Delos

DELOS (Deep-ocean environmental long-term observatory system) was deployed by BP in 2009. The aim of the project is to increase understanding of the deep water areas where we have facilities offshore, and provide long-term monitoring to enhance deep sea scientific research

Two monitoring platforms have been put in place: one within 50 metres of a sea floor well and a second 16 kilometres from any sea floor infrastructure. The platforms will be deployed for 25 years.

During its first five years of operation, the harsh environment for data acquisition (at depths of approximately 1,400 metres) has affected the quality of some of the data we have been able to obtain from the observation modules. The modules are retrieved from the sea floor every 12 months for data offloading, instrument calibration and battery re-charging. We have gradually refined the operation and the system is now a proven concept for data acquisition. 

In 2014, we completed an independent review of data gathered by the DELOS equipment and by remotely operated vehicles, which covered parameters such as oxygen concentration, salinity, turbidity, and temperature. Photographic information was also analysed. The review found a very large and statistically significant month to month variation in the numbers of fish seen at the cameras but no significant temporal difference in the composition of the fish assemblage. There was also no detectable difference between near and far block 18 locations. 

Project aims

Determine long-term natural environmental conditions in Block 18
  • Measure and monitor deep-sea biological communities.
  • Differentiate between natural and man-made changes (i.e. distinguish any influence of oil & gas activities from natural trends).
  • Understand linkage between deep-sea ecology & climate change.
  • Contribute to individual & institutional capacity development in Angola.

Delos equipment

Oceanographic module

Data camera module

Delos partners

We also reviewed acoustic information to learn about noise on the sea bed and its source – whether natural or from facilities. The quality of the data received was not sufficient to draw firm conclusions about noise sources and impacts, but we are committed to continuing this work, which will form part of a wider programme of future monitoring and evaluation. A number of academic papers and conference presentations on the work of the project have been made. Increasing the quality of deep-water data available will make a valuable contribution to marine science.