There’s a reason why your recent trip to the Jersey Shore looked more like one to the Caribbean: phytoplankton.
The normally brownish-green Atlantic waters on the Jersey coast have been greener than usual due to something called upwelling. During upwelling, cold water from the deeper parts of the ocean is sent to the surface where sunlight encourages chlorophyll-pigmented phytoplankton (tiny plants) to bloom. Wind exposes the bloom to sunlight resulting in blue-green waves of light.
Drier weather, which results in less river runoff, is also being attributed to the clear conditions in the Atlantic Ocean.
The Caribbean-looking waters have been visible for over a week, but aren’t expected to last forever.