Transcript How to use our heads in the fishing industry

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 (2nd floor, office 228), Norðurslóð, 600 Akureyri
Tel.: 460 8920 (office)
E-mail: [email protected]
Office hours: By appointment
Introduction
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Hreiðar Þór Valtýsson
University of Akureyri 2016
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. 58-.67. Locate on ACIA web page at:
http://www.acia.uaf.edu/pages/overview.html
2. Arctic flora and fauna – status and conservation: Chapter 8 – The Oceans and seas. Locate
on CAFF web page at:
http://arcticportal.org/uploads/eX/e6/eXe6XNMebXN263nFyvx_Rg/AFF-Status-andTrends.pdf
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. 692695 and section 13.3, p. 709-731). Locate on ACIA web page at :
http://www.acia.uaf.edu/pages/scientific.html.
2. Chapter 9 – Marine systems. Locate on ACIA web page at : http://www.acia.uaf.edu/pages/scientific.htm
2. More on my website http://staff.unak.is/hreidar/index.htm, click NOR0173
Introduction
1.
2.
3.
The Arctic and life in the Arctic
Key findings #4 –
Climate change, Arctic and fisheries
PASSWORD FOR DOCUMENTS =
fish
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Hreiðar Þór Valtýsson
University of Akureyri 2016
What is the Arctic?
The Arctic is in
many ways unique
• The Arctic is a
Mediterranean sea plus
some tundra and ice !!
• Large continental shelves
=> higher productivity
• Gateway between Atlantic
and Pacific
High Arctic
Subarctic
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Hreiðar Þór Valtýsson
University of Akureyri 2016
What is the Arctic?
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Hreiðar Þór Valtýsson
University of Akureyri 2016
COLD
Boundary: Arctic-Subarctic
COLD
What is the Arctic?
Polar fronts
Cold and warmer
currents meet =>
very high productivity
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Hreiðar Þór Valtýsson
University of Akureyri 2016
River inflow
High inflow of
freshwater from
rivers
What is the Arctic?
Sea ice
• Seasonal or permanent 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
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Hreiðar Þór Valtýsson
University of Akureyri 2016
What is the Arctic?
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University of Akureyri 2016
Light
• A very high seasonality in sunlight => highly seasonal primary production
• Little overall sunlight
We are here
Species
• The ecosystem is simple
(i.e. species diversity is
low) compared to
warmer waters
• But: individual species
can however reach
extremely high
abundance
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Hreiðar Þór Valtýsson
University of Akureyri 2016
Species
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Organisms are also divided into several groups by where and how
they live, the most simple division is:
– Plankton (svif ) – Limited ability to move, dependent on currents
– Phytoplankton (Plöntusvif) – Microscopic, base of the food chain
– Zooplankton (dýrasvif) – Small, copepods most abundant
– Benthos (botnlífverur) - Live on or in the bottom, many sessile
– Benthic plants (botnþörungar) – kelp
– Benthic animals (botndýr) – mostly invertebrates, shellfish
– Nekton (sunddýr) – Can move well, fishes and marine mammals
– Pelagic (uppsjávarlífverur ) – Live in the water mass
– Demersal (botnfiskar) – Live close to the bottom
Species
• An extra way of life is
found in the Arctic called
Epontic.
• Species that live on the
underside of ice (inverted
bottom)
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University of Akureyri 2016
Species
• 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
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University of Akureyri 2016
Ecology - Temperature
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University of Akureyri 2016
Cold blooded animals
–
–
–
Body temperature changes with environment
Thousands of enzymes are in the body
Their activity depends on temperature
– The enzymes work faster as it gets warmer
– They get more sluggish as it gets colder
– If to cold some of the do not operate => animal dies
– If to hot some of them cause damage => animal dies
– Each animal (or rather its enzymes) has to adapt to a
rather narrow temperature range
Ecology
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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
Ecology - Whales
Warm blooded animals
–
–
–
Constant internal
temperature 37°C
Whales go where
they want
Map of humpback
whale migration
http://www.nature.nps.gov/biology/migratoryspecies/humpbackwhale.cfm
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Ecology - Whales
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Ecology - Seals
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University of Akureyri 2016
Warm blooded animals
– Seals like to be in cold waters
– Having warm blood gives them advantage
Kovacs, K. M., Aguilar, A., Aurioles, D., Burkanov, V., Campagna, C., Gales, N., … Trillmich, F. (2012). Global threats to pinnipeds. Marine Mammal Science, 28(2), 414–436.
