Cod has a key role in the whole Baltic Sea

A new investigation put in evidence the key role of cod as regulator of the whole Baltic Sea ecosystem. Photo: Roger Jansson<br>

The study shows that when the cod population in the central Baltic increases, it spreads into larger areas and spills over into adjacent marginal systems where it usually does not occur, as for example the Gulf of Riga.

On the other hand, when the cod population size in the central Baltic decreases, it concentrates into the southern Baltic Sea and disappears from the other systems where it cannot reproduce. Cod population size and spatial expansions/contractions in the Baltic landscape depend on fishing pressure and hydro-climatic conditions in the central Baltic that acts as source of cod for the more coastal and northern areas.

The presence/absence of cod in the Gulf of Riga impacts the whole local ecosystem, from the main pelagic fish, the herring, to the zooplankton and phytoplankton through a “trophic cascade”. The presence of cod in the Gulf of Riga can therefore decrease the intensity of the local algal blooms. However, other local factors also affect the Gulf of Riga ecosystem, as local fishing on cod and herring, temperature and river runoff transporting nutrients into the Gulf.

This study increases our knowledge on the predators’ effects on ecosystem structure, and stresses the importance of linking both local and regional processes for a full understanding of ecosystem functioning on a broader landscape scale. Investigations on the functional implications of cross-system fluxes of organisms are central in the management of exploited resources and ecosystem conservation.

SLU-researcher Michele Casini was the leader of the study in collaboration with other scientists from Sweden, Denmark, Latvia, Germany and Norway. The analysis is based on biological and hydrological data collected in the Baltic Sea during a 35-year period.

The results of the study have been published early edition online in the scientific journal Proceedings of the National Academy of Sciences of the USA, 13 April 2012, with the title Predator transitory spillover induces trophic cascades in ecological sinks.

Contacts and more information:
Researcher Michele Casini: link to my SLU personal website:
http://www.slu.se/sv/fakulteter/akvatiska-resurser/organisation/personliga-sidor/michele-casini/
SLU, Department of Aquatic Resources, Institute of Marine Research, Lysekil.

Phone: +46 010-478 40 16, e-mail: michele.casini@slu.se

Media Contact

Mikael Propst idw

More Information:

http://www.vr.se

All latest news from the category: Ecology, The Environment and Conservation

This complex theme deals primarily with interactions between organisms and the environmental factors that impact them, but to a greater extent between individual inanimate environmental factors.

innovations-report offers informative reports and articles on topics such as climate protection, landscape conservation, ecological systems, wildlife and nature parks and ecosystem efficiency and balance.

Back to home

Comments (0)

Write a comment

Newest articles

New yttrium-hydrogen compounds discovered

Researchers at the University of Bayreuth have made a significant scientific breakthrough by discovering new yttrium-hydrogen compounds having serious implications for the research on high-pressure superconductivity. High-pressure superconductivity refers to…

New AI model detects ninety percent of lymphatic cancer cases

Medical image analysis using AI has developed rapidly in recent years. Now, one of the largest studies to date has been carried out using AI-assisted image analysis of lymphoma, cancer…

UTA preps giant particle detectors for neutrino project

Excavation of caverns part of Fermilab’s Deep Underground Neutrino Experiment. With excavation work complete at the site where four gigantic particle detectors for the international Deep Underground Neutrino Experiment (DUNE) will be…

Partners & Sponsors