Introduction to the Circumpolar World The marine environment 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 (2 nd floor, office 228), Norðurslóð, 600 Akureyri Tel.: (office) Office hours: By appointment

Introduction Subject: The Arctic marine environment, biological processes and fisheries Readings: 1.ACIA 2004: Key Finding No. 4: Animal species´ diversity, ranges, and distribution will change; p Locate on ACIA web page at: 2.Arctic flora and fauna – status and conservation: Chapter 8 – The Oceans and seas. Locate on CAFF web page at: Trends.pdfhttp://arcticportal.org/uploads/eX/e6/eXe6XNMebXN263nFyvx_Rg/AFF-Status-and- Trends.pdf 3.Fisheries.is - Information on Icelandic fisheries from A to Z. Find about the species discussed in the overheads under "main species" and information on the marine ecosystem around Iceland under "Ecosystem"Fisheries.is Supplementary material if you want to learn more about this topic: 1.ACIA Scientific report: 1.Chapter 13 – Fisheries and aquaculture, Central North Atlantic – Iceland and Greenland (section 13.1, p and section 13.3, p ). Locate on ACIA web page at : 2.Chapter 9 – Marine systems. Locate on ACIA web page at : 2.BCS 311: Land and Environment I : 1.Module 8 – Life in the ocean: Module 11 – Living Resources in the Arctic Marine Environment: More on my website click NOR0173http://staff.unak.is/hreidar/index.htm NOR0173 Hreidar Thor Valtysson The webThe web

Introduction 1.Key ecological aspects of the Arctic marine environment 2.Introduction to the main species 3.Key findings #4 - Animal species´ diversity ranges and distribution will change 4.The marine ecosystem in Iceland and adjacent waters Further information on (click on NOR0173 in the left upper corner) PASSWORD FOR DOCUMENTS = fish NOR0173 Hreidar Thor Valtysson The webThe web

Introduction NOR0173 Hreidar Thor Valtysson The webThe web The Arctic is a mediterranean sea plus some tundra and ice !! Fisheries and other marine harvest therefore very important for Arctic people The next lectures will be about the Marine environment in the Arctic The focus is on the Northern Atlantic/Arctic but the species are mostly the same in all areas

1. Ecology NOR0173 Hreidar Thor Valtysson The webThe web The Arctic is in may ways unique High proportions of continental shelves and shallow waters => higher productivity

1. Ecology NOR0173 Hreidar Thor Valtysson The webThe web The Arctic is in may ways unique A very high seasonality in sunlight => highly seasonal primary production

1. Ecology NOR0173 Hreidar Thor Valtysson The webThe web The Arctic is in may ways unique Little overall sunlight and thus cold sea temperatures Strong influence of fresh water in the high Arctic Seasonal or permanent sea ice Intense mixing of seawater in the winter => plenty of nutrients Demands special adaptation by animals and plants

1. Ecology NOR0173 Hreidar Thor Valtysson The webThe web Sea ice Some mammals depend very much on it such as polar bears and some seal species It scours the bottom in shallow areas => destroys bottom life However algae thrive on the underside of it in spring, driving the production in the ecosystem

Introduction NOR0173 Hreidar Thor Valtysson The webThe web Cold and warmer currents meet => very high productivity High inflow of freshwater from rivers Polar frontsRiver inflow

1. Ecology NOR0173 Hreidar Thor Valtysson The webThe web Arctic marine animals Tend to grow slow and live long => slow reproductive rate A few groups that live in unstable environments the opposite, grow fast, live short => high reproductive rate Many are able to store large quantities of energy rich lipids (fat) to survive high variability of food abundance – Arctic animals are generally fat – Also serves as insulation in mammals Way to survive the winter – Tolerate it – one has to be tough – Migrate – one has to be easy traveler – Hibernate – one has to find a good spot

1. Ecology NOR0173 Hreidar Thor Valtysson The webThe web The ecosystem is simple (i.e. species diversity is low) compared to warmer waters But: individual species can however reach extremely high abundance

1. Ecology NOR0173 Hreidar Thor Valtysson The webThe web The oceans are divided into different areas where organisms live. Organisms are also divided into several groups by where and how they live, the most simple division is: –Benthos (botnlífverur ) – Live on or in the bottom, some are stuck to the bottom –Pelagic (uppsjávarlífverur ) – Live in the water mass Plankton (svif ) – Limited ability to move, dependent on currents –Phytoplankton (Plöntusvif eða svifþörungar ) –Zooplankton (dýrasvif ) Nekton (sunddýr) – Can move well Many are benthic

