“Environmental impact assessment must evaluate “the likely environmental impacts of, and propos[e] appropriate mitigation measures for, a proposed development, taking into account interrelated socio-economic, cultural and human health impacts, both beneficial and adverse.” 92 b) The obligation to cooperation with States potentially affected 148. However, if significant transboundary impacts are identified, the State in whose jurisdiction the project is being executed must notify the States potentially affected regarding the activity to be implemented and forward it the relevant information from the environmental impact assessment, as established by international practice. 93 Once this information has been transmitted, it is extremely important that the different States that could be affected by the environmental damage cooperate with each other in order to propose appropriate and effective measures of prevention and mitigating measures. 149. In this regard, principle 19 of the above-mentioned Rio Declaration on the Environment and Development establishes: “States shall provide prior and timely notification and relevant information to potentially affected States on activities that may have a significant adverse transboundary environmental effect and shall consult with those States at an early stage and in good faith.” 94 150. Since then, general international law has incorporated the obligation of cooperation between States affected by the risk of harm to the marine environment. In this regard, in the MOX Plant case the International Tribunal for the Law of the Sea stated that: “The duty to cooperate is a fundamental principle in the prevention of pollution of the marine environment under Part XII of the Convention and general international law.” 95 151. In its decision of December 16, 2015, in the cases of Costa Rica v. Nicaragua and Nicaragua v. Costa Rica, the International Court of Justice decided that: “If the environmental impact assessment confirms that there is a risk of significant transboundary harm, the State planning to undertake the activity is required, in conformity with its due diligence obligation, to notify and consult in good faith with the 92 Conference of the Parties to the Convention on Biological Diversity, Seventh meeting (COP-7), Kuala Lumpur, 9-20 February 2004, Decision VII/16, Annex (Akwé: Kon Voluntary Guidelines), para. 6(d). 93 UNEP, Goals and Principles of Environmental Impact Assessment, Decision 14/25, June 17, 1987. Principle 12; Conference of the Parties to the Convention on Biological Diversity, Fourth Meeting, Bratislava, 4 to 15 M a y 1998, “Impact assessment and minimizing adverse effects: implementation of Article 14,” UNEP/CBD/COP/4/20, 11 March 1998, p.2. 94 The Rio Declaration on the Environment and Development is available at: http://www.unep.org/documents.multilingual/default.asp?documentid=78&articleid=1163 95 International Tribunal for the Law of the Sea, Case concerning the MOX Plant between the United Kingdom and Ireland (Ireland v. U.K,), Provisional measures, December 3, 2001, p. 245, paras. 204-207. Series C No. 172. 60