Tez özetleri Astronomi ve Uzay Bilimleri Anabilim Dalı

The İnvestigation of the Effects of Nutrients on The Growth of Prorocentum Micans and Skeletonema Costatum

Phytoplankters, which provide the primary production in marine and freshwater ecosystems are considered to be the most important members of the ecosystem. Members of this group are in a need of different ecological conditions to grow and reproduce. Therefore is the examination of physical and chemical parameters effecting algal evolution has a great importance. It is needed to determine in which concentrations (most important part of these parameters) exist nutrients in water, and to identify their relationship to the species.

In this study, it is to be aimed to expose how nutrients are effecting the growth of a choosen dinoflagellat (Prorocentrum micans) and a diatom (Skeletonema costatum).

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n this study, two different strains of both species were used. Wherase two of these strains consist of the species brought from the Marine Laboratory of Dunnstafnage, the other two same species were isolated from the Izmit Bay. The isolated species had been cultured and their continuity was provided. In the next stage, bioexperiments were made with the species, through various N/P ratios, in environments where nutrients like nitrogen and phosphorus were limited. Due to fluorescent intensities measurements, cell counting, pH measurments, measurements of nutrients like nitrogen, phosphorus and silica and chlorophyll a determination made in bioexperiments it had been achieved some results. It had been proven that P. micans species prefered nitrogen and the S. costatum prefered phosphorous as primary nutrients. However, high values of S. costatum cells were observed N/P ratios with low amounts of phosphorus. As the reason of this situation, it has been shown that silica is one of the primary nutrients which the diatom S. costatum prefers. Furthermore, due to the statistic tests that had been made, it was found out that the most appropriate environment for both species to live and to reach the maximum reproduction is a phosphorus limited environment of N/P ratio 73.