In the long term beaches are essentially 'temporary' features that can come and go based on a variety of different things. By far the number one cause of beach erosion is strong waves and storms that wash up and deposit sediment on the shoreline, or take it away out to sea. As climate change progresses, the belief is that tropical and sub-tropical storms will increase in their intensity and the stronger the storms the greater the damage. Where I live on the Great Lakes we have a beautiful peninsula with 11 fresh water beaches. But, when the winter storms are severe the amount of beach erosion is stunning. To combat this, we have sand replenishment programs based on state funding that occurs in May and June and this helps tremendously. One other thing that was added years ago was a series of stone breakwaters several hundred yards off shore. These also help, though they can be perceived as an 'eye sore' to some (especially when watching an evening sunset). Breakwaters could be of some use on St. Maarten, but IMO wouldn't be worth the cost or effort -- especially when a powerful hurricane comes crashing in. Maybe if we can slow climate change in the future we can turn around things like massive beach erosion and unsightly sargassum sea grass outbreaks. Maybe.
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