Over the recent years, amid unprecedented industry development, the environmental protection was a major objective for all EU member governments, including Romania. To this purpose, at the level of the European Union there have been adopted a series of laws designed to ensure a coherent set of legal rules, including in the criminal law. In this context, Romania, in order to meet the commitments in this area, and also following the needs of environmental protection objectives, adopted in turn a legislative package in the field; the most important piece of legislation is the Government Emergency Ordinance no. 195/2005 on environmental protection. The mentioned normative act provides a series of criminal sanctions where a series of facts found by the legal authorities are likely to endanger the life or human health, animal or plant. In this paper there are examined in general the main criminal facts relating to defending and protecting the aquatic environment, particularly the Danube, as provided in the mentioned legislative act. We also presented a series of critical remarks aimed at improving the legislation and thus ensuring a better protection of the aquatic environment.