Spring drought leads to low water levels at Spittal Pond
Low tides and a lack of rainfall have caused water levels at Spittal Pond to fall, although the change is believed to be temporary.
The water level in the pond is largely determined by the sea level however seepage from rainfall also adds to it, conservation officer Jeremy Madeiros explained.
The combination generally results in the pond remaining several inches above sea level.
Lower tides are common around the spring equinox, Dr Madeiros added.
“It is unusual that we are experiencing both a substantial drought and the low spring tides at the same time, and this is what is causing the low water levels.”
Low water levels can affect wildlife living in wetland areas however blooms of blue-green or red algaes, that can change the colour of the pond to brightly-coloured hues, have a greater impact.
This is due to the concentration of nutrients and higher water temperatures in the shallower ponds, Dr Madeiros said.
Together, they can produce toxic by-products or deplete the oxygen from the water.
Meanwhile the green algaes normally seen in the pond are mostly beneficial, producing oxygen and food for fish, marine snails and waterbirds.
Dr Madeiros said the changes would not likely have any lasting negative effect on life in the wetlands.
“There are relatively few organisms in Spittal Pond compared to the nearby ocean, but those that are found there are normally quite tough and acclimatised to surviving these sorts of varying conditions.
“The mudflats that have been exposed by the low water levels around the edges of both Spittal Pond and Warwick Pond may smell a bit, but they are actually beneficial for some of the waterbirds that are migrating past Bermuda during spring and autumn.
“Shorebirds in particular, especially the Sandpiper family, are quite dependant on these mudflats for much of their food in order to continue their journeys to their wintering or nesting grounds.”
Over the past 25 years, Dr Madeiros has seen water levels in the Island’s ponds fall on several occasions in similar conditions.
“Once the tides return to normal in a few weeks, and hopefully once we get a bit more rainfall, then the water in the ponds should return to more normal levels,” he said. “If the drought persists, however, then water levels will probably remain below normal into the summer.”
Bermuda has recorded 8.61in of rain this year — less than half of the average for the period.
This March was the driest on record, with 0.79in of rainfall recorded. The trend of dry weather has continued this month with 1.81in of rain.