Naslov
The effect of nutrient limitation and metal toxicity for the growth of marine diatom Phaeodactylum tricornutum Bohlin: microplate bioassay

Autori
Peršić, Vesna ; Vukić Lušić, Darija ; Horvatić, Janja

Vrsta, podvrsta i kategorija rada
Poglavlja u knjigama, znanstveni

Knjiga
Marine Phytoplankton

Urednik/ci
Kersey, William T. ; Munger, Samuel P.

Izdavač
Nova Science Publishers

Godina
2009

Raspon stranica
145-169

ISBN
978-1-60741-087-4

Ključne riječi
TRIX, nutrient limitation, metal toxicity, Phaeodactylum tricornutum , Rijeka Bay

Sažetak
In this chapter we consider the trophic state and ambient nutrient limitation by the trophic index (TRIX) calculation and nutrient enrichment bioassay using the unicellular marine diatom Phaeodactylum tricornutum at two differently eutrophicated NE coastal Adriatic locations (in the Rijeka Bay area). The first location in Rijeka Port had significantly higher concentrations of dissolved inorganic nutrients and TRIX indices (up to 7.53) than the location near the Shipbuilding Industry “3 Maj”. The DIN/TP ratios in the seawater at Rijeka Port were lower (11.03 to 44.47) than those at the Shipbuilding Industry “3 Maj” (11.65-73.91), indicating P limitation in Shipbuilding Industry waters. The nutrient enrichment bioassays revealed P as the key limiting nutrient for the diatom growth at both sites. In addition, silica and nitrogen limitation was found in all water samples with the exception of the surface water samples in Rijeka Port. To determine the toxicity of metals (Ni2+, Co2+, Zn2+, Cd2+ and Hg2+), algal growth inhibition test was carried out with the unicellular marine diatom Phaeodactylum tricornutum. The basic design of toxicity test followed the International Standard ISO 10253 marine algal growth inhibition test and was modified for microplates. The following order of toxicity was achieved: Hg>Cd>Ni>Co>Zn in the exponential phase of growth, and Hg>Ni>Co>Zn>Cd in the stationary phase of growth, with mercury as the most toxic metal. The total metal concentration is not the only factor that controls the level of metal toxicity in aquatic environments. Physical and chemical characteristics of water including hardness, pH, salinity, redox potential, dissolved organic matter and nutrients also affect the extent of metal bioavailability and thus the level of toxicity. Therefore, this chapter presents the results of the effect of Pb concentrations on the P. tricornutum growth rate in conditions of different nutrient limitation. The results of standard toxicity tests in synthetic sea water and toxicity test in natural sea water samples from the Rijeka Bay show that standard toxicity tests can underestimate metal toxicity. Also, tested metal was more toxic for the growth of marine diatom in nutrient limited conditions (N, P and Si limitation). Besides providing screening toxicity profiles this method can be useful in determining the effects of pollutants on cell growth and viability of organisms. Establishing the maximum tolerance levels for organisms, this method can be used for evaluating the potential impact of pollution on aquatic system.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA