Article 6(3) of the Protocol for the Protection of the Mediterranean Sea against Pollution from Land-based Sources, and Article 6(1) of the Protocol as amended at the Conference of Plenipotentiaries held in Syracuse on 7 and 8 March 1996, have direct effect, so that any interested party (fishermen) is entitled to rely on those provisions before the national courts against polluters. Those same provisions prohibit, without an authorisation issued by the national competent authorities, the discharge into a saltwater marsh communicating with the Mediterranean Sea of substances which, although not toxic, have an adverse effect on the oxygen content of the marine environment.