Macroalgal diversity of the coralligenous community in the Eastern Adriatic sea

Koraligenska zajednica, nakon livada morske cvjetnice posidonije, predstavlja drugu najvažniju „vruću točku“ raznolikosti vrsta u Sredozemlju. Dobila je ime po inkrustrirajućim crvenim algama iz porodice Corallinaceae koje čine koraligene nakupine. Glavne makroalge koje možemo naći u tim zajednicama su Mesophyllum lichenoides te Lithophyllum stictaeforme. Do danas su podaci o algama koraligena istočnog Jadrana posebno oskudni. Prva bionomska istraživanja Helene Gamulin-Brida 1960-tih i recentnija istraživanja u ovom stoljeću ipak stvaraju potpuniju sliku koraligenske rasprostranjenosti i bioraznolikosti u istočnom Jadranu. Glavni cilj istraživanja bio je analizirati vrste i utvrditi rasprostranjenost bentoskih algi koraligenske zajednice u istočnom dijelu Jadranskoga mora na trinaest lokaliteta i dvadeset i jednoj postaji; varijabilnost duž vertikalnog gradijenta te između istraživanih postaja kao i stanje u odnosu na potencijalni utjecaj temperaturnih promjena. U ovom istraživanju zabilježeno je 79 vrsta makroalgi s najvećom brojnosti crvenih algi. Pokazalo se da su najčešći biokonstruktori koraligena crvene alge Lithophyllum stictaeforme, L. incrustans, Mesophyllum alternans, M. lichenoides, Peyssonnelia rubra, P. squamaria i P. polymorpha. Varijabilnost u strukturi makroalgalne zajednice značajna je između postaja. Najveća sličnost na temelju vrsta algi je između postaja NP Mljet. Pliće i dublje zajednice se ne razlikuju puno po vrstama algi. Na 40 m dubine najviše su zastupljene Cladophora sp., Mesophyllum alternans, Lithophyllum incrustans, te Peyssonnelia rubra dok su na 20 m dubine prisutne iste vrste, ali umjesto alge Peyssonnelia rubra česta je P. squamaria. U ovom istraživanju unutar fotografiranih kvadrata uočena su i oštećenja koralinskih algi koje bi mogle biti posljedica globalnih klimatskih promjena. Prikupljeni podaci koristit će se za daljnja istraživanja i monitoring koraligenske biocenoze istočnog Jadrana.The coralligenous community represents the second most important hot spot in the Mediterranean after the seagrass meadows of Posidonia oceanica. The coralligenous biocenosis got its name after encrusting red algae from the family Corallinaceae that build up coralligenous concretions. The main building algal species are Mesophyllum lichenoides and Lithophyllum stictaeforme. Until today information on the coralligenous algae in the eastern Adriatic Sea has been scarce. Helena Gamulin Brida conducted the first bionomical studies in the 1960s and together with more recent studies during the last century there is now more information about the distribution and biodiversity of the coralligenous in the eastern Adriatic. The main objective of this study was to make a list of benthic algae and determine their distribution in the coralligenous in 21 locations of the eastern Adriatic; to determine the variability among these locations and the vertical gradient; as well as to determine the condition of the coralligenous in relation to the possible effects of climate change. Of the 79 identified species of macroalgae, red algae were found to be the most frequent. The most common bioconstructors of the coralligenous in the eastern Adriatic were red algae: Lithophyllum stictaeforme, L. incrustans, Mesophyllum alternans, M. lichenoides, Peyssonnelia rubra, P. squamaria and P. polymorpha. Variability in the structure of macroalgae was significant among the investigated locations. The biggest similarity regarding algal species was found among the locations in the Mljet National Park. Shallower and deeper communities did not differ much based on algal species. The most common algae at 40 meters of depth were Cladophora sp., Mesophyllum alternans, Lithophyllum incrustans and Peyssonnelia rubra while at 20 meters the most common were all the algae found at 40 meters except of P. squamaria was found instead of P. rubra. From the investigated photographed quadrats of this study, diseases of coralline algae were also noticed, which could be indicative of the effects of global climate change. The results of this study will be used for further research and monitoring of the coralligenous community in the eastern Adriatic Sea