Assessment of tributyltin contamination based on imposex in Stramonita rustica (Mollusca: Gastropoda) along southern Bahia coast, northeastern Brazil / Avaliação da contaminação por tributil-estanho baseada em imposex em Stramonita rustica (Mollusca: Gastropoda) ao longo do Litoral Sul da Bahia

Abstract This study investigated the effects of tributyltin (TBT) on the morphology of the genital system of the gastropod Stramonita rustica in southern Bahia, Brazil. For this, 330 specimens were collected during the summer of 2014 at eight sampling points to ascertain whether male sex organs had developed in addition to the complete female genital tract in females (= imposex). The analyses were made under a stereoscopic microscope. Imposex and their associated indexes, and the sterile females, exhibited the highest rates in harbors and shipyards areas. Despite the total ban of TBT in anti-fouling paints on a global scale since 2003, the results of this and other studies indicate the continued use of those paints on the Brazilian coast. This shows the inefficiency of existing legislation and the need to strengthen enforcement of the ban.

Resumo Este estudo investigou os efeitos de tributil-estanho (TBT) sobre a morfologia do sistema genital do gastrópode Stramonita rustica (Lamarck, 1822) no Litoral Sul da Bahia, Brasil. Para isso, 330 espécimens foram coletados durante o verão de 2014 em oito pontos de amostragem, para verificar se os órgãos sexuais masculinos tinham se desenvolvido para além do trato genital feminino completo (= imposex). As análises foram feitas sob um microscópio estereoscópico. O imposex e seus índices associados, assim como as fêmeas estéreis, apresentaram as maiores taxas em áreas portuárias e estaleiros. Apesar da proibição total do TBT em tintas anti-incrustantes em escala global desde 2003, os resultados deste e de outros estudos indicam a continuidade de uso dessas tintas na costa brasileira. Isso mostra a ineficácia da legislação vigente e reforça a necessidade de se cumprir integralmente o banimento.

Imposex en Voluta musica (Caenogastropoda: Volutidae) en el Noreste de la Península de Araya, Venezuela / Imposex in Voluta musica (Caenogastropoda: Volutidae) from Northeastern Península de Araya, Venezuela

Voluta musica is a dioecious marine gastropod endemic of the South Caribbean. Tributyltin (TBT) and copper (Cu) are potential inducers of imposex, an endocrine disorder by which females develop a penis and/or vas deferens. The goal of this work was to determine the imposex incidence in V. musica populations from Northeastern Península de Araya. For this, we selected three sites (Isla Caribe, Isla Lobos and Bajo Cuspe) and made monthly samplings of 15 snails in each site, during one year, and determined: (1) sizes; (2) sex and imposex incidence and (3) the Relative Penis Length Index (RPLI). We also performed histological analysis of the gonads, and measured TBT and Cu concentrations in sediments from the studied localities. Our results showed that the total number of sampled females affected by imposex was 24.5% at Isla Caribe, 12% at Isla Lobos, and none at Bajo Cuspe. In sediments, Cu was detected mostly in Isla Lobos. The female gonads with imposex did not show any development of male cells in any of the sampled sites. The higher percentage of females with imposex matched with the higher boat traffic locality, and higher TBT level (Isla Caribe). No esterilization was evident in this work, nevertheless, the presence of TBT and Cu in the sediments and females with imposex were considered as a potential threat to V. musica populations in this region. In Venezuela there is no control over this particular issue, possibly because of the lack of information and research in this topic, but certainly, this information will be useful in biodiversity conservation policies.

Voluta musica es un gasterópodo dioico endémico del Caribe sur. El TBT y el Cu, son potenciales causantes del imposex, fenómeno donde las hembras desarrollan un pene y/o vaso deferente. El objetivo fue determinar la incidencia de imposex en V. musica en el noreste de la Península de Araya. Se seleccionaron tres localidades y se captura-ron mensualmente 15 individuos durante un año para determinar: (1) talla de los individuos; (2) sexo y presencia de imposex; (3) índice Largo Relativo del Pene (RPLI). Se realizó histología de la gónada de los individuos. Se determinó TBT y Cu en el sedimento de cada localidad. En Isla Caribe, el 24.5% de las hembras presentó imposex, y se halló 3.9ngSn/g de TBT; en Isla Lobos, el 12% de las hembras desarrollaron imposex; en Bajo del Cuspe no se observó imposex. Se halló Cu en mayor concentración en Isla Lobos. Las gónadas femeninas con imposex no demos-traron masculinización. El mayor porcentaje de imposex coincide con la localidad de mayor tráfico de embarcacio-nes y con mayor nivel de TBT (Isla Caribe). No se eviden-ció esterilización, sin embargo la presencia de TBT, Cu e imposex son potenciales amenazas para las poblaciones de V. musica en la región. Hasta ahora, en Venezuela no se está tomando ninguna medida de control sobre este tema en particular, posiblemente por la escasez de información y orientación de las investigaciones hacia este tema, pero que sin duda se debería tomar en cuenta en las políticas para la conservación de la biodiversidad.

