Diets of the Barents Sea cod (<i>Gadus morhua</i>) from the 1930s to 2018
<p>A new dataset on the diet of Atlantic cod in the Barents Sea from the 1930s to the present day has been compiled to produce one of the largest fish diet datasets available globally. Atlantic cod is one of the most ecologically and commercially important fish species in the North Atlantic. T...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2021-03-01
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| Series: | Earth System Science Data |
| Online Access: | https://essd.copernicus.org/articles/13/1361/2021/essd-13-1361-2021.pdf |
| Summary: | <p>A new dataset on the diet of Atlantic cod in the Barents Sea from the 1930s
to the present day has been compiled to produce one of the largest fish
diet datasets available globally. Atlantic cod is one of the most
ecologically and commercially important fish species in the North Atlantic.
The stock in the Barents Sea is by far the largest, as a result of both
successful management and favourable environmental conditions since the
early 2000s. As a top predator, cod plays a key role in the Barents Sea
ecosystem. The species has a broad diet consisting mainly of crustaceans and
teleost fish, and both the amount and type of prey vary in space and time.
The data – from Russia, Norway and the United Kingdom – represent
quantitative stomach content records from more than 400 000 fish and
qualitative data from 2.5 million fish. Many of the data are from joint
collaborative surveys between Norway and Russia. The sampling was conducted
throughout each year, allowing for seasonal, annual and decadal comparisons
to be made. Visual analysis shows cod diets have changed considerably from
the start of the dataset in the 1930s to the present day. There was a large
proportion of herring in the diets in the 1930s, whereas in more recent
decades capelin, invertebrates and other fish dominate. There are also
significant interannual asynchronous fluctuations in prey, particularly
capelin and euphausiids. Combining these datasets can help us understand how
the environment and ecosystems are responding to climatic changes, and what
influences the diet and prey switching of cod. Trends in temperature and
variability indices can be tested against the occurrence of different prey
items, and the effects of fishing pressure on cod and prey stocks on diet
composition could be investigated. The dataset will also enable us to
improve parametrization of food web models and to forecast how Barents Sea
fisheries may respond in the future to management and to climate change.
The Russian data are available through joint projects with the Polar Branch of
the Russian Federal Research Institute of Fisheries and Oceanography (VNIRO). The UK and Norwegian data (Townhill et al., 2020) are being released
with this paper at <a href="https://doi.org/10.21335/NMDC-2139169383">https://doi.org/10.21335/NMDC-2139169383</a>.</p> |
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| ISSN: | 1866-3508 1866-3516 |