Question: What type of lighthouse once stood in the Mississippi Sound north of The Pass?
Context: Biloxi Lighthouse is a lighthouse in Biloxi, Mississippi, adjacent to the Mississippi Sound of the Gulf of Mexico.  The lighthouse has been kept by female keepers for more years than any other lighthouse in the United States.  It was listed on the National Register of Historic Places in 1973 and declared a Mississippi Landmark in 1987. Plover Scar Lighthouse also known as the Abbey Lighthouse is an active 19th century lighthouse sited at the entrance of the Lune estuary, near Cockersand Abbey in Lancashire, England.  It was built in 1847, as the lower light of a pair of leading lights, and is therefore also called the front or Low Light.  The rear or High light, known as Cockersand Lighthouse once stood next to the Abbey Lighthouse cottage on Slack Lane was originally a wooden tower, later replaced by a metal framework beacon.  The leading lights helped ships navigate into the Lune estuary, to reach Glasson Dock and then onwards via the Lancaster Canal to the port of Lancaster, with Plover Scar marking the rocky outcrop at the edge of the deep water channel into the estuary.  On 5 March 2016 the lighthouse was struck by a commercial vessel and has recently undergone a brick by brick restoration by contractors MPM North West.  The tower crane erected at the site was the same one used for the refurbishment of Blackpool Tower. The Merrill Shell Bank Light was a screw-pile lighthouse which once stood on its eponymous shoal in the Mississippi Sound, west of Cat Island and south of Pass Christian, Mississippi.  It was replaced by a skeleton tower on the same foundation. Pass Christian ( ), nicknamed The Pass, is a city in Harrison County, Mississippi, United States.  It is part of the Gulfport–Biloxi Metropolitan Statistical Area.  The population was 4,613 at the 2010 census. Kildidt Sound is a sound on the Central Coast of British Columbia, Canada, located on the southwest side of Hunter Island.  Cultus Sound is to the north, and Queens Sound north of that. The Dauphin Island Bridge, formally the Gordon Persons Bridge, carries a 3 mi , two-lane section of Alabama State Route 193 from mainland Mobile County, Alabama across the Gulf Intracoastal Waterway to Dauphin Island.  The natural channel followed by the Gulf Intracoastal Waterway at this location is Pass Aux Herons.  The bridge separates the Mississippi Sound on the west from Mobile Bay on the east.  It was named in honor of Seth Gordon Persons, the 46th governor of Alabama. The Cat Island Light was a lighthouse off the coast of Mississippi.  Originally built to guide shipping through the Mississippi Sound, it was discontinued as traffic moved further south. The Mississippi Sound is a sound along the Gulf Coast of the United States.  It runs east-west along the southern coasts of Mississippi and Alabama, from Waveland, Mississippi , to the Dauphin Island Bridge, a distance of about 145 kilometers (90 mi).  The sound is bordered on its southern edge by the barrier islands - Cat, Ship, Horn, West Petit Bois (formerly known as Sand Island), Petit Bois, and Dauphin.  Ship, Horn, West Petit Bois and Petit Bois Islands are part of the National Park Service's Gulf Islands National Seashore.  Those islands separate the sound from the Gulf of Mexico.  The sediment of the islands was created partly by the ancient Mississippi River when the St. Bernard Lobe of the Mississippi Delta was active over two thousand years ago.  The expansion of the St. Bernard subdelta slowly isolated the Mississippi Sound from ocean dynamics of the open Gulf of Mexico. Round Island Lighthouse stood from 1859 to 1998 on the southwest end of Round Island in the Mississippi Sound, 4 mi south of Pascagoula, Mississippi.  In September 1998, the lighthouse was toppled by Hurricane Georges.  In 2010, the base of the structure and other lighthouse remnants were removed from Round Island and relocated within the City of Pascagoula for restoration. The St. Joseph Island Light was a lighthouse which stood at the entrance to Lake Borgne on the north side of Mississippi Sound.  It was replaced by the Lake Borgne Light to the west as the island on which it stood was eroded, and was destroyed by a hurricane in 1893.  An unmanned light was eventually erected on the ruins along with a USGS water monitoring station.
Answer: a screw-pile lighthouse