Page 1 - Dolphin_Tuna_Shark_1996

Arch. Environ. Contam. Toxicot. 31, 19-23 (1996) AROHIVES OF:
Environmental
Contamination
a n d Toxicology
© 1996 Springer-Verlag New York Inc.

Accumulation Pattern of Butyltin Compounds in Dolphin, Tuna, and Shark
Collected from Italian Coastal Waters

K. Kannan ~*, S. Corsolini 2, S. Focardi 2, S. Tanabe l, R. Tatsukawa l
Department of Environment Conservation, Ehime University, Tarumi 3-5-7, Matsuyama 790, Japan
2 Dipartimento di Biologia Ambientale, University of Siena, Via delle Cerchia 3, 53100 Siena, Italy

Received: 22 September 1995/Revised: 16 December 1995

P450 enzymes (e.g., phenobarbitol-inducible type) are consid-
Abstract. Tributyltin (TBT) and its breakdown products, mono-
(MBT) and dibutyltin (DBT) were determined in bottlenose dol- ered to be low in dolphins and porpoises (Tanabe et al. 1988),
phin (Tursiops truncatus), bluefin tuna (Thunnus thynnus thyn- which suggest the possibility of butyltin accumulation in ceta-
nus) and blue shark (Prionace gIauca) collected from the Italian ceans. Butyltin compounds have been shown to accumulate in
coast of the Mediterranean Sea in 1992-1993. Concentrations of finless porpoise (Neophocaena phocaenoides) collected from
total butyltin (BTs) in the liver of dolphin (1,200-2,200 ng/g wet Japanese coastal waters (Iwata et al. 1995). The objectives of this
wt) were an order of magnitude higher than in the blubber (48- study were to understand the accumulation patterns and levels of
320 ng/g wet wt). TBT was the predominant butyltin species in butyltin derivatives in higher trophic vertebrate predators such as,
the blubber while DBT accounted for an higher proportion in the bottlenose dolphin (Tursiops truncatus), bluefin tuna (Thunnus
liver of dolphins. Butyltin concentrations in bluefin tuna were thynnus thynnus) and blue shark (Prionace glauca) collected
lower than those in dolphins, with TBT highest in the muscle and from Italian coastal waters of the Mediterranean Sea.
DBT in the liver. Concentrations of BTs in blue sharks were lower Recent surveys conducted along the French, Spanish and
than those in dolphin and tuna, with kidney having the highest Italian coasts of the Mediterranean Sea revealed contamination
concentrations. TBT was the predominant form ofbutyltin deriv- by butyltin compounds with several water samples exceeding
atives in all the tissues of shark. Accumulation of butyltin com- the environmental quality standard of 2 ng TBT/L introduced
pounds in liver/kidney seems to be associated with the presence in 1987 by the UK (Gabrielides et al. 1990; Alzieu et al. 1991).
of proteins such as glutathione. Seawater, sediments and mussels collected from several Italian
and Spanish harbors along the Mediterranean coasts had consid-
erable concentrations of butyltin compounds (Caricchia et al.
1991; Tolosa et al. 1992; Cocchieri et al. 1993). Dolphins and
higher trophic level predatory fish, such as sharks and tuna,
The toxicological implications of tributyltin (TBT) compounds,
may be exposed to butyltins through their food. Although PCB
originating from antifouling paints, in estuarine and coastal wa-
contamination was considered one of the major causes for the
ters are a matter of great concern. Studies have shown that TBT
mortality of bottlenose dolphins along the Italian coasts (Corsol-
exerts toxic effects at concentrations of a few ng/L to marine
ini et al. 1995), information is lacking on the accumulation
invertebrates (Gabrielides etal. 1990; Bryan etal. 1986; Bushong
of butyltin species. In the Mediterranean region, France has
et al. 1990) and at a few ixg/L to fish (Hall and Pinkney 1985).
restricted the use of organotin antifouling paints since 1982 on
Butyltin compounds have been found in lower trophic organisms
the hulls of some boats (<25 m long) and this regulation has
including algae, mollusks, and fish, but there is little information
been adopted by the European Union since 1991 (Alzieu et al.
on the accumulation and toxic effects of TBT in higher trophic
1991). Analysis of butyltin compounds in dolphins and fish
vertebrate predators such as dolphins and sharks. TBT is bioaccu-
may provide information on the present status of contamination
mulative, with the octanol-water partition coefficients (Kow) in
by these compounds in Mediterranean coasts.
the range of 103-104 (Laughlin and Lind6n 1987). In marine ani-
mals, TBT is metabolized by microsomal cytochrome P450 en-
zyme systems (Lee 1985). The activities of certain cytochrome
Materials and Methods
Collection of Samples
* Present address: Skidaway Institute of Oceanography, 10 Ocean
Science Circle, Savannah, GA 31411, USA
Blubber (excised from mid-dorsal region of the trunk) and liver were
Correspondence to: K. Kannan
obtained from two male bottlenose dolphins (Tursiops truncatus) found