1. Ecology NOR0173 Hreidar Thor Valtysson The webThe web An extra way of life is found in the Arctic called Epontic. Species that live on the underside of ice (inverted bottom)

1. Ecology NOR0173 Hreidar Thor Valtysson The webThe web The phytoplankton is the base of the ecosystem Single celled algae that cannot be seen by naked eyes Eaten by zooplankton => eaten by small fish => eaten by seals => eaten by polar bears (simplyfied) Dead zooplankton and animals sink to the bottom => eaten by benthic invertebrates => eaten by other animals

2. Phytoplankton NOR0173 Hreidar Thor Valtysson The webThe web Fundamental problem in the ocean 1.Phytoplankton need sunlight and nutrients (such as nitrogen and phosphates) to be able to photosynthesize 2.Sunlight only available in the uppermost layers (ca 20 depth) 3.As nutrients are quickly used up by phytoplankton they would not be available in the upper layers under normal circumstances 4.This is indeed the case in tropical waters and as a result they are very unproductive 5.To escape this problem the seawater needs to be mixed regularly to bring the nutrient rich deep waters up to the sunlight 6.This is one of the reasons the areas where cold and warm currents meet are very productive, this collision of currents causes mixing 7.There is however another factor that causes the Arctic waters to be unusually productive

2. Phytoplankton NOR0173 Hreidar Thor Valtysson The webThe web Primary productivity in the ocean (cold temperate waters) 1.Winter a)Surface waters are cooled by cold weather => more dense => sink => nutrient (primarily N and P) rich deep waters up instead – very intense mixing b)However, limited sunlight => primary production low 2.Spring a)Surface waters rich in nutrients after mixing in winter b)Enough sunlight => primary production very high 3.Summer (this applies for the whole year in the tropics but is very short in the high Arctic) a)Plenty of sunlight but... b)Surface waters warm => surface waters less dense than deep waters => stratification (no mixing) => algae finish up nutrients => Primary production low 4.Autumn a)Surface waters are cooled by colder weather => more dense => sink => nutrient (primarily N and P) rich deep waters up instead b)Some sunlight => primary production rather high

2. Benthic algae NOR0173 Hreidar Thor Valtysson The webThe web The main primary producers in the sea are – Phytoplankton (mentioned before), small and unicellular, but provide most of the production – Benthic algae or seaweed, large and multicellular but only in a narrow zone along the coast Benthic algae form kelp forests in cold and temperate oceans which are very productive and important ecosystems Only in shallow waters, to about 30 m Not as important for the ecosystem as the phytoplankton, but important as food for some species (e.g. sea urchin) and shelter for other (e.g. juvenile cod).

2. Zooplankton NOR0173 Hreidar Thor Valtysson The webThe web Copepods, for example Calanus species (rauðáta og póláta), euphausids (ljósáta) and hyperiids (sviflægar marflær) the most prominent Not utilized directly by humans, but is vital link between phytoplankton and fish Eat phytoplankton and other zooplankton Many commercially important species, such as cod are planktonic at young age

2. Benthic invertebrates NOR0173 Hreidar Thor Valtysson The webThe web Much more diverse than the zooplankton Eat detritius, carrion, plankton and other benthos Some species harvested and have become quite important recently. Norway lobster Northern shrimp Green sea urchin Iceland scallop Whelk Blue mussel Ocean quahog

2. Fishes (Atlantic part) Benthic fishes Pelagic fishes Northerners Southerners NOR0173 Hreidar Thor Valtysson The webThe web Saithe - ufsi Haddock- ýsa Sandeel - sandsíli Blue whiting- kolmunni Herring - síld Lumpsucker - hrognkelsi Cod - þorskur Greenland halibut- grálúða Greenland shark - hákarl Polar cod - ískóð Capelin - loðna Salmon - lax Redfish - karfi

2. Marine mammals NOR0173 Hreidar Thor Valtysson The webThe web The Arctic is in fact a heaven for mammals and birds Very few places in the world have as high densities of large mammals Mammal hunting therefore very important for the people of the high Arctic Due to the warm blood and active lifestyle these animals have an advantage in the cold In comparison few species of cold blooded animals have managed to adapt to the Arctic although the few species that have can be really abundant, there is for example only one species of shark in the Arctic, Greenland shark Polar bear- ísbjörn

