~ NF monitors, issues Tilapia die-off alert ~
PHILIPSBURG--Based on the ongoing dry and hot weather associated with the current drought the island has been experiencing, Ministry of Public Housing, Spatial Planning, Environment and Infrastructure VROMI opened Great Bay Channel over the weekend, creating a channel of water that will flow from the bay into Fresh Salt Pond, raising water levels in the ponds. Nature Foundation (NF) was called to monitor the situation.
While measures have been taken to manage the water level of the Great Salt Pond over the weekend, Nature Foundation has issued an alert for possible tilapia fish die- off in the Great Salt Pond, due to the ongoing dry and hot weather associated with the ongoing drought.
The foundation has assisted VROMI in raising the water level of the Fresh and Great Salt Ponds considering the expectation of a higher than normal tide, because of the full moon of the coming days.
Based on the NOAA tidal tables a spring tide is expected, which would mean an above normal tide by about two feet peaking on Tuesday at 6:00am and subsiding gradually over the subsequent six hours. During this time, seawater from the Great Bay entrance will be channelled into the ponds to raise the water levels, which are dangerously low due to the drought.
As the ecosystem is used to a saline to a saline-brackish environment there should be little negative effect on the ecosystems.
The foundation said due to the dangerously low water levels in the Great Salt Pond, the fish were dispersed in areas through the wetland. Once the floodgate was opened between the Fresh and Great Salt Ponds an increased number of tilapia could be seen by the Firgos Channel, many of which were already stressed by low oxygen, salinity and elevated water temperatures.
These fish will eventually die because of the conditions caused by the drought, said the foundation. The area is already being cleaned and the fish disposed of considering the health effects on the communities surrounding that area of the wetland.
Although unfortunate, the reducing of the number of tilapia will have a positive effect on the ecosystem balance of the wetland considering they are an invasive species. This is confirmed by tilapia being the only species affected.
Species such as tarpon (bass) can be seen congregating in large numbers by the Great Bay Channel due to the influx of oxygenated water, which is very beneficial to the species. Nature Foundation will continue to monitor the situation.
According to a Ministry press release, the flood gates were opened and approximately two metres of water was drained into the Great Salt Pond from the Fresh Pond. The channel continued to flow into the Fresh Pond over the weekend and a peak is expected on Tuesday due to a spring tide caused by a full moon, making it an opportune time to practise the approach.
The increase in salinity will act as a self-purifying tool in the bodies of water and eradicate other hazardous circumstances such as mosquitos and unpleasant fumes from decaying fish. VROMI said it would be monitoring the progress of this activity closely with the assistance of the Nature Foundation to ensure a safe and efficient process.
Water quality testing has been conducted by the Nature Foundation to ensure there was no spill of the Fresh Pond into the Great Bay area. Those results proved negative.
Persons are advised against fishing for tilapia, especially for consumption, due to the dangerous quality of the water.
