Local coastal onion planters have discovered, through a trial and error process, an environmentally friendly solution to the invasion of a variety of seaweed which is proliferating in some of our lagoon and washed ashore by tons.

A first experience at composting these seaweeds has been successful with the help of two different species of worm.
The first stage of composting consists at reducing the salinity of these green seaweeds from 50 000 micro Siemens per centimetre (µS/cm) to 1 200 µS/cm through a natural process by exposing it to rainfall.

 During this process, a sea worm which thrives in high salinity is used to start the decomposition process. When the salinity s to a level which enable the use of this seaweed on vegetation, a second stage of composting starts with the use a particular species of land worm.

The green seaweed being used, different from the brown kelp which the sea usually washes on our beaches, has been proliferating in some of our lagoons for some years. It decays on the shoreline with a putrid smell. Public authorities and some hotels are spending big money to collect these seaweeds which are then dumped in the landfill facility of Mare-Chicose.

Industrial exploitation of this type of compost might start soon.

(Read the French version in l’express dimanche)