INVESTIGADORES
FERREYRA Gustavo Adolfo
artículos
Título:
TBT toxicity on a natural planktonic assemblage exposed to enhanced ultraviolet-B radiation
Autor/es:
SARGIAN, P., É. PELLETIER, B. MOSTAJIR, G.A. FERREYRA AND S. DEMERS
Revista:
AQUATIC TOXICOLOGY
Editorial:
Elsevier
Referencias:
Año: 2005 vol. 73 p. 299 - 314
ISSN:
0166-445X
Resumen:
Amicrocosm approachwas designed to study the combined effects of tributyltin (TBT) from antifouling paints and ultraviolet-
B radiation (UVBR: 280320 nm), on a natural planktonic assemblage (<150m) isolated from the St. Lawrence Estuary at the
end of the springtime. Microcosms (9 l, cylindrical Teflon® bags, 75 cm height×25 cm width) were immersed in thewater column
of mesocosms (1800 l, polyethylene bags, 2.3m depth) and exposed to two different UVBR regimes: natural ambient UVBR
(NUVBR), and enhanced level of UVBR (HUVBR). During consecutive 5 days, effects of TBT (120 ng l−1) and enhanced
UVBR (giving a biologically weighted UVBR 2.15-fold higher than natural light condition) were monitored in the samples
coming from following treatments: (i) NUVBR light condition without TBT (NUVBR), (ii) NUVBR light condition with TBTadded
(NUVBR + TBT), (iii) HUVBR light condition without TBT (HUVBR) and (iv) HUVBR light condition with TBT-added
(HUVBR + TBT). Each treatment was conducted in triplicate microcosms. Different parameters were then measured during
5 days, including TBT analysis, bacterial abundance and productivity, phytoplankton abundance, cellular characteristics and
growth rates, as well as in vivo chlorophyll a (Chl a) fluorescence. Following TBT addition (NUVBR + TBT treatment), Chl am) isolated from the St. Lawrence Estuary at the
end of the springtime. Microcosms (9 l, cylindrical Teflon® bags, 75 cm height×25 cm width) were immersed in thewater column
of mesocosms (1800 l, polyethylene bags, 2.3m depth) and exposed to two different UVBR regimes: natural ambient UVBR
(NUVBR), and enhanced level of UVBR (HUVBR). During consecutive 5 days, effects of TBT (120 ng l−1) and enhanced
UVBR (giving a biologically weighted UVBR 2.15-fold higher than natural light condition) were monitored in the samples
coming from following treatments: (i) NUVBR light condition without TBT (NUVBR), (ii) NUVBR light condition with TBTadded
(NUVBR + TBT), (iii) HUVBR light condition without TBT (HUVBR) and (iv) HUVBR light condition with TBT-added
(HUVBR + TBT). Each treatment was conducted in triplicate microcosms. Different parameters were then measured during
5 days, including TBT analysis, bacterial abundance and productivity, phytoplankton abundance, cellular characteristics and
growth rates, as well as in vivo chlorophyll a (Chl a) fluorescence. Following TBT addition (NUVBR + TBT treatment), Chl a® bags, 75 cm height×25 cm width) were immersed in thewater column
of mesocosms (1800 l, polyethylene bags, 2.3m depth) and exposed to two different UVBR regimes: natural ambient UVBR
(NUVBR), and enhanced level of UVBR (HUVBR). During consecutive 5 days, effects of TBT (120 ng l−1) and enhanced
UVBR (giving a biologically weighted UVBR 2.15-fold higher than natural light condition) were monitored in the samples
coming from following treatments: (i) NUVBR light condition without TBT (NUVBR), (ii) NUVBR light condition with TBTadded
(NUVBR + TBT), (iii) HUVBR light condition without TBT (HUVBR) and (iv) HUVBR light condition with TBT-added
(HUVBR + TBT). Each treatment was conducted in triplicate microcosms. Different parameters were then measured during
5 days, including TBT analysis, bacterial abundance and productivity, phytoplankton abundance, cellular characteristics and
growth rates, as well as in vivo chlorophyll a (Chl a) fluorescence. Following TBT addition (NUVBR + TBT treatment), Chl a−1) and enhanced
UVBR (giving a biologically weighted UVBR 2.15-fold higher than natural light condition) were monitored in the samples
coming from following treatments: (i) NUVBR light condition without TBT (NUVBR), (ii) NUVBR light condition with TBTadded
(NUVBR + TBT), (iii) HUVBR light condition without TBT (HUVBR) and (iv) HUVBR light condition with TBT-added
(HUVBR + TBT). Each treatment was conducted in triplicate microcosms. Different parameters were then measured during
5 days, including TBT analysis, bacterial abundance and productivity, phytoplankton abundance, cellular characteristics and
growth rates, as well as in vivo chlorophyll a (Chl a) fluorescence. Following TBT addition (NUVBR + TBT treatment), Chl aa (Chl a) fluorescence. Following TBT addition (NUVBR + TBT treatment), Chl a
concentrations never exceeded 1g l−1 whereas final values as high as 54 g l−1 were observed in TBT-free treatments (NUVBR
and HUVBR). TBT addition resulted also in the lost of fluorescence signal of the maximum efficiency of the photosystem II
in phytoplankton assemblage. TBT toxicity caused on phytoplankton <20 m an increase of mean cell size and changes in
shape reflected a drastic disturbance of the cell cycle leading to an inhibition of the apparent growth rate. These negative effects
of TBT resulted in a final abundance of phytoplankton <20m of 591±35 cells ml−1 in NUVBR+ TBT relative to NUVBRg l−1 whereas final values as high as 54 g l−1 were observed in TBT-free treatments (NUVBR
and HUVBR). TBT addition resulted also in the lost of fluorescence signal of the maximum efficiency of the photosystem II
in phytoplankton assemblage. TBT toxicity caused on phytoplankton <20 m an increase of mean cell size and changes in
shape reflected a drastic disturbance of the cell cycle leading to an inhibition of the apparent growth rate. These negative effects
of TBT resulted in a final abundance of phytoplankton <20m of 591±35 cells ml−1 in NUVBR+ TBT relative to NUVBRm an increase of mean cell size and changes in
shape reflected a drastic disturbance of the cell cycle leading to an inhibition of the apparent growth rate. These negative effects
of TBT resulted in a final abundance of phytoplankton <20m of 591±35 cells ml−1 in NUVBR+ TBT relative to NUVBRm of 591±35 cells ml−1 in NUVBR+ TBT relative to NUVBR