Naslov
Freshwater phytoplankton bloom in Visovac lake: a possible cause of benthic mortality in the Krka estuary (Adriatic Sea, Croatia)

Autori
Petricioli, Donat ; Bakran-Petricioli, Tatjana ; Viličić, Damir ; Požar-Domac, Antonieta

Izvornik
Marine ecology: pubblicazioni della stazione zoologica di Napoli I (0173-9565) 17 (1996), 1-3; 373-382

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
stratified estuary; phytoplankton bloom; anoxia; benthic mortality; Adriatic sea

Sažetak
In the late summer and early autumn of 1989 benthic mortality in the upper part of Krka estuary extended from the Skradinski buk waterfalls to approximately 5 km downstream. Dead benthic organisms were found on the bottom at depths of up to 4-5 m. During August, a freshwater phytoplankton bloom was recorded in Visovac lake (which supplies the Skradinski buk waterfalls). The green tide in the lake was composed of up to 11.9 million cells per litre, predominantly of Synedra acus and Dinobryon sertularia. At that time the maximal total inflow of phytoplankton cells through the waterfalls was approx. 0.41 per sec. (38000 l per day(. Cells of these two species died after reaching the salt wedge and the cummulative effect of their decomposition apparently caused an oxygen demand sufficient enough to trigger the benthic mortality. Due to the water mass dynamics, the spreading of mortality downstream was slow (from August to October, approx. 5 km). Certain benthic fishes (like Gobius sp.) were observed on the bottom of the affected area in mid-October 1989.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

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