The San Juan Daily Star
Scientists express concern about deteriorating La Parguera marine reserve ecosystem
By John McPhaul
Scientists from the Department of Marine Sciences (DCM by its Spanish initials) of the University of Puerto Rico Mayagüez Campus (RUM) raised the alarm Wednesday about the accelerated deterioration of the quality of the environment and the state of marine communities in the La Parguera Natural Reserve (RNLP), the most developed ecosystem of its kind in Puerto Rico.
“The coral reefs, seagrass meadows and mangroves of the RNLP show accelerated deterioration, resulting from a lethal combination of global warming and uncontrolled human activities,” coral reef specialist Dr. Ernesto Weil, who is a professor and director of the DCM, said in a press release. “The increase in the frequency and intensity of storms, reef diseases and sargassum arrivals in the area are natural problems that we cannot control, but we can reduce the impact of human activities.”
La Parguera, in the island’s southwestern region, has been a tourist attraction for many years due to its proximity to recreational areas protected by Puerto Rico’s most developed reef ecosystem. After Hurricane Maria, during and after the pandemic, there has been a significant increase in the number of visitors, hostels, boats, nurseries, restaurants, and people visiting the town, the keys and other areas of the RNLP during the week and mainly, every weekend exacerbated by the lack of vigilance of official agencies, Weil said.
He added that the number of boats that anchor on seagrass meadows, which are further trampled in shallower areas by people wading and the physical damage produced by boat propellers, significantly exceeds the resistance (carrying capacity) to disturbances of these habitats, which currently show a progressive deterioration in their structure and biodiversity, losing the ecological benefits they provide to the reserve and to human beings.
“The frequency with which these events of excess tourists occur prevents the natural recovery of these important habitats,” Weil said.
He noted that the extensive reef development present in the RNLP characterizes it as a unique and special ecosystem throughout Puerto Rico, and stressed that numerous scientific studies have shown that coral reefs and other associated communities are very susceptible to increases in water temperature and the frequent impact of human activities.
“This degradation of reef communities is the result of the combination of natural problems such as increased thermal anomalies, lethal diseases, increased rainfall and the high frequency of hurricanes and storms, which, combined with the constant impacts of uncontrolled human activities, have accelerated the degradation process,” Weil said. “Several of the species listed as endangered by the United Nations (manatees, sea turtles and seven species of reef-building corals, etc.) are susceptible to these factors, and are rapidly disappearing from various reef habitats inside and outside the RNLP.”
Over the past 15 years, for example, the systematic degradation of the RNLP’s coral reefs has resulted in a loss of more than 50% in living coral cover, Weil pointed out. Recovery is going to take hundreds or thousands of years. In the past three years, a significant increase in the number of manatees killed by impacts from boats traveling at high speeds in protected areas for these mammals has been reported, a consequence of the uncontrolled proliferation of motor boats and jet skis in areas of the RNLP, the lack of education and knowledge of the area by users, and of an increase in deforestation and the lack of surveillance and enforcement of regulations by the competent authorities, Weil said.
“The direct effects of user activities inside and outside the RNLP can be clearly observed in the numerous furrows in seagrass meadows and shallow coral habitats caused by boat propellers and/or jet skis passing at high speeds without control or knowledge of the area,” the reef specialist said. “The fragmentation and destruction of coral colonies by propellers, anchors and trampling; the increase in water turbidity due to excess sediments from resuspension and the increase in construction; and the excessive number of boats and bathers also contribute to … chemical imbalances.”