tonnes annually Other 3 Arctic/subarctic Fisheries also very important for northern Canada, Greenland and the Faroes Partly Arctic fisheries Arctic economies 6 Hreiðar Þór Valtýsson University of Akureyri 2016 Example Iceland • • Fisheries always the most important economic activity Nearly always more than 50% of exports in goods Export in goods from Iceland Climate change - Global Global warming – IPCC 2014 The Arctic is warming faster 7 Hreiðar Þór Valtýsson University of Akureyri 2016 Iceland and surrounding waters • Situated close to the Arctic Circle in the North Atlantic. • Right at the boundaries of the cold temperate and arctic zones 8 Hreiðar Þór Valtýsson University of Akureyri 2016 Iceland and surrounding waters • Productivity of the ocean around Iceland is high • Biomass and biomass production high on all levels of the food chain • Due to regular mixing of sunlit surface and nutrient rich deep water • The mixing of the cold currents from the north and warm from the south increases this mixing • However highly variable between years 9 Hreiðar Þór Valtýsson University of Akureyri 2016 The battle of the currents Drawings: Jón Baldur Hlíðberg – www.fauna.is Marine species Arctic Hreiðar Þór Valtýsson 10 University of Akureyri 2016 X X Subarctic X X Temperate X X Iceland and surrounding waters Hreiðar Þór Valtýsson 11 University of Akureyri 2016 Arctic species Greenland halibut • North pacific and North Atlantic • The second largest predatory fish in high Arctic waters • Very valuable • No fisheries agreements • Declining stock size • Warming or overfishing ??? Hreiðar Þór Valtýsson 12 University of Akureyri 2016 Arctic species Northern (or pink) shrimp • • • • • North pacific and North Atlantic Very important in the N. Atlantic Shrimp fisheries mainly north of Iceland => cold water species For a time the second most important commercial species in Iceland Then a disaster ........ Hreiðar Þór Valtýsson 13 University of Akureyri 2016 Arctic species Hreiðar Þór Valtýsson 14 University of Akureyri 2016 Northern shrimp and cod • • • • The stock collapsed and the catch collapsed Reason, warming trend in waters north of Iceland However not directly the temperature => more cod in the area north of Iceland (the shrimp can actually well tolerate this temperature) but ... => the cod eats shrimp What about • • • • Greenland ? Newfoundland ? Arctic species Scallop • • • • • • N Atlantic, closely related in N Pacific Chlamys islandica – the Icelandic scallop Important fisheries in western Iceland Unexpected collapse of the fishery Now no fishery ....... Why? The climate became warmer but the scallop is supposed to tolerate warmer waters ! • Studies revealed a protists disease that killed them • In normal (cold) conditions it is to cold for the protists • It came with the warmer waters and wiped out the scallop stock Hreiðar Þór Valtýsson 15 University of Akureyri 2016 Arctic species Capelin • North Pacific and North Atlantic • A small cold water species and very abundant north of Iceland. • However spawns in shallow and warmer waters off the south coast. • It is during these migrations that it becomes the most important food for many other marine species in Icelandic waters • Usually spawns at the age of 3 and then dies. Hreiðar Þór Valtýsson 16 University of Akureyri 2016 Arctic species Hreiðar Þór Valtýsson 17 University of Akureyri 2016 Capelin • Annual caches more than 1.000.000 t, almost as high as all other species combined • Even if it is a cold water species the effects of warming climate are uncertain as it depends on warm waters for spawning • In previous warm periods it has simply shifted from spawning and spawned in the waters north of Iceland. • We do not know if the stock was smaller Arctic species Capelin • The distribution has been changing • In previous warm periods it has simply shifted from spawning and spawned in the waters north of Iceland. • We do not know if the stock was smaller Hreiðar Þór Valtýsson 18 University of Akureyri 2016 Sub Arctic species Hreiðar Þór Valtýsson 19 University of Akureyri 2016 Herring • One of the most abundant fish in the world when the stock is in good conditions, probably the largest in the N. Atlantic • Fisheries very important for many nations through centuries. • Usually the 2nd most important fish in Iceland, after cod • Most stocks did collapse due to heavy fisheries between 1965 and 1975 • Have recovered 2.500.000 2.000.000 Other nations Catch (t) Icelandic catch 1.500.000 1.000.000 500.000 0 1951 1956 1961 1966 1971 1976 1981 1986 1991 1996 2001 Sub Arctic species Herring • Cooling climate also to blame? Hreiðar Þór Valtýsson 20 University of Akureyri 2016 Sub Arctic species Herring • The herring stock will probably increase in size in northern waters if the warming climate will continue • Given that the fishery is restricted • And diseases will end Hreiðar Þór Valtýsson 21 University of Akureyri 2016 Sub Arctic species Cod • North Atlantic, closely related species in North Pacific • Economically the most important species during most of the centuries, a valuable species per kg • Since the stock is quite large and he fish is greedy it also has a great ecological impact • Historically the largest stocks off Newfoundland (now collapsed), Barents Sea and Iceland • All around Iceland Hreiðar Þór Valtýsson 22 University of Akureyri 2016 Sub Arctic species Cod • Main spawning grounds (meginhrygningarstöðvar) are off the south coast • Egg and larvae drift west and then north, occasionally