Search

Organotin compounds are causing deterioration effect on non-targeted aquatic species in the environment, such as shell anomalies in oysters and imposex in gastropods, even at concentrations as low ...

The marine gastropod Buccinanops globulosus is known to have high imposex incidence in areas moderately polluted by tributyltin (TBT). Acute toxicity was previously studied in adults but no information is known about embryonic intracapsular development. To estimate the potential effects of organotin pollution on the progeny of B. globulosus, acute toxicity tests were conducted on encapsulated and excapsulated pre-hatching embryos. The lethal median concentration estimated for 96 h (LC50 96 h) in B. globulosus excapsulated embryos was 196.70 µg TBTCl L−1, while in encapsulated embryos it was 2951.28 µg TBTCl L−1. The LC50 96 h was 15-fold higher for encapsulated embryos compared to excapsulated embryos, denoting egg capsule protection against pollutants from the external environment. Our results show that TBT pollution can have significant effects in molluscs other than the chronic effect of imposex. Fil: Averbuj, Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina Fil: Primost, Monica Angelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina Fil: Giulianelli, Sebastian Jesus. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina Fil: Bigatti, Gregorio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina. Universidad Nacional de la Patagonia. Facultad de Ciencias Naturales. Sede Puerto Madryn; Argentina

Both field and experimental data examined the influence of exposure to environmental contaminant tributyltin (TBT) on marine organisms. Although most attention focused on the imposex phenomenon in gastropods, adverse effects were also observed in other taxonomic groups. It has been shown that imposex induction involves modulation of retinoid signaling in gastropods. Whether TBT influences similar pathways in fish is yet to be addressed. In this study, larvae of the model teleost Danio rerio were exposed to natural retinoids, all-trans-retinoic acid, 9-cis-retinoic acid, and all-trans-retinol, as well as to the RXR synthetic pan-agonist methoprene acid (MA) and to TBT. Larvae were exposed to TBT from 5 days post fertilization (dpf) to adulthood, and reproductive capacity was assessed and correlated with mode of action. TBT significantly decreased fecundity at environmentally relevant levels at 1 μg TBT Sn/g in diet. Interestingly, in contrast to previous reports, TBT altered zebrafish sex ratio toward females, whereas MA exposure biased sex toward males. Since fecundity was significantly altered in the TBT-exposed group with up to 62% decrease, the potentially affected pathways were investigated. Significant downregulation was observed in brain mRNA levels of aromatase b (CYP19a1b) in females and peroxisome proliferator activated receptor gamma (PPARg) in both males and females, suggesting an involvement of these pathways in reproductive impairment associated with TBT.

Imposex was quantified in Stramonita haemastoma from the Bizerta Channel during a one-year study period and the effect of gastropod size and shell fouling by epibiotic barnacles investigated. Butyltin concentrations (tributyltin (TBT) and its derivatives di- and mono-butyltin) were also investigated in the soft tissue of the gastropods to depict temporal trends in pollution. Kelibia Beach was chosen as a reference site (not polluted by organotin) to depict whether barnacle fouling could intervene in imposex development. Imposex incidence in the Bizerta Channel was greater in females fouled by epibiotic barnacles compared to non-fouled females. Considering the size of the gastropods, large females (fouled and non-fouled) always exhibit higher imposex indices than smaller females. The concentrations of organotin compounds were found to be similar in the studied species, independent of sex or fouling condition. For Kelibia Beach, no imposex was recorded in fouled and non-fouled snails, while butyltin...

Tributyltin exposure is the primary cause of imposex development in gastropods, making them excellent bioindicators. The present research represents the first examination of butyltin (BT) contamination in surface sediments associated with imposex in Leucozonia nassa and L. ocellata in a harbour complex area in Espirito Santo, southeastern Brazil. The objectives of this study were to evaluate the organotin pollution in the area and to assess the sensitivity of both species to BT pollution through imposex development. Specimens were collected between 2007 and 2010 and the sediments were sampled in 2007. Imposex intensity was evaluated based on the percentage of imposexed females, the relative penis length index (RPLI) and the average value of the vas deferens sequence index (VDSI). BTs were analysed using gas chromatography equipped with a pulsed flame photometric detector (PFPD). The results demonstrated the occurrence of elevated concentrations of BTs in the sediment ranging from 383.7 to 7172.9 n...

