In Observance of World Fisheries Day, Thursday, November 21, the Nature Foundation and the Work Group for the Millennium Development Goals has highlighted the fish kills and the invasive Tilapia as a central issue regarding Fisheries Management and the Millennium Development Goal MDG 7, Environmental Sustainability.
Based on the three fish die offs the Nature Foundation St. Maarten has compiled and delivered a report based on research conducted during the week of the 27th of October which outlines the causes, results and possible preventative measures for the increase of fish die off events St. Maarten has been experiencing over the last few years.
The report gives recommendations by the Nature Foundation to the Government/ VROMI Ministry of St. Maarten regarding the issues associated with the introduction and massive fish die-offs of the introduced Tilapia (Oreochromis mossambicus) and the Blue Tilapia (Oreochromis aureus) which are the species of Tilapia most introduced into the wetlands of St. Maarten (Great Salt Pond, Fresh Pond).
Both types of Tilapia are a species of fish in the Cichlidae family. Native to Northern and Western Africa, and the Middle East, through introductions it is now also established elsewhere, including parts of the United States and the Caribbean, where it has been declared an invasive species and has caused significant environmental damage not only through fish die off events but also in harming already depleted ecosystems. The Tilapia invasion in our wetlands can be compared to the Lion Fish Invasion on our Coral Reefs.
Anecdotal reports suggests that, although there have been minor reports of Tilapia being in the Great Salt Pond since the 1970s a large introduction of Tilapia was done into the Great Salt Pond in 2004 by a pet shop owner (since moved to Great Britain)who had his business in the Madam Estate Shopping Center. The proprietor of the Pet Shop introduced the Tilapia into the Great Salt Pond after the specimens became too large to handle. This research is corroborated by the fact that since the initial introduction in 2004 and based on the research none of native St. Maarten fish were found dead during the fish die-offs.
Tilapia is fast growing, breed rapidly, and once introduced into a habitat they generally establish themselves very quickly. In doing so they compete with native fish fauna, reduce the light available for aquatic plants, and eat certain types of aquatic plants causing changes in local aquatic flora. Such problems have been observed in many different places, including Australia, Philippines, and the United States.
Although the testing results show that the Great Salt Pond is indeed faced with poor water quality, the predominant results which stand out are related to a drop in oxygen in conjunction with a rise in salinity or saltiness. This shows that yes, there is an issue with water quality in the Great Salt Pond, but that the primary reason for the fish die-off is the species itself and is not related to the Pond. The Great Salt Pond, as its name suggests, is a Saline to Hyper Saline Environment and although Tilapia can withstand salinity up to a certain point, after attaining a certain level the species dies massively.
World Fisheries Day calls for a greater management of fisheries and fisheries related activities on St. Maarten. The management of fisheries also falls within the Framework of MDG Goal number seven (7) which calls for an increased environmental sustainability.
Author: Tadzio Bervoets , manager at the Nature Foundation and member of the Millennium Development Goals Work group.
Symbols of the Millennium Development Goals this article is based on MDG nr. 7 (Ensure Environmental Sustainability).