Ecology - Seals
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• The only species that breed in Icelandic waters are the common (15.000) and the
grey seals (6.000)
• Further north in the high Arctic they are even more abundant – these are vagrants
here
Arctic
Ringed seal - hringanóri
Harp seal - vöðuselur
Bearded seal - kampselur
Walrus - rostungur
Hooded seal - blöðruselur
Subartic
Grey seal - útselur
Harbor seal - landselur
Ecology - Marine mammals
•
•
•
•
•
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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
Ecology
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University of Akureyri 2016
• Why are the Arctic and the Sub Arctic so productive?
– It is cold and dark for a large part of the year !
• It is because of high phytoplankton growth
– Phytoplankton needs sunlight and nutrients (fertilizers)
– Plenty of sunlight in the Arctic spring and summer
– As nutrients are quickly used up by phytoplankton they would not be
available in the upper layers under normal circumstances
– This is the case in tropical waters and as a result they are very
unproductive
– To escape this problem the seawater needs to be mixed regularly to bring
the nutrient rich deep waters up to the sunlight
– This is the reason Arctic and Sub Arctic waters are so productive => next
page
Ecology
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University of Akureyri 2016
Primary productivity in the ocean (cold or cold temperate waters)
1.
Winter
a) Surface cooled by cold air => denser => sinks => nutrient rich deep waters up
instead => mixing
b) However, limited sunlight => primary production none
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 => less dense
than deep waters => stratification
(no mixing) => algae finish up
nutrients => Primary production low
4.
Autumn
a) Surface waters are cooled by colder air
Jan
Feb
Mar
Apr
Maí
Jún
Júl
Ágú Sep
Okt
Nóv Des
=> mixing again
Mánuður
b) Some sunlight =>
Nutrients
Temperature
Phytoplankton
Length of day
primary production rather high
Drawings: Jón Baldur Hlíðberg
Marine harvest
High Arctic
• Few fish species
• Low biomass
• Fewer harvested
• Low catches
• Very few people
• Mostly subsistence
High Arctic
Subarctic
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University of Akureyri 2016
Drawings: Jón Baldur Hlíðberg
Marine harvest
High Arctic
Narwhal - Náhvalur
Bearded seal - kampselur
But the marine mammals ?
• Usually associate the Arctic with
marine mammals
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•
•
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University of Akureyri 2016
Harp seal - vöðuselur
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
Ringed seal - hringanóri
Hooded seal - blöðruselur
Beluga- Mjaldur
Walrus - rostungur
Northern right whale - Grænlandssléttbakur
Drawings: Jón Baldur Hlíðberg
Marine harvest
But the SubArctic ?
• Many fish species
• High biomass
• Some of the most
important commercial
fisheries in the world
High Arctic
Subarctic
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University of Akureyri 2016
Marine harvest
High commercial
fish catches
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Climate change
Global warming
–
IPCC 2014
The Arctic is
warming
faster
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University of Akureyri 2016
Climate change
Ocean bottom temperature 1970-2013
Marine Research Institute
Ocean surface temperature 1950-2013
Marine Research Institute
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Atmospheric temperature 1830-2014
Icelandic Met Office
Atmospheric temperature : N. Atl. 0-2014
Moberg et al 2005
3. Key findings #4a
Polar bears
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Mostly eat ice-living seals
Among the animals that most
dependent on ice
Unlikely to survive as a species if
the sea ice disappears
Plus 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
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3. Key findings #4b
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Ice-dependent seals
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Ringed seals probably the most
affected
Spend their entire life on ice
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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
•
Harbor and Grey seals from warmer climates would
however thrive as new areas would be opened up for
them
3. Key findings #4c
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University of Akureyri 2016
Walrus
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•
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
–
–
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
The walrus uses the ice to rest on,
therefore it needs to be close to the
feeding grounds
3. Key findings #4d
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Algae
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•
Most of the production in the lower Arctic is driven by icealgae
Warming might (and probably has) cause these species to be
replaced by less productive species
3. Key findings #4e
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Additional threats
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Warmer climates => increased risk of diseases
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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
3. Key findings #4
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University of Akureyri 2016
Summary of threats to Arctic species due to warming
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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
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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
Next fisheries and
climate change