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Published on: April 28, 2023
Butyltin compounds and imposex levels in Ecuador
Ítalo Braga Castro1, Maria Fernanda Arroyo, Patrícia Gomes Costa
1Laboratório de Microcontaminantes Orgânicos e Ecotoxicologia Aquática (CONECO), Institute de Oceanografia, Universidade Federal do Rio Grande, Rio Grande, RS, 96201-900, Brazil. italobraga@gmail.com
Archives of Environmental Contamination and Toxicology
|April 20, 2011
Summary
Butyltin contamination causes imposex in marine snails along Ecuador's coast. Despite regulations, TBT-based paints remain a threat, necessitating biomonitoring with sensitive species like T. kiosquiformis.
Area of Science:
- Marine Ecotoxicology
- Environmental Chemistry
- Marine Biology
Background:
- Butyltins (BT) are persistent organic pollutants found in antifouling paints.
- Imposex, a condition of sex-reversal in female gastropods, is a sensitive indicator of BT contamination.
- The Pacific coast of South America, particularly Ecuador, has limited data on BT contamination and its ecological impacts.
Purpose of the Study:
- To assess butyltin contamination and imposex incidence in marine snails along Ecuador's Pacific coast.
- To identify the most sensitive gastropod species for future biomonitoring efforts.
- To evaluate the effectiveness of international restrictions on tributyltin (TBT)-based antifouling paints in the region.
Main Methods:
- Surveyed imposex occurrence in three muricid snail species (Thais biserialis, T. brevidentata, T. kiosquiformis) across 14 coastal sites.
- Quantified butyltin compounds (TBT, DBT, MBT) in surface sediments from six harbor areas using dry weight analysis.
- Calculated relative penis length index (RPLI) to quantify imposex severity in different species and locations.
Main Results:
- Imposex was detected in 11 out of 14 surveyed sites, affecting all three studied muricid species.
- T. kiosquiformis exhibited the highest imposex levels (RPLI 9.0-40.7) within the Gulf of Guayaquil.
- Sediment analysis revealed significant concentrations of TBT (12.7-99.5 ng Sn g⁻¹), DBT (1.8-54.4 ng Sn g⁻¹), and MBT (44-340 ng Sn g⁻¹), especially in harbor areas.
Conclusions:
- Butyltin contamination and imposex are widespread along Ecuador's Pacific coast, indicating ongoing exposure.
- International restrictions on TBT-based antifouling paints appear ineffective in fully mitigating BT pollution in Ecuador.
- Thais kiosquiformis and T. biserialis are recommended as sensitive biomonitors for assessing coastal pollution in Ecuador.
