Depressing. This article focuses on a Puerto Rico tourist attraction quite popular with kayakers. For almost two weeks, the Fajardo Grand Lagoon (Laguna Grande)—located off Puerto Rico’s northeastern coast—which is usually glowing due to teeming dinoflagellates, has gone almost completely dark and biologists have no idea why. The lagoon usually glows when bioluminescent organisms that live in the water are disturbed, yet they have not been visible for almost two weeks (9 days at the time the article was written). Recent construction in nearby Las Croabas may be to blame. [Thanks to Jo Spalburg and Rod Fusco for bringing this sad news to my attention.]
Nearby construction work is thought to have caused disruption to the area, but biologists also believe a recent spate of bad weather could have caused the glowing lagoon to dull. Another theory is the chopping down of mangrove trees in the area, to let larger boats into the lagoon and its surrounding water, could also have played a part. ‘We have been compiling data,’ Carmen Guerrero, secretary of the Department of Natural Resources said. ‘There are a lot of factors that could be at play.’
The bioluminescent lagoon is often referred to as a bay and is a popular tourist attraction. Visitors row kayaks or take boat trips from the nearby city of Fajardo to watch the water glow. The lagoon is filled with one-celled organisms said to be half-animal and half-plant that glow like fireflies if the water is disturbed. A greenish light swirls off hands and arms as visitors trail them through the water. However, the bioluminescence has dropped so significantly, tour operators have had to cancel trips and reimburse visitors, Guerrero added.
Fajardo Mayor Anibal Melendez blamed surface runoff caused by nearby construction of a water and sewer treatment plant. He has since asked that the plant be moved elsewhere, yet officials involved with the plant deny the work is causing the lagoon’s problems and the government Environmental Quality Board added the treatment plant has adequate erosion and sediment controls that ‘comply with environmental standards.’ As a preventive measure, the government has temporarily suspended construction at the project for two weeks until scientists can figure out what is causing the problem. Alberto Lazaro, president of the state Water and Sewer Authority, said he will evaluate scientists’ findings before deciding how to proceed in several weeks.
Recent rains and a storm that are generating heavy waves is another possibility for affecting the lagoon’s bioluminescence, continued Guerrero. The Conservation Trust of Puerto Rico, which manages the lagoon and surrounding areas, collects water samples three times a week to record data including temperature, salinity and precipitation. Scientists will analyse this data to help solve the mystery of the darkening lagoon.
It is not the first time the lagoon has gone dark. It went nearly dark for a couple of months in 2003 but the glow was restored before scientists could establish the exact cause.