Chronic toxicity of water tributyltin (TBT) and copper to spat of the bivalve Scrobiculaha plana: ecological implications

Abstract

Two 30 d long static toxicity tests were performed on small spat (2 to 3 mm in length) of the estuarine bivalve Scrobicularia plana (da Costa): the effects of tributyltin (TBT) and copper on the survival and burying actklty in sand of juveniles were monitored in 1991, and growth and burying activity as affected by TBT were investigated on a sample of a different cohort in 1992. Results showed that an (concentration killing 50% of the population considered) could be set for TBT at < 1.3 pg Sn 1-' (as analysed), while exposure to up to 80 pg Cu 1.' did not result in increased mortalities with respect to the controls. Every dose of TBT tested In 1991 (nominal 0.5, 1, 2 and 4 pg Sn l") irnpalred the burying activity of spat significantly from Day 6, and Cu concentrations at 20 1-19 1-' and above also increased the burying time of juveniles by the end of the experiment; the no-observed-effect concentration (NOEC) for Cu was the lowest dose tested (i.e. 10 pg I-'). In 1992 the effect of 4 lower TBT concentrations (nominal 50, 125, 250 and 500 ng Sn I-') on the juvenile burying activity was somewhat inconsistent; however, burying time of individuals exposed to 500 ng Sn I-' was always higher than that estimated to be characteristic of spat at initiation of the test. In addition, juvenile growth (weight gain) was significantly reduced by all TBT concentrations (i.e. lowest range of 12 to 43 ng Sn I-', as analysed). It is concluded that TBT has probably caused the &sappearance of some S. plana populations in the UK; similarly, organotin may have also caused the decline in S. plana abundance in populations from elsewhere in Europe.

Intersex in the clam Scrobicularia plana : a sign of endocrine disruption in estuaries?

“…However, although S. plana is obviously capable of substantial lateral migration, this may occur only rarely in nature, making clam populations susceptible to localized effects (Casagranda & Boudouresque 2005). For example, there is evidence that contaminants, including TBT (a known androgenic compound used in antifouling paints), have impacted on populations of S. plana through reductions in larval recruitment (Langston et al 1990;Ruiz et al 1994). Scrobicularia plana may, therefore, be vulnerable to the added pressure of endocrine disruption, particularly near to sources of contamination.…”

Unregulated use of TBT-based antifouling paints in Israel (eastern Mediterranean):high contamination and imposex levels in two species of marine gastropods

“…3) is thus surprising, and might result from a greater mortality of larvae as they approach the highly contaminated area, or of small juveniles after settlement. This assumption appears to be supported by evidence showing that larvae and spats of bivalves are susceptible to TBT, suffering from high mortality rates and low shell growth when exposed to the contaminant (Lapota et al 1993, Ruiz et al 1994, 1995a.…”

Ecotoxicología y alteraciones morfo-funcionales en gasterópodos marinos expuestos a contaminación por Tributilestaño (TBT) y metales

“…En moluscos, las diferencias en la tasa de crecimiento han sido relacionadas con estresores ambientales, entre ellos el TBT y metales pesados (Waldock y Thain 1983;Ruiz et al 1994;Almeida et al 1998;Tablado y López Gappa 2001;Coelho et al 2006;okołowski et al 2008;Smolarz y Bradtke 2011), mientras que los gradientes ambientales conforman una fuente de variación tal que pueden ejercer su influencia en la forma de los organismos (Caravajal- Rodríguez et al 2005;Conde-Padín et al 2007;Cuña et al 2011). Si bien estos gradientes se asocian a grandes variaciones latitudinales (Sepúlveda y Ibáñez 2012), gradientes muy marcados a una micro-escala geográfica (intermareal-submareal) pueden también ejercer influencia sobre la forma de la concha de los gasterópodos respondiendo a una variación local y destacando su capacidad de adaptación a las condiciones del medio (Palmer 1990;Nieto Vilela et al 2012).…”

“…A través de una serie de experimentos se comprobó que el TBT utilizado en las pinturas de las embarcaciones era la sustancia responsable de tales deformidades (Waldock y Thain 1983;Alzieu 1986;Alzieu et al 1986;Scammell et al 1991;Dyrynda 1992;Waldock et al 1996). En consecuencia, hoy se sabe que los compuestos orgánicos de estaño no sólo producen alteraciones en aspectos reproductivos como el desarrollo del fenómeno de imposex (Gibbs y Bryan 1987 ) e intersex en gasterópodos y bivalvos (Oehlmann et al 1998a;Chesman y Langston 2006) sino que también han resultado perjudiciales en el desarrollo de las valvas (Chagot et al 1990;Ruiz et al 1994).…”

“…El Tributilestaño (TBT) es un compuesto de alta toxicidad para organismos (Thain et al 1987;Meador 2000). El análisis de este compuesto y sus derivados se ha enfocado mayormente en los efectos crónicos, ocasionados por la exposición prolongada a concentraciones en el ambiente (Moore et al 1991;Foale 1993;Ruiz et al 1994;Pessoa et al 2001;Antizar-Ladislao 2008). En invertebrados marinos, particularmente en moluscos, la toxicidad del TBT ha sido reportada en términos de efectos subletales como el desarrollo de imposex o el engrosamiento de las valvas, en especies de gasterópodos y bivalvos de interés comercial (Eisler 1989;Ruiz et al 1995a;Horiguchi et al 1997;Horiguchi et al 1998; Bandow y Weltje 2012, entre otros).…”