Naslov
Distribution of Cyanobacteria in highly stratified estuary (The Zrmanja estuary, Croatia)

Autori
Čalić, Marijeta ; Viličić, Damir ; Jasprica, Nenad ; Carić, Marina ; Ćolić, Svjetlana B. ; Burić, Zrinka ; Terzić, Senka

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
The book of abstracts of the 1st Tropical and Subtropical Cyanoprokaryota Workshop / Quintana, M. Antera ; Onis, S. Emilio - Las Palmas : Banco Nacional de Algas, 2005

Skup
Tropical and Subtropical Cyanoprokaryota Workshop (1 ; 2005)

Mjesto i datum
Las Palmas de Gran Canaria, Španjolska, 11.07.2005. - 15.07.2005

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
highly stratified estuary; cyanobacteria; Zrmanja

Sažetak
Cyanobacteria, nano- and microphytoplankton abundance, and pigment analysis were determined in relation to hydrographic conditions in the highly stratified, karstic Zrmanja Estuary, eastern Adriatic coast. Water samples were collected at seven stations along the thermohaline gradient during June 2002. Cyanobacteria were counted using epifluorescence microscope, while nano- and microphytoplankton cells were counted using inverted microscope. Pigment concentrations were determined by HPLC method. Salinity and temperature were determined using a conductivity, temperature and depth profiler, while chemical parameters were determined using standard oceanographic methods. Maximum abundance and biomass of cyanobacteria were detected in the area where marine influences decrease. The observations performed by epifluorescence microscopy mostly showed the presence of class Chroococcales which are distributed in plankton community in both environments, freshwater and marine. During this case study, the maximum cyanobacteria abundance (1.8 x 104 cells mL-1) was detected in the brackish environment of the upper estuary. Cyanobacteria abundances were much lower in the lower estuary, where salinity was increased. In the middle, wider part of the estuary the green flagellates were abundant (2.5 x 105 cells L-1). Phytoplankton pigments are increasingly used as markers of phytoplankton groups. Cyanobacteria are characterized by pigment zeaxanthin although chlorophytes and prasinophytes also contain a small amount of this pigment. Lutein is another pigment which is typical for chlorophytes. Using HPLC methodology is difficult to separate difficult carotenoid pairs such as lutein and zeaxanthin. In this study, increased zeaxanthin/lutein concentrations were attributed to cyanobacteria but not to green flagellates in the estuary. Chlorophyll a concentrations well agree with microphytoplankton and nanophytoplankton abundance pattern.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

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