Effects of polycyclic aromatic hydrocarbons (PAHs) on an aquatic ecosystem: acute toxicity and community-level toxic impact tests of benzo[a]pyrene using lake zooplankton community.
We estimated acute toxicity of benzo[a]pyrene (B[a]P) using two cladoceran species, Ceriodaphnia reticulata and Daphnia magna, and also analyzed its impact on zooplankton community throughout an exposure experiment using small-scale mesocosms. LC(50) of B[a]P for C. reticulata and D. magna was 4.3 and 4.7 µg/l, respectively. However, individuals fed with Chlorella showed higher LC(50), 6.1 µg/l for C. reticulata and 8.0 µg/l for D. magna. In the exposure experiment, we examined the impact of B[a]P on zooplankton community using conceivable concentrations in the environment (5 and 10 µg/l) using typical zooplankton community in eutrophicated systems. Despite the residence time of B[a]P in the water column was short as < 4 days, application of B[a]P induced decrease of zooplankton abundance. However, the recovery pattern was different among cladocerans and rotifers. Consequently, B[a]P showed insecticide-like impacts, suppressing cladoceran populations and inducing the dominance of rotifers particularly under high concentration (10 µg/l). Results have suggested that, even such short duration of B[a]P in the water body can have impact on zooplankton abundance and community structure. Since B[a]P easily precipitate to the bottom and rapidly disappears from the water body, careful monitoring and further assessment of the potential toxicity of polycyclic aromatic hydrocarbons are necessary.
Laboratory of Toxicology, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan.
Yoshinori
Y
Ikenaka
Masaki
M
Sakamoto
Takamaru
T
Nagata
Hirokazu
H
Takahashi
Yuichi
Y
Miyabara
Takayuki
T
Hanazato
Mayumi
M
Ishizuka
Tomohiko
T
Isobe
Jun-Woo
JW
Kim
Kwang-Hyeon
KH
Chang
D000818:Animals; D001564:Benzo(a)pyrene / Q000633:toxicity*; D033361:Cladocera / Q000187:drug effects*; D017753:Ecosystem; D060106:Lakes; D007928:Lethal Dose 50; D023382:Toxicity Tests, Acute; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015048:Zooplankton / Q000187:drug effects*
D014874:Water Pollutants, Chemical; D001564:Benzo(a)pyrene