Analyzing the Costa Rica-Nicaragua Maritime Disputes: An Overview of the Law of the Seas

Background of the Costa Rica-Nicaragua Maritime Dispute ===

The Costa Rica-Nicaragua maritime dispute has been a persistent source of tension between the two neighboring countries, stemming from conflicting territorial claims over the waters surrounding their coastlines. This dispute centers around the San Juan River, which serves as a natural border between the two nations. The conflict primarily revolves around the interpretation of historical agreements, international law, and the rights and responsibilities of coastal states. To gain a comprehensive understanding of the dispute, it is essential to examine the historical context, legal framework, territorial claims, jurisdictional issues, environmental concerns, mediation and arbitration efforts, and the potential implications for both countries and the region.

=== Historical Context: Evolution of the Law of the Seas ===

The evolution of the law of the seas has greatly influenced the Costa Rica-Nicaragua maritime dispute. Historically, coastal states had broad discretion over their adjacent waters and resources. However, the adoption of the United Nations Convention on the Law of the Sea (UNCLOS) in 1982 brought about a significant shift in the legal framework governing maritime disputes. UNCLOS established a comprehensive set of rules and principles to regulate the use and management of the world’s oceans, including the delimitation of maritime boundaries. The convention introduced the concept of exclusive economic zones (EEZ), which grant states exclusive rights to explore and exploit natural resources within a 200-nautical-mile zone from their coastline.

=== Legal Framework: Relevant International Agreements and Treaties ===

Several international agreements and treaties form the legal framework for resolving the Costa Rica-Nicaragua maritime dispute. The most significant is UNCLOS, which both Costa Rica and Nicaragua have ratified. UNCLOS defines the rights and responsibilities of states concerning their maritime zones and provides a framework for resolving disputes through negotiation, mediation, and arbitration. Additionally, the countries’ historical agreements, such as the Cañas-Jerez Treaty of 1858, have been invoked to support their respective territorial claims. These agreements, along with customary international law, shape the legal arguments put forward by both parties.

=== Territorial Claims: Disputing Parties’ Arguments and Evidence ===

Costa Rica and Nicaragua have presented contrasting arguments and evidence to support their territorial claims in the maritime dispute. Nicaragua asserts that the San Juan River is an integral part of its territory, granting it sovereignty over the adjacent waters. Conversely, Costa Rica argues that the river should be considered an international waterway, allowing for freedom of navigation and equal access for all states. Both countries rely on historical documents, maps, and previous agreements to support their claims. Nicaragua points to the Cañas-Jerez Treaty, emphasizing the recognition of its sovereignty over the river. In contrast, Costa Rica cites the 1858 Greytown Convention, which established the river as an international waterway.

=== Jurisdictional Issues: Competing Claims and Their Implications ===

The jurisdictional issues in the Costa Rica-Nicaragua maritime dispute revolve around the conflicting claims of both countries. Nicaragua upholds its territorial sovereignty over the San Juan River and asserts that it has the authority to regulate and control navigation and activities in the adjacent waters. On the other hand, Costa Rica maintains that the river is an international waterway and challenges Nicaragua’s authority to impose restrictions on navigation. These competing claims have far-reaching implications, as they directly affect the rights of coastal states and impact the freedom of navigation in the disputed area.

=== Environmental Concerns: Impact on Marine Ecosystems and Resources ===

The Costa Rica-Nicaragua maritime dispute also raises significant environmental concerns. The disputed area encompasses a rich marine ecosystem that is home to diverse flora and fauna. Unresolved territorial claims and jurisdictional issues can lead to unsustainable exploitation of natural resources, including overfishing, illegal poaching, and environmental degradation. The absence of a clear legal framework and cooperation between the two countries exacerbates these environmental concerns, endangering the long-term sustainability of the marine ecosystems and resources in the area.

=== Mediation and Arbitration Efforts: Seeking a Resolution ===

Given the complexity of the Costa Rica-Nicaragua maritime dispute, both countries have sought mediation and arbitration to resolve their differences. The International Court of Justice (ICJ) has played a crucial role in facilitating dialogue between the parties and providing a forum for resolving the dispute. In 2018, the ICJ issued a ruling that defined the maritime boundary between Costa Rica and Nicaragua in the Caribbean Sea, partially settling the dispute. However, the ruling did not address the issue of the San Juan River’s sovereignty, leaving room for further negotiations and potential mediation efforts.

=== Conclusion: Future Implications and Potential Resolutions ===

The Costa Rica-Nicaragua maritime dispute remains a complex and unresolved issue with wide-ranging implications for both countries and the region. The legal framework provided by UNCLOS and historical agreements forms the basis for the parties’ arguments. The competing territorial claims and jurisdictional issues not only impact the rights and responsibilities of Costa Rica and Nicaragua but also have environmental consequences. The ongoing mediation and arbitration efforts, including the ICJ’s involvement, offer hope for a resolution in the future. However, it is crucial for both countries to prioritize dialogue, cooperation, and sustainable management of marine ecosystems to ensure a peaceful and mutually beneficial outcome to the dispute.


The Costa Rica-Nicaragua maritime dispute serves as a reminder of the complex nature of territorial conflicts and the importance of international law in resolving such disputes. As the parties continue their efforts to seek a resolution, the international community must support peaceful negotiations and encourage sustainable practices to protect the marine ecosystems and resources at stake. This dispute also highlights the need for further clarification and development of the law of the seas to address emerging challenges and ensure the equitable and responsible use of our oceans for future generations.