Imposex and butyltin body burden were assessed in 2011 along the Basque coast (northern Spain) in two gastropod species (Nassarius reticulatus and Nassarius nitidus) four years after an initial survey in 2007. The aim of this re-survey was to monitor the effectiveness of the European ban on the use of tributyltin (TBT) based antifouling paints on ships’ hulls (EC 782/2003). Imposex levels in 2011 were lower than those determined in 2007 at most of the sampling sites. Accordingly, TBT concentrations in the female body burden of Nassarius reticulatus varied from 43 to 250 ng Sn/g in dry weight in 2011, which was a lower maximum than in 2007. Nevertheless, the results for the butyltin degradation index suggest that there have been recent inputs of TBT within the two main Basque harbours. Overall, the legislative measure is contributing to the reduction of TBT effects on the Basque coast although its presence is still evident.

The use of antifouling paints in shipbuilding has led to a significant concentration of organotin compounds in the marine environment. Antifouling paints have become the main source of tributyltin and triphenyltin derivatives loaded into the sea. The toxicity of organotin compounds has been of great concern. High concentrations of organotin compounds are associated with growth abnormalities in mussels and oysters and have also resulted to the decline in their abundance. High concentration of organotin compounds have also been found in the tissues of marine mammals and its presence has been linked to mass mortalities of marine mammals. It causes imposex and calcification anomalities in mollusks. Seafood is thought to be a possible source of organotin compounds in human. Therefore, to evaluate the environmental distribution and fate of these compounds and to determine the effectives of legal provisions adopted by a number of countries, a variety of analytical methods have been developed for the speciation of organotin compounds in the environment. A detailed review of the toxicity and chemical speciation of organotin compounds is given.

Cases of imposex have been reported for some organisms living in areas of the Argentine Atlantic coast. Since this is one of the known effects of the anti-fouling agent tributyltin (TBT), quantitative determinations of organotins in samples of water and sediments collected from sites along the Argentine coast were carried out. Severe cases of imposex were first reported for two gastropod species living in the Mar del Plata area, and determinations of TBT in samples collected from this site gave extremely high values and showed a close correlation between the degree of imposex and TBT concentration. Recent investigations in the area have shown a significant decrease. Surveys were also conducted in sites that exhibit highly irregular coastal profiles to examine the relevance of physical environments. Alarming concentrations of TBT were determined in most of the sites where heavy boat traffic and/or marine activities occur, demonstrating the urgent need for regulations to avoid further input of TBT. Reports from other sites in South America reveal that this should be a subject of regional concern in order to avoid severe damage to the biodiversity of regional marine organisms. Fil: De Waisbaum, R. G.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Orgánica; Argentina Fil: Rodriguez, Cristian Ramon. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Sbarbati, Norma Ethel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Imposex and butyltin concentrations were assessed in Hexaplex trunculus, Conus mediterraneus, Cyclope neritea and Nassarius mutabilis from Menzel Jemil, and H. trunculus and Stramonita haemastoma from the Bizerta channel. All females of the five species exhibited the characteristic development of male sex organs (penis and/or vas deferens). In Menzel Jemil, H. trunculus and C. mediterraneus exhibit similar imposex levels and were most affected (VDS reading 3-4). The development of a bud penis or a vas deferens sequence behind the right ocular tentacle was reported in Cyclope neritea and N. mutabilis (VDS 1). The concentration of tributyltin (TBT) was similar for the four species. The monobutyltin (MBT) was only detected in C. mediterraneus while the dibutyltin (DBT) was found in all gastropods at similar proportions as TBT. In the Bizerta channel, imposex levels were similar in both H. trunculus and S. haemastoma but imposex degree was higher in H. trunculus. This finding was confirmed by higher TBT concentration recorded in female of H. trunculus. These results suggested that H. trunculus is the more suitable bioindicator for monitoring TBT pollution.

Inter- and intra-population variation in the toxicity of the antifouling biocide copper pyrithione (CuPT) was examined for nauplius larvae of the barnacle Balanus amphitrite. Nauplii were collected from brooding adults from four sites within the Newport River estuary (NC), chosen based on an initial estimation of recent and historical human activities that affect local contamination levels. Each site was characterized for the presence of polycyclic aromatic hydrocarbons and for the frequency of gastropod imposex, an indicator of contamination by organotins. Sensitivity of nauplii to CuPT varied significantly across the sites/populations, with LC(50) values ranging from 4.0 microg l(-1) to 6.1 microg l(-1). Larvae from the most contaminated site were the most sensitive to CuPT. Intrapopulation variation in toxicity was investigated by exposing nauplius larvae from 15 maternal families to a fixed concentration of CuPT (6.1 microg l(-1)). Variation in larval mortality among the families was significant, ranging from 15.1% to 98.9%.

