Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 2

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  red tides
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
EN
This investigation focused on weekly variations in cell density and volume of the dinoflagellate Noctiluca scintillans between March 2001 and January 2004 in the Dardanelles. March-June and October-December periods were excessive bloom periods. During the bloom periods the density of N. scintillans reached 2.20 × 105 cells L-1 with a volume of 1.32 × 1012 µm3 L-1. In addition to the high surface density, there was an increase in subsurface waters during the blooms. The bloom of N. scintillans, like that of diatom and other dinoflagellate blooms, was associated not only with eutrophication, but also with stable temperatures and salinities.
EN
To evaluate the potential to control red tides using the mass-cultured heterotrophic grazer, rotifer Brachionus plicatilis, the effects of environmental factors (water temperature and salinity) on physical activities (filtration and oxygen consumption rate) of B. plicatilis were estimated. Experiments were conducted at different water temperatures (15, 20, 25, 30 and 35°C) and salinities (20, 25, 30, 35 and 40 PSU), in 25 different combinations (5 temperatures × 5 salinities). Results showed that water temperature and salinity had significant effects on the filtration rate of B. plicatilis (F=41.66, P<0.05). The results of multiple regression analysis yielded the following functional dependence of filtration rate (F) on water temperature (T) and salinity (S): F=-1.658+0.917T+0.63S (R^2=0.769, P<0.001). The highest filtration rate (4.23 š0.74 μl rot-1 h-1) was obtained at 30°C and salinity 35 PSU, and the lowest one (0.869 š0.13 μl rot-1 h-1) was observed at 15°C and salinity 20 PSU. Both water temperature and salinity had significant effects on the oxygen consumption rate of B. plicatilis (F=34.08, P<0.05). The results of multiple regression analysis yielded the following functional dependence of oxygen consumption rate (O) on water temperature (T) and salinity (S): O=-3.133+0.165T+0.81S (R2=0.938, P<0.001). The highest oxygen consumption rate (5.38 š0.66 ng rot^-1 h-1) was observed at 35°C and salinity 40 PSU, and the lowest one (1.01 š0.15 μg rot^-1 h-1) was observed at 15°C and salinity 20 PSU. Results from this present study indicated that the filtration and oxygen consumption rate of the rotifer were significantly influenced by the water temperature and salinity. The utilization of rotifer for red tide control has to consider the influence of environmental factors.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.