Climate Effects on North East Atlantic Cod Stock and Fisheries

Table of Contents
Chapter 2: Northeast Atlantic Cod Stocks and Fisheries 4
2.1: North East Atlantic (NEA) Cod 4
2.2: Climate Effects on North East Atlantic (NEA) Cod Stock and Fish-
eries 8
Chapter 3: The Bioeconomic Model 9
3.1: Model Introduction9
3.: The Bioeconomic Model 11
Chapter 5: Results and Analysis 21
5.1: Small Vessels 22
5.2: Large Vessels 23
5.3: Comparing the Climate Change and No Climate Change Scenarios
23
5.4 Temperature Effects on BS Cod Growth and Recruitment.
5.5 Temperature-Driven Range Expansions and BS Cod Population Size.
5.6 The job of Management in BS Cod Stock Development.
5.7. The expectation for ocean ice to changes in the Arctic throughout
the following multi-decade.
5.8. Climate change impacts the arrangement of biological system ad-
ministrators supporting fisheries and aquaculture.
Chapter 6: Conclusions and Recommendations 24
6.1. Conclusion
6.2. Recommendation
6.3. Limitation
Chapter 1: Introduction
The stock productivity of a fishery is one of crucial factors that de-
termine their profits. Climate change is one of the environmental
plagues that affect fisheries all over the world direct or indirect
through disaster events like floods or droughts, warmer tempera-
tures, ocean acidification, global warming as well anthropogenic
pressures just to name a few (FAO, 2018).This is evident with the

2015 Paris Climate Agreement that acknowledges the threat of cli-
mate change and the necessity to efficiently and continuously retal-
iate to this critical threat, by using alleviation and medication pro-
cedures (ibid).
Research over the years indicates inevitable effects of climate
change on marine fisheries, inland fisheries and aquaculture (ibid).
This explains why over the past years that researchers have been
continuously studying in order to find tools and solutions, which
can help, manage and adapt to the changes caused by climate. In
addition, researchers also find ways to reduce the human impact
(anthropogenic pressures) that contributes to the depletion of fish
stocks. Climate effects can affect fisheries economically through
changes in the ocean temperature influences which might isolate
small and large fish leading to certain locations being valuable to
exploit due to the state of the ocean altering over time (Haynie &
Pfeiffer, 2012). In addition, in research, there is more focus on the
effects of climate variations on the biological aspects of fisheries
than on the economic aspects specifically in terms of those exploit-
ing the fish resource (ibid). Therefore, it is important to observe
how productivity and profits of a fishery can be affected by changes
in temperature variations over time while taking into consideration
spatial distribution.
The North East Arctic cod, one of the Atlantic cod stocks, is consid-
ered one of the most valuable cod stocks in the world (Helgesen,
Skonhoft, & Eide, 2018) and therefore very important commercially
to the two nations (Norway and Russia) that share this stock. This
study focuses on the Norwegian share of the stock located in the
Barents Sea. The North Atlantic cod has however over the years ex-
perienced the effects of climate change directly through changes in
temperature, warmer waters, and ocean acidification and indirectly

through (Crépin, Karcher, & Gascard, 2017). This has further had
an effect on the productivity of the stock and therefore the profits
as well.
This study therefore aims at identifying the effects of temperature
variations on the productivity cod stock and profitability of NEA
cod fishery over a period of fifty years through the carrying capac-
ity. A bio economic model is employed here to compare two scenar-
ios, one with climate change effects and the other with no effect. In
order to achieve the above objectives, the following questions
would be addressed:
1) Does climate change affect the productivity of cod fisheries over
time?
2) Does climate change affect the profitability of the cod fishery
over time?
The results of this analysis can provide some useful information if
the effect of climate change is plausible.
1.4: Thesis Structure

Being one of the most commercially valuable stocks for over a cen-
tury, the total catch of these cod stocks have gradually declined
over the years due to fishing pressure as well as changing environ-
mental conditions (Marteinsdottir et al., 2005). This was evident
from the 1970 when the north Atlantic total catch was about 3.5
million tonnes but drop to less than a million by 2003 (Svasand et
al., 2007). This has resulted to some of the 22 stocks fishery to get
closed or collapse. The North East Arctic cod stock like several
other cod stocks, has fluctuated over the years (illustrated in figure
4 below)

Figure 4: ICES Standard plots for Northeast Arctic cod (subareas 1
and 2)
As illustrated in figure 4 above the total catch was on an unvarying
decline from about 900,000 tonnes in the 1970s to about 300, 000
tonnes between 1983 to 1985, but increased to about 500,000
tonnes in 1987 before another decline to 212,000 tonnes in 1990
which was the lowest recorded catch (ICES, 2018). However, there
was a rapid increase from 1991 but another noticeable decrease in
the year 2000. Since 2011, the NEA cod catches have been over the
stable average, and as of 2017 the catch was reported to be at 868
276 tonnes (ICES, 2018).
Due to its stock size estimates at 4,2 million tonnes in 2015, NEA
cod is considered one of the largest in the world (Helgesen et al.,
2018). This stock is also regarded to be well managed jointly by
Norway and Russia (Eide et al., 2013).The NEA cod is harvested
with two different fleets, the coastal fleet and the trawlers, this