The effects of imposex and parasite infection on the reproductive cycle of Neptunea arthritica as well as sexual maturity size were examined from April 2003 to August 2004 in Saroma Lagoon, Hokkaido, Japan. Samples were sexed and divided into two groups (normal and abnormal), based on the degree of imposex and parasite infection. In normal whelks, males reached sexual maturity at a smaller size (60 mm in shell length) than females (75 mm). Normal whelks copulated from March to August, with a peak between May and July, and spawned from May to August, with a peak in June–July. In all groups, the female ovary and pallial oviduct, and the male seminal vesicle developed synchronously, and inverse to the male testis. Abnormal whelks follow a normal reproductive cycle. However, significantly lower reproductive organ index values, modifications in the number of individuals and periods extension in each developmental stage were observed. Gonads of individuals with severe imposex (stage 3) and parasite inf...

The age and growth of the whelk, Neptunea arthritica, was estimated based on growth striae on the operculum. Individual whelks were sexed and divided into normal and abnormal groups, based on the presence of imposex and parasite infection. The monthly marginal growth was used to determine the annual growth mark formation on the operculum. The whelk's sex (male and female), condition (normal and abnormal) and size (mature and immature) were evaluated as factors that can affect the marginal growth. Only in normal females did size affect the marginal growth, suggesting that parasite infection and imposex were not a biasing factor in the age estimation. Significant differences between low and high monthly marginal growth in normal males were found. Between operculum length and shell length and total body weight a positive relationship was found, while the same trend was observed in all female groups as well as abnormal males, but differences were not significant. The same relationship was observed be...

Oreochromis mossambicus collected from Koraiyar, a tributary of the river Cauvery exhibited variations in their external genital features such as enlarged male genital papilla among equal sized fish, branching or budding in existing male genitalia, development of imposex (male genital papilla in female fish) and increased gonado-somatic index (GSI) and elevated male sex ratio in the population. All these variations at different levels is observed in their external genitalia indicated that they were all prompted towards maleness. This ambiguous sexual characteristic might be caused by endocrine disrupting environmental androgenic or anti-estrogenic substances, perhaps, present in the agrochemicals and sewage-mixed Koraiyar water.

Summary “Imposex” (imposed sex) is an abnormal anatomical condition of female gastropods in which they develop male sex organs. Imposex is induced by organotin pollutants from antifouling paints and was detected in Chilean gastropods for the first time in 1999. This study examined morphological changes associated with imposex in populations of the marine snail Acanthina monodon on the Chilean coast. Specimens were collected from two differentially polluted sites (Las Cruces and Matanzas) outside the active port of San Antonio, Chile. Sex was anatomically determined by the presence of a normal penis in the male and the presence of the capsule gland in the female. Histological study of the reproductive system in females with imposex was conducted by observing longitudinal and cross sections of individual organs and whole specimens; 54.2% of all females showed evidence of imposex, with a maximum value of 94.7% at Las Cruces, and a minimum value of 37.6% at Matanzas. Imposex-affected females demonstrated invo...

Tributyltin and triphenyltin (TBT and TPT) are biocides that have been used to prevent fouling of boats, preserve wood, kill molluscs, and other uses. Due to observed effects on oysters and snails, their use in boat paints has been banned in many nations. However, use on ships and some uses other than as antifouling paints continue. These uses, the relative persistence of these compounds, their tendency to bioaccumulate, and their toxicity cause lingering concerns about risks to humans and non-human organisms. This paper outlines an integrated assessment of TBT and TPT. Based on prior human health and ecological assessments, it suggests that an integrated assessment that recognized common pathways of transport, fate and exposure, and common modes of action would be more efficient and complete than additional independent assessments. The presentation of risks in an integrated manner could also lead to better decisions by defining the various benefits of any management action.

Summary Imposex was recorded in samples of dogwhelks Thais spp. from each of the sites surveyed in Hong Kong and Singapore, and the majority of those in Phuket and Penang. There was no imposex in samples from Langkawi. The most advanced symptoms were those from shores close to commercial harbours, marinas and mariculture sites, suggesting that tributyltin (TBT) is a primary cause of the condition. All females were categorised as sterile from four sites on Hong Kong. In these cases recruitment has probably occurred as a result of the dispersal of larvae from fecund populations elsewhere. However, severe imposex was surprisingly localised, even in Hong Kong. There was evidence of decreasing symptoms of imposex with increasing distance from centres of shipping activity.

