Uloga litoralne zone kao skloništa planktonskih rakova od predacije riba

master's thesis

• Title (english): The role of littoral zone as a refuge for planktonic crustaceans against fish predation
• Author: Lana Kekelj
• Mentor: Maria Špoljar (mentor)
• Mentor: Ivančica Ternjej (mentor)
• Committee member: Maria Špoljar (predsjednik povjerenstva)
• Committee member: Blanka Cvetko Tešović (član povjerenstva)
• Committee member: Danijel Orešić (član povjerenstva)
• Committee member: Sandra Radić Brkanac (član povjerenstva)
• Committee member: Ivančica Ternjej (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2015-02-27, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Istraživanje je provedeno na plitkim vodenim tijelima u porječju Krapine (mrtvaja Škrčev kut) i Sutle (rukavac). Osnovne hipoteze ovog rada bile su da uslijed povećanog intenziteta predacije litoralna zona bogata makrofitima pozitivno utječe na preživljavanje zooplanktona te da staništa s flotantnim makrofitima ili bez makrofita imaju manju brojnost planktonskih rakova u litoralnoj zoni od staništa sa submerznim makrofitima. Ciljevi istraţivanja bili su utvrditi: (i) utjecaj predacije riba na raznolikost i brojnost Cladocera i Copepoda u sedimentu litorala; (ii) predaciju riba na zooplankton litoralne zone u staništima različite pokrovnosti makrofitima ili bez makrofita; (iii) biotičke interakcije u različitim staništima plitkih vodenih tijela. Rezultati analize fizičko-kemijskih čimbenika ukazali su na povećane vrijednosti mutnoće vode, biomase fitoplanktona, otopljenih organskih tvari te indeksa stupnja trofije u mrtvaji Škrčev kut u odnosu na ostale istraţivane postaje. U litoralnoj zoni bogatoj makrofitima raznolikost i brojnost planktonskih rakova, kao i brojnost ţenki Cladocera i Cyclopoida s jajašcima, bila je statistički značajno veća u odnosu na litoralne zone bez makrofita ili sa flotantnim makrofitima. S povećanjem mutnoće jezera i smanjenjem raznolikosti staništa u litoralnoj zoni, predacija riba slabi, kao i uloga litoralne zone kao skloništa od riba kao vizualnih predatora. Rezultati rada ukazuju da prisustvo ili odsustvo vodenih makrofita moţe značajno promijeniti biotičke interakcije i strukturu biocenoza plitkih jezera, unatoč sličnoj brojnosti, raznolkosti i veličinskoj strukturi predatora.

Abstract (english)

The research was conducted in shallow water bodies in Krapina (oxbow) and Sutla (backwater) watershed. The main hypothesis of this study were that littoral zone with abundant macrophytes has a positive influence on zooplankton survival during increased fish predation, where habitats with flotating macrophytes or without aquatic macrophytes in the littoral zone have lower abundance of planktonic crustaceans in comparison to habitats with submerged macrophytes. Main aims of this study were to determine: (i) the influence of fish predation on diversity and abundance of Cladocera and Copepoda in littoral sediment; (ii) fish predation on littoral zooplankton in habitats with different macrophyte abundance and habitats without aquatic macrophytes; (iii) biotic interactions in different habitats of shallow water bodies. The results revealed significantly higher turbidity, phytoplankton biomass, dissolved organic matter and throphic state index in Škrčev kut Oxbow, compared to other study sites. Abundance and diversity of planctonic crustaceans and abundance of crustacean female with eggs were significantly higher in the littoral zone with abundant macrophytes, compared to littoral zone with flotating macrophytes or without macrophytes. With increased turbidity and lower habitat diversity of the littoral zone, fish predation effects and role of the littoral zone as a refuge for zooplankton decreases. The results of this study suggest that presence or abscence of macrophytes can significantly change biotic interactions and biocenosis structure in shallow water bodies, despite similar abundance, diversity and predator body size.

• Keywords: biotičke interakcije; Cladocera; Copepoda; flotantni i submerzni makrofiti
• Keywords (english): biotic interactions; Cladocera; Copepoda; flotating and submerged macrophytes
• Language: croatian
• URN:NBN: urn:nbn:hr:217:464927
• Study programme: Title: Enviromental Sciences; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra struke znanosti o okolišu (magistar/magistra struke znanosti o okolišu)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-04-21 11:08:47