It looks like lagoon is separated from the ocean by a sand bar... so I would have thought the lagoon is fed by the sea... if not it must be a fresh water lagoon then... maybe it's a mixture... fed by a river and the sea... in any case a very nice looking spot. Hope the rain comes.
not a sandbar.
fed by a lake few km away thru a river.
The water level of the lake is also low, so no water passes thru to the lagoon.
Sometimes with really high tide, water makes it from the ocean into the lagoon.
If lots of rain comes and the lake's level rises, the water passes thru the lagoon and then into the ocean, like a river mouth.