Naslov
The relationship between resource ratios and abundance of diatoms and dinoflagellates in the river Ombla estuary (South Adriatic)

Autori
Carić, Marina ; Jasprica, Nenad

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

Izvornik
Abstract of 16th International Diatom Symposium / Economou-Amilli, Athena - Atena : The University of Athens & ISDR, 2000

Skup
16th International Diatom Symposium

Mjesto i datum
Atena, Grčka, 25.08.2000. - 01.09.2000

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
nutrients; molar ratios; phytoplankton; estuary; southern Adriatic

Sažetak
Spring of river Ombla is located on the Adriatic coast near the town of Dubrovnik and is town's most important source of potable water. The spring discharges at sea level forming a river Ombla that almost immediately flows into the sea forming a small, 4-km long, highly stratified estuary, which, together with surrounding area, bears the name of Rijeka Dubrovačka. Highly stratified estuaries are typical for the areas where a high volume of river discharge is combined with low tides. Samples for analysis of hydrographic, chemical and biological parameters were collected once a month (1999/2000) on three stations along the estuary. Molar ratios of nutrients, that are considered important regulators of phytoplankton growth, were calculated for the first time in this estuary. Resource - ratio hypothesis is most prominent prediction of Tilman´s competition theory, according to which the ratio of the limiting resources determines the taxonomic outcome of competition. According to Tilman resource is any substance or factor used by organisms for growth, including light energy. Molar ratios of Si:P, N:P, Si:N, Si:light, N:light are considered as the most important phytoplankton growth regulators while NO3:NH4 are considered as substitutable resources. All the above mentioned ratios were compared to changes in species composition to test the hypothesis that the seasonal change of phytoplankton species composition was a response to changes in ratios of resources. Rank correlation test was used for the analysis of relationship between the abundance of diatoms and dinoflagellates and resource ratios. Also, optimal resource ratios were determined for most abundant species of diatoms and dinoflagellates. During the spring, when high molar ratios of Si:P (100-130), Si:N (10-30) and N:P (20-50) were found, diatom population densities were >105 cells l-1. Diatom population densities of <103 cells l-1 were found at lower Si:P and Si:N ratios.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA