Fouling communities and degradation of archeological metals in the coastal sea of the Southwestern Gulf of Mexico

Abstract

Corrosion and biofouling phenomena of cast iron and brass were evaluated under natural conditions to determine the degradation process of archeological artifacts. Field exposure studies of experimental materials were conducted over 15 months at an offshore position in the sea of Campeche in the Gulf of Mexico. Corrosion was determined by gravimetric measurements. The community structure of the benthic assemblage inhabiting the surfaces of both materials was evaluated. A total of 53 species was identified. The community in both cases was composed of a small number of species. Encrusting, attached and erect life forms were dominant on iron. Attached life forms were dominant on brass. Biofouling produced a decrease in the weight loss measurements of cast iron samples. Biofouling provided a beneficial factor for in situ preservation of iron archeological artifacts in wreck sites.

Keywords:

• biological colonization
• anodic and cathodic reactions
• metal dissolution
• metallic artifacts
• shipwreck
• species richness

Acknowledgements

Thanks are due to the Vice Directorate of Underwater Archaeology at the National Institute of Anthropology and History, especially archeologist Pilar Luna Erreguerena for all the support and facilities to fulfill this work. Special thanks to Dr Pierre Legendre for help in the planning of the experimental devices and statistics analyses. Also to the archeologists Helena Barba, Jesus Castro Dzib and Luis May Cajum for their support in logistics and fieldwork. Thanks also to the Centre for Corrosion Research at the Autonomous University of Campeche and the Institute of Marine Sciences & Limnology at National Autonomous University of Mexico. The authors also acknowledge help in the taxonomic identification of algae from Drs Catalina Mendoza Gonzalez and Luz Elena Mateo Cid. Finally, special thanks to Dr Ann Grant for grammatical revision of this work.

Conflict of interest disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Funding FOMIX-CAMPECHE of the National Science and Technology Council (CONACYT) of Mexico and the Government of the State of Campeche under Grant [125063].