If there's been a breakwater built on either side or if there have been mangroves cut down somewhere nearby. Coral reefs need mangroves to filter organic compounds out of river water or the reefs get taken over by algae and die. It also simply be seasonal currents. Dredging in a bay to make for better swimming or boating can also disrupt currents.
Many years ago (early nineties) the beach in Bavaro/Punta Cana was still pristine, beautiful and BROAD.
There was a substantial coral reef that ran parallel to the beach and ensured calm and crystal waters. Then came the
onslaught of construction for all the new hotel complexes.
Although lip-service was paid to the idea that mangroves must be protected......Back in those days the foreign owners
paid little or no attention to any government demands.
What I would consider to be the most devastating memory of my time in the D.R. was the morning that we woke up to
the spectacle of the entire bay of the Bavaro Beach Resort a horrible brown, brackish colour. It lasted for a couple of weeks
and ended up drifting and affecting the beaches further north.
Work had been progressing at a furious pace on the construction of Bavaro's 18 hole golf course.
We had a week of non-stop rain....serious Noah's Ark type stuff. Everything was soaked and water logged.
The entire village of Juanillo was under about three feet of water, more in some places and FINALLY the government
stepped in and forced the powers that be in Bavaro to open up the flood gates that they had been damming to protect their
beach from overflow from the Bavaro Lagoon.
DISASTER.
It was a huge river of dirty, brackish, filthy water that rushed into the bay.
It was to break a few hearts, including mine, that day.
The beach all along the hotel strip in the area of Bavaro has been slowly disappearing and while some of the erosion
can be put down to natural weather events/cycles.....The loss is irrevocable.
The shortsightedness is unbelievable.