Scientists at the nonprofit MarViva Association in San José have alerted the Costa Rican government that tropical algae thriving on fertilizers from hotel golf courses and badly treated sewage is killing one of the country’s most important coastal reefs.
MarViva is a non-governmental, non-profit organization that works jointly with local authorities and communities to protect the coastal and marine resources of the Eastern Tropical Pacific and the Caribbean. It also promotes the safeguarding and creation of marine protected areas in oceanic and coastal areas in Latin America and the Caribbean.
By supporting the implementation of legislation protecting these areas, the enforcement of existing laws and efforts to establish new reserves, MarViva’s overall aim is more sustainable use of coastal and marine resources.
The feather-like Caulerpa sertularioides alga is currently spreading along the reefs of Culebra Bay in the Gulf of Papagayo in northwest Costa Rica, home to a rare species of coral. Fed by the nitrogen- and phosphate-rich waste created by the ongoing tourism and construction boom in the area, it blocks the sunlight and suffocates the reefs.
According to MarViva researchers about 80% of the percent of the 2.4 km reef is covered in the alga.
If left unchecked, the alga could seriously upset the Culebra Bay ecosystem, allowing non-native species of fish to come in and displace native ones.
The plague of Caulerpa sertularioides is posing a major challenge for the Costa Rican authorities, which are currently making every effort to market their country as an ecotourism paradise.