Summary Concentrations of butyltins in the tissues of gastropods and measures of imposex in Nucella spp. and intersex in L. littorea were used to assess the levels of TBT contamination in two estuaries, Puget Sound and Narragansett Bay, both of which are subject to high shipping activity. Concentrations of butyltins in gastropods collected from both areas were low, although higher than those in adjacent coastal waters of open Pacific or Atlantic Ocean sites. Commercial harbours and dry docks were still hot-spots of contamination, but serious impacts were localised to within a few kilometres of the sources. Marinas were formerly highly polluted, but levels of contamination are now low, indicating that regulations prohibiting the use of TBT-based antifoulants on vessels

Dissection of 197 specimens of the thaid Morula granulata from Rowley Shoals, on the outer continental shelf 300 km west of Broome, northwestern Australia, revealed that none were affected by imposex. While imposex is known to be caused by tributyltin (TBT), there are also other possible causes such as copper, paint matrix and environmental factors. In addition to the relatively low TBT levels in their tissue, the other environmental factors which can cause imposex may also be missing from Bedwell Island.

The effects of dredge spoil disposal on contaminant concentrations and benthic macrofauna were examined at a shallow marine disposal site used for c. 20 years. The site had received c. 50 000 m3 yr‐1 of maintenance dredgings annually, from the Port of Nelson. Port sediments were contaminated to varying degrees with some trace metals, organo‐chlorine pesticides, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons. They showed mildly elevated toxicity in laboratory bioassays, and their macrofauna was dominated by small‐bodied polychaetes. Despite this, there was very little indication of impact in the spoil disposal area. The disposal area, spoil spreading zone and control sites were all similar in terms of sediment contaminants, sediment toxicity, neogastropod imposex, and macrofauna. The lack of discernible impact is probably because of the dynamic sedimentary environment in the disposal area, which disperses dumped dredgings and mixes them with ambient sediment.

Neogastropod snails are gonochorist, i.e. the sexes are separate, but when exposed to tributyltin, a biocide used in marine antifouling paints, the female becomes masculinized, typically developing a penis and a vas deferens. This process is termed ‘imposex’ (describing a superimposition of male sex organs onto the female) and the phenomenon has been recorded in many species world‐wide. Evidence suggests it is caused by an hormonal imbalance induced by tributyltin at a very low ambient concentration of just a few nanograms per litre. Thus, imposex can be used as a highly sensitive bioindicator of tributyltin pollution, especially as the degree of its development appears to be dose‐dependent. In the Mediterranean, only Hexaplex trunculus (Muricidae) has been studied in this context, but information is limited and the status of H. trunculus populations along the Italian coast remain to be investigated in detail. The present survey is based on examinations of nearly 3000 specimens collected at vario...

Summary Surveys of imposex in the dogwhelk Nucella lapillus suggest that most parts of the north Atlantic are free of TBT contamination at biologically significant levels. Imposex was absent or poorly developed at the large majority of sites, including coasts adjacent to major shipping lanes passing through Pentland Firth, the Minches and North Channel. There were “hot-spots” of TBT pollution at ports and harbours along the northeast coast of England but, with the exception of the stretch of coast which includes the major ports of Hartlepool and Teesside, impacts were highly localised. The severity of imposex has declined dramatically during the past decade in those areas for which there are comparative data from earlier surveys. This can presumably be attributed to the success of regulations prohibiting the use of TBT-based antifoulants on vessels

Environmental research into tributyltin (TBT) continues to elicit considerable research effort, despite the usage of such compounds having been controlled in antifouling paints for 15 years. This prevailing interest stems from the recognition that the legislation has not been universally effective in abating TBT fluxes to the marine environment, although greater success does seem to have been attained in freshwater ecosystems. Good indicators of the global extent of TBT pollution are imposex in gastropods and butyltin content in cetaceans. Key questions about toxicological mechanisms, particularly in mammals, remain unanswered. Whereas past and present investigations have been reductionist in nature, future emphasis is likely to be placed on model development and application in coastal marine environments.

Ireland was the first country to introduce a legislative ban in April 1987 on the usage of organotin antifouling paints, this included tri-butyl-tin (TBT). Vessels under 25 metres were not permitted to use these substances because of harmful effects to shallow water sea inlets. The ban prevented use of organotins on most fishing vessels and pleasure craft. TBT causes a condition, imposex, resulting in sexual impairment in neogastropods. This condition was examined in the dogwhelk Nucella lapillus at 66 stations in Bantry Bay, SW Ireland, to determine dispersal from source from the main input areas. Highest imposex levels were recorded in the harbour of the fishing port Castletownbearhaven. High levels of TBT in sediments and use of TBT antifouling paints by the fishing fleet have resulted in reductions of dogwhelk abundance at the harbour entrance. Nearby, dogwhelks had high levels of imposex, which declined with distance from source. The lower frequency of imposex observed elsewhere within Bantry Bay may...

