Utjecaj kaveznog uzgoja tune na naselja morske cvjetnice Posidonia oceanica (L.) Delile u području otočića Fulija (Srednji Jadran)

master's thesis

• Title (english): Inshore capture-based tuna mariculture impact on Posidonia oceanica (L.) Delile meadows in the area of Fulija Islet (Central Adriatic Sea)
• Author: Blanka Vrgoč
• Mentor: Petar Kružić (mentor)
• Granter: University of Zagreb; Faculty of Science; (Department of Biology); Zagreb
• Defense date and country: 2013, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology

Abstract

Kartiranje i praćenje stanja morske cvjetnice Posidonia oceanica u hrvatskom dijelu Jadranskog mora pokazuju značajno smanjenje gustoće livada u područjima pod utjecajem priobalnog kaveznog uzgoja tune. Predstavljeni su rezultati istraživanja područja u blizini otočića Fulije koje je pod utjecajem uzgajališta tune. Ovaj rad dokazuje da su obogaćivanje nutrijentima i rizik od eutrofikacije veliki problem ovog područja. Akvakulturni otpad izvor je onečišćenja nutrijentima koje stimulira cvjetanje fitoplanktona i zajednica alga, te obogaćuje sediment organskom tvari. Analizirani su stanje i gustoća livada vrste Posidonia oceanica pod utjecajem uzgajališta tune (otočić Fulija) i izvan njega (dvije kontrolne stanice na otoku Ižu i otočiću Mrtovnjaku). Istraživane su fizikalno-kemijske i biološke varijable u svrhu procjene utjecaja tunogojilišta na litoral u blizini otočića Fulije. Pored bioloških i standardnih osnovnih kemijskih parametara, poput koncentracije otopljenih nutrijenata, ispitani su i utjecaj ribogojilišta na distribuciju otopljenog organskog ugljika (DOC) te površinski aktivnih tvari (SAS). Pronađene su značajne razlike između koncentracije nutrijenata među istraživanim postajama pod utjecajem uzgajališta tune (otočić Fulija) i onima izvan njega (kontrolne postaje). Mukozni agregati bentoskih alga na livadama posidonije primijećeni su tijekom proljeća i ljeta. Broj izdanaka livada vrste P. oceanica smanjen je na postajama u blizini uzgajališta tune, što potvrđuje da aktivnosti ribogojilišta značajno utječu na okolne livade.

Abstract (english)

Mapping and monitoring of the seagrass Posidonia oceanica in Croatian part of the Adriatic Sea showed significant decline in meadows density in the area influenced by inshore capture-based tuna aquaculture. The results of Posidonia meadows survey in the area of Fulija Islet, which are under the influence of tuna farms, are presented. This paper proves that nutrient enrichment and the risk of eutrophication is a significant issue in this area. Aquaculture wastes are a source of nutrient pollution and stimulate blooms of phytoplankton and algae population, as well as organic matter enrichment in the sediment. The condition and density of Posidonia oceanica meadows under the influence of tuna farms (at Fulija Islet) and out of its reach (two control stations at Iž Island and Mrtovnjak Islet) have been analyzed. Physico-chemical and biological variables have been examined in order to evaluate the impact of a tuna farm on the littoral near Fulija Islet. Besides biological and standard basic chemical parameters, such as the concentration of dissolved nutrients, the influence of fish farming on the distribution of dissolved organic carbon (DOC) and surface active substances (SAS) in the water column were also investigated. Significant differences were found between nutrient concentrations among the investigated stations under the influence of tuna farm (Fulija Islet) and out of its reach (control stations). The mucous aggregates of the benthic algae were observed during the spring and summer on the P. oceanica meadows. Shoot density of the P. oceanica meadows decrease at the stations close to the tuna farm, which confirms that the tuna farm activity strongly affects the surrounding meadows.

• Keywords: Posidonia oceanica; uzgajalište tune; otopljeni nutrijenti; organska tvar; Jadransko more
• Keywords (english): Posidonia oceanica; tuna farm; dissolved nutrients; organic matter; Adriatic Sea
• Language: croatian
• URN:NBN: urn:nbn:hr:217:906518
• Study programme: Title: Biology; specializations in: Ecology; Course: Ecology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra biologije (magistar/magistra biologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2018-04-27 10:47:43