Scientists and environmental experts who went to the Isla Calero Tuesday were heckled by about 50 young Sandinistas who arrived in three boats.
The group that came from Barra del Colorado included María Rivera of Colombia, Manuel Antonio Contreras of Chile and Alfonso Rivera from Canada, said the foreign ministry in San José. With them were Carlos Roverssi, a deputy foreign minister, and Lorena Guevara a vice minister in the environmental ministry.
The goal of the trip was to chronicle environmental damage inflicted on the area by the invasion of Nicaraguan troops and their efforts to dig a canal that will become a new mouth for the Río San Juan.
The Nicaraguan government opposed the visit, although the March 8 ruling by the International Court of Justice appears to give Costa Rica the right to make an environmental survey.
The rowdy group of Nicaraguans carried signs, chanted and yelled at the Costa Ricans and the three foreigners who arrived by helicopter. The demonstrators were identified as members of Juventud Sandinista but there also were reporters and camera operators from Managua.
The three foreigners are representing the Convention on Wetlands of International Importance, known as Ramsar for
the Iranian city in which the international treaty was reached.
The trio are expected to return today.
Costa Rica has coupled environmental damage with the breach of sovereignty resulting from the Nicaraguan invasion. Managua, of course, claims the island, and the final determination will come later at the international court in The Hague, Netherlands.
The court told both countries to withdraw any military or police personnel from the disputed area, and Nicaragua did. Costa Rica did not have troops or police there.
Costa Rican officials said they hoped to be able to create a plan to repair some of the environmental damage. Nicaragua dumped silt from a dredging operation on the island and workers felled trees to create a path for the canal. Residents of the area expect a swollen river to greatly enlarge the canal, which now is about six feet deep and about 20 feet wide.
The new mouth to the river will give rapid access to the body of the Río San Juan. Nicaragua said the goal is to promote tourism.
Nicaragua President Daniel Ortega has been accused by some Costa Rican commentators of fabricating the controversy in order to rally nationalistic spirit as he approaches elections.