Triorganotin as a compound with potential reproductive toxicity in mammals

Organotin compounds are typical environmental contaminants and suspected endocrine-disrupting substances, which cause irreversible sexual abnormality in female mollusks, called "imposex". However, little is known about the capability of triorganotin compounds, such as tributyltin and triphenyltin, to cause disorders in the sexual development and reproductive functions of mammals, including humans and rodents. Moreover, these compounds can act as potential competitive inhibitors of aromatase enzyme and other steroidogenic enzymes, affecting the reproductive capacity of male and female mammals. In this review, we discuss the cellular, biochemical, and molecular mechanisms by which triorganotin compounds induce adverse effects in the mammalian reproductive function.

Effects of tributyl-tin on a marine microalga, Tetraselimis suecica.

Marine pollutants induce changes in microalgal metabolism. In this study effects of tributyl-tin chloride (TBTCl) on a marine microalga Tetraselmis suecica was studied. The changes induced by TBTCI on growth rate, viability and biochemicals were assessed. In acute exposure to TBTCl, EC50 estimated for 24 hr was 2.02 microg ml(-1), whereas total lethality was observed at 4 microg ml(-1). In chronic exposure to TBTCl, at higher concentrations (0.5-1 microg ml(-1)) growth rate, chlorophyll pigments, carbohydrate and protein contents were reduced. The results of this study indicate that TBTCl toxicity made drastic changes in growth and biochemical composition of T. suecica.

Fouling coverage of a green tide alga, Ulva pertusa on some antifouling test surfaces exposed to Ayagin harbor waters, east coast of South Korea.

Toxic antifouling chemicals released into the seawaters leads to marine environmental degradation. In order to identify a nontoxic antifoulant, an assessment of antifouling (AF) efficacy of some AF candidates was made at Ayagin harbor, east coast of South Korea. In this static panel study conducted during October 2000-March 2001, some commercial antifoulants, seaweed and seagrass extracts were screened. On panel surfaces coated with a seaweed extract, Ishige okamurae exhibited effective AF activity. Ulva pertusa was encountered as a 'monospecific' fouler with fairly high fouling coverage on many of the test panel surfaces. In recent years the increased influx of inorganic pollutants in the coastal waters causes exorbitant growth of fouling marine algae found all along the Korean peninsula. Especially, a cosmopolitan ship fouling alga U. pertusa occur with high abundance. It was largely suggested that the proposed international ban on the toxic antifoulant tributyltin (TBT) had significant effect on the 'green tide' phenomenon occurring in different parts of the world. However, it appears that Korean scenario of 'green tide' is a localized. Antifouling efficacy of some AF coatings and fouling coverage of a green tide alga, U. pertusa are discussed.

Interaction of EDTA with tributyltin induced cellular toxicity.

Tributyltin inhibited the growth of cells in concentration dependent manner. The inhibitory effect of tributyltin on E. coli was enhanced in the presence of metal ion chelator, EDTA. This was due to EDTA induced increase of permeability of bacterial cell envelope to tributyltin. In case of EDTA treated cells the rate of uptake of tributyltin was more pronounced as compared to control.

The effect of controlled release copper sulfate and tributyltin fluoride on the mortality and infectivity of Schistosoma mansoni miracidia.

The experiments were conducted to assess the effect of sublethal concentration of controlled release copper sulfate (EC-8) and tribultyltin fluoride (CBL-9B) on the mortality and infectivity of Schistosoma mansoni miracidia. It was found that LC50 and LC90 of EC-8 to the miracidia were 8.5 mg/l per hr and 15.75 mg/l per hr respectively. For CBL-9B, LC50 was 19.75 microgram/l per hr and LC90 was 32.0 microgram/l per hr. Exposing of the miracidia to 0.5 mg/l of EC-8 or 4.0 microgram/l of CBL-9B respectively, for only one hour can prevent their transmission to the snail host. The results indicate that immobilization of the free living stages of the schistosome parasite was not required to interrupt their transmission to the next hosts.