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Icelandic nature and geology Fisheries #2

Icelandic nature and geology Fisheries #2. Hreiðar Þór Valtýsson Assistant professor, MSc fisheries biology University of Akureyri / The Marine Research Institute Borgir v/ Nordurslod, IS-600 Akureyri, Iceland hreidar@unak.is. Fishes in Iceland - codfishes. Cod - þorskur. Saithe - ufsi.

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Icelandic nature and geology Fisheries #2

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  1. Icelandic nature and geologyFisheries #2 Hreiðar Þór Valtýsson Assistant professor, MSc fisheries biology University of Akureyri / The Marine Research Institute Borgir v/ Nordurslod, IS-600 Akureyri, Iceland hreidar@unak.is

  2. FishesinIceland - codfishes Cod - þorskur Saithe - ufsi Blue whiting- kolmunni Haddock- ýsa Ling - langa INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  3. Cod (Gadusmorhua) Cod 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 INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  4. Cod (Gadusmorhua) Cod Many stocks in the N. Atlantic Historically the largest off Newfoundland (now collapsed), Barents Sea and Iceland All around Iceland INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  5. Cod (Gadusmorhua) Cod Main spawning grounds are off the south coast Egg and larvae drift west and then north, occasionally also to Greenland Main juvenile grounds 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 INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  6. Cod (Gadusmorhua) Cod Catches highest about 500.000 t/y Overfishing going on then Now about 150.000 t/y INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  7. Cod (Gadusmorhua) Cod • Took around 40% of the stock annually • Trying to get it down to 20 % • The stock reached historical lows in 1992 • Slowly rebuilding since then INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  8. Haddock (Melangrammusaeglefinus) Haddock Distribution almost the same as its close relative, the cod, but more warm loving (not really a Arctic species) The fish that Icelanders normally eat Food: Mainly eats benthic invertebrates thougout its life, muvh more specialized in that regard than the cod Fisheries usually around 50.000 t/y. but the stock has been growing very spectacularly now. Catches now about 100.000 t/y Rare in waters north of Iceland in cold periods but now for example the most common fish in Eyjafjörður Almost certainly because of warming climate INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  9. Bluewhiting Blue whiting A pelagic codfish Not really common in Icelandic waters until recently More common in warmer waters Now among the highest catch species in Icelandic waters Almost certainly due to warming climate INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  10. FishesinIceland – pelagicfish Capelin - loðna Blue- fin tuna Mackerel Herring - síld Sandeel - sandsíli INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  11. Herring (Clupeaharengus) Herring • One of the most abundant fish stock in the world when the stock is in good conditions, probably the largest in the N. Atlantic • Two stocks now in Icelandic waters • Arcto-Scandian – Oceanoc/International stock, spawns in Norwegian waters • Icelandic summer spawning stock – coastal stock, only in Icelandic waters • Fisheries very important for many nations throughout the centuries. • Was for a time the most important fish species in Icelandic waters • Most stocks did collapse due to heavy fisheries between 1965 and 1975 INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  12. Herring (Clupeaharengus) • Most stocks did collapse due to heavy fisheries between 1965 and 1975 • Unfavourable environmental conditions also contributed INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  13. Herring (Clupeaharengus) Herring • The herring stock will probably increase in size in northern waters if the warming climate will continue • Given that the fishery is restricted • But it might have consequences .... INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  14. Capelin (Mallotusvillosus) Capelin 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 A very short life span, usually spawns at the age of 3 and then dies. INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  15. Capelin (Mallotusvillosus) Capelin Fishing stock from 500.000 to 2.000.000 t and therefore the largest fish stock in Icelandic waters. Annual caches around 1.000.000 t, in some years almost as high as for all other species combined INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  16. Capelin (Mallotusvillosus) • 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 Capelin and cod Even if it is a cold water species the effects of warming climate are uncertain In previous warm periods it has simply shifted from spawning and spawned in the waters north of Iceland. It is however quite possible that the stock was smaller However if the stock will be reduced it will have adverse effects on the cod stock as it is such a important food for the cod INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  17. Bluefin tuna and mackerel Blue fin tuna and mackerel Neither one really an Icelandic species Previously sometimes found here in warmer periods Both species very important in warmer regions Per kg the tuna is one of the most valuable catch from the sea Both species are now appearing in Icelandic waters Some experimental fisheries for tune Large catches of mackerell last year, the first time ever Almost certainly due to warming climate INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  