| Summary: | 碩士 === 國立東華大學 === 海洋生物多樣性及演化研究所 === 101 === Planktonic organisms play an important role in driving the fate of persistent
organic pollutants (POPs) in the marine environment. As a first step in the aquatic
food web, plankton is a key to bring POPs from the aquatic environment into the food
web. The objectives of this study are (i) to investigate the bioaccumulation of
polycyclic aromatic hydrocabons (PAHs) in rotifer (Briachionus sp.), (ii) to compare
the sorption and accumulation kinetics of PAHs in rotifer by diffusive uptake, feeding
on phytoplankton, and both, and (iii) to discuss the relationship between
bioconcentration factor (BCF),bioaccumulation factor (BAF), and octanol-water
partition coeffient (Kow).This study includes three experiments. First, use gas-purging
system to maintain constant dissolved PAH levels in the reactor and carry on sorption
experiment. Second, feed rotifer on contaminated Nannochlorpsis oculata (as the
ingestion experiment). Third, we maintain constant dissolved PAH levels in the
reactor and feed rotifer on contaminated Nannochlorpsis oculata for the mixing
experiment. For each experiment, we sampled every 24 hours to analysis PAHs
concentration and biology condition for 120 hours. This study shows that the
adsorption of four PAHs on rotifer approaches to saturation after 72 hours.
Furthermore, there is no obvious biomagnification in transfer from phytoplankton to
rotifer. Lastly, the passive uptake instead of active ingestion dominates the
accumulation of PAHs in rotifer. Distribution of BCF and BAF of PAHs are correlated
with their hydrophobicities ( Kow values). The knowledge of the PAHs accumulation
in rotifer through sorption and ingestion opens a door to future understanding of the
biogeochemical exchanges of PAHs in field primary food webs.
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