By John McPhaul
San Jose, Costa Rica - A tropical algae thriving on fertilisers from hotel golf courses and badly treated sewage is killing one of Costa Rica's most important coastal reefs, scientists say.
A tourism and construction boom along the palm tree-lined beaches is creating nitrogen- and phosphate-rich waste that feeds the algae, known as Caulerpa sertularioides, and Costa Rica is only just becoming aware of the problem.
The algae is the latest challenge facing Costa Rican authorities as the Central American country struggles with conserving its unique tropical biodiversity while attracting tourists and marketing itself as an ecotourism paradise.
