Structuring effect of submerged macrophytes on trophic relationships and distribution of fish in deep lakes (MacFish) 


Project ID No. 7F14316

Project promoter: Biology Centre of the Czech Academy of Sciences, Branišovská 1160/31, 370 05 České Budějovice, Czech Republic

Project partner: Norwegian Institute for Nature Research, Høgskoleringen 9, NO-7034 Trondheim, Norway

Principal investigators: RNDr. Jiří Peterka, Ph.D., Karl Oystein Gjelland, Ph.D.

Financial support: Czech-Norwegian Research Programme CZ09

Duration: 2014-2017

Programme general information: The overall objective of the Czech Research Fund is to enhance research-based knowledge development in the Czech Republic through enhanced research cooperation between the Czech Republic and Norway. 

Programme operator: Ministry of Education, Youth and Sports, Department of Support for Universities and Research

Programme contact persons: Ing. Jan Aschermann,, tel.: +420 234 812 164, Ing. Klára Musilová,, tel.: +420 234 812 218, Bc. Mgr. Štěpán Obrtlík,, tel.: +420 234 811 665

Donor programme partner: Research Council Norway (RCN), Ms Aleksandra Witczak Haugstad, awh@rcn.notel.: +47 92 28 24 62


Project abstract:

Predation by fish is the primary top-down structuring force in aquatic ecosystems, and a change in predator-prey interactions involving fish may cause a change in the strength of trophic cascades and finally result in ecosystem shifts. Submerged macrophytes play an important role beyond that of primary production, as they provide increased structural complexity and niche potentials for fish. However, most of the scientific attention on habitat use in fish and the influence of macrophytes have been given to small and shallow lakes, where the vegetated areas are well-developed and the availability of a large deep water refugium is absent or limited. Our goal is to gain a detailed understanding of the structuring effect the submerged macrophytes have on fish communities in deep lakes. In order to achieve this, we will contrast two newly formed deep lakes of similar size and colonization history, but one with and the other without submerged macrophytes. We will use the latest developments in high-resolution positioning telemetry to assess individual habitat use and activity patterns in the different species of the multispecies assemblages in the two lakes. This will be combined with other sampling techniques, such as echosounding, acoustic cameras, video cameras, electrofishing, trawling and gillnetting, with an emphasis on the non-lethal methods and covering all ontogenetic stages from fish larvae to mature adults. Individual trophic position will be assessed by diet studies and stable isotope analyses. We will use the resulting data to study intra- and interspecific overlap in habitat and trophic niche use, as well as activity patterns with high spatiotemporal resolution. Combined with consumption estimates in piscivorous predator fishes and life-history characteristics such as growth and age at maturation in prey fish, a comprehensive and detailed insight into the effect of submerged macrophytes on the fish community structures and dynamics will be reached. The project will provide novel basic research results that will have important relevance for the management and restoration of water bodies, and it will strengthen the cooperation and knowledge transfer between Czech and Norwegian aquatic ecosystem research.


Project promoter:

The Biology Centre (BC) of the Academy of Sciences of the Czech Republic performs research and provides education in a number of biological disciplines. Research conducted at the BC is predominantly ecological, involving collaboration across disciplines, use of diverse methodological approaches (molecular biology, genetics, taxonomy, field ecology, mathematical modelling, etc.), and a combination of analytical and holistic approaches to problem solving. Core facilities with shared equipment augment the output of all the BC’s institutes. The Institute of Hydrobiology (IH) is one of the institutes associated within the BC. The main aim of the IH is to conduct research of biotic interrelations and their interactions with abiotic factors in lentic water bodies, especially man-made reservoirs and natural lakes. The specialization of the staff members of the institute includes water chemistry, biochemistry, bacteriology, protozoology, algology, zooplanktonology and ichthyology. This structure enables studies of the interrelations within the trophic food chains using both principal approaches: bottom-up (from chemistry to fish biology) and top-down (from fish biology to chemistry). Another characteristic feature of the IH is a mixture of experimental and field approaches and regular basic long-term ecological research of selected water bodies, which allows for studies at different time-scales. Researchers of the IH regularly publish their findings in peer-reviewed international journals and scientific books and present their results at international conferences. International collaboration also has a long tradition at the IH, with associates located all around the globe. The IH hosts a number of foreign students and postdocs and also sends those educated at the institute for postdoctoral stays abroad. To further enhance the international cooperation IH itself organizes international training courses and conferences, and participates in international research projects. Because education is equally important as research, the IH researchers tutor graduate and undergraduate students in collaboration with several universities, primarily the University of South Bohemia in České Budějovice.


Project partner:

The Norwegian Institute for Nature Research (NINA) is Norway’s leading institution for applied ecological research and a key research institute in Europe. The institute employs approximate 150 research scientists, and in 2012 the annual number of peer-reviewed publications was 235, in addition to 190 technical reports. The institute offers broad-based ecological expertise covering the genetic, individual, population, species, ecosystem and landscape levels, in terrestrial, freshwater, and coastal marine environments. The institute’s research and its collaborative networks in Norway and abroad, enable it to provide management agencies, industry and civil society with top-notch information and advisory services on all aspects of natural resource management and the sustainable use of renewable resources. NINA has a strong tradition for combining field observations with ecological theory through modelling approaches, and these models are often tailored for advisory use. NINA’s research involves studies of individual habitat requirements, use, and movement, and the institute has for two decades been one of the leading institutes in Europe on the use of biotelemetry for such studies. Recruitment of young researchers is important for the vitality of research communities, and NINA involves master and PhD students in their work, as well as offering postdoctoral positions.


Project objectives:

By detailed comparisons of fish communities in deep lakes contrasted by absent or abundant macrophyte cover, the project shall generate detailed knowledge on the effects submerged macrophytes have on fish community structure and interactions. This includes effects on habitat and trophic niche use by individuals of the same species in the contrasted lake, community structure and trophic relationships including ontogenetic aspects.


Project aims:

i) To describe, quantify and evaluate trophic relationships within percid-cyprinid and pike-wels piscivores in deep lakes with presence and absence of submerged macrophytes.

ii) To describe, quantify and evaluate species specific differences in habitat and food niche, as well as fish distribution patterns in deep lakes with presence and absence of submerged macrophytes.

iii) To describe and quantify spatiotemporal habitat use, activity patterns and consumption in the most important piscivorous fishes in the lakes (pike, wels and perch).

iv) To describe and evaluate differences in aggregative behaviour of fish in deep lakes as related to complexity of littoral habitat provided by submerged macrophytes.