No, that is forbidden. The flemish government decided on March 13th 2015 that it is no longer admitted to fish making use of gill or tangle nets for recreational fishing along the whole of the Belgian coast.
Gill nets are long panels of netting that can be set at any depth in the sea. They can measure up to a few dozens of metres in length and consist of strong nylon fibres in which fish become entangled as they swim into the net. However, frequently porpoises also get entangled in such nets. When trapped, they can no longer come up for air and drown.
That is why in certain coastal municipalities a prohibition on gill nets was already in place, but not everywhere the same rules applied, which could cause some confusion. Now it is forbidden to use gillnets everywhere along the Belgian coast. Sports fishermen can still use fyke nets, trawls or flat nets.