Translate the following English sentence to French:
"Thirdly, the European Union should undertake to enhance its monitoring and prevention of extensive pollution prevalent in Community waters and which is harmful to marine life including fishery resources."
Troisièmement, l'Union européenne devrait s'engager à améliorer la surveillance et la prévention de l'importante pollution des eaux communautaires qui dégrade la faune et la flore marines, y compris les ressources halieutiques.