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Climate change and its effect on cod One of the many consequences of climate change, which is changing migration patterns of many animal species and changes in the distribution of plant and animal species, as happens in certain algae, which must find appropriate conditions for their development. Something similar is what you are seeing is happening to North Sea cod (Gadus morhua
L.) that must migrate farther north to find zooplankton to feed.
Gadus morhua L. -
photo by Joachim S. Flickr Müller
Temperature is one of the main factors involved in distribution of different organisms in the ocean, affecting the growth of primary producers and fish, as many of them require the existence of certain temperature ranges for their development.
For years, it is known that the temperature change, causing changes in species distribution and its effect on
acidification, as happens to the coral
or involvement in increasing
hurricane s. In this case, the increase in water temperature caused the migration of a species of zooplankton such as Calanus finmarchicus
Gunnerus, the North Sea to the Ocean Arctic in search of colder waters. C. finmarchicu
s, served as the main food for cod larvae in the North Sea, so it was affected by migrating C. In other cases, it was the cod that migrated in search of food.
Cod needs cold temperatures in the water when the ocean temperature increased, between 1 and 3 º C, cod stocks, migrated between 48 and 403 miles farther north in search of cooler temperatures (Perry
et al.
, 2005). In other cases,
has reached a migration of zooplankton up to 1200 km (750 miles) or what is it about 30 km per year northward.
addition, according to various studies, it appears that the increase in temperature would cause the spawning grounds, the people moved to areas further north (on the coast of Labrador to the Arctic Ocean) and migration Spring occur sooner (Drinkwater, 2005).
According to him in the Gulf of Maine,
a rise of 1 degree in the water, cause a decrease in performance of the cod stocks up 21% and in the case of 2 degrees Celsius, up to 42%, with an expected that fisheries could
halving by 2050 the United States (Cheung et al., 2008) .
Thus, populations in areas closer to the Arctic, increase with warmer temperatures, while areas farther Ecuador, decrease with increasing temperature.
Something similar happens with the subspecies of Cod, Gadus morhua
callaris
L. (Baltic cod), where mild winters and less water coming
Sea Skagerrak Sea
and increased fresh water from rivers in the region, causes a progressive desalination.
The salt water heavier than fresh water, fell in the water column and cod eggs need a particular salinity for development to remain in suspension, which would cause them to descend in the water column where there is less oxygen, so its survival is endangered, with a consequent reduction of cod stocks (Brander, 2007).
Finally, a recent survey by the English Institute of Oceanography (IEO), concluded that if the North Sea warming continues at the pace projected by the Intergovernmental Panel on Climate Change, the survival of the larvae of this species was significantly reduced, making it difficult to recover the stock and therefore the survival of a vital fishery to the region.
As studied by the IEO, there is a relationship between the size of cod broodstock and their offspring who would be influenced by water temperature and food availability for larvae, which agrees with that previously published
This video
2009 of the Deutsche welle
, touches upon the problems in Norway with changes in cod ( in groin s).
Norway: Climate Change Drives off Norwegian Cod
- Olsen MS, Ottersen G, Llop M, Chan KS, Beaugrand G, & Stenseth NC (2010) Spawning stock and recruitment
in North Sea cod and climate shaped by food. Proceedings of the Royal Society B,
doi: 10.1098/rspb.2010.1465
- Perry et al. (2005). Climate Change and Distribution Shifts in Marine Fishes. Science, VOL 308: 1912-1915
- Fisheries and aquaculture in Europe. Climate change: what impact on fisheries?. European Commission Directorate General for Fisheries and Maritime Affairs. N ° 35 August 2007
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Gadus morhua
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Calanus finmarchicus
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Ocean Acidification - Climate change threatens
populations of North Sea cod -
Why is coral bleaching? -
Hurricanes, earthquakes and climate change
-
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And Fisheries Climate Change: U.S. Atlantic Cod Population To Drop By Half By 2050
-
Cod, climate, and Nature's new Climate Change
journal
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