The paper describes development of policies for TBT in relation to antifouling history, scientific assessment of environmental impact and future developments. Major break throughs in development of policies for TBT were triggered by scientific evidence of a specific and very sensitive effect, Vs imposex. Consequently policies were developed in a step-wise process. Restrictions for small vessels followed alarm about coastal dog whelks, while policy initiatives for offshore shipping only started after findings of imposex in relation to shipping in the North Sea. Global policies were further inspired by a consequent inventory in tropical offshore waters. At present global policies, with the framework of IMO, move towards a total ban of TBT within the next decade together with a strong stimulation of development and application of environmentally safe alternatives.

Tributyltin (TBT) used in marine antifouling paints causes masculinization, i.e. the development of a penis and vas deferens, in female neogastropod snails. This ‘imposex’ phenomenon is used as a bioindicator of TBT contamination. The occurrence of imposex in the dogwhelk (Nucella lapillus) was surveyed in eastern Canada from the Atlantic seaboard into the St Lawrence estuary for the first time in 1995. Imposex was present at 13 of 34 sites throughout the region, but usually at less than 100% frequency. Seven sites had dogwhelks not affected by imposex. Dogwhelks were absent at 14 harbour sites with seemingly ideal habitat. All females were affected at only two sites: Portuguese Cove, within Halifax Harbour, and north of South Bar in Sydney Harbour. Other harbours where imposex was present included Chester, N.S., Les Mechins, Que., Saint John, N.B., and Arnold's Cove and Come-by-Chance, Nfld. Relative female/male Penis Size Index (RPSI) ranged 0.4–38.5%. These frequencies and RPSI indices are relatively l...

The study aimed to survey the presence and extent of imposex in sublittoral gastropods in relation to shipping traffic in the Gulf of Thailand and the Strait of Malacca. Females of several species of meso- and neogastropods showed a high incidence (up to 100%) of imposex at several sites. These females had a penis of variable size and a vas deferens (sperm duct), two typically male characteristics. Imposex has been found to be caused by TBT from antifouling paints. The occurrence of imposex was related to the distance to the main shipping routes, but not to water depth or diet of the investigated gastropods. TBT remains active far away from the target area and influences non-target animals. Some gastropods affected by imposex were found within shellfish culture plots and on the fish markets.

Five neogastropod species collected from a tributyltin (TBT)-polluted site near the port of Fare within the Ria Formosa on the Algarve coast of Portugal were examined in April 1996 for 'imposex'. All females of four of these species - Hexaplex trunculus, Ocenebra erinacea, Ocinebrina aciculata (all Muricidae) and Nassarius reticulatus (Nassariidae) - exhibited the characteristic development of male sex organs (penis plus vas deferens) but no female of the fifth Columbella rustica (Columbellidae) - showed any sign of being similarly masculinised. Only two neogastropods have been previously described as lacking the imposer response to TBT exposure. These two species, along with C. rustica, can be considered as 'zero-response' forms. Other species can be grouped according to the maximum level of masculinisation they exhibit: level I species develop just a penis and vas deferens; in level II forms oviduct structure and function are disrupted, and in level III species ovary transformation to testis is observed. Such a comparative scheme of ordering can be used as a guide to the differential sensitivity of species to TBT pollution. info:eu-repo/semantics/publishedVersion

Imposex, i.e. penis and vas deferens development on females induced by tributyltin pollution from antifouling paint, was found in the dogwhelk Nucella lapillus (Linne, 1758) at 38 of 45 studied localities in southwestern, western and northwestern Iceland. Imposex was most frequent near Reykjavik and Hafnarfjorður in southwestern Iceland, but fairly widely distributed in the whole study area. Its absence from 16 % of the studied sites scattered in-between sites where imposex was present, is noteworthy, as imposex has elsewhere been found within this species on virtually all studied sites. The effects of the tributyltin were most often restricted to vicinity of the harbours < 18 km). The presence of imposex in Icelandic waters indicates that tributyltin pollution is widely distributed even in a fairly remote northern environment.

Summary Concentrations of tributyltin (TBT) less than 5 ng/l were recorded in most coastal water samples taken from a series of sites in north-east England during autumn 1991. Levels in the industrialized Tyne estuary still exceeded the Environmental Quality Standard (EQS) in 1991 but had fallen from values recorded in 1989–90. Coastal dogwhelk Nucella lapillus (L.) samples taken in 1991 had low concentrations of