18. FishesinIceland - flatfishes Greenland halibut- grálúða Plaice - skarkoli Halibut- lúða Witch flounder - langlúra INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  19. Greenlandhalibut Greenland halibut Besides the Greenland shark the Greenland halibut is the largest predatory fish in high Arctic waters Mostly fished N and NW of Iceland The stock is close to a collapse now as many cold water stocks But difficult to say if this is due to warming as the stock is heavily ovefished INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  20. FishesinIceland – otherfishes Greenland shark - hákarl Lumpsucker - hrognkelsi Redfish - karfi Salmon - lax Monkfish or anglerfish INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  21. Monkfish Monkfish Common in the southernmost part of Iceland Sustains rather low catches ( about 2.000 t/y each) but are very highly prized The monkfish stock is now growing rapidly Previously unknown from waters north of Iceland now the monkfish is frequently found there Almost certainly due to warming climate INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  22. Invertebrates Norway lobster Northern shrimp Whelk Iceland scallop Ocean quahog Blue mussel INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  23. Lobster Lobster • Lobsters are elongate and with a large tail (that we eat) • Common in the southernmost part of Iceland • Sustain rather low catches ( about 2.000 t/y each) but are very highly prized • Onlyonespecies of lobsterfoundhere, Norwaylobster • Onlyinthewarmersouth • Livesinholesinthebottom, movesout of theholestofeed INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  24. Northern (or pink) shrimp (Pandalus borealis) • Shrimps are elongate and with a large tail (that we eat) • Are detritius and carrion eaters, also carnivores • Diverse habitats, many are demersal, many panktonic and some are burrowers • Many species found here, only one is large enough and abundant enough to the commercyally exploited, northern shrimp (Pandalus borealis). • Shrimp fisheries mainly north of Iceland => cold water species • A few stocks of Pandalus borealis found here both offshore and inshore INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  25. Northern (or pink) shrimp (Pandalus borealis) • Invertebrate fisheries began in the middle of the 20th century, initially on shrimp and lobster • Catch almost 70.000 t and it is valuable • Was for a time the second most important commercial species in Iceland • Then a disaster struck ........ INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  26. Northern (or pink) shrimp (Pandalus borealis) Northern shrimp and cod • The stock collapsed and the catch fell down to 860 t in 2006 • Reason, warming trend in waters north of Iceland • => more cod in the area north of Iceland (the shrimp can actually well tolarate this temperature) but ... • => the cod eats shrimp like popcorn INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  27. Northern (or pink) shrimp (Pandalus borealis) 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 • Warming climate will (given that the cod stocks are not heavily overfished) drive shrimp stocks down or further north INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  28. Bivalves • Blue mussel - Mytilus edulis common all around Iceland. Only in very shallow waters or at the seashore, stuck to a and surface. Filters food (phytoplankton). Mussel farming is increasing mostly in Eyjafjörður • Iceland scallop - Chlamys islandica All around Iceland. Filters food (phytoplankton). Lives on the surface of the bottom, can actually swim in a limited way. Important fisheries for scallop during the last decades, mostly in Breiðarfjörður. The stock has collapsed in the last years. Probably due to diseases caused by warming of the ocean • Ocean quahog – Arctica islandica. All around Iceland. Lives buried in the sedments. Filters food (phytoplankton). Can get very old, more than 200 year old. Among the longest living animals on earth. Fished from Þórshöfn in the NE corner, catch slightly less than 10.000 t/y INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  29. Iceland and surrounding waters Capelin Herrring Greenland halibut Shrimp Cod and haddock Scallop Oceanic redfish Blue whiting Lobster and monkfish Blue fin tuna INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  30. Main stocks - fisheries • About 25+ commercially important species, but only a handful dominate the catches • After WWII the catches and have fluctuated from 1 to 2 million t/y. • These fluctuations are explained by the volatile changes in the Pelagic stocks, mainly capelin and herring, but also blue whiting recently. These 3 species are usually more than half of the total catch • As in other areas of the North Atlantic, cod has always been commercially the most important species, although its relative importance has been declining during the later part of the 20th century. • Other large gadoids such as saithe and haddock have also been fished extensively for the whole 20th century by the groundfish fleet, which, in the later part of the century also moved to deeper water to target redfish and Greenland halibut. INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  31. Total landings Collapse of herring stocks World war I Economic exclusive zone to 200 miles World war II Catch by Icelanders INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

  32. Total landings • Readingmaterial: www.fisheries.is • Overheadsonhttp://staff.unak.is/hreidar End of lecture II Next: History of fisheries INJFU03 Fall 2009 Hreidar Thor Valtysson Theweb

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