India follows the following provisions of law while implementing an International treaty in the domestic terrain:

Article 51 of the Indian Constitution specifically states that the State shall endeavour to 'foster respect for international law and treaty obligations in the dealings of organized peoples with one another'. 

• Under Article 253 of the Constitution of India, the Parliament and the Union of India have the power to implement treaties and can even interfere in the powers of the state government in order to give power to provisions of an international treaty.
• In the landmark case of Kesavananda Bharti v. State of Kerala, it was observed that the court must interpret the provisions of the constitution in light of Charter of the United Nations. 
• In the case of Magan Bhai Patel v Union of India, the court held that if a treaty or international agreement restricts the rights of the citizens or modifies the laws of the state it would require to have a legislative measure. 
• In the case of Sheela Barse v Secretary Children's Aid Society, the Supreme Court held that India had ratified conventions regarding the protection of children and this placed an obligation on the State Government to implement these principles. 
• The most revolutionary of these cases was the case of Vishaka v State of Rajasthan, in which the Indian courts used the provisions of the Convention on Elimination of all forms of Discrimination against Women, (CEDAW), to create legally binding obligations regarding sexual harassment. 

In the current case, where under an International treaty, to which India is a signatory, a species of fish is declared as endangered and restrictions are put on the right to trade of that species by prohibiting the killing of the fish. 

If this treaty is to be enforced in India, the Indian Parliament needs to pass a domestic legislation regarding prohibition of the killing of such species of fish.