also to Greenland • Main juvenile grounds (meginuppeldisstöðvar) are off the north coast • Main feeding areas after they are mature are where the cold and warm currents meet off the west and east coast Hreiðar Þór Valtýsson 23 University of Akureyri 2016 Sub Arctic species Hreiðar Þór Valtýsson 24 University of Akureyri 2016 Cod • Very small native cod stock in Greenland • During warm periods cod can however become very abundant • new grounds open up • Due to larval drift from Icelandic grounds • Is self sustained during warm periods but collapses in cold • A large part of this stock migrates back to Iceland to spawn and stays there • Very good for the Icelandic cod fisheries • Mainly because of that it has been predicted that the cod stock in Icelandic waters will grow with warming climate • Has not happened (yet?) Sub Arctic species Hreiðar Þór Valtýsson 25 University of Akureyri 2016 Capelin and cod • However …….. • The subarctic cod depends heavily on the arctic capelin as food • If the capelin stock will be reduced due to warming it will have adverse effects on the cod stock • This causes great uncertainties on the fate of the cod stock because warmer waters might either mean larger cod stock as cod in warmer waters generally grows faster (such as in the North sea) or it might mean smaller cod stock if the capelin stock collapses Sub Arctic species Northern shrimp and cod • • • This relationship between shrimp and cod now well known in many other areas These species just don't mix, you cannot have both in abundance Warming climate will (given that the cod stocks are not heavily overfished) drive shrimp stocks down or further north Hreiðar Þór Valtýsson 26 University of Akureyri 2016 Temperate species Hreiðar Þór Valtýsson 27 University of Akureyri 2016 Even more southern species Temperate species moving further north Blue- fin tuna Mackerel Norway lobster Monkfish or anglerfish Iceland and surrounding waters Hreiðar Þór Valtýsson 28 University of Akureyri 2016 Summary if warming continues in Icelandic waters • Valuable species added to the Icelandic fisheries (temperate) – – • Blue fin tuna Mackerel Valuable species will increase in abundance (subarctic and temperate) – – – – • Herring Haddock Monkfish Lobster (not in Greenlandic waters but might if warmer) (not in Greenlandic waters but might if warmer) Valuable species will decline in numbers (Arctic) – – • Shrimp Scallop Valuable species that are great uncertainties about (arctic an subarctic) – – Cod Greenland halibut (probably increase) (probably decline) Iceland and surrounding waters Hreiðar Þór Valtýsson 29 University of Akureyri 2016 Norwegian and Barents Seas The same species and the same consequences Global warming and fisheries Hreiðar Þór Valtýsson 30 University of Akureyri 2016 What happens with warming oceans in the north • A very few animals just do not tolerate higher temperatures – • More diseases – – • cold water species losers Warmer water species winners More/different predators – – • Especially cold waters species not tolerant Warmer water species more tolerant More/different competitors for food – – • Usually in the tropics cold water species losers Warmer water species winners Different food sources – Animals might not be able to change diet Global warming and fisheries Humans and fisheries • • • • • • Humans are however very adaptive Collapse of the cod in Newfoundland led to an great increase in the shrimp and crab fisheries (previously eaten by cod) Fishery for those is now actually more valuable than the cod fishery before Warming trend in Greenland also meant that seal numbers decreased and cod numbers increased Former sealers therefore became cod fishers and profited well A shift in the other direction is however more difficult Hreiðar Þór Valtýsson 31 University of Akureyri 2016 Global warming and fisheries Hreiðar Þór Valtýsson 32 University of Akureyri 2016 Summary of threats to Arctic species due to warming • Arctic animals will decline, especially marine mammals – – – • More competition with species from warmer waters Loss of suitable habitat, increased risk of diseases, more pollution, more human traffic The species are however few of little commercial interest Subarctic species might however increase in numbers or simply move further north as their normal distributional range gets to warm – Many of these are fishes of great commercial interest Conclusion • If the Arctic will continue to warm it will probably still be teaming with life, there might even be more life This will however be very different from the current as warmer water species will move in and pure Arctic species will retreat north • • • • It is however impossible to retreat further north when you are on the North Pole Commercial fisheries will benefit Management problems as fish will move between countries Global warming and fisheries Hreiðar Þór Valtýsson 33 University of Akureyri 2016 The rest of the globe? • • • • • • More of the worlds waters will get warm BUT warm waters are LESS productive than cold Less catch in warm climates Often poor and undeveloped countries Many people => Big problem Global warming and fisheries Hreiðar Þór Valtýsson 34 University of Akureyri 2016 How about the globe? Cold countries Warm countries Cheung, W. W., Lam, V. W. Y., Sarmiento, J. L., Kearney, K., Watson, R. E. G., Zeller, D., & Pauly, D. (2009). Large-scale redistribution of maximum fisheries catch potential in the global ocean under climate change. Global Change Biology, 16(1), 24–35.