Geography is everything.
At the Louisiana-Mississippi border you'll find the Pearl River breaks free from its landlocked meandering. That's the western edge of the Mississippi Sound. Sail over to Alabama under the Dauphin Island Bridge, and you will cross the eastern boundary of the Sound.
To the south, five dynamic islands created by an ancient delta of the Mississippi River have been holding the line for millennia (west to east: Cat, Ship, Horn, Petit Bois, Dauphin). These narrow but mighty swaths of anchored sand literally make a barrier to the Gulf of Mexico and prevent those stunning blue waters from crashing directly onto our mainland.
Between these landmarks, several rivers and bays interact with the Mississippi Sound. Sediments from the rivers (and especially the powerful Mississippi River) escape their deltas and are ushered along the shores of Texas, Louisiana, and Mississippi.
The Mississippi Sound is where the ocean and river meet. They conspire to create vibrant estuaries. The mix of nutrient-rich fresh water and warm salt water becomes a nursery for an abundance of land and aquatic life along our coastlines and the Gulf.
The geographical setup that shapes our home means those salty brown waters may not be mesmerizing like the Caribbean Sea. But from storm protection to fin-tastic fishing, the Mississippi Sound is undeniably important for sustaining life on the Gulf Coast and beyond.