Distribution and ecology of endemic macroalga Fucus virsoides J.Agardh in the area of Poreč, Funtana and Vrsar

Vrsta Fucus virsoides, smeđa mediolitoralna makroalga reda Fucales, je endemska vrsta u jadranskom moru i jedina vrsta svog roda koja stvara specifični fukoidni pojas u Mediteranu. Naselja jadranskog fukusa ubrzano nestaju zbog pretjeranog antropogenog utjecaja na morsku obalu. Ciljevi ovog istraživanja bili su kartirati sva naselja na području Poreča, Funtane i Vrsara, odrediti abundanciju i morfometriju u odabranim postajama te upoznati popratnu biotu u naseljima jadranskog fukusa. Nadalje, proveo se i eksperiment kako bi se odredila brzina rasta jedinki F. virsoides u kontroliranim uvjetima. Istraživanje je pokazalo da su većina naselja na kartiranom području u veoma degradiranom stanju osim naselja na 5 odabranih postaja na kojima je određena brojnost i pokrovnost jedinki fukusa, kao i pokrovnost i frekvencija popratne biote u naselju te specifične karakteristike naselja. Prijašnja kartiranja u tom području nisu bila izvršena. Najveća i najabundantnija naselja nalazila su se na postajama AC Bijela uvala (Postaja 1) i AC Valkanela Sj. 1 i 2 (Postaje 4 i 5). U usporedbi s prijašnjim istraživanjima na području Rovinja i južne obale Istre, izgleda da su naselja fukusa na sjevernom djelu istarske obale u boljem stanju. U nadi za uspješnu zaštitu vrste F. virsoides i njenog staništa, potrebna su daljnja kartiranja i detaljnija ekološka istraživanja.Fucus virsoides, a brown intertidal macroalgae of the order Fucales, is an endemic species in the Adriatic Sea and the only belt forming fucoid species in the Mediterranean. Due to excessive anthropogenic effects on the coastline, the Adriatic Fucus settlements are experiencing a rapid decrease in numbers. The goals of this study were to map every settlement of F. virsoides in the area of Poreč, Funtana and Vrsar, to assess the abundance, morphometric characteristics in selected stations and to explore accompanying biota living in Fucus settlements. In addition, an experiment was performed to assess the growth rate of F. virsoides in controlled conditions. The study has shown that most of the settlements in the mapped area were in severely degraded conditions, except for the five selected stations in which the abundance and coverage measurements for Fucus plants were taken. Furthermore, coverage and frequency measurements for the accompanying species found in the settlement and specific settlement conditions were assessed. To this date, no previous mapping procedures were undertaken in the area. The largest and the most abundant settlements were located on stations AC Bijela uvala (Station 1), and AC Valkanela Sj.1 and 2 (Stations 4 and 5). In comparison with previous studies performed along the Rovinj and the southern Istrian coastlines, Fucus settlements appear to be in better condition in the northern areas of the Istrian peninsula. In order to achieve a successful conservation of the species and its habitat, future mapping and more detailed ecological studies of F. virsoides are required