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Climate change and Atlantic cod (Gadus morhua): does the increasing temperature affect its growth rate?

Ribeiro, Joana (2014) BIOP35 20132
Degree Projects in Biology
Abstract
Climate change and the associated temperature increments are a reality, with temperature already rising in the last century. With a changing climate dissolved oxygen levels in the water will also suffer changes. The combination of changes due to alterations in the climate affects fish stocks, through alterations in the spawning-stock biomass. One of the fish stocks that are being affected is the Atlantic cod (Gadus morhua) in the Baltic Sea. Climate change affects the quality and availability of cod’s habitats, having those a consequence in its growth rate. Thus it makes sense that studies in how Atlantic cod will react to a changing climate are performed. In this project, the reaction of Atlantic cod to temperature in the Arkona and... (More)
Climate change and the associated temperature increments are a reality, with temperature already rising in the last century. With a changing climate dissolved oxygen levels in the water will also suffer changes. The combination of changes due to alterations in the climate affects fish stocks, through alterations in the spawning-stock biomass. One of the fish stocks that are being affected is the Atlantic cod (Gadus morhua) in the Baltic Sea. Climate change affects the quality and availability of cod’s habitats, having those a consequence in its growth rate. Thus it makes sense that studies in how Atlantic cod will react to a changing climate are performed. In this project, the reaction of Atlantic cod to temperature in the Arkona and Bornholm basins in the Baltic Sea was studied by the means of a growth model based on temperature. Historical oxygen levels were used to empirically observe whether cod has enough oxygen in the depths it is using in the mentioned basins in the Baltic Sea. In the Arkona basin, cod seems not to be favoured by temperature increments and has all depths available, regarding oxygen. In the Bornholm basin cod achieves bigger sizes with climate change, although it does not have the entire layer of water available to set habitats in. The results suggest that in the Arkona basin temperature is already close to that that is optimal for the growth of cod, whereas in the Bornholm basin those temperatures are yet to be achieved. Furthermore, cod seems to have a habitat restriction in the Bornholm basin, which might constitute of a bigger problem with climate change, since it will change the oxygen levels in the water as well. (Less)
Popular Abstract
The weather will get warmer, how will a fish species grow?

It is safe to say that almost everyone is familiar with the term “Climate Change”. It is talked about in the news. Climate change implies, in some cases, a rise in temperature and changes in other environmental factors, as the amount of dissolved oxygen in the water. One example of how climate change will affect animals is the history in the movie “Ice age”, where the ice melted because of a rise in temperature. However, most people do not know that the temperature started to increase in the 20th century. It will, most likely, continue to increase in this century. Climate change will affect ecosystems. Marine ecosystems are important for the human population, as they provide... (More)
The weather will get warmer, how will a fish species grow?

It is safe to say that almost everyone is familiar with the term “Climate Change”. It is talked about in the news. Climate change implies, in some cases, a rise in temperature and changes in other environmental factors, as the amount of dissolved oxygen in the water. One example of how climate change will affect animals is the history in the movie “Ice age”, where the ice melted because of a rise in temperature. However, most people do not know that the temperature started to increase in the 20th century. It will, most likely, continue to increase in this century. Climate change will affect ecosystems. Marine ecosystems are important for the human population, as they provide important services, like fisheries. What I wanted to study is how one specific kind of fish, the Atlantic cod (Gadus morhua), will react to the rising of the temperature. I also wanted to see if they have enough oxygen to breathe and develop properly.

Atlantic cod lives all through the North Atlantic Ocean, including the Baltic Sea. In my work, I tried to understand how Atlantic cod will react to temperature increments by the means of modelling. I studied Atlantic cod in the Arkona and Bornholm basins in the Baltic Sea.

In the Arkona basin, cod will be negatively impacted by climate change. This means it will get smaller than the actual size as the temperature increases. The implications of this are, for example, that the Atlantic cod will we fish might be smaller and in a worse physical condition than right now. There was enough oxygen in the water for cod to develop in a proper manner, being the reason it is not growing as much due to biological processes.

In the Bornholm basin, Atlantic cod gets bigger with climate change. Although Atlantic cod is getting bigger with increasing temperature in the Bornholm basin, it does not have enough oxygen in the water to develop as it should. This is a cause of concern, as the resources Atlantic cod needs might be found at deeper depths, which it cannot access. This can lead to fish in a worse physical condition.

On a general note, climate change will affect Atlantic cod in the Arkona basin by not allowing them to grow as big. In the Bornholm basin, Atlantic cod will not have enough oxygen to live properly, even though it gets bigger with climate change.

Supervisor: Anders Persson
Master´s Degree Project 60 ECTS in Biology, Aquatic Ecology 2014
Department of Biology, Lund University (Less)
Please use this url to cite or link to this publication:
author
Ribeiro, Joana
supervisor
organization
course
BIOP35 20132
year
type
H2 - Master's Degree (Two Years)
subject
language
English
id
4883029
date added to LUP
2014-12-22 09:59:26
date last changed
2014-12-22 09:59:26
@misc{4883029,
  abstract     = {Climate change and the associated temperature increments are a reality, with temperature already rising in the last century. With a changing climate dissolved oxygen levels in the water will also suffer changes. The combination of changes due to alterations in the climate affects fish stocks, through alterations in the spawning-stock biomass. One of the fish stocks that are being affected is the Atlantic cod (Gadus morhua) in the Baltic Sea. Climate change affects the quality and availability of cod’s habitats, having those a consequence in its growth rate. Thus it makes sense that studies in how Atlantic cod will react to a changing climate are performed. In this project, the reaction of Atlantic cod to temperature in the Arkona and Bornholm basins in the Baltic Sea was studied by the means of a growth model based on temperature. Historical oxygen levels were used to empirically observe whether cod has enough oxygen in the depths it is using in the mentioned basins in the Baltic Sea. In the Arkona basin, cod seems not to be favoured by temperature increments and has all depths available, regarding oxygen. In the Bornholm basin cod achieves bigger sizes with climate change, although it does not have the entire layer of water available to set habitats in. The results suggest that in the Arkona basin temperature is already close to that that is optimal for the growth of cod, whereas in the Bornholm basin those temperatures are yet to be achieved. Furthermore, cod seems to have a habitat restriction in the Bornholm basin, which might constitute of a bigger problem with climate change, since it will change the oxygen levels in the water as well.},
  author       = {Ribeiro, Joana},
  language     = {eng},
  note         = {Student Paper},
  title        = {Climate change and Atlantic cod (Gadus morhua): does the increasing temperature affect its growth rate?},
  year         = {2014},
}