A new concept for clearing plastic waste from the oceans has successfully completed a feasibility study and is now looking for funding to take it further.
The concept developed by seismic ship operator Petroleum Geo Services (PGS) may be valuable in certain areas and during seasons or events when plastic densities are high. PGS says its next step is to seek funding for a full-scale pilot test.
In 2017 PGS launched a concept for collecting plastics at sea that uses the inherent capabilities of seismic vessels. PGS then commissioned a desktop review by an independent consultant of the potential and feasibility of the concept, using funds received from the Norwegian development and investment bank 'Innovation Norway'.
The results of the feasibility study were published in Q3 2018 and conclude that, "pelagic microplastic densities are too low for surface plastic collection to be efficient on the open ocean, but densities may be higher in certain areas or during certain seasons, or during flush-out events." A review of synthesis and modelling studies identified areas where plastic could be available in high densities, due to the likelihood of high input flows from runoff and rivers during wet seasons. These include the Gulf of Mexico, the Caribbean Sea and the West Coast of Africa around the north Atlantic Margin.
PGS is now progressing with a more detailed technical study that will include theoretical engineering and hydrodynamics considerations. Discussions are ongoing with potential partners and suppliers for the boom arrangement, bubble curtain and collection unit.
Based upon the recommendations in the feasibility study and if funding can be secured PGS says a full-scale pilot would involve a single seismic vessel towing a boom and skirt arrangement with a bubble curtain that lifts plastic to the surface for collection in a permeable collection bag. The pilot would be conducted offshore, over a period of approximately two months in either the Atlantic or the Caribbean.
The purpose of the pilot will be two-fold, testing the efficiency of the collection concept both offshore and near-shore and conducting scientific research on the occurrence, density and characteristics of plastics in the ocean. To facilitate the latter, PGS proposes a large aperture sampling system enabling unprecedented coverage. Academic institutions will be invited to join us, using our vessel for the duration of the pilot to conduct relevant research on plastic pollution in the oceans.