The Water Authority Cayman has
denied claims from private citizens that its sewage treatment plant is leaking
waste into the North Sound.
Those statements were made
following photos that were e-mailed around Grand Cayman depicting what was
described as raw sewage floating in the sound.
Water Authority Director Gelia
Frederick van Genderen said claims made in that e-mail were incorrect.
However, pollution is occurring in
the calm body of water that is one of Cayman’s favourite boating and tourism
destinations, according to both the authority and Department of Environment
officials. Evidence of that pollution is beginning to show up in the form of
little green and brown coloured plants growing in the water.
Algae is taking hold in some of the
near to shore areas of the sound.
According to Department of
Environment Director Gina Ebanks-Petrie marine plants tend to proliferate in
tropical waters where higher levels of nutrients are available. Waste is one of
those nutrients that can cause plant life to flourish.
A department study conducted since
2003 has revealed that marine plant growth is occurring along some areas of the
North Sound shoreline.
What’s causing it isn’t exactly
“There are several possible
contributing factors which include: leachate (liquid that drains) from the
unlined George Town landfill, out current methods for on-site wastewater treatment
and disposal, poorly planned canal developments, fertiliser-enriched run-off
from golf courses and other landscaping, and inputs from recreational use of
the marine environment,” read a statement from the Water Authority and
Department of Environment.
The Department of Environment also
noted that large-scale removal of coastal mangrove wetlands to accommodate
development, particularly on the western side of the North Sound, had reduced
the ability of the environment to make up for the effects of pollution.
“Each of these issues has a direct
or indirect impact on water quality in North Sound,” the statement read. “Areas
where canals drain into the North Sound are the most affected.”
Growth of algae and other marine
plants can cause the water to turn green and cloudy. They can also cause a
reduction in oxygen levels in the water at night and reduced sunlight exposure
to plants like turtle grass. Lack of oxygen in the water can also kill the
local fish population, or drive it away.
The grimmest news, according to the
department, is that there’s no easy way to fix this problem.
“It is not possible to turn back
the clock,” the joint statement read. “Changes and improvements need to be made
in the ways in which we plan future development and manage existing
One change that needs to occur,
according to Department of Environment Assistant Director Tim Austin, involves
the continued use of septic tanks on Grand Cayman.
“The water table is very close to
the underlying ground level,” Mr. Austin said. “Anything that gets put into the
ground eventually makes its way into the marine environment.”
That nutrient rich soil seeps into
the water around the shore and leads to growth of seaweed, sea grass and the
“They call it the ‘island-halo’
effect, because all the water comes out at about 30 feet around the Island and
you start to see this noticeable difference in algae makeup where these waters
are exiting,” he said.
Cayman has not seen a massive proliferation of algae in one or two
coral reef areas. However, Mr. Austin said there has been an across-the-board
increase in algae growth around Grand Cayman.
“That may just be an artefact of
declining coral cover,” he said.
The proliferation of algae in areas
can lead to a decline in coral reef growth, Department of Environment officials
said. The algae make it too difficult for juvenile corals to put down roots and
Mr. Austin said Grand Cayman is
down to about 15 per cent healthy coral cover around the Island. The first
study of coral cover done here in the mid-90s put that number in the high 20s or
even 30 per cent in some places.