The Weddell Sea is the semi-enclosed body of water of about one million square miles south of the South Atlantic Ocean, east of the Antarctic Peninsula, and west of Coats Land. It is named for James Weddell, the British master of the sealing brig Jane, who first entered those waters in 1823. American sealing captain Benjamin Morrell sailed in those same waters that same year, but failed to fully document his voyage. The waters were explored for the first time by William Speirs Bruce on the ship Scotia in 1903. The southern portion of the Weddell Sea is covered by the Filchner-Ronne Ice Shelf. The Weddell Sea was the scene in 1915 of the besetting and eventual crushing of the ship Endurance, followed by the amazing voyage of Ernest Shackleton to save his entire crew. The area is home to the Weddell seals, various penguins, and sea birds such as the petrel. There has been some retreat of the ice shelf in recent years, but not to the extent experienced in the Arctic. The water there has been deemed as the clearest of any sea. The United States recently proposed that a large portion of the Weddell Sea be designated a marine protected area (MPA) so as to preserve its unique biosphere. The great depth of the Weddell Sea (averaging about 1,600 feet) and its extreme polar location have resulted in a large mass of very cold water near the sea floor, which fosters a number of unique flora and fauna.