2. Whales (Icelandic) NOR0173 Hreidar Thor Valtysson The webThe web High Arctic species

2. Seals (N. Atlantic) NOR0173 Hreidar Thor Valtysson The webThe web Grey seal - útselur The only species that breed in Icelandic waters are the common and the grey seals Others are true Arctic seals, most common along the sea Ice and vagrants here Ringed seal - hringanóri Bearded seal - kampselur Northerners Southerners Hooded seal - blöðruselur Harp seal - vöðuselur Grey seal - útselur Harbor seal - landselur Walrus - rostungur

2. Seals (Akureyri) NOR0173 Hreidar Thor Valtysson The webThe web Ringed seal - hringanóri Bearded seal - kampselur Hooded seal pup - blöðruselskópur Harp seal - vöðuselur Grey seal - útselur Harbor seal - landselur Walrus - rostungur

2. Seabirds NOR0173 Hreidar Thor Valtysson The webThe web Are warm blooded and can therefore live in all climates All seabirds nest on land, often in large colonies Seabirds are very abundant in the Arctic The puffin is the most abundant seabird in Iceland with 2 to 3 million breeding pairs, the fulmar is next Feeding habits are diverse, eiders live on benthic invertebrates, cormorants and auks are active hunters, and gulls are scavengers

1. Ecology NOR0173 Hreidar Thor Valtysson The webThe web

3. Key findings #4 Polar bears Mostly eat ice-living seals Among the animals that most dependent on ice Unlikely to survive as a species if the sea ice disappears Already documented changes in the Hudson Bay (Canada) Polar bears are long lived and at the top of the food chain Therefore they accumulate toxic chemicals in the liver fat These chemicals are persistent in the Arctic NOR0173 Hreidar Thor Valtysson The webThe web

3. Key findings #4 Ice-dependent seals Ringed seals probably the most affected Spend their entire life on ice – Forage under or near the ice – Need enough ice to build lairs – Need ice cover to protect pups Although the ringed seal is the most dependent on ice other high Arctic species would also suffer NOR0173 Hreidar Thor Valtysson The webThe web Harbour and Grey seals from warmer climates would however thrive as new areas would be opened up for them

3. Key findings #4 Walrus As strange as it might sound, if the Arctic warms up walruses, other marine mammals and some birds might decline because of competition with warmer water fishes. The walrus also depends on shallow waters, if the ice edge retreats from the continental shelf two bad things might happen to the walrus NOR0173 Hreidar Thor Valtysson The webThe web 1.Productivity is very high at the edge of the ice, this in turn supports rich bottom life that the walrus feeds on. If the edge retreats over deeper waters the walrus will no longer have the same food supply 2.The walrus uses the ice to rest on, therefore it needs to be close to the feeding grounds

3. Key findings #4 Algae Most of the production in the lower Arctic is driven by ice- algae Warming might (and probably has) cause these species to be replaced by less productive species NOR0173 Hreidar Thor Valtysson The webThe web

3. Key findings #4 Additional threats Warmer climates => increased risk of diseases Animals in colder waters are not resistant to these More precipitation is predicted and this can lead to increased pollution, but pollution is already a problem in the Arctic Less ice => more shipping => more accidents => more pollution More ultraviolet radiation largely due to depletion of ozone (key finding #9) => many species are vulnerable to this => less production NOR0173 Hreidar Thor Valtysson The webThe web

3. Key findings #4 Fishes and fisheries High Arctic species will decline in numbers The species are however few and of little commercial interest Low- or subarctic species might however increase in numbers or simply move further north as their normal distributional range gets to warm Many of these are of great commercial interest Commercial fisheries will benefit NOR0173 Hreidar Thor Valtysson The webThe web

3. Key findings #4 Fishes and fisheries Great changes have already been observed in the Bering Sea Walleye pollack fishery now among the largest fisheries in the world NOR0173 Hreidar Thor Valtysson The webThe web

3. Key findings #4 Fishes and fisheries Lesser changes are expected in the short run in the Atlantic But there are already some signs of warming there, more later ….. There we also have a good example of dramatic collapse of a fishery due to climate change However this was not due to warming but cooling + other factors About t were caught of Newfoundland cod at its peak, now there is almost no fishery allowed NOR0173 Hreidar Thor Valtysson The webThe web

3. Key findings #4 Fishes 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 NOR0173 Hreidar Thor Valtysson The webThe web

3. Key findings #4 Summary of threats to Arctic species due to warming More competition with species from warmer waters Less or different less suitable food Loss of suitable habitat Increased risk of diseases More pollution More human traffic Conclusion If the Arctic will continue to warm it will probably still be teaming with 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 NOR0173 Hreidar Thor Valtysson The webThe web

3. Key findings #4 NOR0173 Spring 2008Hreidar Thor Valtysson The webThe web Next fisheries in Iceland and climate change