Figure 1.3. Releases of heptane and toluene

      The positions of the two drifting buoys and the tanks at their opening and their recovery are shown in Figure 1.4. Buoys and tank data show a WSW direction drift. Toluene and heptane are highly volatile chemicals, and their persistence at sea surface is limited (prediction of 30 minutes persistence with the software CHEMAP). However, drifting buoys are of interest during such experiments to obtain in situ information, which enables us to readjust the prediction models.

      The second release took place on May 22, from 13:25 to 13:55 UTC. There was a heavy swell, restricting any activity at sea; hence, products were discharged directly from the back of the vessel (French Navy) advancing towards the east at a speed of 1 knot: methanol was released from 12:35 to 12:45 UTC and xylene from 12:55 to 13:25 UTC. The sea state made it impossible to use the dinghy, to deploy the drifting buoys or to sample the slick and water column.

      Figure 1.4. Map of sea surface of tank and drifting buoy positions during the first release. For a color version of the figure, see www.iste.co.uk/lefloch/remote.zip

      The airborne sensors implemented for this release were:

      The third release took place on May 22, from 15:20 to 16:50 UTC. Because of the swell, products were also released directly from the back of the boat advancing towards the east at a speed of 1 knot: rapeseed oil was discharged from 15:00 to 15:30 UTC and FAME from 15:25 to 15:40 UTC (Figure 1.5). No samplings and no deployment of drifting buoys were possible due to the sea state.

      The airborne sensors implemented for this release were:

      Figure 1.5. Releases from on board the Ailette (a) and rapeseed oil slick (b)

1.4. Conclusion

      The POLLUPROOF project aims to set up a procedure for collecting evidence of illegal maritime pollution from noxious liquid substances using airborne sensors. To achieve this goal, an experimental approach was divided into two parts. First, optical sensors were calibrated in a mesoscale spill experiment. Then, optical and radar sensors were implemented in a realistic experiment at sea to image the slicks from noxious substances.

      The optical and radar results obtained during these experiments are beyond the scope of this presentation and will be presented elsewhere. However, they are clearly promising and demonstrate how hyperspectral sensors are complementary to classic optical and radar sensors for the detection of chemicals at the sea surface.

      The research presented in this chapter is part of the POLLUPROOF research program (ANR-13-ECOT-007) funded by the French National Research Agency (ANR). The authors are very grateful to everyone involved in the experiment at sea (ONERA, CEDRE, AVDEF, DGDDI and the French Navy).

1.5. References

      [CED 15] CEDRE ACCIDENTAL WATER POLLUTION, Database of spill incidents and threats in waters around the world, available at: http://wwz.cedre.fr/en/Resources/Spills, (accessed June 2020), 2015.

      [CUN 15] CUNHA I., MOREIRA S., SANTOS M.M., “Review on hazardous and noxious substances (HNS) involved in marine spill incidents – An online database”, Journal of Hazardous Materials, vol. 285, pp. 509–516, 2015.

      [MAR 73] MARPOL, International convention for the prevention of pollution from ships, 1973, as modified by the Protocol of 1978 relating thereto and by the Protocol of 1997, International Maritime Organization (IMO), available at: http://www.imo.org (accessed June 2020), 1973.

      [OLA 09] OLAFSEN G., “Chemical tanker trade”, Chemical and Product Tanker Conference, Back to Fundamentals, London, UK, March 10–11, 2009.

      [OPR 00] OPRC, Protocol on Preparedness, Response and Co-operation to pollution Incidents by Hazardous and Noxious Substances, International Maritime Organization (IMO), available at: http://www.imo.org, (accessed June 2020), 2000.

      Chapter written by Sophie CHATAING, Sébastien ANGELLIAUME, Pierre-Yves FOUCHER, Eldon PUCKRIN and Stéphane LE FLOCH.