Deep-Sea Tailings Placement

Terrestrial mining activity produces large volumes of waste, formed by the non-processed rock from overburden or access tunnels and shafts, and by the processed tailings. The tailings are the waste produced after the extraction of the targeted metal from the ore through crushing and milling to obtain particles that consist of one mineral and separating the minerals by their physical or surface characteristics. This fine-fraction slurry waste usually accounts for a high proportion of the ore.

Traditionally, tailings have been stored in land dams, but the lack of land availability, potential risk of dam failure, geological instability and topography in coastal areas in certain countries results in increasing disposal of tailings into marine systems. However, there are many important gaps in the understanding of the environmental impacts (including abiotic and biological processes) of such disposals and recovery potential of affected areas, particularly in poorly known deep-sea ecosystems.

The DOSI DSTP working group aims to provide an international platform to promote discussion and communication amongst stakeholders to provide guidance on issues related to deep-sea mine tailings placement (DSTP). The WG includes natural sciences researchers, industry, environmental groups, consultants and policy makers.

Current Working Group  Activities:

1) Scoping paper: A DSTP Scoping Paper will be designed as a tool that will help all stakeholders to better understand DSTP, and therefore a better understanding and context to any proposed actions suggested by this working group.

2) DSTP online questionnaire: your participation in this online questionnaire would be very much appreciated: 

3) DSTP data repository: a central source of information for data related to DSTP issues is being prepared.

Recent Working Group Activities:

1) DSTP workshop, Lima (Peru), June 2015: workshop organised in collaboration with GESAMP/IMO. Co-funded by IMO and the MITE-DEEP project (INDEEP & NFR). DOSI-DSTP funded the participation of 10 scientists which presented up to date data and knowledge on DSTP issues, from ecology, chemistry and physical oceanography to modelling.  Meeting report with contributions from DOSI.

Want to get involved?

If you are interested in participating in the DOSI-DSTP working group, please contact WG Lead Eva Ramirez-Llodra:

DSTP Meeting Peru June 2015
DSTP Meeting Peru June 2015